ARADUR 42

ARADUR 42 is a low-viscosity cycloaliphatic diamine epoxy curing agent based on isophorone diamine (IPDA) and used in solvent-free coatings, flooring compounds, epoxy mortars, mastics, adhesives and high-performance composite systems. The commercial grade is a single-ingredient amine with very low viscosity, high amine functionality, good color stability and strong mechanical, chemical and corrosion-resistance potential when combined with a suitable epoxy resin and cure schedule. ARADUR 42 is especially useful where rapid wetting, low formulation viscosity, solvent-free processing and high cured-network performance are required, but resin selection and stoichiometry must be controlled because some liquid or semi-solid epoxy resins do not develop satisfactory films when cured with ARADUR 42 alone.

PRODUCT IDENTITY

Product name: ARADUR 42
Chemical name: Isophorone diamine
Abbreviation: IPDA
Product type: Epoxy curing agent / hardener
Chemical family: Cycloaliphatic amine
Specific chemical class: Cycloaliphatic diamine
Single ingredient: Yes
Blend: No
CAS Number: 2855-13-2
EC Number: 220-666-8
Molecular Formula: C10H22N2
Molecular Weight: 170.30 g/mol
IUPAC name: 3-(Aminomethyl)-3,5,5-trimethylcyclohexan-1-amine
Physical form: Liquid
Appearance: Liquid
Color: Colorless in current SDS information; Gardner color ≤1 
Odor: Amine
Water solubility: Water soluble according to current product information
Viscosity at 25°C: Approximately 10-20 mPa·s
Amine value: Approximately 645-665 mg KOH/g
Active hydrogen equivalent weight: Approximately 42.5 g/eq in current data; selector literature commonly rounds to 42 g/eq
Density at 20°C: Approximately 0.92 g/cm³
Flash point: Minimum approximately 110°C by Pensky-Martens closed-cup / ISO 2719
Reference gel time: Approximately 95 minutes with ARALDITE GY 250 in selector literature
Recommended reference ratio with ARALDITE LY 1564: Approximately 22.5 g ARADUR 42 per 100 g resin
Reference ratio with ARALDITE LY 1564 SP composite system: Approximately 25 parts by weight ARADUR 42 per 100 parts resin 
Primary current end uses: 2K coatings, epoxy mortars, floorings, mastics, primers, self-leveling floors, solventless and high-solids coatings and top coats
Composite processing methods: Compression molding, infusion, pultrusion, resin transfer molding, wet lay-up and, in resin-system documentation, filament winding and pressure molding
viscosity, low VOC, UV-resistance positioning and VOC-free
Storage temperature: Current SDS field approximately 2-40°C
Preferred storage condition in current technical information: Dry location, sealed original container, preferably approximately 15-40°C, protected from direct sunlight
Crystallization behavior: ARADUR 42 can crystallize below approximately 10°C
Crystallization recovery: Heating above approximately 30-40°C for sufficient time can reverse crystallization without changing chemical composition or suitability as an epoxy hardener
Shelf life: Current product information states at least approximately 3 years within the stated storage range, subject to the expiry date on the original container

Synonyms: Isophorone Diamine, IPDA, Isophoronediamine, 3-(Aminomethyl)-3,5,5-trimethylcyclohexan-1-amine, 3-(Aminomethyl)-3,5,5-trimethylcyclohexanamine, 1-Amino-3-(aminomethyl)-3,5,5-trimethylcyclohexane, 1-Amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 1-Aminomethyl-5-amino-1,3,3-trimethylcyclohexane, 1,3,3-Trimethyl-1-aminomethyl-5-aminocyclohexane, 3-Aminomethyl-3,5,5-trimethylcyclohexylamine, 3,3,5-Trimethyl-5-aminomethylcyclohexylamine, 5-Amino-1,3,3-trimethylcyclohexanemethanamine, 5-Amino-1,3,3-trimethylcyclohexanemethylamine, Cyclohexanemethanamine 5-amino-1,3,3-trimethyl-
ARADUR 42 is unusual among commercial epoxy hardeners because current product page identifies the grade directly as a single ingredient rather than as a proprietary multi-component blend. The product is isophorone diamine, a cycloaliphatic diamine commonly abbreviated IPDA, so a defined CAS number, EC number, molecular formula and molecular weight can be assigned accurately. Product-specific documentation should still control specification, safety and regulatory decisions because commercial grade requirements can be narrower than generic substance data.

WHAT IS ARADUR 42?

ARADUR 42 is a low-viscosity cycloaliphatic diamine that functions as a reactive hardener for epoxy resins. Two primary amine groups supply multiple reactive hydrogens, allowing ARADUR 42 to open epoxy rings and build a densely crosslinked thermoset network.
The combination of low molecular weight and very low viscosity makes ARADUR 42 particularly effective for reducing mixed-system viscosity without introducing conventional solvent. This is useful in solvent-free coatings, floorings, mastics, mortars and composite processes where resin must wet pigments, aggregate, substrate pores or reinforcing fibers efficiently.

ARADUR 42 also provides a comparatively high concentration of amine functionality. Its active-hydrogen equivalent weight is only about 42.5 g/eq, so relatively small hardener additions can cure common liquid epoxy resins when stoichiometry is appropriate.
The grade is not universally suitable as the sole hardener for every epoxy resin. 

