PHOTOMER® 4226

CAS Number: 57472-68-1
EC Number: 260-754-3
Molecular Formula: C12H18O5 (nominal DPGDA molecule; commercial material can contain isomers and stabilizer)
Molecular Weight: 242.27 g/mol (calculated nominal molecule; the historical PHOTOMER® 4226 product sheet gives a rounded 240 g/mol)
INCI Name: No relevant, verified INCI designation is established for this industrial grade.
E Number / INS Number: Not applicable.
Boiling Point: Not reliably established as a PHOTOMER® 4226 specification at atmospheric pressure; uncontrolled heating may promote polymerization.
Melting Point: Not reliably established as one grade-specific value; cold material may congeal or stratify according to the product sheet.
Viscosity: 7–13 mPa·s, dynamic viscosity at 25 °C, Brookfield / ISO 2555, in the published 2015 PHOTOMER® 4226 product data sheet; current catalogue typical value: 10 mPa·s at 25 °C.
Density: 1.040–1.100 g/cm3 at 25 °C in the historical product data sheet, listed there as “specific gravity” with density units.

COMMON PRODUCT AND CHEMICAL NAMES

PHOTOMER® 4226
Dipropylene glycol diacrylate
Dipropyleneglycol diacrylate
DPGDA
Oxybis(methyl-2,1-ethanediyl) diacrylate
2-Propenoic acid, oxybis(methyl-2,1-ethanediyl) ester

PHOTOMER® 4226 is the product-specific trade designation. DPGDA is an abbreviation for the underlying chemical; it does not guarantee that products offered under different trade names have the same inhibitor system, water content, color, purity, package or performance. Suffix-bearing designations such as PHOTOMER® 4226 LT and PHOTOMER® 4226 F must be checked against their own technical and safety documents rather than treated as automatically identical to the unsuffixed grade.

WHAT IS PHOTOMER® 4226?

PHOTOMER® 4226 is a reactive acrylic monomer intended for polymer-forming UV and EB processes. A reactive diluent differs from a conventional evaporating solvent because its acrylate groups can react into the coating network, so viscosity reduction and crosslink chemistry are obtained from the same ingredient.

The published product sheet describes a clean, clear liquid and identifies applications in overprint varnishes, industrial varnishes, screen-printing inks, flexographic inks and other inks for paper, paperboard, metal, plastic and wood. The current product catalogue also identifies inkjet and graphic-arts uses; in all of these applications, suitability still depends on viscosity requirements, curing equipment and the actual ink or coating composition.

DPGDA is neither an oligomeric resin nor a finished photoinitiator. It cannot by itself supply the complete mechanical properties, pigmentation, adhesion package, photochemistry and processing stability required by most commercial products. Formulators combine it with appropriately selected oligomers or resins, and under typical UV free-radical conditions a matching photoinitiator system is used.

The very low viscosity of PHOTOMER® 4226 is attractive where an oligomer is too thick for the intended coating head, roller, printing press or dispensing method. However, a lower initial viscosity is only one design objective: cured-film brittleness, dimensional change, substrate wetting, residual monomer, and chemical or water resistance must be measured after the full cure cycle.

CAS NUMBER, EC / EINECS NUMBER AND CHEMICAL IDENTIFICATION

Main Product Name: PHOTOMER® 4226
Underlying Substance: Dipropylene glycol diacrylate (DPGDA)
CAS Number: 57472-68-1
EC / EINECS Number: 260-754-3
Molecular Formula (nominal molecule): C12H18O5
Calculated Molar Mass: 242.27 g/mol
Historical Product-Sheet Molecular Weight: 240 g/mol (rounded manufacturer entry, not a different chemical identity)
Chemical Category: Difunctional acrylate ester monomer; aliphatic polyether-derived diacrylate
Reactive Functionality: 2 acrylate C=C groups per nominal molecule
Physical Supply Form: Stabilized liquid
Typical Use: Reactive viscosity reducer and co-crosslinking monomer in free-radical radiation curing

The chemical identifiers refer to DPGDA as a substance rather than every characteristic of the supplied commercial grade. Dipropylene glycol feedstock can contain structural isomers; therefore, a commercial DPGDA composition may not correspond exclusively to one idealized connectivity illustrated in a database drawing. Stabilizer and residual manufacturing constituents can also be present.

The difference between a rounded “240 g/mol” in an older product sheet and the calculated 242.27 g/mol does not establish a formulation change. Molecular masses are calculated from molecular structures, while product sheets sometimes round values for general identification. For molecular stoichiometry, the verified molecular formula and 242.27 g/mol nominal mass are the appropriate reference, with supplier clarification for analytical composition.

A registration number, CAS number or catalogue entry is not proof that a particular batch meets every regional use rule. Before procurement or distribution, check the relevant local chemical inventory, classification and product-specific documentation. Regulatory status can differ by jurisdiction and by commercial variant.

CHEMICAL STRUCTURE AND MOLECULAR CHARACTERISTICS

DPGDA is produced conceptually by linking the two hydroxyl-bearing ends of dipropylene glycol to acrylic acid-derived ester functions. A simplified description is “acrylate ester – dipropylene glycol ether segment – acrylate ester.” Each terminal acrylate features the CH2=CH–C(=O)–O– motif and can be attacked by propagating carbon-centered radicals.

The backbone includes a central ether oxygen atom as well as ester oxygen atoms. These polar connections and the hydrocarbon methyl-containing segments influence resin compatibility, solvation and molecular mobility. They help explain why DPGDA and hexanediol diacrylate, although both difunctional and low in viscosity, are not identical in wetting, cure stress, flexibility or hydrophilic interactions.

Two acrylate groups can connect growing polymer chains and thereby contribute to crosslink formation. In practice, the network is statistical rather than perfectly regular: propagation, termination, intramolecular cyclization, oxygen inhibition, diffusion limits and incomplete conversion determine how many acrylate groups become effectively crosslinked.

The nominal molecular formula C12H18O5 refers to the monomer. After polymerization, the material forms part of a macromolecular network, so the original monomer mass should not be used as the molecular weight of the cured coating. Cured-film properties are functions of all reactive constituents and processing conditions.

Technical DPGDA is not a monofunctional acrylate and must not be confused with tripropylene glycol diacrylate (TPGDA). TPGDA has an additional propylene-oxide-derived unit, a different molecular formula and different reactivity and formulation characteristics. Similar names are not chemical equivalence.

PHYSICAL AND CHEMICAL PROPERTIES

Appearance: Clean and clear liquid in the published PHOTOMER® 4226 product data sheet.
Chemical Identity: Dipropylene glycol diacrylate (DPGDA).
CAS Number: 57472-68-1.
EC Number: 260-754-3.
Molecular Formula: C12H18O5 (nominal molecular species).
Molecular Weight: 242.27 g/mol calculated; historical product sheet rounds to 240 g/mol.
Acrylate Functionality: 2.
Dynamic Viscosity at 25 °C: 7–13 mPa·s, Brookfield, ISO 2555 (published 2015 product sheet).
Current Catalogue Typical Dynamic Viscosity at 25 °C: 10 mPa·s; a typical comparative value, not a new batch-specific specification.
Color: APHA / Hazen 60 maximum, ISO 6271 (published 2015 product sheet and current catalogue).
Acid Value: 0.5 mg KOH/g maximum, NF EN ISO 660 (historical product sheet).
Moisture: 0.1% maximum, Karl Fischer, with ISO 4317 identified in the historical sheet.
Inhibitor Content: 600 ppm maximum, determined by GC analysis in the historical grade sheet; the statement does not establish a required minimum or the identity of the inhibitor.
Solvent Content: 2,000 ppm maximum, determined by GC analysis in the historical grade sheet.
Density at 25 °C: 1.040–1.100 g/cm3; manufacturer sheet labels this “specific gravity,” but reports mass-per-volume units.
Refractive Index at 25 °C: 1.4450–1.4550, historical grade sheet.
Surface Tension at 25 °C: Typical 33 mN/m, latest published product-family guide, not a lot-release limit.
Comparative Homopolymer Glass-Transition Temperature: Approximately 96 °C as presented in the product-family guide; not a monomer melting point or a promised finished-formulation Tg.
Water Solubility: No PHOTOMER® 4226 grade-specific numerical specification in the verified product data sheet. A distinct laboratory DPGDA product reports 5.2 g/L at 20 °C; that figure should not be adopted as an official PHOTOMER® 4226 limit.
Flash Point: Not established by the reviewed PHOTOMER® 4226 product sheet. A 137 °C reference for a separate DPGDA laboratory grade should not be substituted for the commercial grade's current SDS.
Boiling Point at Atmospheric Pressure: Not reliably established for this stabilized reactive grade.
Melting / Freezing Point: Not reliably established as a single grade specification; cold-related congealing or stratification is specifically noted by the manufacturer.
Vapor Pressure: No directly verified PHOTOMER® 4226 grade specification in the reviewed product sheet.
pH: Not a meaningful intrinsic property of this neat, nonaqueous liquid; aqueous-solution pH requires defined test conditions.
Shelf Life: Historical manufacturer product sheet states at least 12 months under appropriate usual storage and temperature conditions; confirm current batch, packaging and storage recommendations before purchasing.

