ground to pass a 3 mm screen dried at 80 u00b0 110 u00b0 c for 24 hours in a vacuum oven and molded on a one ounce watson stillman injection molding machine to give 5 u00d7 1 2 u00d7 1 8 inch flexure bars the notched izod impact strength is determined by taking an average of five breaks following the procedure of astm d256 the following examples are submitted for a better understanding of the invention the following example illustrates the preparation of a polymer consisting of 60 mol terephthalic acid repeating units 40 mol trans 4 4 39 stilbenedicarboxylic acid repeating units and 100 mol 70 trans 30 cis 1 4 cyclohexanedimethanol repeating units a mixture of 87 5 g 0 45 mol dimethyl terephthalate 88 8 g 0 30 mol dimethyl trans 4 4 39 stilbenedicarboxylate 185 1 g 0 90 mol 70 trans 30 cis 1 4 cyclohexanedimethanol 70 solution in meoh and 0 14 g titanium tetraisopropoxide is placed in a 1 litre flask equipped with an inlet for nitrogen a metal stirrer and a short distillation column the flask is gradually heated to 190 u00b0 c to allow the excess methanol to distill the flask is then heated about 20 minutes at 190 u00b0 c 20 minutes at 220 u00b0 c and 20 minutes at 280 u00b0 c the reaction temperature is raised to 300 u00b0 c and a vacuum of 0 5 mm is gradually applied full vacuum is maintained for about 50 60 minutes a light yellow high melt viscosity polymer is obtained with an i v of 0 83 and a t g of 120 u00b0 c the polymer is ground and molded to give.