Lactic Acid Modified Polyester Resin

In 1847, 15 years before Alexander Parkes introduced Parkesine, the great Swedish chemist, Berzelius, reacted tartaric acid with glycerol and formed are sinous mass poly (glyceryl tartrate). Since this was the reaction product o f a polyhydric alcohol and a polybasic acid, it was a polyester resin, although it remained a laboratory curiosity for many years. Polyester resins can claim to be among the first of the many synthetic resins which are now the basis of the plastics industry. The next landmark in the history of polyester resins was the publication by Vorlander in 1894 of the development of the first unsaturated polyester resins, the glycerol maleates. This was followed by the work of W. J. Smith in 1901. He reacted phthalic anhydride with glycerol to produce poly (glyceryl phthalate) and this led to the development of alkyd resins by G.E.C. and B.T.H. from 1913 onwards. By modifying this resin with various vegetable oils an excellent base for paints was produced having outstanding durability and the commercial exploitation of alkyd resins for surface coating took place over the following 20 years.