Values above are not interchangeable in evidentiary status. The grade sheet's limits identify historical product specifications, the catalogue values are comparative typical data, and a separate laboratory supplier's reference measurements describe another commercial DPGDA grade. None of these measurements removes the need for the current product data sheet and batch-specific certificate of analysis.

The term “specific gravity” strictly means a ratio without units, while density uses g/cm3. Because the manufacturer sheet presents a numerical range accompanied by g/cm3, it is reproduced above as a published mass-per-volume range while retaining the original labeling caveat. No conversion to relative density at a reference water temperature has been assumed.

The 96 °C Tg is especially easy to misunderstand. It describes a comparative polymerized material in the manufacturer's product guide, not the temperature at which PHOTOMER® 4226 liquid melts or solidifies, nor the Tg of an oligomer-containing UV coating. A formulation's measured Tg may differ markedly owing to its reactive constituents and degree of cure.

HOW DOES PHOTOMER® 4226 WORK AT THE MOLECULAR LEVEL?

The first action occurs before curing: the liquid monomer dilutes more viscous reactive resins and can improve their flow by reducing the blend's overall viscosity. This effect is a physical consequence of mixing low- and high-viscosity components and depends on resin compatibility, temperature and the full formulation.

During free-radical curing, an initiating species adds to one carbon-carbon double bond of a DPGDA acrylate group. The resulting radical continues to react with further acrylate groups from DPGDA, oligomers and other monomers. As chain growth and intermolecular linking proceed, the liquid composition passes through gelation and can become a solid network.

In most UV systems, photoinitiators absorb appropriate light and generate the radicals that begin polymerization. PHOTOMER® 4226 is not itself an ordinary photoinitiator, so specifying the monomer without specifying the initiating chemistry does not define a workable UV-curing process. For EB systems, electron irradiation can provide initiation through another physical mechanism, subject to process design.

Crosslinking contributes mechanical integrity, solvent resistance and resistance to flow after cure, but these effects are not monotonic. Excessive network rigidity or cure contraction can increase internal stress and damage adhesion on sensitive substrates. The optimum composition therefore depends on the whole material and the target balance of performance.

Oxygen at the film surface can inhibit free-radical conversion by trapping reactive radicals. Light absorption by pigment, high film thickness, insufficient lamp intensity and poor initiator matching can also produce incomplete cure. These mechanisms matter because an incompletely cured DPGDA-containing coating can retain residual monomer and fail physical, sensory or migration criteria.

Stabilizers help suppress premature polymerization during supply and storage. Inhibitor content does not mean that arbitrary heat exposure is safe; its effectiveness depends on stabilizer identity, oxygen conditions and contamination control. Storage instructions therefore come from the grade-specific SDS and manufacturer recommendations rather than an assumed universal “inhibited = stable” rule.

WHICH INDUSTRIES USE PHOTOMER® 4226?

The confirmed application portfolio includes graphic arts, overprint varnishes, screen and flexographic printing inks, inkjet-related UV formulations and industrial radiation-curable coatings. The manufacturer specifically cites formulations intended for metal, paper, paperboard, plastic and wood substrates, and its current product listing includes plastic, wood and metal coatings.

Graphic-arts systems use DPGDA as a reactive carrier and rheology-adjustment component. It can support pigment-containing mixtures by helping resin wet-out and dilution, although pigment dispersion quality also depends on milling, surface-treatment chemistry and dedicated dispersing agents. It should not automatically be marketed as a stand-alone pigment dispersant.

Industrial coatings use this monomer as one adjustable part of UV/EB film formation. Oligomers may supply toughness, chemical resistance or adhesion, while multifunctional monomers adjust the density and kinetics of reactive sites. DPGDA contributes both rheology and polymerization functionality, which is why its content can affect more than viscosity.

Other radiation-curable uses, including specialized adhesives, screen-printing pastes or prototyping resins, are technically plausible for the chemical family but require application-specific validation. Unless a particular use is documented for PHOTOMER® 4226 itself, it should be described as a possible development direction, not as an assured product certification or supplier performance claim.

PHOTOMER® 4226 IN UV- AND EB-CURABLE OVERPRINT VARNISHES

Overprint varnishes, often abbreviated OPV, are thin protective or decorative films applied over printed substrates. They may be designed to develop controlled gloss, tactile response, rub resistance or surface protection without compromising the underlying ink and substrate. The historical PHOTOMER® 4226 product sheet specifically identifies UV/EB-curable OPV and industrial varnishes as suitable application areas.

A low-viscosity diacrylate can reduce the amount of nonreactive diluent needed in some formulations and help the coating spread or transfer over the printed surface. Because it reacts into the film during curing, it changes the final polymer network rather than simply leaving by evaporation. It remains necessary to measure wetting on the printing ink, cure depth, blocking behavior and any residual odor or extractables.

The manufacturer describes a contribution to improved water resistance. That should be treated as a potential formulation benefit rather than a stand-alone water-barrier guarantee, because the final response to water depends on oligomer chemistry, conversion, pigment loading, the substrate and the film's microstructure.

Overprint varnishes for packaging are not automatically cleared for food contact simply because they use UV-cured chemistry. The entire article, potential set-off, residual monomer and migratable photoinitiator system require assessment against the intended jurisdiction and use conditions. The trade grade's SDS and technical data sheet are not a food-contact approval certificate.

PHOTOMER® 4226 IN PRINTING INKS AND GRAPHIC ARTS

Screen printing typically uses relatively structured ink formulations that must pass through a mesh and retain edge definition. DPGDA may assist viscosity adjustment of curable binder phases; however, a screen ink must also exhibit suitable rheology, thixotropy, pigment stability and cured-film adhesion. Formulators should validate all of these parameters at the actual deposition thickness.

Flexographic printing requires controlled flow and transfer through the plate and anilox system. A low-viscosity monomer offers a useful design tool for selecting rheology in UV-curable flexographic inks, but it does not establish drying or curing speed without the photoinitiator, light intensity, film thickness and pigment absorption profile.

In UV inkjet systems, jetting viscosity, temperature, nozzle compatibility, particle size, surface tension, satellite droplets and substrate spreading must be managed together. The product's approximately 10 mPa·s typical monomer viscosity and the catalogue's 33 mN/m surface-tension figure may be relevant to initial formulation screening, but finished-ink numbers cannot be inferred by averaging monomer properties alone.

Pigment wetting and resin solvency are manufacturer-catalogue attributes. A workable printing ink may additionally need a dedicated dispersant, defoamer, polymerization stabilizer and rheology modifier, with careful consideration of cure inhibition and color stability. Different pigment grades can have widely different absorption and surface-chemistry effects on an otherwise similar DPGDA-containing ink.

