Design and Synthesis of Crystalline Carboxyl-terminated Polyester Resin

Abstract

In this work, a novel semi-crystalline polyester resin synthesis was explored, then influence of alcohol/acid ratio and monomer’s structure on crystallinity of poliester resin were studied in details. The crystalline polyester resin was synthesized via a two-step melt-condensation method. The structure and performance of the polyester resin was characterized by X-ray diffraction, infrared radiation, differential scanning calorimeter, thermogravimetric analysis and melt flow rate. The effect of molar ratio between alcohol monomer and carboxyl monomer on the structure and performance of polyester resin was studied, based on these, how the modifications (1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedimethanol) affected the crystalline properties of the resin were further studied and optimized with the multi-factors orthogonal test method, and the results show that the synthesized polyester resin meets the expected design, and has some crystalline structure. The change of hydroxyl/carboxyl ratio (-OH/-COOH) can affect the crystallinity: the larger the crystallinity, the smaller the melt flow rate. Two modifications containing rigid cyclohexyl groups with high symmetry can improve the crystallinity of polyester resin.

Keywords

• molecular design
• crystallinity
• multi-factors orthogonal test method
• optimization