ARADUR 43-1

ARADUR 43-1 is a low-viscosity modified cycloaliphatic polyamine epoxy curing agent developed for ambient-temperature curing systems that require rapid hardness development, strong adhesion, chemical resistance and practical processing at relatively low mixed viscosity. The commercial grade is a clear light-yellow liquid with an amine value of approximately 260-280 mg KOH/g, viscosity of approximately 200-400 mPa·s at 25°C and an active-hydrogen equivalent weight of approximately 115 g/eq. ARADUR 43-1 is especially relevant to anti-corrosion coatings, epoxy mortars, industrial floorings and other two-component epoxy systems where nonylphenol-free formulation, good mechanical performance and efficient substrate or filler wetting are important.

PRODUCT IDENTITY

Product name: ARADUR 43-1
Product type: Epoxy curing agent / hardener
Chemical family: Polyamines
Specific chemistry: Modified cycloaliphatic polyamine
Physical form: Liquid
Appearance: Clear liquid
Color: Light yellow
Gardner color: Approximately ≤1 in published selector literature
Odor: Amine
Viscosity at 25°C: Approximately 200-400 mPa·s
Amine value: Approximately 260-280 mg KOH/g
Active hydrogen equivalent weight: Approximately 115 g/eq
Density at 20°C: Approximately 1.02 g/cm³
Flash point: Minimum approximately 130°C by Pensky-Martens closed-cup testing
Reference gel time with ARALDITE GY 250: Approximately 45 minutes at 23°C using a 250 g mass and a 100:60 resin/hardener ratio
Reference gel time with ARALDITE GY 783: Approximately 60 minutes at 23°C using a 250 g mass and a 100:60 resin/hardener ratio
Reference mix ratio with ARALDITE GY 783: Approximately 100:60 parts by weight resin to hardener
Comparative selector AHEW: Approximately 115 g/eq
Primary functions: Curing agent, hardener and crosslinker
Primary current end uses: Anti-corrosion coating, epoxy mortars and floorings
Additional established application areas: Industrial maintenance, construction, primers, protective coatings, flooring binders, repair systems and formulated adhesives
Primary product feature: Low viscosity
Current labeling claim: Nonylphenol-free
Typical cure mode: Ambient-temperature cure
Typical substrate classes: Metallic and mineral substrates when the full formulation is suitable
Storage range: Approximately 2-40°C
Storage condition: Dry place, preferably sealed original container, protected from direct sunlight
Regional inventory listings in current technical information: IECSC, PICCS, TCSI and TSCA
CAS Number: Commercial modified cycloaliphatic polyamine hardener; no single CAS number should be assigned to the complete trade grade without the current SDS
EC Number: Commercial formulated amine product; no single EC number should be assigned without current product-specific confirmation
Molecular Formula: Not applicable to the complete commercial product
Molecular Weight: Variable / not applicable as one fixed value

Synonyms: ARADUR 43-1, Modified Cycloaliphatic Polyamine Hardener, Cycloaliphatic Polyamine Curing Agent, Low-Viscosity Epoxy Hardener, Ambient-Cure Epoxy Hardener, Nonylphenol-Free Epoxy Curing Agent, Polyamine Epoxy Hardener, Epoxy Curing Agent, Epoxy Hardener, Industrial Epoxy Hardener, Flooring Epoxy Hardener, Epoxy Mortar Hardener, Anti-Corrosion Epoxy Hardener, Protective-Coating Hardener, Cycloaliphatic Amine Hardener
ARADUR 43-1 should be treated as a formulated commercial curing agent rather than as one pure low-molecular-weight substance. The product is described by its functional chemistry, amine value, AHEW, viscosity and cure behavior, while formal component identities and concentration ranges belong to the current SDS. Assigning a single molecular formula or one universal substance CAS number to the complete trade grade would therefore be technically misleading.

WHAT IS ARADUR 43-1?

ARADUR 43-1 is a modified cycloaliphatic polyamine used to cure epoxy resins at ambient temperature.
Cycloaliphatic polyamines contain amine functionality associated with cyclic hydrocarbon structures, providing a useful balance of reactivity, mechanical strength, color performance and chemical resistance.
ARADUR 43-1 is modified to provide lower practical viscosity and a controlled cure profile suitable for coatings, mortars and flooring systems.
The product is significantly more viscous than a very small neat diamine but far less viscous than many polymeric polyamidoamine or waterborne adduct hardeners.

This 200-400 mPa·s viscosity range makes ARADUR 43-1 easy to meter, pump and mix and helps it wet fillers, pigments, concrete pores and aggregate surfaces efficiently.
The hardener also has a relatively concentrated active-hydrogen content, with an AHEW near 115 g/eq, so moderate hardener levels can cure many liquid epoxy resins.
Current product positioning emphasizes anti-corrosion coatings, epoxy mortars and floorings, while the underlying chemistry is also relevant to other ambient-cure industrial epoxy applications when compatibility and stoichiometry are validated.

MODIFIED CYCLOALIPHATIC POLYAMINE CHEMISTRY

Cycloaliphatic polyamines contain amine groups attached to or associated with cyclic aliphatic molecular structures.
This structure differs from simple linear aliphatic amines and from aromatic amines.
Cycloaliphatic amines generally provide good cured hardness, chemical resistance and mechanical strength while retaining practical ambient-temperature reactivity.
Modification changes the behavior of the base amine system to improve application characteristics such as viscosity, cure balance, compatibility or surface performance.

ARADUR 43-1 should therefore not be treated as equivalent to a generic cycloaliphatic diamine by weight.
The commercial hardener has its own AHEW, amine value and resin-specific mix ratios that must be used for formulation.
The modified chemistry also helps explain why ARADUR 43-1 can combine relatively low viscosity with a less extreme amine value than very low-molecular-weight neat amines.
This balance is useful in protective coatings and filled systems because the hardener can wet surfaces effectively without introducing an excessive amount of non-reactive solvent.