The words “low viscosity” and “high solvency” are not substitutes for solubility tests. Even when a monomer dissolves an acrylated oligomer at one temperature, another resin may separate during low-temperature storage or after introducing pigment and additives. Compatibility checks should include physical stability, appearance, filtration performance and post-aging rheology.

PHOTOMER® 4226 IN WOOD COATINGS

Wood-coating systems may use radiation-curable acrylic blends for finishing panels, engineered wood, flooring or furniture components. PHOTOMER® 4226 is identified for wood coatings in the manufacturer's current application listing and can be studied as a viscosity-adjustment and network-forming monomer within such formulas.

The formulation challenge is to combine good wood wetting with attractive appearance, abrasion resistance, acceptable flexibility and reliable adhesion. Wood presents porous and variable surfaces, and performance changes with species, sanding, moisture content, previous treatment and coating thickness. The monomer cannot compensate for inadequate substrate preparation or an incompatible binder.

A diacrylate may help create a coherent film, but additional crosslinking can also increase stress as the film cures. Wood expands and contracts with environmental moisture, so flexibility and edge-cracking resistance may be as important as hardness. Cross-cut adhesion, abrasion testing and aging under humidity should be performed on the target substrate.

Cure evaluation needs attention at textured surfaces, deep pores and locations shielded from direct light. The UV system, photoinitiator, additive package and lamp geometry must be selected for the actual coating arrangement. Complete processing conditions cannot be prescribed from PHOTOMER® 4226 identity alone.

PHOTOMER® 4226 IN PLASTIC COATINGS

Plastic coatings involve substrates that differ substantially in surface energy, thermal tolerance and resistance to monomer-induced swelling or stress cracking. The manufacturer lists plastic coatings as a field of application, but this should not be interpreted as demonstrated compatibility with every plastic resin.

On plastics, reactive monomer choice affects wetting, solvency and the stress generated as polymerization progresses. Good initial spreading does not guarantee final adhesion: a coating can wet a surface yet detach after thermal cycling or mechanical bending. Certain polymers also require flame, plasma, corona or primer treatment before coating.

PHOTOMER® 4226 can be screened where low-viscosity processing is required, but potential substrate softening, dimensional stability, yellowing and brittleness must be assessed. Representative qualification tests include adhesion after aging, scratch and abrasion resistance, flexing or impact where relevant, and exposure to the intended cleaning or environmental media.

Temperature control is especially important for heat-sensitive plastics. A UV or EB process can create substrate heating from equipment, reaction exotherm and absorbed radiation, and the selected cure cycle must be validated. No generic “plastic-safe” designation can be inferred from the monomer's chemical name.

PHOTOMER® 4226 IN METAL COATINGS

Metal coatings require careful balance among wetting, anchorage, hardness, corrosion resistance and mechanical durability. PHOTOMER® 4226 is listed for metal coatings, but its presence does not confer inherent anticorrosion performance. Substrate pretreatment, surface oxides, primers, pigment package, binder chemistry and film defects govern actual corrosion behavior.

Low-viscosity reactive diluents may support even deposition of varnishes or inks on pretreated metal. Their cured networks can contribute to chemical and water resistance, although moisture permeability and barrier function are highly formulation dependent. A coating with poor interface preparation can fail despite good bulk polymer properties.

Application-specific work should measure cross-cut or pull-off adhesion, film flexibility, solvent rubs, water immersion and resistance to expected industrial fluids. For formed-metal parts, bending and deformation after cure are critical, because a highly crosslinked film that performs on a flat laboratory panel may crack in use.

When the metal is printed and subsequently exposed to downstream processing, the entire film stack needs examination. Adhesion between pigment, primer, cured film and topcoat cannot be predicted from a single DPGDA specification.

INKJET, DIGITAL PRINTING AND CONTROLLED DROPLET DEPOSITION

The current PHOTOMER® 4226 catalogue identifies inkjet among its application markets. Digital deposition typically requires a low-viscosity liquid that remains stable during recirculation, filtration and printhead operation; DPGDA's low viscosity makes it a candidate reactive constituent rather than a finished printable fluid.

Surface tension influences drop formation, satellite generation and contact-line movement after deposition. The published 33 mN/m product-guide figure is useful comparative information at 25 °C, but inkjet equipment generally requires the surface tension of the complete ink at its operating temperature. Surfactants, resin concentration and pigment dispersion can change that value materially.

In pigmented UV inkjet, cure depth can be affected by light screening and scattering. The initiating system, available light spectrum, print density and substrate reflectivity affect conversion. Reliable production requires qualification of printhead compatibility, nozzle life, particle contamination, image quality and cure performance rather than selection on neat-monomer viscosity alone.

Adhesion on nonporous media and substrate-temperature sensitivity are equally important. Some designs prioritize flexibility and impact resistance, while others prioritize abrasion resistance and blocking. Changing DPGDA loading can shift those balances; there is no reliable universal replacement ratio for all inks.

UV, UV-LED AND ELECTRON-BEAM CURING REQUIREMENTS

In conventional UV curing, the light source and photoinitiator must have compatible spectral characteristics. PHOTOMER® 4226 supplies acrylate double bonds but does not define a wavelength requirement of its own in the way a photoinitiator does. A claim that the monomer cures under a specified LED wavelength without identifying the complete formulation would therefore be misleading.

UV-LED systems commonly provide a narrower spectral band than broad-spectrum discharge lamps. In such systems, initiating efficiency, available radiant exposure, oxygen inhibition and pigment loading require special attention. Substituting one lamp type for another can alter the depth and speed of cure even if the DPGDA concentration is unchanged.

Electron-beam curing induces reactive events through energetic electron exposure and can avoid conventional added photoinitiators in selected formulations. EB is nevertheless an engineered industrial process requiring shielding, maintenance, dosimetry, suitable process geometry and occupational radiation protection. Material selection alone does not determine the necessary dose.

The phrase “fast cure” in a product guide is a comparative descriptor and not a universal time or line-speed guarantee. The actual process window depends on energy delivery, film thickness, temperature, oxygen management, formulation reactivity and acceptance requirements. Laboratory studies should include surface tack, through-cure, extraction and relevant mechanical tests.

INDUSTRIAL APPLICATIONS AND PERFORMANCE

A useful way to evaluate DPGDA is to consider its dual influence on the uncured and cured states. In the liquid, its comparatively small molecular size lowers viscosity when compatible with the base resin. During polymerization, the same molecules participate in network formation and can change the distribution of crosslinks and the fraction of low-molecular-weight material left unconverted.

The manufacturer's current product guide highlights pigment wetting, reactivity and high solvency or “cutting power.” These are qualitative development indicators, not standardized numerical assertions that PHOTOMER® 4226 outperforms all other monomers. When comparing formulations, a measured viscosity at a defined temperature, corresponding resin-solubility observations and a cure-response curve are more useful than broad descriptors.

The historical product sheet also notes an improvement contribution to water resistance. Formulators should interpret this in the context of a completed cured film. Practical tests may include water immersion, water-spot evaluation, humidity cycling, stain resistance or chemical extraction, each of which measures different performance mechanisms.

A film's flexibility or hardness is not a fixed intrinsic property of DPGDA in isolation. The product guide's 96 °C comparative homopolymer Tg is informative about a reference polymer, but oligomer architecture, reactive diluent combinations and cured conversion determine the final material. A different material design can move the measured glass transition substantially.

Where coated products will undergo folding, lamination, winding or forming, cure contraction and internal stress deserve explicit measurement. Increased conversion can improve mechanical integrity while simultaneously changing brittleness or substrate adhesion. Those possible trade-offs are reasons to run trials, not reasons to presume a predictable direction of change.

WHAT PROBLEMS CAN PHOTOMER® 4226 HELP ADDRESS?

High formulation viscosity: DPGDA can reduce the viscosity of compatible radiation-curable resin blends and help them fit certain application systems. The degree of viscosity reduction is formulation-dependent and must be measured at process temperature and shear conditions.

Limited reactive dilution options: As a difunctional monomer, PHOTOMER® 4226 contributes polymerizable acrylate functionality while performing a dilution role. It is not equivalent to adding a volatile solvent, because the monomer is intended to become part of the cured film.