ISOPHORONE DIAMINE CHEMISTRY

Isophorone diamine is a cycloaliphatic diamine containing a substituted cyclohexane ring, one amine group attached directly to the ring and a second aminomethyl group. The compact cyclic backbone gives the molecule a balance of rigidity and asymmetry that influences both reactivity and cured-network performance.
The molecular formula is C10H22N2 and the molecular weight is approximately 170.30 g/mol. Commercial IPDA is commonly supplied as an isomeric mixture, which does not prevent the material from functioning as a well-defined industrial curing agent.

The two primary amine groups provide four active amine hydrogens in the idealized molecule. These hydrogens react with epoxy groups through nucleophilic ring opening. As the reaction proceeds, primary amines become secondary amines and can continue reacting, allowing extensive network formation.
The cycloaliphatic structure often provides better color stability and thermal performance than many simple linear aliphatic amines while maintaining much lower viscosity than high-molecular-weight polyamide or polyamidoamine curing agents.

HOW EPOXY CURING WORKS

Epoxy resins contain strained three-membered oxirane rings. The lone pair on the amine nitrogen attacks an electrophilic carbon atom in the epoxy ring and opens the ring, creating a carbon-nitrogen bond and a hydroxyl group.
A primary amine can react more than once because the first epoxy addition converts it into a secondary amine that can still contain one reactive hydrogen. ARADUR 42 therefore provides multiple reactive sites per molecule and can build a highly crosslinked network efficiently.

The newly generated hydroxyl groups can participate in hydrogen bonding and can influence later stages of cure. As molecular weight rises, viscosity increases until the mixture reaches gelation and can no longer flow.
Cure continues after gelation. Mechanical strength, hardness, glass-transition behavior, chemical resistance and dimensional stability continue developing as conversion approaches its final level.
Temperature strongly influences reaction rate. Ambient cure can be possible in some resin systems, while structural composites based on ARADUR 42 are often post-cured or heat-cured to maximize thermal and mechanical performance.

ACTIVE HYDROGEN EQUIVALENT WEIGHT

Current product data give ARADUR 42 an active-hydrogen equivalent weight of approximately 42.5 g/eq. selector guides commonly round this value to approximately 42 g/eq.
AHEW describes how many grams of curing agent provide one equivalent of reactive amine hydrogen. The low value reflects the small molecular size and high functional concentration of isophorone diamine.
The theoretical hardener demand for an epoxy resin can be estimated from resin epoxy equivalent weight. The basic relationship is parts hardener per 100 parts resin = 100 × AHEW / epoxy equivalent weight.

For a resin with EEW 190 g/eq, the simple stoichiometric starting point is approximately 22.4 parts ARADUR 42 per 100 parts resin. This closely matches the 22.5-part reference ratio. The theoretical calculation is useful but should not replace resin-system documentation where a validated formulation exists. Reactive diluents, multifunctional epoxy components and intentional off-stoichiometric design can change the recommended ratio.

AMINE VALUE

 It is listed an amine value of approximately 645-665 mg KOH/g for ARADUR 42.
Amine value is a titration-based measure of basic amine functionality expressed as an equivalent amount of potassium hydroxide. The high value is consistent with a low-molecular-weight diamine containing a high concentration of basic nitrogen.

Amine value is useful for incoming quality control and identity confirmation. A substantial shift can indicate contamination, composition change or product degradation.
Amine value is not the same as AHEW. AHEW directly relates to reactive amine hydrogen, while amine value measures basicity. Both are useful, but stoichiometric epoxy formulation should be based primarily on AHEW and resin EEW.

LOW VISCOSITY

ARADUR 42 has a viscosity of approximately 10-20 mPa·s at 25°C according to current data. This is exceptionally low compared with many polymeric epoxy hardeners.
Low viscosity improves pumping, metering and mixing. It can also reduce the mixed viscosity of a high-viscosity epoxy resin without requiring large amounts of organic solvent or non-reactive diluent.
In composites, low viscosity improves fiber impregnation and resin flow through reinforcement. In floorings and mortars, it helps the binder wet mineral filler and aggregate.
Low viscosity can also create formulation challenges. Vertical coatings or thick mastics may require thixotropic additives because the uncured binder can flow too easily.
Temperature affects viscosity, and the material can crystallize at low storage temperatures. A cold or partly crystallized sample should not be evaluated for viscosity until it has been restored to a homogeneous liquid state.

DENSITY

Current product information gives a density of approximately 0.92 g/cm³ at 20°C.
This relatively low density is useful when converting between gravimetric and volumetric dispensing.
Epoxy formulations should normally be designed and quality-controlled by weight because resin and hardener densities differ and temperature can affect volume.
Density can also serve as an identity or quality-control check, although amine value and viscosity are more chemically informative.

FLASH POINT

ARADUR 42 has a published minimum flash point of approximately 110°C by Pensky-Martens closed-cup testing and ISO 2719.
This relatively high flash point distinguishes the grade from low-boiling solvent solutions.
The product is nevertheless an organic amine and can burn or decompose under severe heating. A high flash point should not be interpreted as absence of fire hazard.
Firefighting procedures, decomposition hazards and protective equipment should follow the current SDS.

COLOR AND COLOR STABILITY

Current SDS information describes ARADUR 42 as colorless, while selector literature gives a Gardner color no higher than approximately 1.
Good color stability is a current product feature and is advantageous in clear systems, pale coatings and decorative formulations.
Cycloaliphatic amines generally offer better color performance than many aromatic amine curing agents, although epoxy resin chemistry and UV exposure also affect long-term appearance.
Low initial hardener color does not guarantee permanent exterior color stability. Conventional epoxy resins can yellow, chalk or lose gloss under prolonged ultraviolet exposure.