HOW EPOXY CURING WORKS

Epoxy resins contain reactive oxirane rings.
Primary and secondary amine hydrogens in ARADUR 43-1 attack these rings and open them, forming new carbon-nitrogen bonds and hydroxyl groups.
Because both the epoxy resin and hardener contain multiple reactive sites, repeated reaction creates a three-dimensional thermoset network.
The mixed system initially remains liquid and processable, then increases in molecular weight and viscosity as cure proceeds.
At gelation, the network becomes continuous enough that bulk flow largely stops.

Chemical reaction continues after gelation, building hardness, mechanical strength, chemical resistance and thermal performance.
The final cured properties depend on the epoxy resin, hardener ratio, temperature, filler or pigment package and cure time.
A film that is dry to the touch is not necessarily fully cured.
For chemical-resistance or heavy mechanical service, sufficient post-application cure time should be allowed before full exposure.

LOW VISCOSITY

Low viscosity is the primary current product feature of ARADUR 43-1.
The published viscosity range is approximately 200-400 mPa·s at 25°C.
This relatively low viscosity improves pumping, metering, mixing and transfer.
In coating systems, it can reduce total formulation viscosity without requiring the hardener itself to be supplied in a volatile solvent.
In epoxy mortars, low viscosity helps the binder wet mineral fillers and sand efficiently.
In flooring systems, low binder viscosity supports leveling, substrate wetting and filler incorporation.
Low viscosity can also improve pigment wetting and reduce the shear required during final let-down.
The final formulation may still need thixotropic control for vertical coatings or mastics because a low-viscosity binder alone can sag.

AMINE VALUE

ARADUR 43-1 has a published amine value of approximately 260-280 mg KOH/g.
Amine value is a titration-based measurement of basic nitrogen functionality expressed as an equivalent quantity of potassium hydroxide.
It is useful for batch identification and incoming quality control.
A significant change in amine value can indicate contamination, compositional drift or an incorrect product.
Amine value should not be treated as identical to active-hydrogen equivalent weight.
Basic nitrogen contributes to titration behavior, while AHEW reflects the mass of hardener associated with one equivalent of reactive amine hydrogen.
For epoxy stoichiometry, AHEW and validated resin-specific ratios are the more direct formulation tools.

ACTIVE HYDROGEN EQUIVALENT WEIGHT

The active-hydrogen equivalent weight of ARADUR 43-1 is approximately 115 g/eq.
AHEW indicates how many grams of hardener provide one equivalent of reactive amine hydrogen.
The value is central to calculating theoretical resin-to-hardener stoichiometry.
For a simple epoxy resin with an epoxy equivalent weight near 190 g/eq, a theoretical calculation based only on AHEW would give roughly 60.5 parts ARADUR 43-1 per 100 parts resin.
This is consistent with the approximately 100:60 reference systems used with ARALDITE GY 250 and ARALDITE GY 783.
The close agreement shows that the published reference ratio is chemically reasonable for epoxy resins in that EEW range.
Different commercial resins can contain reactive diluents, different EEW values or functional modifications, so the 60 phr value should not be copied automatically to every epoxy resin.

DENSITY

ARADUR 43-1 has a typical density of approximately 1.02 g/cm³ at 20°C.
Density is useful for production calculations and conversion between mass and volume.
Mix ratios should preferably be controlled by weight because the resin and hardener do not necessarily have the same density.
If volumetric dispensing is used, the equipment should be calibrated using actual product density at the relevant temperature.
Density can also serve as a secondary identity or concentration check when combined with viscosity and amine value.
Unexpected density change should be investigated before production use.

FLASH POINT

The current minimum flash point is approximately 130°C by Pensky-Martens closed-cup testing.
This high flash point is a significant handling advantage compared with solvent-cut hardeners containing large amounts of low-boiling aromatic or alcohol solvents.
A high flash point does not mean the product cannot burn or decompose under severe heat.
The organic amine material can generate hazardous decomposition products in a fire.
Fire response, storage and PPE should therefore follow the current SDS.
The high flash point also supports high-solids and solvent-free formulation strategies where the resin side is selected accordingly.

NONYLPHENOL-FREE CHARACTER

ARADUR 43-1 is currently identified as nonylphenol-free.
Nonylphenol and related alkylphenol chemistry have faced substantial environmental and regulatory scrutiny.
A nonylphenol-free curing agent can therefore support formulations designed to avoid this substance class.
The claim applies to the commercial hardener itself.
The complete coating, mortar or flooring formulation should still be reviewed because nonylphenol or related substances could theoretically enter through other raw materials.
Formal regulatory declarations should always be supported by current product-specific documentation when required.

COLOR

ARADUR 43-1 is described as a clear light-yellow liquid.
Published selector literature gives a Gardner color of approximately ≤1.
This low color is advantageous in clear, pale or decorative epoxy systems.
Pigments, fillers and the epoxy resin itself can still dominate the final color.
Long-term yellowing also depends on UV exposure and resin chemistry.
Low initial hardener color should not be interpreted as unlimited outdoor color stability because conventional epoxy networks can yellow or chalk under prolonged sunlight.

GEL TIME

Current product data provide two useful gel-time reference points.
With ARALDITE GY 250 at a 100:60 resin/hardener ratio, a 250 g mass at 23°C gels in approximately 45 minutes under the referenced method.
With ARALDITE GY 783 at the same 100:60 weight ratio, the referenced gel time is approximately 60 minutes.
The difference demonstrates that gel time depends on the exact epoxy resin even when the hardener ratio is similar.
Gel time should not be treated as identical to application pot life.
A coating can lose ideal flow, sprayability or leveling before formal gelation.
Large mixed batches can also react faster than small batches because epoxy-amine cure releases heat.
Practical pot life should therefore be established with the complete formulation at realistic batch size and temperature.