Pigment-processing demands: Manufacturer documentation identifies pigment wetting and solvency characteristics that may support ink and coating development. Actual dispersion quality depends on the pigment, dispersant, milling operation and other components; the monomer does not guarantee dispersion stability on its own.

Surface protection requirements: The historical manufacturer data sheet identifies contribution to water resistance in UV/EB coatings. This possible benefit must be shown by testing the final product, because poor cure or interfacial adhesion can outweigh any monomer-related advantage.

Production-process constraints: Low viscosity may aid coating transfer, leveling or jetting in appropriately designed systems. At the same time, excessively low viscosity may cause misting, spreading, edge bleed or other defects, so the objective is controlled process rheology rather than minimum viscosity at any cost.

Crosslink-density adjustment: DPGDA can contribute two reactive acrylate sites per nominal molecule. This provides a formulation variable for network design, but excessive shrinkage, brittleness and residual stress can limit the amount that is practically useful.

IMPORTANT CONSIDERATIONS WHEN USING PHOTOMER® 4226

Acrylic sensitization is a central occupational issue. Uncured DPGDA can cause skin irritation and allergic skin reactions, and sources for the underlying substance report serious eye damage classification. The correct current regional SDS determines the label and protective measures for a particular PHOTOMER® 4226 shipment.

Never infer that a fully cured coating is automatically free from unreacted monomer. Light access, energy delivery, diffusion, pigment absorption and oxygen inhibition can limit conversion. Residual substances may matter for skin contact, indoor environments, product odor, solvent resistance and regulated packaging uses.

Stabilization must be preserved during storage. Exposure to excessive heat, sunlight, incompatible chemicals or contamination may promote undesired polymerization. The verified historical sheet requires cool, shaded, well-ventilated, dry storage; current supplier SDS guidance should be used when specifying temperature limits and tank blanketing conditions.

Acrylate chemistry may be incompatible with strong radical initiators, uncontrolled oxidizing agents, certain reducing environments and substances that damage inhibitors or trigger polymerization. Detailed compatibility should follow the SDS and a documented process hazard assessment. Do not assume that a container or transfer hose previously used for another chemical is clean enough for this monomer.

Substrate attack is a possible concern, particularly when applying small reactive molecules onto certain plastics or printed layers. The full formulation must be assessed for swelling, pigment bleeding, intercoat interaction and chemical resistance. Visual clarity alone cannot demonstrate a safe substrate interaction.

The historic product sheet reports that cold storage may cause congealing or stratification and advises warming to room temperature and mixing before use. That statement does not authorize uncontrolled heating: any warming operation must respect the current safety data sheet and internal site procedures.

FORMULATION DEVELOPMENT AND STARTING EVALUATION APPROACH

There is no universally validated PHOTOMER® 4226 addition level across all UV inks, overprint varnishes, wood coatings, plastics and metal finishes. Supplier product literature confirms broad applications and technical properties but does not establish a single formula or cure schedule for every use. Providing one would create false precision.

A practical development program begins by setting target viscosity at the actual application temperature, substrate class, expected dry or cured film thickness, acceptable cure response and required physical performance. Candidate reactive diluents can then be screened within a controlled matrix while keeping the oligomer, initiator, pigments and processing conditions clearly documented.

Comparative formulations should be characterized before and after exposure. Before cure, record appearance, viscosity, storage stability, print or coating transfer and pigment dispersion as relevant. After cure, assess surface tack, through-cure, adhesion, flexibility, abrasion resistance, solvent rubs, water resistance and extractables where required.

When comparing PHOTOMER® 4226 with HDDA, TPGDA or monofunctional acrylates, use a matched test objective rather than assuming equal weights produce equal crosslink density. Their molecular masses, segment structures and acrylate-equivalent contents differ. The equal-volume or equal-weight test may be useful for processing comparisons but not for attributing every cured property to one variable.

If sensitivity to residual monomer is high, use validated analytical methods appropriate to the substrate and target limits. Migration and extraction measurements should represent foreseeable storage and end-use conditions, and any regulatory compliance decision should be based on the whole finished formulation, not the monomer's inventory listing.

Due to the risk of unwanted free-radical polymerization and hazardous exotherm, this profile does not give ad hoc initiator recipes, bulk-polymerization schedules or uncontrolled heating instructions. Process conditions must be supplied by qualified formulation and equipment specialists after safety assessment.

SIMILAR PRODUCTS AND ALTERNATIVES

Tripropylene glycol diacrylate (TPGDA) is a related difunctional aliphatic polyether acrylate, but it contains a longer glycol-derived segment and has different molecular identity. It may provide a different balance of solvency, viscosity and film flexibility; PHOTOMER® 4226 and TPGDA should not be treated as chemically identical or substituted without testing.

1,6-Hexanediol diacrylate (HDDA) is another common low-viscosity difunctional reactive diluent. Its hydrocarbon-based spacer differs from DPGDA's ether-containing backbone. That structural difference can influence polarity, resin compatibility and cured-film behavior, so selection should reflect process requirements rather than viscosity alone.

Neopentyl glycol diacrylate (NPGDA) and propoxylated neopentyl glycol diacrylate are further possibilities in certain radiation-curable systems. They have their own molecular structures, supplier specifications and comparative performance attributes. Their substitution must be assessed for cure conversion, adhesion, surface tension, residual stress and safety.

Ethoxylated or higher-molecular-weight diacrylates may offer different flexibility and polar interactions but usually require different viscosity and cure-design decisions. Multifunctional triacrylates can increase reactive-site concentration and alter hardness or brittleness, while monofunctional acrylates offer a different crosslinking contribution. Neither group is a universal one-for-one replacement for DPGDA.

Even another DPGDA product bearing the same CAS and EC numbers may not be a drop-in replacement. The reported inhibitor level, degree of purification, residual acid and solvent, color, moisture, packaging and regional SDS may differ. For a change-of-supplier decision, a controlled comparison of representative lots is prudent.

INITIAL FORMULATION APPROACHES FOR PHOTOMER 4226

The following examples illustrate how PHOTOMER 4226 can be evaluated during formulation and process development. These are proposed laboratory starting approaches, not validated commercial recipes, production instructions or regulatory-compliant final formulations.

PHOTOMER 4226 is a dipropylene glycol diacrylate (DPGDA) grade, CAS 57472-68-1. IGM Resins identifies this aliphatic difunctional acrylate as a low-viscosity diluent for UV- and EB-curable formulations. [1] Its typical neat-product viscosity is reported as 10 mPa·s at 25 °C; this is not the viscosity of the finished formulation. [1] DPGDA participates in acrylate curing; it should not be treated as a non-reactive solvent that simply evaporates.

All percentages below are by weight of the complete trial mixture and refer to raw materials as supplied. The numerical levels are illustrative screening proposals, not IGM Resins dosage recommendations. The same DPGDA chemical identity does not make different supplier grades or pre-diluted resin blends automatically interchangeable. Each composition totals 100%. Use undiluted oligomer grades for these comparisons, or recalculate any monomers already present in supplied oligomer blends. Confirm current specifications, inhibitor information and Safety Data Sheets before work.

The examples concern UV curing. Select the photoinitiator package for the lamp spectrum, film thickness and formulation, and verify that its proposed loading is suitable. Establish a workable exposure window before comparing compositions. Keep measured irradiance, radiant exposure, lamp spectrum, atmosphere and film thickness constant within each initial series. UV-LED, mercury-lamp and electron-beam processes are not interchangeable versions of the same recipe.

EXAMPLE 1: PHOTOMER 4226 DOSAGE SCREENING IN A CLEAR UV WOOD VARNISH

Objective: Assess how replacing part of an oligomer with PHOTOMER 4226 affects application viscosity, film formation, hardness and adhesion.

Starting components:

PHOTOMER 4226 (DPGDA): approximately 20.00%, 30.00% and 40.00% in separate trials.

