ARADUR 90

Aradur 90 is a polymercaptane formulation produced by Huntsman Advanced Materials, used as a fast-curing epoxy hardener exhibiting unusually high reactivity, very short pot life, rapid cure at ambient temperature, good flexibility, and excellent cohesion and adhesion properties.
Aradur 90 is benzyl alcohol-free and suitable for the production of solvent-free coatings, adhesives for the construction industry, mastics, and repair mortars where rapid curing and good substrate adhesion are required.
Aradur 90 belongs to the polymercaptane (polythiol) class of epoxy curing agents, which cure epoxy resins through thiol-epoxide addition reactions that proceed rapidly at room temperature without requiring heat, making them suitable for ambient-cure applications demanding very short open time.

Manufacturer: Huntsman Advanced Materials (Switzerland) GmbH, Basel, Switzerland
Product Type: Polymercaptane epoxy curing agent (polythiol hardener)
Chemical Type: Polymercaptane
Brand: Aradur® (registered trademark of Huntsman Corporation)
Applications: CE (Civil Engineering), IM (Industrial Maintenance), A (Automotive)
BzOH Free: Yes
Shelf Life: Minimum 1 year

Synonyms: Aradur 90, Aradur® 90, Huntsman Aradur 90, Polymercaptane Hardener 90, Epoxy Curing Agent Aradur 90, Polythiol Hardener Aradur 90

Aradur 90 belongs to the broader Aradur range of curing agents, which includes reactive polyamides, polyamidoamines, aliphatic amines, cycloaliphatic amines, aromatic amines, anhydrides, and novolacs, all designed to be used with Araldite epoxy resins to achieve a wide range of thermal, mechanical, and electrical properties.
Aradur 90 uses a polythiol (polymercaptane) curing mechanism in which the sulfhydryl (SH) groups react with epoxide rings; this reaction is faster than amine-epoxide curing and proceeds readily at room temperature and even at low temperatures, making Aradur 90 one of the most reactive ambient-cure hardeners in the Aradur range.

Aradur 90 has a gel time of only 4 to 5 minutes when measured with 20 g of mixture with Araldite GY 250 at 23°C, making it one of the fastest-curing hardeners in the Huntsman Aradur product family and particularly suitable for applications requiring immediate structural integrity and rapid return to service.
Aradur 90 provides relatively good flexibility compared to rigid amine-cured epoxy systems, making it suitable for applications where some degree of movement, impact resistance, or deformation tolerance is required in the cured system.

Aradur 90 has limited resistance to heat compared to cycloaliphatic or aromatic amine hardeners, reflecting the lower crosslink density achievable with polythiol systems and the lower glass transition temperature of the resulting thermoset network.
Aradur 90 is part of a product family that is nonyl phenol-free, phenol-free, and tert-butyl phenol-free, and is registered or pre-registered under REACH regulation; the MSDS should be consulted prior to handling.

Uses of Aradur 90:
Aradur 90 is used as a fast-curing hardener in solvent-free epoxy coatings for civil engineering applications including concrete primers, protective coatings, and floor coatings where rapid through-cure, minimal disruption time, and return-to-service speed are critical.
Aradur 90 is used in the production of two-component epoxy adhesives for the construction industry where rapid bond strength development, good cohesion and adhesion to mineral, metallic, and composite substrates are required.

Aradur 90 is used in the formulation of mastics and repair mortars for civil engineering and industrial maintenance applications, providing rapid hardening and durable adhesion to concrete, stone, metal, and other construction substrates.
Aradur 90 is used in industrial maintenance coatings and protective coating systems where rapid return-to-service or cold-temperature curing is required, exploiting the polythiol hardener's ability to cure effectively at temperatures below those practical for amine hardeners.

Aradur 90 is used in automotive adhesive applications including exterior vehicle assembly (OEM), interior vehicle components, vehicle assembly, battery cover sealing, battery assembly, cable sealing, motor and magnet bonding, potting and encapsulating, and thermally and electrically conductive bonding.
Aradur 90 is used in a wide range of structural bonding and assembly applications including household appliance assembly, sporting goods, medical device assembly, aircraft and aerospace, marine, rail, recreational vehicle, truck, sport and leisure, and wind energy applications.