AMBIENT-TEMPERATURE CURE

ARADUR 43-1 is intended for ambient-temperature curing epoxy systems.
Ambient cure is useful in flooring, repair and protective-coating applications where oven curing is impractical.
Reaction rate remains temperature dependent.
Warm conditions shorten working time and accelerate hardness development.
Cool conditions extend pot life but can delay final cure and increase the risk of surface effects related to moisture.
Mechanical and chemical service should begin only after sufficient cure has developed.
Where higher thermal performance is required, a controlled post-cure may improve conversion in some resin systems if the full formulation is designed for it.

APPLICATIONS

Anti-corrosion coatings
Anti-corrosion coatings are a primary current end use for ARADUR 43-1. The hardener can produce strong epoxy networks with good adhesion and chemical resistance when combined with an appropriate resin and pigment package. Steel preparation, dry-film thickness and barrier continuity remain critical.

Epoxy mortars
Epoxy mortar is a primary application. The low viscosity of ARADUR 43-1 helps the resin-hardener binder wet silica, sand and mineral aggregate. Filler grading can be optimized for strength, workability and cost.

Floorings
Industrial and commercial floorings are another primary end use. ARADUR 43-1 can support self-leveling, filled or mortar-type epoxy floor systems where mechanical strength and chemical resistance are required.

Industrial flooring
Factories, workshops and warehouses can use ARADUR 43-1-based flooring formulations where abrasion, cleaning resistance and adhesion to prepared concrete are important.

Self-leveling floors
Low mixed viscosity can support self-leveling floor systems. Rheology must be balanced so the material levels smoothly without excessive aggregate settlement.

Epoxy floor primers
Low-viscosity primer systems can penetrate prepared concrete and improve adhesion of subsequent flooring layers.

Concrete primers
ARADUR 43-1 can be used in compatible concrete primer systems where surface wetting and adhesion are required.

Concrete repair mortars
Filled epoxy systems can use ARADUR 43-1 for patching and repair of prepared concrete. Structural applications require dedicated mechanical validation.

Epoxy screeds
Highly filled screed systems can use the hardener where the binder wets aggregate efficiently and working time is sufficient for placement.

Floor toppings
Protective floor toppings can use ARADUR 43-1 with silica, quartz or other mineral aggregate to increase wear resistance.

Chemical-resistant floors
High crosslink density and suitable resin chemistry can provide resistance to many industrial chemicals. The exact exposure should be tested on the complete 
cured flooring.

Workshop floors
ARADUR 43-1-based systems can be formulated for workshops exposed to oils, cleaners and mechanical traffic.

Warehouse floors
Warehouse flooring can use filled epoxy systems designed for abrasion resistance and easy cleaning.

Plant-room floors
Utility and mechanical areas can use durable epoxy floors where chemical and water resistance are needed.

Parking-area coatings
Sheltered parking areas can use epoxy primers or floor systems where concrete condition and UV exposure are considered.

Protective coatings
General protective coatings can use ARADUR 43-1 where low viscosity, adhesion and chemical resistance are desired.

Industrial maintenance coatings
Machinery, fabricated steel and plant equipment can use compatible ambient-cure epoxy coatings.

Steel primers
Prepared steel can be protected with pigmented epoxy primers based on ARADUR 43-1.

Direct-to-metal coatings
ARADUR 43-1 can be evaluated in DTM formulations where primer and finish functions are combined. Pigment design and corrosion testing are essential.

Barrier coatings
Epoxy films can slow diffusion of water and oxygen. Lamellar fillers can increase the diffusion path and improve barrier performance.

High-build coatings
The hardener's low viscosity can support higher-solids binder designs, although sag control and exotherm must be managed.

Machinery coatings
Industrial machinery can use compatible epoxy primers and finishes where adhesion and chemical resistance are important.

Equipment coatings
Pumps, frames, housings and fabricated equipment can use ARADUR 43-1 systems after suitable substrate preparation.

Pipe coatings
Prepared steel pipe can use ambient-cure epoxy coatings for atmospheric and selected industrial service.

Tank exteriors
Exterior tank surfaces can use epoxy primers or intermediate coats based on ARADUR 43-1 beneath weather-resistant topcoats.

Structural-steel coatings
Industrial structural steel can use compatible anti-corrosion systems where the primer formulation has been validated.

Marine maintenance primers
The chemistry can be evaluated in marine maintenance systems where salt contamination is removed and environmental conditions are suitable.

Coastal infrastructure coatings
Steel near coastal environments can use appropriate epoxy primers designed for chloride exposure.

Zinc-phosphate primers
Zinc phosphate and related inhibitive pigments can supplement the barrier properties of the epoxy binder.

Lamellar-pigment primers
Mica and micaceous iron oxide can improve barrier performance through a tortuous diffusion path.

Concrete protective coatings
Prepared concrete can be protected against water, oils and selected chemicals using compatible fully cured epoxy formulations.

Masonry coatings
Mineral wall surfaces can use compatible epoxy systems where substrate moisture is controlled.

Primer-sealers
Low-build primer-sealers can use the grade where penetration and substrate consolidation are important.

Clear sealers
Pale hardener color can support clear or lightly tinted sealers where the complete resin system remains visually acceptable.

Epoxy adhesives
Modified cycloaliphatic polyamine chemistry can be used in formulated epoxy adhesives where bond strength and ambient cure are required.

Structural adhesives
Two-component structural adhesives can use ARADUR 43-1 where cure speed, toughness and bond-line geometry are appropriate.

Metal bonding
Steel and aluminum can be bonded with suitable ARADUR 43-1 epoxy adhesive systems after proper surface preparation.

Concrete-to-metal bonding
Low-viscosity binder can wet rough concrete and metal surfaces effectively in compatible bonding formulations.

Anchoring systems
Epoxy anchoring formulations can use reactive amine hardener technology where gel time and mechanical performance have been validated.

Construction chemicals
Repair, bonding, flooring and protective applications in construction can use ARADUR 43-1 as part of engineered epoxy systems.