Compatible aliphatic urethane acrylate oligomer: approximately 75.00%, 65.00% and 55.00%, respectively.

Photoinitiator package matched to the selected UV source: approximately 4.00%, held constant after compatibility assessment.

Compatible leveling additive: approximately 0.50%.

Compatible defoamer: approximately 0.50%.

Wood species, moisture, sanding, sealer and applied film thickness: held constant.

Application approach:

Blend the urethane acrylate oligomer and PHOTOMER 4226 under controlled mixing and temperature conditions.
Incorporate the additives and photoinitiator package under lighting suitable for handling photosensitive mixtures.
Confirm uniform incorporation, then measure viscosity at a defined temperature and shear condition.
Apply equal-thickness films to consistently prepared wood panels, with additional reference panels where required by the test method.
Cure at the established exposure conditions and record substrate temperature.
After identical conditioning, compare tack, hardness, adhesion, gloss and resistance to intended service conditions.
Assess cure using a suitable analytical or validated performance method; surface dryness alone is insufficient.

This is an oligomer-for-DPGDA substitution study, so changes reflect both components. Select PHOTOMER 4226 dosage by balancing application and cured-film properties. Lower viscosity does not automatically mean better adhesion, flexibility or cure. Reassess the curing window after selecting a composition.

EXAMPLE 2: PHOTOMER 4226 REACTIVE-DILUENT BALANCE IN A WHITE UV COATING

Objective: Examine the effect of replacing a monofunctional reactive diluent with PHOTOMER 4226 at constant oligomer and pigment loading.

Starting approach:

PHOTOMER 4226 (DPGDA): approximately 15.00%, 20.00% and 25.00% in separate trials.

Isobornyl acrylate (IBOA): approximately 18.00%, 13.00% and 8.00%, respectively.

Compatible epoxy acrylate oligomer: approximately 40.00%, held constant.

Titanium dioxide suitable for radiation-curable coatings: approximately 20.00%, held constant.

Photoinitiator package selected for the pigmented system and UV source: approximately 5.00%, held constant after assessment.

Compatible pigment dispersant: approximately 1.50%.

Compatible leveling additive: approximately 0.50%.

Application approach:

Prepare each pigment dispersion with the selected oligomer, reactive diluents and dispersant, using the same equipment and dispersion protocol.
Control processing temperature and check grind fineness before adding the remaining components.
Incorporate the photoinitiator package and leveling additive under controlled light conditions.
Measure viscosity, pigment dispersion quality and short-term physical stability.
Apply identical film thicknesses to the same prepared substrate and cure under documented exposure conditions.
Compare opacity, gloss, adhesion and cure at both the surface and the substrate interface.
Check resistance to relevant liquids and evaluate cracking or loss of flexibility after conditioning.

Keep pigment grade and surface treatment constant because they can affect dispersion and light penetration. A dry top surface does not prove through-cure. If curing is inadequate, optimize the photoinitiator, exposure or film thickness in a separate series and repeat the composition comparison. Do not assume that increasing PHOTOMER 4226 alone resolves optical limitations in a pigmented film.

EXAMPLE 3: PHOTOMER 4226 REACTIVE-DILUENT SCREENING IN A UV OVERPRINT VARNISH

Objective: Assess how PHOTOMER 4226 affects varnish flow, gloss, adhesion and fold performance on printed paper or board at constant oligomer content.

Starting approach:

Compatible polyester acrylate oligomer: approximately 60.00%, held constant.

PHOTOMER 4226 (DPGDA): approximately 15.00%, 20.00% and 25.00% in separate trials.

Isobornyl acrylate: approximately 20.00%, 15.00% and 10.00%, respectively.

Photoinitiator package compatible with the selected UV source: approximately 4.00%, held constant after assessment.

Compatible slip/leveling additive: approximately 0.50%.

Compatible defoamer: approximately 0.50%.

Paper or board grade, printing ink, ink drying condition, coating weight and UV exposure: held constant.

Application approach:

Blend the polyester acrylate oligomer, PHOTOMER 4226 and isobornyl acrylate until uniform.
Incorporate additives and the photoinitiator under controlled lighting, confirming full incorporation.
Measure viscosity at the intended application temperature and inspect for entrained air.
Apply equal coating weights to matched printed panels and include unprinted reference panels.
Cure under established conditions and document radiant exposure, irradiance and substrate temperature.
After identical conditioning, compare gloss, adhesion, rub resistance, blocking tendency and cracking on folding.
Inspect the ink/varnish interface for colour bleeding or poor intercoat adhesion and evaluate the selected composition in the intended packaging process.

A PHOTOMER 4226 overprint varnish requires application-specific validation; a glossy, tack-free surface is not proof of complete cure. These trials do not establish food-contact or low-migration suitability. If such use is intended, assess the complete formulation, substrate, printing system and migration under the applicable conditions before approval.

For all three examples, avoid skin and eye contact with uncured acrylates and follow the current Safety Data Sheets for protective equipment, ventilation and storage. Protect photosensitive formulations from unintended exposure and monitor mixing temperature. Do not remove or alter the supplied inhibitor system without explicit supplier guidance. Requirements for oxygen during storage and atmosphere during curing must be assessed separately. Verify residual monomer, final performance, packaging compatibility and relevant end-use requirements before scale-up; these examples do not establish food-contact, cosmetic, dental or medical suitability.

QUALITY CONTROL AND PURCHASING CRITERIA

The historical PHOTOMER® 4226 product data sheet provides quantitative reference criteria for viscosity, color, acid value, moisture, inhibitor, residual solvent, density and refractive index. These parameters help characterize delivery consistency, storage behavior and processability. A current supplier-issued specification should determine contractual acceptance limits, because the cited product sheet dates from 2015.

Viscosity: Changes in measured viscosity can indicate a different temperature, blend state, contamination, partial reaction or batch variation. Compare results at the same temperature and using the specified test method rather than relying on an unqualified “low viscosity” claim.

Color and optical clarity: APHA color and a clean, clear appearance can be relevant to light-colored coatings and inks. The documented APHA 60 maximum should be distinguished from measurements after long storage, which may be affected by aging, contamination and light exposure.

Acid value: Residual acidity can influence interactions with additives and metal surfaces and may indicate differences in manufacturing or storage condition. The historical limit is 0.5 mg KOH/g, measured according to the stated standard. Higher acidity can be important even when a batch remains physically clear.

Moisture: The 2015 published limit is 0.1%, determined by Karl Fischer. Water can alter some formulations' clarity, interactions with additives and downstream performance, although it does not automatically make DPGDA unusable. Its importance should be evaluated against the user's chemistry and specification.

Stabilizer: The historic sheet lists inhibitor content up to 600 ppm by GC analysis, but it does not prove which inhibitor is used or an appropriate minimum level. Those details matter for preventing unintended polymerization and for testing cure behavior. Never remove or change a stabilizer merely to improve cure speed without formal process safety review.

Residual solvent: The published upper limit of 2,000 ppm reflects that historical specification and is distinct from an assurance of zero VOC or zero residuals in the finished coating. The chemical identity, actual residual profile and product use should be reviewed where odor, emissions or regulatory limits matter.

Documentation: A technical data sheet (TDS or PDS) summarizes product characteristics and potential applications; a safety data sheet (SDS) addresses hazard classification and safe handling; and a batch-specific certificate of analysis (COA) records tested lot results against defined specifications. These documents serve different purposes and should not be substituted for one another.

Packaging and supply: The 2015 product sheet listed 200 kg drums and 1,000 kg IBCs, which is historical manufacturer packaging information and not an Ataman Kimya stock promise. Discuss current package choices, sealing arrangements, transport requirements and lot traceability with the seller before concluding a purchase.

REGULATORY CONSIDERATIONS, FOOD CONTACT AND FINISHED ARTICLES

PHOTOMER® 4226 is an industrial radiation-curing monomer and is not an E-numbered food additive. A CAS record or an industrial chemical-inventory listing does not establish permission to use it as a food ingredient, pharmaceutical excipient, medical material or cosmetic ingredient.

