GRP resins explained simply – properties & applications |…

Thermosetting resins are used, which contain sufficient catalysts, UV stabilisers and pigments. This mixture forms a compound that ensures the required mechanical and chemical properties.

Polyester

Unsaturated polyester resins are among the most commonly used resins in composite materials. UP resins are colourless to slightly yellowish solutions of unsaturated polyester in a reactive solvent, usually styrene. They cure at room temperature or when heat is applied, releasing heat of reaction in the process.

Unsaturated polyester resins are resistant to:

aromatic hydrocarbons
aliphatic hydrocarbons
oil
acids
salt solutions
Petrol
Alcohols

Properties:

Appearance: opaque
Viscosity: low
Operating temperature: -30 to 200°C

Vinyl ester

Vinyl ester resins are produced by reacting epoxides with methacrylic acid. Using vinyl ester resins as the matrix results in significantly higher chemical resistance in GRP profiles and GRP gratings.

Vinyl ester resins are resistant to:

aromatic hydrocarbons
aliphatic hydrocarbons
acids
alkalis
alcohols
Fats
Oils
Petrol

Characteristics:

Appearance: yellowish colour
Toughness: low
Operating temperature: -30 to 180°C

Phenolic resins

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

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Epoxy resins

Epoxy resins are compounds containing one or more reactive epoxy and hydroxyl groups. They are usually produced from bisphenol A and epichlorohydrin through a combination of polyaddition and polycondensation, followed by curing.

Epoxy resins are resistant to:

aromatic hydrocarbons
aliphatic hydrocarbons
organic solvents
petrol
oils
Alcohols
salt solutions
Acids
Alkalis

Characteristics:

Appearance: opaque
Toughness: low
Operating temperature: -30 to 180°C

Acrylic resins

Acrylic resins are synthetic resins produced by the polymerisation of acrylic acid, formic acid and their corresponding esters.

Acrylic resins play a minor role in pultrusion. Like phenolic resins, they are generally used in applications where high fire resistance and minimal smoke emission are essential.

Acrylic resins are resistant to:

Solvents