Epoxy grouts
Filled grouts can use the hardener where low binder viscosity helps wet mineral filler and aggregate.

Machinery-base grouts
High-strength epoxy grout formulations can be developed for equipment bases where compressive strength and dimensional stability are required.

Repair compounds
Filled repair compounds can use ARADUR 43-1 where rapid ambient cure and adhesion are useful.

Mastics
Thixotropic filled epoxy mastics can use the hardener for vertical repair or protective applications.

Composite repair
ARADUR 43-1 may be evaluated in compatible wet-lay-up repair formulations where pot life and viscosity are suitable.

Casting compounds
Filled casting systems can use the hardener when exotherm and section thickness are controlled.

Potting compounds
Low-viscosity epoxy formulations can flow around components, although electrical properties and exotherm should be validated.

Tooling compounds
Filled epoxy tooling formulations can use cycloaliphatic polyamine cure where dimensional stability and hardness meet requirements.

High-solids coatings
Low hardener viscosity can help reduce solvent demand in high-solids protective coatings.

Solvent-free systems
When combined with a solvent-free epoxy resin and compatible additives, ARADUR 43-1 can support solvent-free binder technology.

Low-VOC systems
The high flash point and low hardener viscosity can support low-VOC design by reducing dependence on external solvent.

Decorative flooring
Low color can be beneficial in pigmented and decorative epoxy floors.

Quartz-filled floors
Colored or natural quartz aggregate can be used in ARADUR 43-1 flooring systems where binder wetting and cure are balanced.

Broadcast floors
Broadcast aggregate systems can use the hardener in primer, body or seal layers depending on formulation.

Mortar repair
Highly filled repair mortars can use the hardener where adhesion and early mechanical strength are important.

Chemical plant flooring
Specialized floors can be designed for selected chemical exposure after laboratory resistance testing.

Food-processing-area floors
Epoxy flooring may be used in hygienic industrial environments, but regulatory and food-contact requirements belong to the complete system and must be 
verified separately.

Laboratory floors
Smooth chemical-resistant floor systems can use compatible ARADUR 43-1 epoxy formulations.

Utility coatings
Plant rooms, service areas and industrial interiors can use durable epoxy coatings where ambient cure is required.

ARALDITE GY 783 REFERENCE SYSTEM

Current technical information gives a reference mix ratio of approximately 100 parts ARALDITE GY 783 to 60 parts ARADUR 43-1 by weight.
At 23°C and a 250 g test mass, the referenced gel time is approximately 60 minutes.
This ratio is consistent with the approximately 115 g/eq AHEW of the hardener and the epoxy equivalent range expected for the reference resin system.
The ratio should not be transferred automatically to another epoxy resin.
A resin with higher or lower EEW requires a different theoretical hardener level.
The complete formulation should also be checked for pot life, flow, hardness, chemical resistance and final mechanical performance.

ARALDITE GY 250 REFERENCE SYSTEM

ARALDITE GY 250 is used as a comparative reference resin in curing-agent selector data.
At approximately 100 parts resin to 60 parts ARADUR 43-1 by weight, the 250 g test mass at 23°C gives a gel time of approximately 45 minutes.
The shorter gel time compared with the GY 783 reference demonstrates that resin identity affects cure kinetics even at the same nominal ratio.
The GY 250 value is especially useful for comparing ARADUR 43-1 with related hardeners under a common test method.
It should not be interpreted as a universal application pot life for every coating or mortar based on ARADUR 43-1.

MIX-RATIO CALCULATION

Theoretical hardener ratio can be estimated from AHEW and resin epoxy equivalent weight.
The formula is parts hardener per 100 parts resin = 100 × AHEW / resin EEW.
Using AHEW 115 g/eq and resin EEW 190 g/eq gives approximately 60.5 parts hardener per 100 parts resin.
At resin EEW 185 g/eq, the calculated level is approximately 62.2 parts.
At resin EEW 200 g/eq, the calculated level is approximately 57.5 parts.
These values are theoretical starting points.
Commercial resin systems can contain reactive diluents or mixed epoxy functionality, so product-specific formulation guidance should be preferred whenever available.

EFFECT OF HARDENER RATIO

Using too little ARADUR 43-1 can leave unreacted epoxy groups and reduce cure completeness.
Using too much hardener can leave residual amine functionality and can increase polarity or water sensitivity.
Off-ratio cure can affect hardness, flexibility, chemical resistance, adhesion and glass-transition behavior.
Accurate weighing is therefore important.
The approximately 60 phr reference ratio should be adjusted only when the resin EEW or formulation objective justifies the change.
Any intentional off-stoichiometric formulation should be validated through mechanical and chemical testing.

POT LIFE

Pot life is the period during which the mixed resin-hardener system remains suitable for processing or application.
Reference gel times of approximately 45-60 minutes indicate that ARADUR 43-1 is a moderately reactive ambient-cure hardener.
Practical pot life can be shorter than formal gel time because viscosity, leveling or sprayability can deteriorate before the mixture gels.
Large batches can react faster because the exothermic cure raises the internal temperature.
Warm application conditions also shorten pot life.
Pigments, fillers, accelerators and resin type can change the working window.
The final formulation should therefore establish its own maximum use time.

EXOTHERM CONTROL

Epoxy-amine cure releases heat.
Thin coatings dissipate this heat efficiently, while thick masses can retain heat and accelerate their own reaction.
Epoxy mortars are less prone to severe exotherm than neat resin because mineral filler absorbs heat and reduces the reactive binder fraction.
Large unfilled batches can nevertheless become hot.
Mix only the amount that can be applied safely within the validated pot life.
Deep castings should be qualified separately because internal temperature can rise far above ambient conditions.