Where UV-cured inks and varnishes are used in packaging, suitability depends on the structure of the packaged article, direct or indirect contact, barrier layers, migration mechanisms, set-off and the relevant legal framework. Residual acrylates and other low-molecular-weight substances may need to be controlled and analytically measured. The product's industrial application listing is not evidence of food-contact approval.

Finished coatings may have requirements that do not apply to neat monomer, including residual monomer limits, organoleptic acceptability, occupational installation conditions and end-of-life environmental rules. Material selection should account for the entire supply chain and the intended end use.

Regional chemical inventory information in historical literature can become outdated. Manufacturing, importation and use may trigger reporting, hazard communication or chemical registration duties that depend on location and transaction details. Obtain current confirmation for the specific shipment and jurisdiction rather than repeating old inventory claims as blanket compliance certificates.

FIRST AID

Inhalation
If PHOTOMER® 4226 vapor, mist or aerosol is inhaled, move the affected person to fresh air and keep them comfortable for breathing. Obtain medical attention if symptoms occur or persist; severe respiratory symptoms require urgent medical assessment. Avoid rescue exposure and follow the current SDS.

Skin Contact
If PHOTOMER® 4226 contacts the skin, remove contaminated clothing and wash exposed skin thoroughly with plenty of water and soap. Seek medical advice for irritation, rash or signs of allergic sensitization; contaminated clothing should be washed before reuse. Repeated skin contact with uncured acrylate material should be prevented.

Eye Contact
If PHOTOMER® 4226 enters the eyes, start immediate, gentle rinsing with clean water while holding the eyelids open. Remove contact lenses if present and easy to do, continue rinsing and obtain urgent medical or poison-center advice because DPGDA is reported to cause serious eye damage. Do not delay professional assessment to try improvised neutralization.

Ingestion
If PHOTOMER® 4226 is swallowed, rinse the mouth if the person is conscious and able to do so, and contact a medical professional or poison center promptly for product-specific advice. Do not induce vomiting unless directed by a qualified medical professional, and never give anything by mouth to an unconscious person.

Note to Physicians
Management of exposure to PHOTOMER® 4226 should be guided by symptoms, exposure route and the currently supplied safety data sheet. Provide the product identity and label to medical personnel; eye injury and delayed allergic skin responses may require particular attention. This profile is not a replacement for emergency medical protocols.

HANDLING AND STORAGE

Handling
Handle PHOTOMER® 4226 as a reactive acrylic monomer in a controlled industrial workplace. Minimize splashes and mist formation, avoid direct contact with skin and eyes, and prevent contamination with substances that may promote unintended polymerization. Use closed or well-contained transfer procedures where reasonably practicable.

Engineering Controls
Provide PHOTOMER® 4226 handling areas with suitable general ventilation and local exhaust where mist, aerosol or other exposure may arise. Process equipment must be designed for the handling of reactive monomers, including heat removal and emergency response planning when appropriate for the storage volume or operation.

Personal Protection
Wear chemical-resistant gloves, protective clothing and suitable sealed eye or face protection when handling PHOTOMER® 4226. Glove selection depends on measured permeation performance, exposure duration and other formulation components; disposable glove labels alone do not establish adequate protection.

Respiratory Protection
For PHOTOMER® 4226 tasks that could generate aerosol or significant airborne exposure, assess the need for appropriately selected respiratory protection according to workplace measurements and the current SDS. Respirators supplement rather than replace suitable ventilation, and must be selected under the applicable respiratory-protection program.

Storage
Store PHOTOMER® 4226 in a cool, dry, shaded and well-ventilated area, protected from direct heat and sunlight, as stated in the manufacturer product sheet. Maintain compatible sealed packaging and monitor storage conditions in accordance with the currently supplied SDS. The old sheet's at-least-12-month durability statement assumes appropriate conditions and should not be generalized to every opened container.

Material Compatibility
Use construction materials, closures, pumps, seals and transfer lines verified for PHOTOMER® 4226 and the intended temperature range. Keep the monomer away from incompatible reactants and contamination sources identified by the current SDS; avoid transferring it into vessels of uncertain prior service. Do not assume storage under an inert atmosphere is appropriate without confirming the stabilizer's oxygen requirements.

Cold-Storage Behavior
The PHOTOMER® 4226 product sheet states that the liquid may congeal or stratify if cold. If that occurs, follow manufacturer instructions for controlled return to room temperature and mixing; never apply unapproved direct heat or infer that a separated container is safe for use without inspection.

Spill Procedures
For a PHOTOMER® 4226 spill, restrict access, use appropriate PPE and prevent contact with drains, soil and waterways. Collect released liquid with compatible inert absorbent or authorized containment methods under the site spill plan. Avoid processes that introduce reactive contaminants, excess heat or aerosol.

Environmental Precautions
Prevent PHOTOMER® 4226 from entering sewers or natural waters. Environmental hazard classifications can vary with the exact grade and jurisdiction, but environmental releases should be treated as unacceptable regardless of whether a transport class is assigned. Arrange permitted disposal of contaminated absorbents and wash materials.

Fire Response
In a fire involving PHOTOMER® 4226, use suitable extinguishing agents and protective equipment as directed by the site emergency plan and current SDS. Heat may increase the risk of uncontrolled polymerization and pressure build-up in closed containers. Firefighters should consider cooling exposed containers from a protected location when safe to do so.

Waste Disposal
Dispose of PHOTOMER® 4226 residues, contaminated packaging and cleanup materials through authorized waste-management procedures and applicable local rules. Do not pour uncured monomer into drains or assume that informal open-air curing constitutes an approved treatment method. Distinguish solid cured waste from hazardous uncured liquid after appropriate characterization.

SAFETY AND TRANSPORT INFORMATION

Substance-Associated Hazards: DPGDA is widely classified in supplier and classification records as causing skin irritation (H315), being capable of allergic skin sensitization (H317), and causing serious eye damage (H318). These classifications are a strong safety basis for handling the monomer, but product labels must be drawn from the current regional PHOTOMER® 4226 SDS.

Signal Word and Pictograms: Refer to the current regional grade-specific SDS. Published supplier information on DPGDA often uses “Danger” with eye-damage and skin-sensitization pictograms; exact label elements can be affected by formulation, impurities and jurisdiction.

Environmental Hazards: Some DPGDA supplier SDS documents identify aquatic hazards, but that statement must not be copied as an exact PHOTOMER® 4226 grade classification without its current SDS. Prevent uncontrolled environmental discharge.

Polymerization Hazard: Inhibited acrylate monomers can react prematurely if subjected to inappropriate heating, contamination or exposure conditions. The current storage and handling instructions, including any requirements for inhibitor preservation, oxygen and temperature controls, are operationally important.

UN Number: Not verified for the exact PHOTOMER® 4226 grade using an accessible current SDS.
Proper Shipping Name: Not verified for the exact grade.
ADR / RID Classification: Consult the current supplier SDS, Section 14, and applicable transport rules.
IMDG Classification: Consult the current supplier SDS, Section 14, and applicable marine transport rules.
IATA / ICAO Classification: Consult the current supplier SDS, Section 14, and applicable air transport rules.
Packing Group: Not independently verified for the exact grade.

The absence of a confirmed UN number in this profile does not mean that the product is automatically unregulated for transport. Conversely, classifications found on general chemical-aggregator websites should not be assigned to PHOTOMER® 4226 without grade-specific documentary support. Before shipping, check packaging, quantity, mode of transport, jurisdiction and the current product SDS.

Workplace hazard classification must also be kept separate from transport classification. A substance can require eye and skin hazard warnings in a workplace even if it is not classified as a dangerous good for a particular transportation mode. Neither classification should be inferred solely from the other.

FREQUENTLY ASKED QUESTIONS ABOUT PHOTOMER® 4226

What is PHOTOMER® 4226?
PHOTOMER® 4226 is a commercial grade of dipropylene glycol diacrylate (DPGDA), a low-viscosity, difunctional acrylate monomer used mainly as a reactive diluent in UV- and EB-curable formulations.

