D.E.R. (Dow epoxy resins), 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 exceptional formulation versatility, consistent reactivity, and reliable performance across a broad range of industries.

This resin provides excellent adhesion, chemical resistance, and mechanical strength when cured with standard epoxy hardeners. Its balanced viscosity, stability, and compatibility with fillers and modifiers make D.E.R. 331 the preferred foundational resin for coatings, adhesives, composites, electrical encapsulation, casting, and civil engineering systems.

Key Properties

• Chemical Type: Bisphenol-A based liquid epoxy resin (DGEBA).

• Weight per Epoxide Equivalent (WPE): 182.0 – 192.0

• Viscosity: Medium viscosity suitable for blending, wet-out, and processing.

• Reactivity: Highly reactive epoxide groups enable a wide selection of curing agents.

• Performance: Produces strong, rigid, chemically resistant thermoset networks.

• Thermal Behavior: Supports high Tg values when formulated with appropriate hardeners.

• Compatibility: Mixes well with fillers, pigments, flexibilizers, diluents, and reinforcing fibers.

• Appearance: Clear to pale-yellow liquid with low color for coatings and electronic applications.

• Processing: Reliable cure characteristics for both 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