Synthesis And Application Of The Polyester Plasticizers

The polyester plasticizers in this research are a kind of the additives for Polyvinyl Chloride (PVC) with good characters. They have the excellent performances of low toxicity and solvents withstanding. The polyester plasticizers are called the"permanent plasticizers".The adipate polyester plasticizers (poly 1,2-propylene adipate, poly 1,3-butylene adipate and poly 1,4-butylene adipate) and phthalate polyester plasticizers (poly 1,2-propylene phthalate, poly 1,3-butylene phthalate and poly 1,4-butylene phthalate) were synthesized by adipate, phthalandione, 1,2-propylene glycol, 1,3-butanediol and 1,4-butanediol, via polyesterification reaction respectively, with tetra-n-butyl titanate as the catalyst and 2-ethyl-hexanol as the chain-termination reagent. The technology of synthesis was optimized. The reaction conditions that influence the synthesis, such as the reaction time, the catalysts, the stuff ratio and the amount of chain-end reagent, were investigated.The acid value, hydroxyl value and saponification value of the products were determined and compared by chemical analysis methods. Viscosimeter, Infrared Absorption Spectroscopy, Nuclear Magnetic Resonance Apparatus, Gel Permeation Chromatography, megohmmeter and Thermo gravimetric Analyzer - Differential Thermal Analysis were adopted to detect and compare the structure, the number average molecular weight, volume resistivity and the thermostability of the polyester plasticizers systematically. The toxicity of poly 1,2-propylene adipate and poly 1,3-butylene phthalate were determined by the acute toxicity tests.The application performances of polyvinyl chloride (PVC) plasticized by the polyester plasticizers, including the mechanical properties, withstand extraction properties, electrical properties, were tested and compared. The structure of the section was observed under the microscope.The results indicate that the temperature, reaction time, catalysts and stuff ratio affect the synthesis. The polyester plasticizers are basically innocuity. They exhibit good withstanding extraction performances. It is proved that the order of the poly 1,2-propylene phthalate synthesis is 2.4 and the activation energy is 42.89 kJ·mol^-1. The activation energy of the thermal decomposition of poly 1,2-propylene phthalate, poly 1,3-butylene phthalate and poly 1,4-butylene phthalate are 77.36 kJ·mol^-1, 66.80 kJ·mol^-1 and 71.22 kJ·mol^-1 respectively.