WATER SOLUBILITY

Current information identifies ARADUR 42 as water soluble.
The two amine groups create strong polarity and hydrogen-bonding capability, which contributes to water compatibility despite the hydrophobic cycloaliphatic portion of the molecule.
Water solubility is relevant to cleaning, handling and environmental behavior but does not make a cured epoxy network water soluble.
After reaction with epoxy resin, the amine becomes chemically incorporated into a crosslinked thermoset that has very different solubility and mobility from free ARADUR 42.

SOLVENT-FREE CHARACTER

 It is currently identified ARADUR 42 as solvent-free and VOC-free.
The extremely low viscosity is an inherent molecular property of isophorone diamine rather than the result of dilution with xylene, alcohol or another organic solvent.
This makes ARADUR 42 useful for high-solids and solventless formulations where viscosity must remain manageable without introducing large amounts of volatile material.
The complete formulation is not automatically VOC-free because epoxy resin solutions, additives or cleaning solvents can still contribute reportable VOC.

BENZYL-ALCOHOL-FREE CHARACTER

Current information identifies ARADUR 42 as benzyl-alcohol-free.
Benzyl alcohol is used in some epoxy hardeners as a viscosity reducer, accelerator or formulation aid. ARADUR 42 does not require it to achieve low viscosity.
The absence of benzyl alcohol can simplify formulation where migration, water resistance or VOC considerations make benzyl alcohol undesirable.
A finished epoxy product can still contain benzyl alcohol or other auxiliary solvents if they are introduced through other components.

GEL TIME

Literature lists an approximate gel time of 95 minutes for ARADUR 42 with ARALDITE GY 250 under the specified comparative method.
Gel time gives a controlled reference for cure reactivity but should not be equated automatically with practical pot life in every application.
Large reactive batches can self-heat and gel faster than thin films because epoxy-amine cure is exothermic. Cooler thin films can cure more slowly because they dissipate heat efficiently.
Resin type, stoichiometry, fillers, pigments, catalyst and temperature all influence gel time. Application-specific working time should therefore be established with the final formulation.

APPLICATIONS

Solvent-free coatings
ARADUR 42 is suitable for formulated solvent-free epoxy coating systems where its low viscosity helps maintain application flow without conventional solvent. Resin selection is critical because not every liquid epoxy forms a satisfactory coating when cured solely with ARADUR 42.

High-solids coatings
The product can be used in high-solids systems where a small hardener addition and low viscosity support high non-volatile content. Pigments, fillers and rheology modifiers can be used to tune film build and application behavior.

2K epoxy coatings
Current product information lists two-component coatings as an end-use category. ARADUR 42 can form the reactive hardener side of suitable epoxy systems.

Primers
ARADUR 42 can be used in formulated primers where low viscosity, adhesion and corrosion resistance are required. Anti-corrosion performance depends on the complete binder, pigment package and surface preparation.

Epoxy mortars
Epoxy mortars are a major application area. ARADUR 42's low viscosity helps the binder wet sand, silica and mineral filler efficiently.

Floorings
Flooring formulations can use ARADUR 42 in suitably designed resin systems where high mechanical strength, abrasion resistance and chemical resistance are needed.

Self-leveling floors
Current information specifically lists self-leveling floors. Low binder viscosity helps the formulation spread before cure, while rheology and filler grading determine final leveling behavior.

Mastics
Filled epoxy mastics can use ARADUR 42 where low-viscosity hardener supports pigment and filler wetting. Thixotropic modification is usually required for vertical or gap-filling use.

Industrial maintenance coatings
Protective coatings for machinery, process equipment and structural steel can use ARADUR 42 as part of a formulated curing package where resin compatibility and cure speed are appropriate.

Corrosion-resistant coatings
Corrosion resistance is a current product feature. ARADUR 42 can support anti-corrosion epoxy systems when combined with suitable resin, pigments, dry-film thickness and substrate preparation.

Chemical-resistant coatings
Current information highlights chemical resistance. Fully cured epoxy systems can resist many neutral aqueous and alkaline solutions and selected industrial chemicals depending on resin chemistry.

Abrasion-resistant coatings
Abrasion resistance is another current product feature. Flooring and industrial coatings can use hard mineral filler or aggregate to further improve wear performance.

Concrete floor systems
Epoxy flooring on prepared concrete can use ARADUR 42-based binder technology where substrate moisture and resin compatibility are controlled.

Concrete repair mortars
Filled epoxy repair materials can use ARADUR 42 to cure resin binders that bond to prepared concrete. Repair performance should be validated through adhesion and mechanical testing.

Grouts
Low-viscosity binder can be converted into grout by adding graded filler or aggregate. Structural grout performance requires dedicated compressive and creep testing.

Primer-sealers
Low-viscosity epoxy systems can penetrate porous mineral substrates and act as primer-sealers where the resin-hardener system remains compatible.

Machinery coatings
Equipment housings, frames and machine components can use ARADUR 42-based epoxy where chemical and mechanical durability are required.

Steel coatings
Properly prepared steel can be protected with epoxy systems cured using ARADUR 42. Surface cleanliness and profile remain essential.

Tank exteriors
Epoxy primers and intermediate coats based on ARADUR 42 can be used on exterior tank surfaces beneath appropriate topcoats.

Pipe coatings
Prepared pipes can use ARADUR 42 epoxy systems for atmospheric or selected process exposure where formulation testing confirms suitability.

Coastal infrastructure
Strong adhesion and corrosion resistance make formulated ARADUR 42 epoxy systems relevant to coastal steel where chloride exposure is important.

Industrial flooring
Factories and workshops can use ARADUR 42 epoxy floors where abrasion, chemical resistance and mechanical strength are required.