HARDNESS DEVELOPMENT

Cycloaliphatic polyamine cure can provide strong hardness development.
Hardness is important in floors, protective coatings and repair systems because it contributes to abrasion and indentation resistance.
A surface can become hard before full chemical resistance develops.
Hardness should therefore be measured at multiple cure ages where early return to service is important.
Very high hardness is not always desirable if impact resistance or substrate movement requires flexibility.
Resin modification and filler package can be used to balance hardness and toughness.

MECHANICAL STRENGTH

ARADUR 43-1 can support strong mechanical properties in suitably formulated epoxy systems.
Flooring and mortar performance can include compressive strength, tensile strength, flexural strength and bond strength.
The exact values depend heavily on the epoxy resin, filler loading, aggregate grading, cure schedule and specimen geometry.
Mineral aggregate can raise compressive strength and reduce shrinkage.
Toughening agents can improve impact and fracture resistance where needed.
Performance should be tested on the final system rather than inferred from hardener chemistry alone.

ADHESION

Strong adhesion is an important reason cycloaliphatic polyamine systems are used in coatings and construction epoxy.
Epoxy resins provide strong polar interaction with metal and mineral surfaces.
Low binder viscosity helps the resin-hardener mixture wet surface texture and pores.
Adhesion still depends on proper surface preparation.
Oil, grease, soluble salts, dust, rust, weak concrete laitance and curing compounds can all create a weak boundary layer.
Pull-off, lap-shear or other appropriate tests should be performed after full cure and after relevant aging.

CHEMICAL RESISTANCE

ARADUR 43-1 can support very good chemical resistance in properly formulated and cured epoxy systems.
Chemical resistance depends on crosslink density, resin backbone, hardener ratio and degree of cure.
Neutral aqueous solutions, oils, cleaners and many industrial chemicals can be tolerated by appropriate epoxy formulations.
Strong acids, oxidizers, aggressive solvents or elevated temperatures can be more demanding.
Splash resistance and continuous immersion should be considered separately.
The exact formulation should be tested against the real service chemical at the intended concentration and temperature.

WATER RESISTANCE

Fully cured epoxy systems can provide good resistance to water.
Early water exposure can cause whitening or softening if cure is incomplete.
Residual amine functionality from an incorrect mix ratio can also increase water sensitivity.
Concrete floors should therefore be protected from washing or standing water until sufficient cure has developed.
Immersion applications require dedicated testing.
The complete system should be evaluated for blistering, swelling, mass change and adhesion after wet exposure.

CORROSION RESISTANCE

Anti-corrosion coating is a primary current end use.
The cured epoxy network acts as a barrier that slows movement of water, oxygen and ions toward the metal substrate.
Strong adhesion reduces the ability of corrosion to spread under the film.
Barrier protection can be supplemented with inhibitive or lamellar pigments.
Dry-film thickness and absence of pinholes are critical.
Salt-spray or cyclic-corrosion testing should be performed on the complete primer or DTM formulation.
The hardener contributes to network quality but is not itself a substitute for proper corrosion-pigment design.

ANTI-CORROSIVE PIGMENTS

Zinc phosphate and related pigments can provide corrosion inhibition at coating defects.
Micaceous iron oxide, mica and other lamellar fillers can increase diffusion path length.
Titanium dioxide and iron oxides provide color and can contribute to opacity but are not equivalent to dedicated corrosion inhibitors.
Pigment surfaces can interact with amine chemistry and change viscosity or cure.
The pigment package should therefore be optimized with the complete binder system.
Excess pigment volume can create porosity and reduce protective performance even when the pigment itself is beneficial.

ZINC-RICH SYSTEMS

Metallic-zinc primers require very high pigment loading and electrical connectivity between zinc particles.
ARADUR 43-1 can be evaluated in compatible zinc-rich epoxy technology, but metallic zinc stability must be verified carefully.
Binder level must remain low enough to preserve zinc-to-zinc contact while still providing adhesion and mechanical integrity.
Gas evolution, storage stability, pot life and corrosion performance require dedicated testing.
Zinc-rich use should therefore be treated as a specialized formulation rather than assumed from generic anti-corrosion suitability.

PIGMENT DISPERSION

Pigment dispersion affects color, gloss, settling, rheology and protective performance.
High-shear grinding is generally carried out before final hardener addition so the fully reactive mixture is not subjected to prolonged processing.
ARADUR 43-1's low viscosity simplifies final let-down.
Pigment surfaces can adsorb amine or dispersant and change cure behavior.
The fully mixed two-component coating should therefore be checked for viscosity stability and flocculation.
Poor dispersion can create porous films and reduce corrosion resistance.

FILLERS AND AGGREGATES

Epoxy mortars and floors can contain large quantities of silica, quartz, calcium carbonate or other mineral filler.
ARADUR 43-1's low viscosity helps the binder wet these particles.
A broad particle-size distribution can allow high filler loading with lower binder demand.
Dry filler is preferred because excess moisture can interfere with cure and adhesion.
Aggregate hardness influences abrasion resistance.
Filler loading also reduces polymer shrinkage and can reduce exotherm.
The final mixture must remain workable enough for placement, troweling or self-leveling.

RHEOLOGY CONTROL

Rheology requirements differ by application.
Self-leveling floors need enough flow to smooth but enough low-shear structure to resist filler settlement.
Vertical coatings and mastics require stronger anti-sag behavior.
Fumed silica, organoclays, polymeric thixotropes and fine mineral fillers can be used where compatible.
ARADUR 43-1's low viscosity provides room to build the desired rheology through formulation.
Excessive thickener can trap air and reduce wetting.
Rheology should be measured through pot life because cure gradually changes viscosity.

DEFOAMING AND AIR RELEASE

Mixing epoxy resin, hardener and filler can entrain air.
Air bubbles can create pinholes, reduce mechanical strength and damage appearance.
In floors and mortars, porous concrete can also release air after the coating wets the surface.
Suitable defoamers and air-release additives can help.
Excess defoamer can create craters or intercoat-adhesion problems.
Application during stable or falling substrate temperature can reduce concrete outgassing.
Primer use can also seal porous surfaces before a thicker body coat is applied.