What is the CAS number of PHOTOMER® 4226?
The CAS number of the underlying DPGDA substance is 57472-68-1. The product grade may also contain stabilization and minor constituents.

What is the EC or EINECS number of DPGDA?
Its EC / EINECS number is 260-754-3, as listed in substance records and the historical PHOTOMER® 4226 data sheet.

What does DPGDA stand for?
DPGDA means dipropylene glycol diacrylate, the chemical identity underlying PHOTOMER® 4226.

Is PHOTOMER® 4226 a monomer or an oligomer?
PHOTOMER® 4226 is a difunctional monomer and reactive diluent. It is not an oligomeric resin or a complete cured coating.

What is the molecular formula of dipropylene glycol diacrylate?
The nominal molecular formula is C12H18O5; technical material may contain isomers and stabilizer.

What is the molecular weight of PHOTOMER® 4226?
The calculated nominal molecular mass of DPGDA is 242.27 g/mol. An older PHOTOMER® 4226 sheet rounds the entry to 240 g/mol.

Why are 240 g/mol and 242.27 g/mol both encountered?
The first value is a rounded historical product-sheet entry, while 242.27 g/mol is calculated from the nominal C12H18O5 molecular formula. This difference is not evidence of a different product.

Is DPGDA the same as TPGDA?
No. TPGDA is tripropylene glycol diacrylate and contains a different glycol-derived backbone, formula and molecular mass.

Is PHOTOMER® 4226 the same as PHOTOMER® 4226 LT?
The grades share a DPGDA chemical identity, but suffix-bearing versions must be checked against their own data sheets and certificates. Do not assume identical inhibitor levels or specifications.

Is PHOTOMER® 4226 the same as PHOTOMER® 4226 F?
Not automatically. A document referring to an F-suffix grade should not be treated as the exact safety or composition documentation for unsuffixed PHOTOMER® 4226.

What does difunctional mean for this monomer?
A nominal DPGDA molecule has two polymerizable acrylate groups, allowing it to join growing radical polymer chains and contribute to network formation.

What is the appearance of PHOTOMER® 4226?
The historical manufacturer product sheet describes a clean, clear liquid.

What is the typical viscosity of PHOTOMER® 4226?
The current manufacturer product catalogue gives 10 mPa·s at 25 °C as a typical value.

What is the published viscosity specification?
The 2015 product data sheet reports 7–13 mPa·s at 25 °C by Brookfield / ISO 2555. Confirm current limits for the shipment.

Is viscosity measured dynamically or kinematically?
The published viscosity uses mPa·s, indicating dynamic viscosity. It should not be substituted for kinematic viscosity expressed in mm2/s.

What density is reported for PHOTOMER® 4226?
The historical sheet lists 1.040–1.100 g/cm3 at 25 °C, although its property heading uses the term “specific gravity.”

What is its refractive index?
The historical product sheet reports 1.4450–1.4550 at 25 °C, not a universal guaranteed value for all DPGDA grades.

What is its color specification?
The published product sheet lists a maximum APHA color of 60, determined according to ISO 6271.

What is the maximum acid value?
The historical PHOTOMER® 4226 product sheet reports 0.5 mg KOH/g maximum, measured according to the cited NF EN ISO 660 method.

How much water may the published grade contain?
The historical manufacturer specification gives a moisture maximum of 0.1% by Karl Fischer analysis.

What is the inhibitor content in the product sheet?
The historical sheet lists up to 600 ppm inhibitor by GC analysis. It does not by itself define the inhibitor identity or required minimum level.

What is the residual solvent limit?
The published 2015 product sheet lists solvent content of 2,000 ppm maximum by GC analysis; the current grade specification and actual lot should be confirmed.

What surface tension is reported?
The manufacturer’s current product-family guide gives a typical 33 mN/m at 25 °C, a comparative monomer property rather than a finished-ink specification.

Is 96 °C the melting point of PHOTOMER® 4226?
No. The product-family guide lists approximately 96 °C as a comparative polymerized-material glass-transition temperature, not the melting point of the liquid monomer.

What is the actual melting point of PHOTOMER® 4226?
A single grade-specific melting point was not verified in the reviewed data sheet. The manufacturer notes that cold product may congeal or stratify.

What is the boiling point of PHOTOMER® 4226?
A reliable atmospheric-pressure boiling specification for the stabilized PHOTOMER® 4226 grade was not established; do not use unqualified estimates as product data.

What is the flash point?
The reviewed PHOTOMER® 4226 sheet does not establish an exact flash point. Values for another DPGDA supplier grade should not replace the current PHOTOMER® 4226 SDS.

Is DPGDA soluble in water?
DPGDA is not freely miscible with water; solubility measurements depend on grade and temperature. No verified numerical PHOTOMER® 4226 limit was available in the reviewed sheet.

What is its principal function in UV coatings?
PHOTOMER® 4226 reduces resin-mixture viscosity while participating in polymerization and helping build the final crosslinked film.

Does PHOTOMER® 4226 evaporate like a normal solvent?
PHOTOMER® 4226 is designed to react into the cured film rather than function primarily as an evaporating carrier; incomplete cure can nevertheless leave residual monomer.

Can PHOTOMER® 4226 initiate UV curing by itself?
No. It supplies reactive acrylate groups; normal UV formulations generally also require a compatible photoinitiator system.

How does PHOTOMER® 4226 participate in polymerization?
Free radicals add to its acrylate carbon-carbon double bonds, allowing chain growth and the creation of network connections in combination with other reactive ingredients.

Can PHOTOMER® 4226 be used in electron-beam-curable coatings?
Yes. The manufacturer identifies EB-curable formulations, although the actual EB system requires its own validated process and safety design.

Can PHOTOMER® 4226 be used with UV-LED lamps?
Potentially, within a properly formulated and validated system. Lamp wavelength and photoinitiator selection, not the monomer name alone, determine the useful LED cure response.

Can PHOTOMER® 4226 improve water resistance?
The historical product sheet states that it contributes to improved water resistance; the benefit must be checked in the complete cured coating.

What is an overprint varnish application?
An OPV is a protective or decorative coating applied over printing. DPGDA can adjust its liquid viscosity and contribute to the cured acrylic network.

Is PHOTOMER® 4226 useful in flexographic inks?
The manufacturer specifically lists flexographic inks among suitable application areas, subject to printability, pigment and curing validation.

Is PHOTOMER® 4226 useful for screen-printing inks?
Yes, screen printing is included in the published product-sheet applications, but the final screen ink requires appropriate rheology and reliable cure.

Can PHOTOMER® 4226 be used for UV inkjet printing?
The current manufacturer listing includes inkjet. Jetting suitability depends on the complete ink viscosity, surface tension, temperature, filtration and printhead compatibility.

Is DPGDA a pigment dispersant?
No, it is fundamentally a reactive monomer. The manufacturer identifies pigment-wetting characteristics, but a dedicated dispersant may still be required.

Can PHOTOMER® 4226 be used in wood finishes?
Wood coatings are among the listed markets. Finished coatings must be assessed for adhesion, abrasion resistance, flexibility and wood-moisture-related movements.

Can PHOTOMER® 4226 be used on plastic substrates?
Plastic coatings are listed, but compatibility with a specific plastic must be tested for stress cracking, swelling, adhesion and cure-related heating.

Is PHOTOMER® 4226 suitable for metal coatings?
The manufacturer lists metal coatings as an application. Corrosion protection and adhesion still depend on pretreatment, binder selection and the complete coating system.

Does it automatically provide good adhesion?
No. Substrate preparation, coating formulation, crosslink density, cure stress and surface chemistry are all important determinants of adhesion.

Will a higher amount always improve curing?
No. Changes in DPGDA concentration can affect conversion, shrinkage, network rigidity, tack, flexibility and stress in different directions.

Does it always make coatings harder?
Not necessarily. The final hardness depends on oligomers, other monomers, film thickness, conversion and network architecture rather than one ingredient alone.