Warehouse flooring
High-strength epoxy flooring can protect concrete in warehouses. Aggregate and filler design determine slip resistance and wear.

Workshop flooring
ARADUR 42 can support floors exposed to oils, equipment and cleaning agents when the final resin network is properly cured.

Maintenance mortars
Epoxy mortars used for patching machinery bases, floors and concrete defects can use ARADUR 42 as a reactive curing component.

Adhesives
Low viscosity and high functionality make ARADUR 42 suitable for many formulated epoxy adhesive systems. Toughening may be required where peel and impact are critical.

Structural adhesives
Two-component structural adhesives can use IPDA-based curing where bond-line geometry, working time and required heat resistance are suitable.

Metal bonding
ARADUR 42 epoxy systems can bond steel, aluminum and other properly prepared metals. Surface pretreatment strongly affects durability.

Concrete-to-metal bonding
Epoxy adhesives can bond steel plates, anchors or reinforcement to concrete. Low viscosity helps wet rough mineral and metallic surfaces.

Composite laminates
ARADUR 42 is widely used in high-performance epoxy laminating systems because its low viscosity promotes fiber wet-out and its cured network can provide high mechanical and thermal performance.

Wet lay-up
Wet lay-up is a current processing method. Resin and hardener are mixed and applied directly to reinforcement before consolidation.

Infusion
Infusion is also listed. Low mixed viscosity helps resin flow through dry reinforcement under vacuum or pressure.

Resin transfer molding
RTM is a current supported processing method. Resin must fill the mold and wet reinforcement before gelation.

Pultrusion
Pultrusion is explicitly listed. Continuous fibers are impregnated with reactive resin and passed through a heated die where cure develops.

Compression molding
Compression molding is another current processing method. ARADUR 42 can participate in heat-cured epoxy molding systems where formulation viscosity and cure schedule are optimized.

Pressure molding
Pressure molding appears in composite-system documentation with ARADUR 42. Controlled pressure supports consolidation and void reduction.

Structural composites
ARALDITE LY 1564 / ARADUR 42 is currently positioned for industrial and structural composites. Heat cure can develop high thermal and mechanical performance.

Industrial composites
Machine components, panels, pipes and other reinforced structures can use ARADUR 42-based epoxy matrices where process and cure conditions are appropriate.

Glass-fiber composites
Low mixed viscosity supports wet-out of glass fiber fabrics, rovings and unidirectional reinforcement.

Carbon-fiber composites
ARADUR 42 can be used in compatible carbon-fiber epoxy systems where high stiffness, thermal resistance and chemical resistance are needed.

Tooling laminates
Epoxy tooling structures can use IPDA-based systems where dimensional stability and heat resistance are important.

Composite repair
Wet-lay-up repair laminates can use ARADUR 42 where working time and cure schedule suit the repair size.

Potting and encapsulation
Low-viscosity epoxy systems can flow around components, though electrical properties and exotherm must be validated for the final formulation.

Filled casting systems
Mineral-filled castings can use ARADUR 42 where low hardener viscosity helps wet the filler and where exotherm is controlled.

Protective mastics
Thick filled mastics can use ARADUR 42 as part of the hardener design when sag control and substrate wetting are balanced.

High-performance laminating resins
Heat-cured LY 1564 / ARADUR 42 systems demonstrate that the hardener can support high-Tg structural laminate technology when paired with a specifically designed resin.

Solventless industrial systems
The inherently low viscosity and solvent-free character of ARADUR 42 make it a useful building block for solventless industrial formulations.

ARALDITE LY 1564 REFERENCE SYSTEM

Current product information gives a mix ratio of approximately 22.5 g ARADUR 42 per 100 g ARALDITE LY 1564 epoxy resin.
A separate LY 1564 SP / ARADUR 42 resin-system page gives approximately 25 parts by weight ARADUR 42 per 100 parts resin, reflecting the specific system version and formulation.
The resin system is described as a warm-to-hot curing laminating system with high reactivity and flexibility. Processing methods include filament winding, pressure molding, RTM and wet lay-up.
The cured system can develop high glass-transition temperatures and strong tensile and flexural properties when the prescribed heat cure is achieved. These values belong to the specific LY 1564 resin system and should not be generalized to every epoxy cured with ARADUR 42.

ARALDITE GY 250 REFERENCE GEL SYSTEM

ARALDITE GY 250 is used in selector literature as a common reference resin for comparing amine curing-agent gel time.
ARADUR 42 gives approximately 95 minutes under the selector protocol.
This number is useful for comparative reactivity but should not be interpreted as a recommended standalone coating formulation with GY 250.
Current product information specifically warns that liquid to semi-solid epoxy resins or resin solutions such as GY 250, GY 260 and GY 280 do not cure fully into satisfactory films when processed solely with ARADUR 42.

LIMITATION WITH SOME LIQUID EPOXY RESINS

A critical formulation limitation is that ARADUR 42 should not automatically be used as the sole hardener for every standard liquid or semi-solid epoxy resin.
This does not mean ARADUR 42 is unsuitable for coatings. It means that formulated curing-agent systems, modified resins, co-hardeners, accelerators or specifically designed resin systems may be necessary.
The warning is especially important because a theoretically correct stoichiometric ratio does not guarantee good film formation or balanced cured properties.

FORMULATED HARDENER SYSTEMS

ARADUR 42 is often valuable as a reactive building block inside a formulated hardener rather than as the only curing component.
A formulated hardener can combine ARADUR 42 with slower or more flexible amine chemistry to balance cure speed, hardness, pot life, adhesion and toughness.
Accelerators can also be incorporated where appropriate, although acceleration reduces working time.
Any blend creates a new AHEW and cure profile and must therefore be recalculated and tested rather than treated as pure ARADUR 42.