CONCRETE PREPARATION

Concrete should be sound, clean and free from weak laitance, curing compounds, oil, dust and loose material.
Grinding, shot blasting or other mechanical preparation can expose sound concrete and create a suitable profile.
Concrete moisture should be evaluated before application.
Very wet concrete can interfere with adhesion or create vapor-pressure problems beneath low-permeability coatings.
Cracks and movement joints should be assessed separately.
Rigid epoxy repair should not be used blindly across active structural movement.

STEEL PREPARATION

Steel should be cleaned of grease, soluble salts, rust and loose scale.
Abrasive blasting is generally preferred for demanding anti-corrosion service because it provides both cleanliness and surface profile.
Residual chloride contamination can reduce coating life even when the initial film looks satisfactory.
Prepared steel should be coated before significant flash rust or contamination develops.
The required preparation grade should match the corrosion category and coating specification.

SURFACE WETTING

Low viscosity helps ARADUR 43-1 systems wet both metal and mineral substrates.
Good wetting allows the binder to contact microtexture rather than bridging over it.
This improves adhesion and reduces local void formation.
Wetting is influenced by resin surface tension, substrate cleanliness and filler content.
Surfactants or wetting agents can be used where necessary, but excessive low-molecular-weight additive can reduce water or chemical resistance.
The final formulation should therefore use only the amount needed for reliable wetting.

AMINE BLUSH

Amine-cured epoxy systems can develop surface carbamate deposits when free amine reacts with moisture and carbon dioxide.
Blush can appear greasy, waxy or cloudy.
It can reduce gloss and interfere with intercoat adhesion.
Cool humid conditions increase the risk.
Good ventilation and appropriate application temperature can reduce surface problems.
Any visible or suspected blush should be removed before sanding, recoating or secondary bonding.

RECOATABILITY

Epoxy coatings have a finite recoat window.
Applying the next coat while the first layer retains some chemical reactivity can promote strong intercoat bonding.
After full cure, sanding or abrasion may be required to create mechanical profile.
Dust, blush, oil or other contamination should be removed before recoating.
The recoat interval shortens in warm conditions and lengthens in cool conditions.
The final coating specification should therefore define both minimum and maximum recoat time.

WEATHERING

Cycloaliphatic amine chemistry can provide relatively good color compared with some other amine classes.
Conventional epoxy resin itself can still yellow, chalk or lose gloss under prolonged ultraviolet exposure.
ARADUR 43-1 should therefore not be treated as a complete substitute for a dedicated exterior weather-resistant topcoat.
For demanding outdoor appearance, an epoxy primer or intermediate layer is commonly protected with polyurethane, acrylic or polysiloxane technology.
Weatherability should be evaluated on the complete coating stack.

LOW-TEMPERATURE APPLICATION

Low temperature increases viscosity and slows epoxy-amine reaction.
ARADUR 43-1 can still be formulated for ambient cure, but the practical minimum application temperature belongs to the complete system.
Cold concrete or steel can also fall below the dew point and accumulate condensation.
Condensation can damage adhesion and surface cure.
Resin, hardener and substrate temperatures should therefore be monitored rather than relying only on room-air temperature.
Accelerators can be used in some formulations, but they shorten pot life and must be validated carefully.

WARM-CONDITION APPLICATION

Warm conditions lower viscosity and accelerate cure.
This can improve early hardness but shorten working time substantially.
Large mixed batches are especially vulnerable because reaction heat is retained.
Components should not be stored unnecessarily hot before mixing.
Batch size can be reduced during summer application.
The coating should be applied quickly and consistently so all areas experience similar pot-life age.

POST-CURE

Many ambient-cure coating and flooring systems do not require deliberate post-cure.
However, moderate heating after initial cure can increase conversion in some epoxy systems.
Higher conversion can improve chemical resistance and thermal performance.
Post-cure should only be used when the resin, substrate and application permit it.
Concrete floors, for example, may not tolerate aggressive thermal cycles.
The cure schedule should therefore be designed for the exact system rather than inferred from generic epoxy chemistry.

QUALITY CONTROL

Important ARADUR 43-1 quality-control parameters include appearance, viscosity, amine value, density and functional cure response.
The material should remain a clear light-yellow liquid without abnormal separation or sediment.
Viscosity confirms handling consistency.
Amine value provides a chemical measure of basic functionality.
Density offers a secondary physical check.
A standardized resin cure test can confirm gel behavior if application consistency is especially important.
Current product specifications should be used as the acceptance basis.

WHY VISCOSITY MATTERS

The 200-400 mPa·s viscosity range is central to ARADUR 43-1 processing.
A significant increase can affect pumpability, filler wetting and final application viscosity.
Cold temperature can temporarily increase viscosity.
Unexpectedly low viscosity can indicate contamination or dilution.
Viscosity should therefore be measured at the specified temperature.
The value should be interpreted together with density and amine value rather than alone.

WHY AHEW MATTERS

The approximately 115 g/eq AHEW directly determines theoretical hardener demand.
If the wrong AHEW is used, the resin-hardener ratio can become significantly off stoichiometry.
This can reduce hardness, chemical resistance or water resistance.
The value should be paired with the actual epoxy equivalent weight of the resin.
The approximately 100:60 reference ratios with GY 250 and GY 783 are consistent with the published AHEW.
Different resin grades require recalculation.

WHY AMINE VALUE MATTERS

The 260-280 mg KOH/g amine-value range provides a useful chemical fingerprint.
A lower value can indicate dilution, contamination or a composition change.
An abnormally high value can indicate the wrong material or analytical error.
Amine value should be compared with current specification and not with a generic cycloaliphatic amine range.
It supports quality control but does not replace AHEW in formulation calculations.

