Resins and properties
Different resins and their properties: polyester, vinyl ester, phenolic, epoxy, and acrylic. The choice of resin affects the product’s performance, especially in terms of chemical resistance, fire properties, and durability.
Resins for GRP – properties and applications.
In the manufacture of GRP (glass fibre reinforced plastic) products, different types of thermosets are used which, with the help of catalysts, UV stabilizers and pigments, provide the right combination of mechanical, chemical and thermal properties. The choice of resin affects the performance of the product, especially in terms of chemical resistance, fire properties and durability.
Polyester resins
- The most widely used type of resin in the composites industry.
- Consists of unsaturated polyester dissolved in a reactive solvent, usually styrene.
- Cures at room temperature or by heating, triggering an exothermic reaction.
- Used where cost effectiveness and good all-round performance are required.
- Suitable for most standard applications in construction, industry and water treatment.
- Service temperature: -30 to +200 °C
Polyester resin is resistant to:
- Aromatic hydrocarbons
- Aliphatic hydrocarbons
- Oils
- Acids
- Saline solutions
- Gasoline
- Alcohols
Vinylester resins
- Used for applications where high chemical resistance is essential – e.g. in chemical plants, offshore and wastewater treatment plants.
- Has higher mechanical strength and better durability than polyester.
- Service temperature: -30 to 180°C
Vinylester resin is resistant to:
- Aromatic hydrocarbons
- Aliphatic hydrocarbons
- Acids
- Bases (lye)
- Alcohols
- Fats
- Oils
- Gasoline
Phenolic resin
- Mainly used where fire resistance and low smoke generation are critical requirements – e.g. in subways, offshore or public infrastructure.
- Provides very good fire safety but is mainly used in niche applications.
Epoxy resin
- Provides excellent adhesion, high mechanical strength and good electrical insulation.
- Suitable for technically demanding constructions where dimensional stability is essential.
- Service temperature: -30 to 180°C
Epoxy resins are resistant to:
- Aromatic hydrocarbons
- Aliphatic hydrocarbons
- Organic solvents
- Gasoline
- Oils
- Alcohols
- Saline solutions
- Acids
- Bases (lye)
Acrylic resins
- Has limited use in the pultrusion process but is used in environments with high fire safety requirements and low smoke emission, like phenolic resin.
- Used e.g. in vehicles, building products and special constructions.
Acrylic resins are resistant to:
- Solvents
- Alcohols