MIX-RATIO CALCULATION

The theoretical hardener ratio can be estimated from AHEW and resin EEW.
For example, using AHEW 42.5 g/eq and resin EEW 185 g/eq gives approximately 23.0 parts hardener per 100 parts resin.
At EEW 190 g/eq, the calculation gives approximately 22.4 parts per 100 parts resin.
At EEW 200 g/eq, the calculation gives approximately 21.3 parts per 100 parts resin.
These values are chemical starting points only. Resin-specific formulations should be used where available, especially because ARADUR 42 alone can produce unsatisfactory films with certain common liquid epoxy resins.

EFFECT OF HARDENER LEVEL

Too little ARADUR 42 can leave unreacted epoxy groups and reduce cure conversion.
Too much ARADUR 42 can leave unreacted amine functionality, increase polarity and reduce water or chemical resistance.
Off-stoichiometric cure can also affect Tg, toughness, hardness and dimensional stability.
Accurate weighing is therefore important, especially because the required hardener quantity is relatively low compared with the resin mass.

POT LIFE MANAGEMENT

ARADUR 42 is reactive, and pot life decreases as temperature rises.
Large mixed masses retain reaction heat and can cure faster than the same formulation spread as a thin film.
Only the amount that can be processed safely within the validated working time should be mixed.
Cooling the components before mixing can extend working time, but moisture condensation must be avoided and the resin system must remain within its approved processing range.

EXOTHERM CONTROL

Epoxy-amine cure is exothermic. Thick castings and large mixing vessels can develop significantly higher temperatures than thin films or laminates.
High temperature accelerates the reaction further, creating the possibility of thermal runaway in very large reactive masses.
Fillers, smaller batch size and staged processing can reduce peak exotherm.
Composite and casting development should measure internal temperature when thick sections are expected.

HEAT CURE AND POST-CURE

ARADUR 42 can support ambient cure in some systems, but high-performance composite systems commonly use heat cure and post-cure.
Elevated temperature increases molecular mobility and allows the network to approach higher conversion.
Higher conversion can increase Tg, modulus retention and chemical resistance.
The optimum cure schedule belongs to the specific resin-hardener system. A schedule designed for LY 1564 should not be transferred automatically to another epoxy resin.

MECHANICAL PROPERTIES

Good mechanical properties are a current product feature.
The high functionality and cycloaliphatic structure of ARADUR 42 can support strong, stiff epoxy networks when the resin and cure schedule are optimized.
Mechanical properties can include tensile strength, flexural strength, compression resistance and fracture behavior, but the actual values are resin-system-specific.
Composite reinforcement can increase apparent structural strength dramatically because fibers carry much of the load while the matrix transfers stress between them.

CHEMICAL RESISTANCE

Chemical resistance is a current product feature.
Also it is noted that good resistance to aqueous neutral and alkaline solutions in properly formulated and optimally cured systems.
Resistance to solvents, acids and other aggressive chemicals depends strongly on the epoxy resin, crosslink density and cure level.
Application-specific testing should use the actual chemical concentration, temperature and exposure mode expected in service.

CORROSION RESISTANCE

Corrosion resistance is another current product feature.
The cured epoxy network can act as a barrier that slows transport of water, oxygen and salts toward a metal substrate.
Strong adhesion helps prevent corrosion from spreading underneath the coating.
Protective performance depends on surface preparation, pigment package, film thickness and porosity. ARADUR 42 should be considered part of the binder system rather than a stand-alone corrosion inhibitor.

ABRASION RESISTANCE

Abrasion resistance is especially relevant to floors, mortars and industrial coatings.
The cured epoxy binder provides hardness and cohesive strength, while mineral aggregate or filler can substantially increase wear resistance.
Too brittle a network can crack under impact even when surface hardness is high, so formulation balance matters.
Abrasion testing should be performed on the complete flooring or coating system after full cure.

UV RESISTANCE AND WEATHERING

It is listed that UV resistance as a current ARADUR 42 product feature and also highlights good color stability.
These characteristics are advantageous relative to more strongly yellowing amine systems.
Conventional epoxy resin networks can still chalk or lose gloss under prolonged outdoor UV exposure even when the hardener itself has good color stability.
For demanding exterior decorative durability, a UV-resistant topcoat may still be appropriate.

COMPOSITE PROCESSING

Low viscosity is a major advantage in composite processing because reinforcement must be impregnated before gelation.
Wet lay-up requires the mixed resin to spread over fiber and displace air. Infusion and RTM require the resin to flow through reinforcement under vacuum or pressure.
Pultrusion requires rapid wetting before the impregnated fibers enter a heated die.
Filament winding requires stable viscosity while fiber passes through the resin bath or delivery system. ARADUR 42's low viscosity supports all of these operations when resin and cure schedule are matched properly.

FIBER WET-OUT

Fiber wet-out means replacing air at the reinforcement surface with liquid resin.
Poor wetting creates dry spots and voids that reduce load transfer and can initiate failure.
ARADUR 42's low viscosity helps the mixed matrix penetrate bundles of glass or carbon fiber.
Fiber sizing chemistry also affects wetting and adhesion, so the reinforcement should be compatible with the selected epoxy resin system.

VOID CONTROL

Voids reduce composite strength and increase moisture pathways.
Air can enter during mixing, reinforcement impregnation or transfer through a mold.
Low viscosity helps bubbles move and escape, but excessive mixing shear can introduce more air than the resin can release.
Vacuum degassing, careful mold design and controlled resin flow can reduce void content.