TDS, SDS AND COA

The current Technical Data Sheet should be used for present product specifications, mix ratios, storage conditions and application guidance.
The Safety Data Sheet governs formal component disclosure, hazard classification, first aid, fire response, handling, transport and disposal.
The Certificate of Analysis provides batch-specific controlled values where supplied.
Historical selector literature can provide useful comparative data such as Gardner color and AHEW, but current product-specific information should take precedence when values or claims change.
Regulatory and compliance statements should always be based on current documents.

SAFETY AND HANDLING

ARADUR 43-1 is a reactive amine curing agent and should be handled according to the current SDS.
Direct skin and eye contact should be avoided.
Chemical-resistant gloves, suitable eye protection and protective clothing should be selected through workplace risk assessment.
Good ventilation is required during mixing and application.
Spray application can create aerosol even when the hardener itself has a high flash point.
The complete epoxy formulation can contain other ingredients with additional hazards, so protection should be based on the full system.

SKIN CONTACT

Reactive amine hardeners can irritate skin and may contribute to sensitization.
Contaminated skin should be washed promptly according to the current SDS.
Solvents should not be used for skin cleaning because they can increase irritation and penetration.
Contaminated clothing should be removed and cleaned or disposed of appropriately.
Repeated low-level exposure should be prevented through gloves and good work practices.

EYE CONTACT

Eye protection is essential during pouring, metering, mixing and application.
If product enters the eyes, immediate prolonged rinsing with clean water should begin.
Medical attention should be obtained according to current SDS guidance.
Emergency eyewash equipment should be accessible in routine handling areas.
Contact lenses should not delay flushing.

INHALATION

Normal handling should minimize inhalation of vapor, mist and aerosol.
Spraying can create airborne droplets even when vapor pressure is relatively low.
Local exhaust ventilation can reduce exposure near mixing and application points.
Respiratory protection should be selected according to workplace exposure assessment and current SDS guidance.
Heating the material can increase airborne exposure and should be controlled.

INGESTION

ARADUR 43-1 is an industrial reactive chemical and must not be ingested.
Food and drink should be excluded from handling areas.
After accidental ingestion, current SDS instructions and professional medical guidance should be followed.
Generic first-aid advice should not replace product-specific instructions.

SPILL MANAGEMENT

Spilled ARADUR 43-1 can create a slippery surface and should be contained promptly.
Personnel should wear appropriate PPE.
Compatible absorbent can be used for small spills, while larger releases may require pumping and specialized response.
Uncontrolled discharge to drains, soil or surface water should be prevented.
Recovered liquid and contaminated absorbent should be placed in suitable labeled waste containers.
Cleanup should follow the current SDS and local waste requirements.

FIRE RESPONSE

ARADUR 43-1 has a high flash point of at least approximately 130°C but can still burn or decompose under severe heating.
Thermal decomposition of organic amine material can generate hazardous fumes.
Firefighters may require self-contained breathing apparatus and suitable protective clothing.
Extinguishing media should be selected according to the current SDS and surrounding fire conditions.
Containers exposed to fire can become pressurized and should be managed under the facility emergency plan.

STORAGE

ARADUR 43-1 should be stored in a dry place, preferably in the sealed original container, at approximately 2-40°C.
Direct sunlight should be avoided.
Containers should remain tightly closed to prevent contamination and moisture uptake.
Material should be conditioned to a suitable processing temperature before viscosity-sensitive metering.
The container expiry date and current product documentation should control shelf-life decisions.
Storage near strong acids or incompatible reactive chemicals should be avoided according to SDS guidance.

REGULATORY CONSIDERATIONS

ARADUR 43-1 is a commercial modified cycloaliphatic polyamine curing agent.
Current technical information identifies the grade as nonylphenol-free.
Current inventory information lists IECSC, PICCS, TCSI and TSCA status.
These regulatory listings are time-sensitive and should be confirmed from current documentation whenever used formally.
Generic suitability for flooring, anti-corrosion coatings or epoxy mortars does not establish approval for food contact, potable water, medical devices or other specialized regulated uses.
Compliance must be assessed for the complete formulation and intended market.

ENVIRONMENTAL CONSIDERATIONS

Uncured reactive amine hardener should not be released directly to soil, drains or surface water.
Cleaning waste can contain uncured epoxy resin, amine hardener, pigment and solvent or detergent and should be managed appropriately.
Low-viscosity solvent-free formulation can reduce the need for added volatile solvent, but the actual environmental profile belongs to the complete product.
Fully cured epoxy has different mobility and reactivity from the uncured components.
Disposal requirements remain jurisdiction-specific and should follow local regulations.

COMMON FORMULATION PROBLEMS

Pot life shorter than expected
High temperature, large batch size, reactive pigments or accelerators can shorten working time. Reduce batch size, standardize temperature and confirm the formulation.

Slow cure
Low temperature, incorrect stoichiometry or incompatible resin can delay cure. Verify the resin EEW, mix ratio and application temperature.

Soft film
Too much hardener, too little resin, incomplete cure or moisture interference can reduce hardness. Confirm weighing and cure conditions.

Brittle film
Too little hardener, overly rigid resin or excessive filler can create brittleness. Rebalance stoichiometry and toughness within validated limits.

Poor adhesion
Oil, salts, dust, rust, weak concrete laitance or curing compounds can create a weak boundary layer. Correct surface preparation before changing chemistry.

Poor corrosion resistance
Low film thickness, pinholes, weak steel preparation or an unsuitable pigment package can reduce protection. Evaluate the complete primer system.

Poor self-leveling
Too much filler, excessive thixotrope, low temperature or late-pot-life application can reduce flow. Adjust rheology and application timing.

Sagging
Very low binder viscosity or excessive wet-film thickness can cause sag. Increase compatible low-shear structure or reduce film thickness.

Foaming
High-speed mixing, porous-substrate outgassing or incompatible additives can trap air. Optimize mixing and defoaming.

Pinholes
Entrained air, substrate outgassing or poor wetting can create pinholes. Prime porous substrates and improve air release.

