Abstract: The present invention relates to a copolyester having intrinsic viscosity greater than 0.50 dL/gm, comprises: terephthalate polyester composition; and a modified transparent polybutylene naphthalate, wherein the modified polybutylene naphthalate comprises naphthalene dicarboxylic acid, 1,4-butane diol, and isophthalic acid or monoethylene glycol or diethylene glycol or cyclohexane dimethanol or polyethylene naphthalate, nucleating agent, and a modified nanoclay.

Abstract: A polybutylene naphthalate polyester and process for preparing polybutylene naphthalate polyester, for improving barrier performance of polyesters used in making of monolayer or multilayer containers. The process comprising: a) mixing butane diol with polymerization catalysts, monoethylene glycol, color toner, and at least one crystallization suppressing agent; b) reacting said mixture with naphthalene dicarboxylic acid or ester thereof to obtain oligomerized product via esterification or ester interchange; c) polymerizing said oligomer using at least one polymerization catalyst to obtain amorphous polybutylene naphthalate polyester chips; d) crystallizing said polybutylene naphthalate polyester chips; and e) subjecting said polyester chips to solid state polymerization to upgrade the intrinsic viscosity (I.V.) up to more than 0.40 dl/gm.

Abstract: The present disclosure relates to a process for preparing polyester. The process for preparing the polyester essentially involves the preparation of the isosorbide oligomer and the isosorbide polymer from the isosorbide oligomer. The isosorbide oligomer or isosorbide polymer is then co-polymerized with the polyester. The copolymerization isosorbide oligomer or isosorbide polymer may be carried out at any stage of the preparation of the polyester. The polyester obtained in accordance with the process of the present disclosure can be used in packaging applications such as preparing packaging materials or containers. The material or container obtained from the polyester of the present disclosure is capable of withstanding a temperature of 60 to 90° C. without undergoing any deformation and shrinkage. Further, the material or container obtained from the polyester of the present disclosure is transparent or has lower color b* value.

Abstract: A method of forming a polymer includes polymerizing a first pre-polymer, produced by the reaction of a dicarboxylic acid, or ester thereof with a first alkylene diol; with a second pre-polymer produced by the reaction of an aromatic sulfonate or a salt thereof, or ester thereof, with a second alkylene diol; to form a metal sulfonate co-polymer; reacting the metal sulfonate co-polymer with a fast crystallizing polyester block having a degree of polymerization of at least about 20 to provide an amorphous sulfonated co-polyester; and crystallizing the amorphous sulfonated co-polyester to form a crystallized sulfonated co-polyester.