FILLERS AND AGGREGATES

Mineral fillers can be added to ARADUR 42 epoxy systems to adjust viscosity, cost, shrinkage, thermal expansion and mechanical properties.
Silica, quartz, calcium carbonate, barytes, talc, mica and alumina are examples of filler classes used in epoxy technology.
Epoxy mortars and flooring systems can use larger aggregate to increase compressive strength and reduce polymer demand.
Filler moisture should be controlled because water can interfere with amine cure and surface quality.

RHEOLOGY CONTROL

Because ARADUR 42 is very low in viscosity, vertical coatings and mastics often require rheology modification.
Fumed silica, organoclays, polymeric thixotropes or fine fillers can create anti-sag structure.
Self-leveling flooring needs a different balance: enough flow to level but enough body to prevent aggregate settlement.
Excessive rheology modifier can trap air and reduce wetting, so formulation should match the application geometry.

PIGMENT COMPATIBILITY

ARADUR 42 can be used in pigmented coatings where pigment chemistry is compatible with the amine cure system.
Pigment surfaces can adsorb amine, change local pH or affect cure rate.
Titanium dioxide, iron oxides and mineral extenders can be incorporated in suitable formulations.
Anti-corrosive pigments require separate evaluation because ionic chemistry and film permeability influence corrosion performance.

ANTI-CORROSIVE PIGMENTS

Zinc phosphate and related anti-corrosive pigments can supplement epoxy barrier protection.
Lamellar materials such as mica or micaceous iron oxide increase diffusion path length for water and oxygen.
Pigment volume should be optimized so the cured binder remains continuous.
Salt-spray and cyclic-corrosion tests should be performed on the final coating rather than inferring performance from binder chemistry alone.

SURFACE PREPARATION

Surface preparation strongly influences adhesion.
Steel should be free from oil, salts, rust and loose scale, and severe service often requires abrasive blasting.
Concrete should be sound and free from laitance, curing compounds, dust and weak surface material.
Composite bonding surfaces may require sanding, solvent-compatible cleaning or other pretreatment. Good resin chemistry cannot fully compensate for a contaminated interface.

MOISTURE DURING APPLICATION

Amine-cured epoxy can be affected by humidity and substrate moisture.
Excess moisture can interfere with adhesion and can promote surface carbamate formation.
Condensation should be avoided by maintaining substrate temperature above the dew point.
Concrete moisture should be evaluated before coating or bonding, especially for thick low-permeability systems.

AMINE BLUSH

Amine blush is a surface deposit formed when reactive amines interact with moisture and carbon dioxide during cure.
It can appear greasy, waxy or cloudy and can interfere with recoating.
Humidity, temperature and cure speed affect blush tendency.
Any blush should be removed according to the coating procedure before sanding, recoating or secondary bonding.

RECOATABILITY

Epoxy coatings have a finite recoat window.
A subsequent coat applied before the first layer becomes fully inert can achieve chemical as well as mechanical bonding.
After full cure, abrasion may be needed to create a suitable surface profile.
Dust, blush, oils or other contamination should be removed before recoating.

CRYSTALLIZATION

ARADUR 42 can crystallize at temperatures below approximately 10°C according to current technical information.
Crystallization is a physical phase change rather than chemical degradation.
The presence of crystals can make the material appear cloudy, semi-solid or non-uniform and can interfere with accurate metering.
Crystallized material should be restored completely before use rather than simply decanting the remaining liquid phase.

REVERSING CRYSTALLIZATION

Crystallization can be reversed by heating ARADUR 42 above approximately 30-40°C for sufficient time.
The material should be warmed uniformly until all crystals dissolve and the liquid becomes homogeneous.
Local overheating should be avoided, and the container should be handled according to the SDS.
reversible crystallization does not change chemical composition or suitability as an epoxy hardener when the material is properly restored.

STORAGE

ARADUR 42 should be stored in a dry place, preferably in the sealed original container, protected from direct sunlight.
Current technical guidance states a preferred storage region around 15-40°C, while the SDS field gives approximately 2-40°C.
Temperatures below approximately 10°C can cause reversible crystallization.
Current information states a shelf life of at least approximately three years within the stated storage range, subject to the expiry date on the original container.

QUALITY CONTROL

Important ARADUR 42 quality parameters include appearance, color, viscosity, amine value, density and functional cure behavior.
Because the product is a single ingredient, identity testing can also be related directly to isophorone diamine chemistry.
Viscosity should be measured only after any crystallization has been completely reversed.
Functional testing with a standardized epoxy resin can provide additional confirmation of cure response.

WHY AMINE VALUE MATTERS

The 645-665 mg KOH/g range provides a sensitive chemical quality-control parameter.
A lower-than-expected value can indicate dilution or chemical change, while an abnormal higher value can signal testing or composition problems.
Amine value should be interpreted together with viscosity and density.
It is not a substitute for AHEW in stoichiometric calculations.

WHY AHEW MATTERS

The approximately 42.5 g/eq AHEW determines the theoretical amount of ARADUR 42 required to cure a given number of epoxy equivalents.
Because the value is low, small weighing errors can create noticeable stoichiometric deviation in laboratory batches.
Accurate balances are therefore preferable to rough volumetric measurement.
The specific resin-system mix ratio should take precedence where available.