Low chemical resistance
Off-ratio cure, insufficient cure time or unsuitable resin can reduce resistance. Allow full cure and validate against the actual chemical.

Early water whitening
Premature water exposure can cause whitening before full cure. Delay washing or immersion until sufficient conversion has developed.

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

Intercoat adhesion failure
Overcure, blush or surface contamination can interfere with later coats. Observe the recoat window and prepare the surface when needed.

Excessive exotherm
Large unfilled batches can self-heat rapidly. Reduce batch size, use filler where appropriate and avoid warm component storage.

FREQUENTLY ASKED QUESTIONS

What is ARADUR 43-1?
ARADUR 43-1 is a low-viscosity modified cycloaliphatic polyamine epoxy curing agent for ambient-temperature cure.

What is the viscosity?
Approximately 200-400 mPa·s at 25°C.

What is the amine value?
Approximately 260-280 mg KOH/g.

What is the active hydrogen equivalent weight?
Approximately 115 g/eq.

What is the density?
Approximately 1.02 g/cm³ at 20°C.

What is the flash point?
Minimum approximately 130°C by Pensky-Martens closed-cup testing.

What is the current labeling claim?
ARADUR 43-1 is identified as nonylphenol-free.

What is the mix ratio with ARALDITE GY 783?
Approximately 100 parts resin to 60 parts ARADUR 43-1 by weight.

What is the reference gel time with ARALDITE GY 783?
Approximately 60 minutes at 23°C in the referenced 250 g 100:60 test system.

What is the reference gel time with ARALDITE GY 250?
Approximately 45 minutes at 23°C in the referenced 250 g 100:60 test system.

What are the main applications?
Anti-corrosion coatings, epoxy mortars and floorings are the primary current end uses.

Can ARADUR 43-1 be used for industrial flooring?
Yes. Its low viscosity, ambient cure and mechanical-performance profile make it suitable for properly formulated industrial floor systems.

Can ARADUR 43-1 be used in epoxy mortar?
Yes. Epoxy mortar is a primary application and the low viscosity helps wet sand and mineral filler.

Can ARADUR 43-1 be used in anti-corrosion primers?
Yes. Anti-corrosion coating is a primary end use, but final protection depends on surface preparation, pigment package and film thickness.

Can ARADUR 43-1 be used with other epoxy resins?
Yes, provided the resin EEW, compatibility and required hardener ratio are calculated and validated.

Is the 100:60 ratio universal?
No. The 100:60 ratio applies to specific reference resin systems and should not be transferred automatically to every epoxy resin.

Is ARADUR 43-1 a pure substance?
No. It is a commercial modified cycloaliphatic polyamine hardener and should not be assigned one molecular formula or universal CAS number without product-specific confirmation.

Does ARADUR 43-1 contain nonylphenol?
Current product information identifies ARADUR 43-1 as nonylphenol-free.

Is ARADUR 43-1 low viscosity?
Yes. Low viscosity is its primary current product feature.

Does ARADUR 43-1 require heat cure?
No. It is designed for ambient-temperature curing, although cure rate and final properties remain temperature dependent.

Can ARADUR 43-1 be used in solvent-free systems?
Yes, when paired with a compatible solvent-free epoxy resin and suitable additives.

How should ARADUR 43-1 be stored?
Store dry in the sealed original container at approximately 2-40°C and protect from direct sunlight.

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

FINAL TECHNICAL SUMMARY

ARADUR 43-1 is a low-viscosity modified cycloaliphatic polyamine curing agent designed for ambient-temperature epoxy systems.
The commercial product is a clear light-yellow liquid with viscosity around 200-400 mPa·s at 25°C.
Its published amine value is approximately 260-280 mg KOH/g and its active-hydrogen equivalent weight is approximately 115 g/eq.
Typical density is approximately 1.02 g/cm³ at 20°C and the minimum closed-cup flash point is approximately 130°C.
The product is currently identified as nonylphenol-free.
Low viscosity is the principal product feature and supports easy mixing, filler wetting, substrate wetting and high-solids or solvent-free formulation strategies.

Primary current end uses include anti-corrosion coatings, epoxy mortars and floorings.
ARALDITE GY 783 is an important reference resin system with a ratio of approximately 100 parts resin to 60 parts ARADUR 43-1 by weight.
At 23°C and a 250 g test mass, that reference system has a gel time of approximately 60 minutes.
A separate ARALDITE GY 250 reference at the same 100:60 weight ratio gives a gel time of approximately 45 minutes under the stated comparison method.
The difference shows that resin identity affects cure kinetics and that one universal pot-life value should not be assigned to ARADUR 43-1 independent of resin.

The approximately 115 g/eq AHEW also explains why a 60 phr hardener level is chemically reasonable with epoxy resins having EEW near approximately 190 g/eq.
Anti-corrosion formulations can combine ARADUR 43-1 with appropriate inhibitive pigments and barrier fillers, but corrosion protection belongs to the complete coating system.
Epoxy mortars and floorings benefit from the low hardener viscosity because the binder can wet mineral filler and aggregate efficiently.
Mechanical, chemical and water resistance depend on correct stoichiometry, sufficient cure and the selected resin.
Large mixed masses should be managed carefully because epoxy-amine cure is exothermic and self-heating can shorten pot life.
Surface preparation remains essential for steel, concrete and other substrates.

Quality control should focus on appearance, viscosity, amine value, density and functional cure response.
ARADUR 43-1 is a commercial formulated hardener and should not be assigned an invented fixed molecular formula, molecular weight, CAS number or EC number without current product-specific documentation.
Storage should be dry, preferably in sealed original packaging, at approximately 2-40°C and away from direct sunlight.

For ARADUR 43-1 technical specifications, application guidance, TDS, SDS, COA and formulation information, contact Ataman Chemicals with the intended epoxy resin, substrate, application method, mix ratio and required mechanical or chemical performance.

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