Does PHOTOMER® 4226 reduce formulation viscosity?
It can reduce viscosity when properly mixed with compatible higher-viscosity resin components; actual results must be measured at process conditions.

Can PHOTOMER® 4226 lower the need for volatile solvent?
It may serve as a reactive alternative to some evaporating diluents in suitable systems, but a VOC or emissions claim requires a complete formulation and regulatory assessment.

Can PHOTOMER® 4226 be used in adhesives?
DPGDA chemistry can be relevant to selected radiation-curable adhesives, but the reviewed main PHOTOMER® 4226 product listing does not substantiate universal adhesive suitability.

Can PHOTOMER® 4226 be used in 3D-printing resins?
Difunctional acrylates can be studied in some photo-curable resin development, but PHOTOMER® 4226 should not be represented as a validated 3D-printing grade solely from its chemistry.

Is there one recommended concentration for all formulas?
No. The manufacturer information reviewed does not provide a universal validated dosage, so loading must be determined by controlled formulation experiments.

Can DPGDA replace HDDA directly?
Not without testing. Both are difunctional acrylates, but their linkers, polarity, resin compatibility and cured-film behavior differ.

How does DPGDA differ from TPGDA?
DPGDA has a dipropylene glycol-derived segment, while TPGDA has a tripropylene glycol-derived segment, so the nominal formulas, masses and resulting processing behavior are different.

How does it compare with triacrylates?
Triacrylates have three acrylate groups per nominal molecule, altering network design and potentially cured rigidity. They are not interchangeable solely by weight.

What does the product-sheet shelf-life statement say?
The historical sheet says the product is durable for at least 12 months under appropriate usual storage and temperature conditions; obtain current guidance for specific lots.

How should PHOTOMER® 4226 be stored?
The product sheet specifies a cool, shaded, dry and well-ventilated storage area away from heat and sunlight; further requirements come from the current SDS.

What if PHOTOMER® 4226 becomes cloudy or separates in the cold?
The manufacturer notes possible congealing or stratification and instructs users to allow return to room temperature and mix before use, subject to current safety procedures.

Is it safe to heat PHOTOMER® 4226 to lower viscosity?
Do not apply uncontrolled heat. This is a reactive monomer and heating practices must follow the current product SDS and a suitable process safety assessment.

Why are inhibitors present?
Inhibitors help limit premature radical polymerization during storage and handling. The actual inhibitor identity and operational requirements must be confirmed for the specific product.

Can I store this monomer under nitrogen?
Do not assume that inert blanketing is compatible with the stabilizer. Some inhibited acrylates require oxygen for inhibition; check the current supplier guidance first.

What are the main health hazards?
DPGDA has widely reported classifications for skin irritation, allergic skin sensitization and serious eye damage. Always use the current regional grade-specific SDS for labeling.

Can PHOTOMER® 4226 cause a skin allergy?
DPGDA can cause an allergic skin reaction, so contact with uncured monomer should be prevented and any exposure-related rash should be evaluated medically.

What should be done after eye contact?
Rinse immediately and thoroughly with clean water, remove contact lenses if easy, and seek urgent medical or poison-center advice because serious eye injury is possible.

What should be done after skin contact?
Remove contaminated clothing, wash exposed skin with plenty of water and soap, and obtain advice if irritation or an allergic rash occurs.

What if PHOTOMER® 4226 is swallowed?
Contact a poison center or physician promptly, provide the product label, and do not induce vomiting unless a qualified professional directs it.

Are gloves required when working with the uncured monomer?
Chemical-resistant gloves and appropriate eye and skin protection are important. Select the exact glove material and replacement interval using manufacturer guidance and the current SDS.

Is cured DPGDA automatically nonhazardous?
No blanket statement is justified. The final coating needs appropriate assessment for residual monomer, migration, extractables and its intended exposure scenario.

Can PHOTOMER® 4226 be used for food-contact packaging?
Not on the basis of the product name alone. The specific legal requirements and the migration and composition of the finished packaging article must be assessed.

Does PHOTOMER® 4226 have an INCI name or E number?
No relevant verified INCI designation is established for the industrial grade, and an E/INS food additive number is not applicable.

Is the product classified as dangerous goods for transport?
A current PHOTOMER® 4226 SDS transport classification was not accessible for independent verification. Check its Section 14 for each mode and shipment.

What is the UN number for PHOTOMER® 4226?
No exact-grade UN number was verified from an accessible current SDS. Do not assume either a specific UN entry or exemption without official shipping documentation.

Does PHOTOMER® 4226 contain solvent?
It is marketed as a reactive monomer; the historical sheet separately lists a residual solvent maximum of 2,000 ppm, which is not a declaration that the liquid is a solvent blend.

What is the difference between a TDS and an SDS?
The technical data sheet describes product properties and applications, whereas the safety data sheet provides hazard, first-aid, storage and transport information.

What does a COA establish?
A batch-specific certificate of analysis reports the tested properties of the lot against applicable criteria; it does not substitute for the SDS or guarantee finished-formulation performance.

Which tests matter most for ink formulation?
Typical tests include blend viscosity, printability, pigment dispersion, surface tension, cure conversion, adhesion, blocking and suitable extractables or migration tests.

Which tests matter most for protective coatings?
Adhesion, hardness, flexibility, abrasion, water and chemical resistance, cure conversion, aging and residual monomer may all be relevant depending on substrate and end use.

How should I compare two DPGDA suppliers?
Compare current specifications and COAs, inhibitor identity and content, impurities, color, water, handling guidance and performance in matched production-representative trials.

Are 200 kg drums and 1,000 kg IBCs available?
Those sizes appear in the 2015 manufacturer document, but present-day packaging and Ataman Kimya availability must be confirmed directly.

Where can buyers request documentation or a quotation?
Customers may contact Ataman Kimya to discuss intended application, appropriate grade documentation, packaging options, current availability and quotations without assuming that a specific lot is in stock.

TECHNICAL SUMMARY

PHOTOMER® 4226 is a stabilized liquid grade of dipropylene glycol diacrylate, CAS 57472-68-1, EC 260-754-3, nominal formula C12H18O5. The monomer has two acrylate functionalities and is intended primarily as a low-viscosity reactive diluent for UV/EB-curable varnishes, graphic-arts inks and industrial coatings.

The 2015 product data sheet reports 7–13 mPa·s dynamic viscosity at 25 °C, APHA color 60 maximum, acid value 0.5 mg KOH/g maximum, moisture 0.1% maximum, inhibitor 600 ppm maximum, residual solvent 2,000 ppm maximum, density 1.040–1.100 g/cm3 at 25 °C and refractive index 1.4450–1.4550 at 25 °C. Current manufacturer catalogue materials give a typical 10 mPa·s viscosity and approximately 33 mN/m surface tension at 25 °C, together with a comparative 96 °C polymerized-material Tg figure; these data are not interchangeable with batch COA values.

PHOTOMER® 4226 helps formulators manage viscosity, reactive functionality and selected coating-performance objectives, including the manufacturer's reported contribution to water resistance. It is not a photoinitiator or a complete ink/coating. Because uncured DPGDA can irritate or sensitize skin and damage eyes, appropriate containment, hygiene, PPE, cure validation and careful stabilized-monomer storage are essential.

Current commercial conditions, safe transport classification, inhibitor details and regulatory suitability require the latest supplier-issued documentation for the exact product. No universal loading, lamp wavelength, cure schedule, food-contact approval or guaranteed application result is implied by this profile.

CONTACT ATAMAN KIMYA

For information about PHOTOMER® 4226 and dipropylene glycol diacrylate, customers may contact Ataman Kimya to discuss their intended UV/EB application, necessary material specifications and available technical documentation. The appropriate commercial grade should be selected with reference to processing method, cured performance, current safety data sheet and any applicable end-use restrictions.

Ataman Kimya can be contacted to inquire about packaging options, batch documentation, current availability and a quotation. Availability, certification status, origin and delivery conditions should be confirmed for the proposed supply rather than assumed from historical manufacturer literature.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com