WHY VISCOSITY MATTERS

The 10-20 mPa·s viscosity is central to ARADUR 42's processing value.
Low viscosity supports resin dilution, wetting and composite impregnation without conventional solvent.
An unexpectedly high viscosity can result from low temperature or crystallization rather than chemical degradation.
The material should be conditioned and homogenized before judging specification compliance.

TDS, SDS AND COA

The current Technical Data Sheet or product page should be used for present specifications, mix ratios, storage guidance and application limitations.
The Safety Data Sheet governs hazard classification, first aid, firefighting, handling, storage, transport and disposal.
The Certificate of Analysis provides batch-specific controlled results where supplied.
Historical selector literature is valuable for comparative amine value, gel time and color data but should not override current specification documents.

SAFETY AND HANDLING

ARADUR 42 is isophorone diamine, a reactive strongly basic diamine, and should be handled according to the current SDS.
Direct skin and eye contact should be avoided. Isophorone diamine is corrosive and can cause serious injury, and repeated exposure can cause sensitization.
Chemical-resistant gloves, eye protection and suitable protective clothing should be selected through workplace risk assessment.
Ventilation should control vapor, aerosol and any volatile components present in the complete epoxy formulation.

SKIN CONTACT

Reactive diamines can damage skin and can lead to sensitization.
Contaminated skin should be washed promptly according to the current SDS.
Solvents should not be used to clean skin because they can increase irritation and penetration.
Contaminated clothing should be removed and handled appropriately.

EYE CONTACT

ARADUR 42 can cause severe eye injury and splash protection is essential during transfer, metering and mixing.
If eye contact occurs, immediate and prolonged rinsing with clean water should begin and urgent medical attention should be obtained according to the SDS.
Emergency eyewash equipment is appropriate in routine handling areas.

INHALATION

Although ARADUR 42 has a relatively high flash point, vapor or aerosol exposure should still be minimized.
Heating, spraying or vigorous mixing can increase airborne exposure.
Local exhaust ventilation can reduce concentration near the work area.
Respiratory protection should be based on workplace exposure assessment and the current SDS.

INGESTION

ARADUR 42 is an industrial reactive chemical and must not be ingested.
Food, drink and smoking materials should be excluded from handling areas.
After accidental ingestion, immediate medical guidance and current SDS instructions should be followed.

SPILL MANAGEMENT

The low-viscosity liquid can spread rapidly after a spill.
Personnel should use chemical-resistant PPE and prevent the material from reaching drains or uncontrolled environmental pathways.
Compatible absorbent can be used for smaller spills, while larger releases may require pumping or specialized emergency response.
Recovered material and contaminated absorbent should be managed according to local waste requirements.

FIRE RESPONSE

ARADUR 42 has a flash point of at least approximately 110°C but can burn or decompose under strong heating.
Combustion can generate carbon oxides, nitrogen-containing gases and other hazardous fumes.
Firefighters may require self-contained breathing apparatus and chemical-resistant protective equipment.
The current SDS should determine suitable extinguishing media and emergency procedures.

REGULATORY CONSIDERATIONS

Current information lists ARADUR 42 on multiple chemical inventories including AIIC, DSL, ENCS, IECSC, KECI, NZIoC, PICCS, TCSI and TSCA.
The current product page also lists FDA 21 CFR 175.300 under regulatory compliance information.
Such listings are application- and jurisdiction-specific and should not be interpreted as automatic approval of every finished epoxy formulation.
Food-contact or other regulated applications require current compliance documentation for the exact resin-hardener system, formulation, cure conditions and intended use.

ENVIRONMENTAL CONSIDERATIONS

Free ARADUR 42 is water soluble and biologically active as a reactive amine, so uncontrolled discharge should be prevented.
Uncured resin-hardener mixtures should not be released directly to soil, drains or surface water.
Cleaning solvent, absorbents and contaminated process waste should be managed according to local regulations.
Fully cured epoxy has very different mobility and reactivity from free isophorone diamine, but disposal rules remain jurisdiction-specific.

COMMON FORMULATION PROBLEMS

Brittle or exuding film
Certain liquid to semi-solid epoxy resins such as GY 250, GY 260 and GY 280 do not form satisfactory films when cured solely with ARADUR 42. Use a validated formulated hardener or resin system rather than relying only on theoretical stoichiometry.

Pot life shorter than expected
High component temperature, large batch mass or accelerator contamination can shorten working time. Standardize temperature and batch size.

High exotherm
Large reactive masses can self-heat strongly. Reduce batch size, add suitable filler or use staged processing.

Poor adhesion
Oil, salts, rust, release agents, dust or weak concrete can block substrate contact. Correct surface preparation before changing the hardener.

Soft cure
Incorrect mix ratio or insufficient cure temperature can leave residual functionality. Verify EEW, AHEW and cure schedule.

Brittleness
A highly crosslinked unmodified resin can produce a rigid network. Toughening agents, flexible resin components or blended hardeners may be needed.

Crystallized hardener
Storage below approximately 10°C can cause ARADUR 42 to crystallize. Restore the material by uniform warming above approximately 30-40°C until homogeneous.

Sagging
Very low hardener viscosity can reduce formulation body. Use compatible rheology control for vertical coatings and mastics.

Voids in composites
Air entrainment, poor vacuum or rapid gelation can create voids. Improve degassing, flow design and processing time.

Poor fiber wet-out
Mixed viscosity may still be too high if the resin itself is highly viscous or too cold. Condition the resin and optimize processing temperature.

Low chemical resistance
Incomplete cure or unsuitable resin chemistry can reduce resistance. Test the fully cured system under actual exposure conditions.

Amine blush
Cool humid cure conditions can produce surface deposits. Improve environmental control and clean the surface before recoating.

