Polyesters are a family of materials made from a dicarboxylic acid and an alcohol with two or more hydroxy functionalities.  The alternating reaction of a carboxylic acid and a hydroxy group, called a condensation reaction, yields a polyester.  This report covers a number of specialty polyesters, including PETG, PTT, Copolyester (i.e. TRITAN) and a thermoplastic elastomeric polyester generically referred to as copolyester elastomer (COPE).   PET and PBT are covered in separate TECH reports; PETG, PTT and Copolyester were selected for coverage as they are the largest volume materials of the remaining materials.  COPE is covered due to its interesting properties and ongoing growth opportunities.