Patent ID: 9580543
Date: 2017-02-28
CPC Classifications: C08G,G03G

Claim:
1. A method of making a branched polyester resin with a target glass transition temperature, the method comprising: reacting monomer bisphenol A (BPA) with a first cyclic alkylene carbonate in the presence of a first base to obtain a first alkoxylated BPA monomer; reacting monomer BPA with a second cyclic alkylene carbonate in the presence of a second base to obtain a second alkoxylated BPA monomer; copolymerizing one or more alkoxylated BPA monomers with a first diacid and a second diacid in the presence of a catalyst to obtain a copolymer, wherein the one or more alkoxylated BPA monomers comprises the first and the second alkoxylated BPA monomers; and condensing the copolymer with an acid anhydride; wherein the target glass transition temperature is achieved by adjusting the molar ratio of the first cyclic alkylene carbonate to the second cyclic alkylene carbonate, adjusting the molar ratio of the first alkoxylated BPA monomer to the second alkoxylated BPA monomers, adjusting the molar ratio of the first diacid to the second diacid, or any combination thereof.