D.E.R. 331 Epoxy Resin (Grade 331)
D.E.R. 331 Epoxy Resin is the most widely used general-purpose liquid epoxy resin and is recognized as the benchmark
grade from which many epoxy resin variations have been developed. Based on bisphenol-A diglycidyl ether chemistry,
it offers formulation versatility, consistent reactivity, and reliable performance across a broad range of industries.
When cured with appropriate epoxy hardeners, this resin is commonly formulated for strong adhesion, chemical
resistance, and mechanical strength. Its balanced viscosity, stability, and compatibility with fillers and modifiers
support use in coatings, adhesives, composites, electrical encapsulation, casting, and civil engineering systems.
Key Properties
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Chemical type: Bisphenol-A based liquid epoxy resin (DGEBA)
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Weight per epoxide equivalent (WPE): 182.0 – 192.0
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Viscosity: Medium viscosity suitable for blending, wet-out, and processing
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Reactivity: Reactive epoxide groups support a wide selection of curing agents
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Performance: Forms strong, rigid, chemically resistant thermoset networks (formulation-dependent)
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Thermal behavior: Can support high glass transition temperatures (Tg) with appropriate hardeners
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Compatibility: Mixes well with fillers, pigments, flexibilizers, diluents, and reinforcing fibers
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Appearance: Clear to pale-yellow liquid; low color for coatings and electronics applications
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Processing: Reliable cure characteristics for ambient- and heat-cured systems
Applications
D.E.R. 331 is suitable for use in a wide range of commercial, industrial, and specialty formulations, including:
Adhesives
- Structural adhesives
- Industrial bonding systems for metals, plastics, and composites
Casting & Tooling
- Molding compounds
- Prototype tooling
- Filled casting systems
Civil Engineering
- Grouts and mortars
- Crack injection and repair
- Concrete bonding agents
Composites
- Fiber-reinforced laminates (glass, carbon, aramid)
- Hand lay-up, filament winding, and infusion systems
Coatings
- Automotive coatings
- Can and coil coatings
- Marine and protective coatings
- Photocure industrial coatings (UV/EB systems)
Potting & Encapsulation
- Electrical and electronic encapsulation
- General-purpose potting compounds
- Protective insulating systems
FAQs
Common questions about D.E.R. 331 Epoxy Resin (Grade 331).
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What is D.E.R. 331 epoxy resin?
D.E.R. 331 is a widely used general-purpose liquid epoxy resin based on bisphenol-A diglycidyl ether (DGEBA)
chemistry. It is commonly used as a foundational resin for a broad range of epoxy formulations.
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What does WPE mean for epoxy resins?
WPE (weight per epoxide equivalent) indicates the mass of resin that contains one equivalent of epoxide
functionality and is used to calculate stoichiometric curing agent requirements.
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What curing agents are typically used with DGEBA epoxy resins?
DGEBA epoxy resins are commonly cured with amine-based hardeners or anhydrides, depending on desired cure
speed, processing temperature, and final performance requirements.
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Why is D.E.R. 331 considered a versatile epoxy resin?
It is widely used because it blends well with fillers, pigments, flexibilizers, and reinforcing fibers and
can be cured under a wide range of conditions to achieve different mechanical and thermal properties.
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What factors influence the performance of cured epoxy systems?
Performance is influenced by curing agent selection, formulation ratios, cure schedule, additives, and
processing conditions, which collectively affect properties such as adhesion, chemical resistance, and
glass transition temperature.