Aradur 90 is used in combination with standard bisphenol A and bisphenol A/F liquid epoxy resins such as Araldite GY 250, and the gel time and pot life can be adjusted by modifying the mix ratio or blend with slower hardeners.
Aradur 90 may also be used as a component in hybrid curing systems combined with amine hardeners to achieve intermediate reactivity profiles between fast polythiol systems and slower amine systems.

Benefits or Advantages of Aradur 90:
Aradur 90 provides an unusually high level of reactivity and very rapid cure at ambient temperature, with a gel time of only 4 to 5 minutes, making it the fastest-curing option in the Aradur polyamidoamine and polymercaptane hardener range for civil engineering and industrial maintenance applications.
Aradur 90 enables effective curing at low temperatures where conventional amine hardeners are slow or ineffective, because the thiol-epoxide addition reaction has lower activation energy than the amine-epoxide reaction and proceeds well even at temperatures approaching 0°C.

Aradur 90 is completely benzyl alcohol-free, avoiding the use of this SVHC (Substance of Very High Concern) reactive diluent while still achieving very low viscosity and excellent substrate wetting in the uncured state.
Aradur 90 provides relatively good flexibility in the cured system compared to rigid amine-cured epoxies, offering improved impact resistance, crack bridging capability, and tolerance of substrate movement or vibration in the cured coating or adhesive.

Aradur 90 delivers good cohesion and adhesion properties to a wide range of substrates including concrete, metal, wood, and composites, making it versatile across construction, industrial maintenance, and bonding applications.
Aradur 90 has a low Gardner color of ≤3, producing lightly colored cured systems suitable for applications where aesthetics or transparency of the cured layer are relevant.

Features of Aradur 90:
Aradur 90 is a high-viscosity liquid at ambient temperature with a viscosity of 10,000 to 16,000 mPa·s at 25°C, requiring thorough mixing with the epoxy component and possibly gentle warming to improve flowability in cold conditions.
Aradur 90 is supplied as a 100% active polymercaptane liquid hardener with an H+ active equivalent of approximately 200 g/Eq, which is used to calculate the stoichiometric mix ratio with the epoxy resin.

Aradur 90 has no amine value as it is a polythiol hardener rather than an amine, and the curing mechanism is fundamentally different from polyamine or polyamidoamine hardeners — sulfhydryl groups react with epoxides without generating the CO2 sensitivity or amine blush associated with amine hardeners.
Aradur 90 exhibits a short pot life of 4 to 5 minutes for 20 g batches at 23°C; larger batches will have shorter effective pot lives due to exothermic heat buildup, and formulations should be designed accordingly with appropriate batch size management.

Chemical Properties of Aradur 90:
Aradur 90 is a polymercaptane (polythiol) formulation, a class of sulfur-containing polymers bearing multiple pendant thiol (–SH) groups that react with epoxide rings through nucleophilic addition, producing thioether (–S–) linkages in the cured network without generating byproducts.
Aradur 90 curing proceeds by nucleophilic attack of the sulfhydryl hydrogen on the epoxide carbon, forming a β-hydroxythioether structure; this reaction is catalyzed by amines and accelerators and can be initiated even without external heat, providing genuine ambient-cure performance.

Aradur 90 is chemically stable under recommended storage and handling conditions in its original sealed container; however, polythiol hardeners are sensitive to oxidation and may discolor or crosslink if exposed to air, heat, or strong oxidizing agents over extended periods.
Aradur 90 is incompatible with strong oxidizing agents, strong acids, strong bases, isocyanates, and heavy metal salts; contact with these materials should be avoided during handling and storage.

Production of Aradur 90:
Aradur 90 is available directly from Huntsman Advanced Materials and through their global authorized distribution network; the Product Safety Data Sheet should be obtained from the local Huntsman representative and reviewed before use.
Aradur 90 has a shelf life of at least 1 year when stored in the original sealed container under recommended conditions; consult the Product Safety Data Sheet for specific storage temperature requirements.

