| abstract |
A process for making thermoplastic polyester with controlled branching or even with linear structures comprising of branching agents in its backbone, the process comprising a preparation of condensation product of at least one trifunctional carboxylic acid or anhydride thereof with at least one mono alkyl alcohol at temperature 255-265°C and under pressure 1.5- 1.8 kg/cm2 and reacting the same with diols such as monoethylene glycol, 1,3 propane diol, 1,6 hexane diol or 1,4 butane diol to form an adduct. The polymer is further polymerized by solid state polymerization in nitrogen atmosphere at 190-210 °C to obtain chips of high molecular weight and are extruded and melt spun into filament or fiber or extruded into films and post process curable articles. The polyester formed resulted in increased rate of Solid state polymerization and reduced rate of polymer crystallizability. |