Unsaturated Polyester Resins

General

At first glance, unsaturated polyesters would seem to be something of a misfit for a website covering solvent based resins for coatings, as they are normally though of exclusively for use in glass reinforced plastics. However, unsaturated polyesters are utilised by some coatings manufactures who are engaged in supplies to the automotive industry, namely as body putties (alternatively called 'body fillers' depending on the geographical region). A second usage of unsaturated polyesters by the coatings industry is more region specific, where they are utilised as sanding sealers for wooden substrates, particularly furniture. Unsaturated polyesters are produced by condensation reactions between organic acids and polyhydric alcohols, such as ethylene glycol, propylene glycol etc. The unsaturated polyesters differ from the saturated polyesters in that they contain one or more monomers containing a reactive double bond, such as maleic anhydride or fumaric acid. These polymers are dissolved in a reactive solvent, almost exclusively one with the chemical name of styrene monomer. In use, the unsaturated polyester is cured by reacting the base polymer with the styrene monomer, by a variety of means, resulting in a hard, cross-linked, solid polymer with varying characteristics depending on the formulation of the base polymer.

Chemistry

To be completed at a later date