In use are special duroplastic resins, which contain adequate catalysts, UV-stabilizers and pigments to get a matrix, which meets the required mechanical and chemical properties.

Polyester

The unsaturated polyester resins have become the most popular resins for GRP application in the last years. They are colourless to light yellow coloured solutions of UP in a reactive solvent, in general styrene, which can be cured at room temperature or under heat treatment. Heat is released during the curing.

Unsaturated polyester is resistant to:			Properties:
aromatic hydrocarbons			optical: opaque
aliphatic hydrocarbons			viscosity: low
oil			service temperature: -30 to 200°C
acids
saline solutions
petrol
alcohols

Vinylester

Vinylester resins are produced by conversion of epoxy with methacrylic acid. The use of vinylester resins for GRP-profiles and gratings provides a high resistance to chemical attacks.

Vinylester resins are resistant to:			Properties:
aromatic hydrocarbons			optical: yellow
aliphatic hydrocarbons			viscosity: low
acids			service temperature: -30 to 180°C
lyes
alcohols
grease
oil
petrol

Phenolic resin

Phenolic resins are produced by polycondensation of phenol (m-cresol) with methanal (formaldehyde). Phenoplastics (production)

Epoxy resin

Epoxy resins are compounds, which have one or more reactive epoxy or hydroxyl groups. As a rule they originate from bisphenol A and epichlorhydrine by a combination of polyaddition and polycondensation with a followed curing process.

Epoxy resins are resistant to:			Properties:
aromatic hydrocarbons			optical: opaque
aliphatic hydrocarbons			viscosity: low
organic solvents			service temperature: -30 to 180°C
petrol
oil
alcohols
saline solutions
acids
lyes

Acrylic resin

Acrylic resins are produced by polymerisation of acrylic acid, methylic acid and the corresponding esters.

Acrylic resins are used in areas in which a high resistance to fire and a low smoke emission is requested. For pultrusion acrylic resins are not so common.

Acrylic resins are resistant to:			Properties:
solvents			good burnig properties
alcohols			low smoke emission
			weather proof
			optical: opaque