Material Safety Data Sheet (MSDS) of Aradur 90:

Handling of Aradur 90:
Aradur 90 should be handled in accordance with good industrial hygiene and safety practices and in compliance with the Product Safety Data Sheet (PSDS) available from Huntsman Advanced Materials.
Aradur 90 handling requires avoiding contact with eyes, skin, and clothing, avoiding inhalation of vapors, and using appropriate personal protective equipment including chemical-resistant gloves and eye protection, as polymercaptane compounds may cause skin and eye irritation and emit characteristic sulfur odor during use.

SDS of Aradur 90:

Stability and Reactivity of Aradur 90:

Chemical stability:
Aradur 90 is stable under recommended storage and handling conditions when kept sealed in its original container and protected from heat and oxidizing agents.

Reactivity:
Aradur 90 reacts rapidly with epoxy resins when mixed; the curing reaction is exothermic and proceeds very quickly at ambient temperature.
Aradur 90 may react with strong oxidizing agents, strong acids, strong bases, isocyanates, and heavy metal salts.

Conditions to avoid:
Excessive heat.
Open flames and ignition sources.
Direct sunlight.
Prolonged exposure to air and moisture.
Contact with strong oxidizing agents, strong acids, and strong bases.
Large batch mixing without adequate heat dissipation management (rapid exotherm risk).

Incompatible materials:
Strong oxidizing agents.
Strong acids.
Strong bases (alkalis).
Isocyanates.
Heavy metal salts (may catalyze premature gelation).
Reactive chemicals capable of reacting with thiol groups.

Hazardous decomposition products:
Carbon monoxide (CO).
Carbon dioxide (CO2).
Sulfur dioxide and sulfur-containing fumes.
Hydrogen sulfide (H2S) in fire conditions.
Irritating organic fumes.

Handling and Storage of Aradur 90:

Handling:
Handle Aradur 90 in accordance with good industrial hygiene and safety practices.
Avoid contact with eyes, skin, and clothing; use appropriate chemical-resistant gloves and eye protection.
Avoid inhalation of vapors or aerosols; use adequate ventilation.
Wash hands thoroughly after handling and before eating, drinking, or smoking.
Mix Aradur 90 with the epoxy resin only when ready for immediate application due to the very short pot life of 4 to 5 minutes.
Control batch size to manage exothermic heat generation and prevent premature gelation in the container.

Storage:
Store in a dry place in the sealed original container.
Keep Aradur 90 away from direct sunlight, heat sources, and oxidizing agents.
Protect from freezing and prolonged exposure to air.
Store away from incompatible materials including strong acids, bases, oxidizing agents, and isocyanates.
Shelf life is at least 1 year under recommended storage conditions; consult PSDS for specific temperature range.

First Aid Measures of Aradur 90:

Inhalation:
Move affected person to fresh air.
If the characteristic sulfur odor or vapors cause respiratory irritation, coughing, or discomfort, seek medical advice.

Skin contact:
Remove contaminated clothing.
Wash affected skin thoroughly with soap and plenty of water.
Polymercaptane compounds may cause skin irritation or sensitization in some individuals; seek medical advice if redness, itching, rash, or irritation develops or persists.

Eye contact:
Immediately rinse cautiously with clean water for at least 15 minutes while holding eyelids open.
Remove contact lenses if present and easy to do.
Seek immediate medical attention if irritation, redness, pain, or blurred vision persists.

Ingestion:
Rinse mouth with water.
Do not induce vomiting unless instructed by medical personnel.
Seek medical advice if discomfort, nausea, or other symptoms develop.

Firefighting Measures of Aradur 90:

Suitable extinguishing media:
Water spray, foam, dry chemical powder, or carbon dioxide.

Specific hazards:
Aradur 90 is combustible.
Thermal decomposition or combustion may produce carbon monoxide, carbon dioxide, sulfur dioxide, hydrogen sulfide, and irritating or toxic organic and sulfur-containing fumes.

Protective equipment for firefighters:
Wear self-contained breathing apparatus (SCBA) and full protective clothing.

Firefighting instructions:
Cool exposed containers with water spray.
Prevent contaminated firefighting water from entering drains or waterways.
Avoid breathing sulfur-containing combustion fumes.

