Epoxy Resin And Hardeners In Uttar Pradesh

Epoxy Resin and Hardener: Detailed Overview

Epoxy resins are a class of reactive prepolymers and polymers containing epoxide groups. These resins are widely used in adhesives, coatings, laminates, composites, and casting materials when cured with a hardener (also called a curing agent).

1. Epoxy Resin

Chemical Composition

Typically based on bisphenol-A (BPA) and epichlorohydrin.

Formula (general): C21H24O4 (for common resins like DGEBA - Diglycidyl Ether of Bisphenol A)

Physical Properties

Viscosity: Thick, syrup-like liquid

Color: Clear to amber

Density: ~1.1–1.2 g/cm³

Shelf life: 1–2 years if properly stored

Types of Epoxy Resin

Bisphenol A-based (DGEBA): Most common, good mechanical and adhesive properties.

Bisphenol F-based: Lower viscosity, better chemical resistance.

Novolac-based: High heat and chemical resistance.

Cycloaliphatic: Excellent electrical properties.

2. Hardener (Curing Agent)

Function

Reacts with the epoxy groups in the resin to form a cross-linked, thermoset polymer.

Determines the final mechanical, thermal, and chemical properties.

Types of Hardeners

Amine-based (most common)

Aliphatic amines (e.g., triethylenetetramine)

Aromatic amines (e.g., methylene dianiline – high temp use)

Polyamides – Flexible, moisture-resistant

Anhydrides – High-temp, electrical insulation

Thiols (mercaptans) – Very fast cure, low strength

Cycloaliphatic amines – Good UV and chemical resistance

Physical Properties

Appearance: Usually clear, amber, or yellowish

Odor: Often ammonia-like (especially amine types)

Viscosity: Medium to low, depending on type

3. Mixing and Curing

Parameter Details

Mix Ratio Typically 1:1 to 3:1 by volume or weight, depending on formulation

Pot Life 5 minutes to 2 hours (based on formulation)

Curing Time 5 min to 24 hours (room temp or with heat)

Curing Temperature Room temp to 150°C (can vary)

4. Applications

Adhesives: Metal, wood, plastic, concrete bonding

Composites: Aerospace, automotive, marine (carbon/glass fiber)

Coatings: Protective paints, floor coatings

Electrical: Encapsulation, insulators, PCBs

Casting/Molding: Art, jewelry, prototypes

5. Advantages

High strength and adhesion

Chemical and heat resistance

Dimensional stability

Electrical insulation

Customizable with additives (fillers, pigments, flexibilizers)

6. Safety and Handling

Irritant: Skin and eye contact may cause irritation

Sensitizer: Can cause allergic reactions on prolonged exposure

Ventilation: Use in a well-ventilated area

PPE: Gloves, goggles, and protective clothing recommended