1. Preparation

To achieve the final stage of a fully cured polyester, several steps are necessary:

• unsaturated polyester is produced by esterification-condensation of diols or epoxides;

• this polyester is then diluted with a monomer, such as styrene, to produce an unsaturated polyester resin;

• the final use of the resin is polymerization to form a three-dimensional network (cross-linking). The resin, pure or formulated with added fillers or fibers, is polymerized catalytically, thermally or by irradiation. This operation, performed in situ on a surface, in a mold or in a special machine, produces the desired object, part or coating.