Accidental Release Measures of Aradur 90:

Personal precautions:
Avoid contact with eyes and skin; avoid inhalation of vapors and characteristic sulfur odor.
Use appropriate personal protective equipment.
Spilled Aradur 90 may create a slipping hazard; contain immediately.

Environmental precautions:
Prevent Aradur 90 from entering drains, sewers, soil, or waterways.
The sulfur-containing components of Aradur 90 may be harmful to aquatic organisms in larger quantities.

Methods for cleaning up:
Contain spilled Aradur 90 with inert absorbent material such as sand or vermiculite.
Collect into properly labeled waste containers for disposal according to local regulations.
Ventilate the affected area after cleanup to disperse any residual sulfur odor.

Exposure Controls / Personal Protective Equipment of Aradur 90:

Engineering controls:
Provide adequate ventilation, particularly in enclosed spaces, as polymercaptane compounds emit a characteristic sulfur odor that may be detectable at very low concentrations.
Use local exhaust ventilation when Aradur 90 is applied by spraying or at elevated temperatures.

Eye protection:
Wear safety glasses with side shields or chemical splash goggles.

Hand protection:
Wear chemical-resistant protective gloves; nitrile or neoprene gloves are recommended.

Skin and body protection:
Wear suitable protective clothing to prevent skin contact; polymercaptane compounds may cause sensitization in some individuals with repeated exposure.

Respiratory protection:
Not normally required under well-ventilated ambient conditions.
Use a suitable organic vapor respirator if Aradur 90 is sprayed, heated, or used in poorly ventilated spaces where the sulfur odor is persistent.

Hygiene measures:
Wash hands thoroughly after handling Aradur 90 and before eating, drinking, or smoking.
Remove and launder contaminated clothing before reuse.

Identifiers of Aradur 90:
Product Name: Aradur 90
Manufacturer: Huntsman Advanced Materials (Switzerland) GmbH
Chemical Type: Polymercaptane (polythiol) formulation
Brand: Aradur® (Huntsman Corporation)
Application Codes: CE (Civil Engineering), IM (Industrial Maintenance), A (Automotive)
BzOH Free: Yes
Shelf Life: Minimum 1 year
Regulatory Status: Pre-registered and registered under REACH (or REACH-exempt); compliant with Huntsman REACH pre-registration

Properties of Aradur 90:
Physical state: Liquid
Appearance: Liquid with characteristic appearance
Odor: Characteristic sulfur (mercaptan) odor
Viscosity (25°C): 10,000–16,000 mPa·s
H+ active equivalent: ~200 g/Eq
Amine value: Not applicable (polythiol hardener)
Gel time (Araldite GY 250, 20 g, 23°C): 4–5 minutes
Color (Gardner): ≤3
Benzyl alcohol content: Free (BzOH Free)
Curing mechanism: Thiol-epoxide addition (polythiol/polymercaptane)
Reactivity: Very high
Pot life: Very short (4–5 min for 20 g at 23°C)
Flexibility: Relatively good
Heat resistance: Limited

Specifications of Aradur 90:
Product name: Aradur 90 (Aradur® 90)
Manufacturer: Huntsman Advanced Materials
Chemical type: Polymercaptane (polythiol) epoxy curing agent
Viscosity (25°C): 10,000–16,000 mPa·s
H+ active equivalent: ~200 g/Eq
Gel time (Araldite GY 250, Tecam, 20 g, 23°C): 4–5 minutes
Gardner color: ≤3
Benzyl alcohol: Free
Applications: Civil Engineering (CE), Industrial Maintenance (IM), Automotive (A)
Recommended epoxy resins: Araldite GY 250 and compatible BPA/BPF liquid epoxy resins
Physical form: Liquid, 100% active (solvent-free)
Shelf life: Minimum 1 year in original sealed container
REACH status: Pre-registered / registered or exempt

Names of Aradur 90:
Aradur 90
Aradur® 90
Huntsman Aradur 90
Polymercaptane Hardener 90
Polythiol Epoxy Hardener 90
Epoxy Curing Agent Aradur 90
Fast-Cure Polythiol Hardener Aradur 90