Poor corrosion resistance
Insufficient dry-film thickness, pinholes, poor surface preparation or weak pigment design can reduce protection. Evaluate the complete coating system.

Color change
Epoxy resin, UV exposure or contaminants can cause yellowing even when ARADUR 42 itself has good color stability. Use appropriate topcoat technology for demanding exterior appearance.

FREQUENTLY ASKED QUESTIONS

What is ARADUR 42?
ARADUR 42 is a low-viscosity cycloaliphatic diamine epoxy curing agent based on isophorone diamine.

Is ARADUR 42 a mixture?
No. Current information identifies ARADUR 42 as a single ingredient rather than a blend.

What is the CAS number?
2855-13-2.

What is the EC number?
220-666-8.

What is the molecular formula?
C10H22N2.

What is the molecular weight?
Approximately 170.30 g/mol.

What is the viscosity?
Approximately 10-20 mPa·s at 25°C.

What is the amine value?
Approximately 645-665 mg KOH/g.

What is the active hydrogen equivalent weight?
Approximately 42.5 g/eq.

What is the density?
Approximately 0.92 g/cm³ at 20°C.

What is the flash point?
Minimum approximately 110°C by closed-cup testing.

What is the current mix ratio with ARALDITE LY 1564?
Approximately 22.5 g ARADUR 42 per 100 g resin on the current product page.

Is ARADUR 42 solvent-free?
Yes. ARADUR 42 as solvent-free and VOC-free.

Is ARADUR 42 benzyl-alcohol-free?
Yes. The grade as benzyl-alcohol-free.

What are the main coating applications?
2K coatings, epoxy mortars, floorings, mastics, primers, self-leveling floors, solventless and high-solids coatings and top coats.

What composite processes are supported?
Compression molding, infusion, pultrusion, RTM and wet lay-up are listed.

Can ARADUR 42 be used alone with every liquid epoxy resin?
No. Certain liquid to semi-solid resins such as GY 250, GY 260 and GY 280 do not form satisfactory films when cured solely with ARADUR 42.

Does ARADUR 42 crystallize?
Yes. Crystallization can occur below approximately 10°C.

Can crystallized ARADUR 42 be restored?
Yes. Warming above approximately 30-40°C for sufficient time reverses the crystallization without changing chemical composition or suitability as a hardener.

How should ARADUR 42 be stored?
Store dry in the sealed original container, protect from direct sunlight and follow the current storage guidance; low temperature can cause reversible crystallization.

What documents should be checked before use?
Use the TDS, SDS and batch-specific quality documentation where available.

FINAL TECHNICAL SUMMARY

ARADUR 42 is commercial isophorone diamine curing agent, a single-ingredient cycloaliphatic diamine with CAS 2855-13-2, EC 220-666-8, molecular formula C10H22N2 and molecular weight approximately 170.30 g/mol.
Current product data specify approximately 10-20 mPa·s viscosity at 25°C, 42.5 g/eq active-hydrogen equivalent weight, approximately 0.92 g/cm³ density at 20°C and a minimum flash point around 110°C. Literature gives approximately 645-665 mg KOH/g amine value, about 95 minutes reference gel time with GY 250 and Gardner color no higher than approximately 1.
ARADUR 42 is distinguished by very low viscosity, high functional concentration and solvent-free delivery. These properties allow the hardener to reduce mixed-system viscosity while maintaining high reactive content.

Current product features include abrasion resistance, chemical resistance, corrosion resistance, good color stability, good mechanical properties, low viscosity, low VOC, UV-resistance positioning and VOC-free formulation. The grade is also identified as benzyl-alcohol-free.
Current end uses include 2K coatings, epoxy mortars, floorings, mastics, primers, self-leveling floors, solventless and high-solids coatings and top coats.
ARADUR 42 is also important in composite processing. 

The current ARADUR 42 product page gives approximately 22.5 g hardener per 100 g ARALDITE LY 1564 resin. A dedicated LY 1564 SP resin-system page gives approximately 25 parts by weight hardener per 100 parts resin, demonstrating that exact ratio depends on the specific commercial resin system.
Heat-cured ARADUR 42 composite systems can develop high glass-transition temperatures and strong tensile, flexural and interlaminar properties when paired with the appropriate resin and cure schedule.
A critical formulation limitation is that ARADUR 42 should not be treated as a universally suitable standalone hardener for every liquid epoxy resin. Examples such as GY 250, GY 260 and GY 280 do not fully cure into satisfactory films when processed solely with ARADUR 42 and can become brittle or exude.

This limitation explains why ARADUR 42 is often used in formulated hardener packages or specifically designed resin systems. Chemical stoichiometry alone does not guarantee good coating film formation.
ARADUR 42 can crystallize below approximately 10°C. Warming the material above approximately 30-40°C for sufficient time reverses crystallization without changing chemical composition or hardener suitability.
Current storage information recommends dry storage in sealed original packaging away from direct sunlight. a shelf life of at least approximately three years within the indicated storage range, subject to the expiry date on the original container.

As isophorone diamine, ARADUR 42 is a reactive corrosive amine and requires suitable gloves, eye protection, ventilation and SDS-based handling procedures. Low VOC and high flash point do not remove direct-contact hazards.
For ARADUR 42 technical specifications, application guidance, TDS, SDS, COA and formulation information, contact ATAMAN KIMYA with the intended epoxy resin, substrate, application method, mix ratio and required mechanical, chemical or thermal performance.

ATAMAN KIMYA
Phone: +90 216 577 10 10
Email: info@atamankimya.com