Polyesters
The polymers which contain an ester linkage are known as polyester, e. g., dacron.
1. Polymethylmethacrylate( PMMA)
It is prepared by the polymerisation of methylmethacrylate in the presence of suitable organic peroxide.
The polymer is known by several commercial names such as lucite, acrylite, plexiglass and perspex.
Properties and uses
It is a hard and transparent polymer and is quite resistant to the effect of light, heat and ageing. It is used, in the manufacture of unbreakable lights, protective coatings, dentures, and in making windows for aircrafts.
2. Glyptal
It is a polyester having crosslinks. It is a thermosetting plastic. It is obtained by condensation of ethylene glycol and phthalic acid or glycerol and phthalic acid.