Preparation of Chlorendic Acid Based Polyester Resins

Four polyesters were prepared by stepwise condensation of isopbthalic acid, cblorendic acid and maleic anhydride with propylene glycol using p-toluenesulpbonic acid as catalyst and xylene as entrainer. The quantities of maleic anbydride and propylene glycol used were 1 and 2.2 moles respectively and tbe molar ratios of cblorendic acid to isopbtbalic acid were 0.2: 0.8. 0.4: 0.6, 0.6: 0.4 and 0.8:0.2 for tbe four polyesters prepared. The polyesters obtained bad better colour and relatively more uniform distribution of cblorendic acid over tbe polymer cbain compared to the polyester made in one step. They were crosslinked using 30%