Study On Preparation And Application Of The New Titanic Catalyst For Polyester

In this paper, the multiphase titanic catalysts for preparing polyesters weresynthesized by alkaline cohydrolysis of tetra isopropyl titanate,as mainly rawmaterials,with other metal element compounds. By orthonormal experiments, the effects of preparing factors on yield andactivity of catalyst and performance of polyester product were investigated,suchas the amount of solvent, the pH of hydrolysis medium, the aqueous amount andaddition time. The properties of the prepared catalyst were determined in aspectsof aqueous sensitivity, particle size and its distribution, thermal properties andsolubility in ethylene glycol. The compositions of catalysts and the preparingprocess were optimized. The polymerization reactions were carried out by the preferred catalyst usingthe direct esterification process of terephthalic acid and ethylene glycol. Theinfluences of amount and addition way of catalyst, the amount of stabilizationagent, the polymeric temperature, the agitating rate and the amount of extinctionagent on the polymeric process were studied .The polyester products prepared bythe new catalyst were compared with that prepared by the traditional antimonycatalyst in the performance of the chips, DSC, thermal analysis, molecular weightand its distribution and thermal stability. The results showed that the prepared new catalyst could be used as anenvironmentally friendly polycondensation catalyst which has a lot of advantagescomparing to conventional antimony catalyst such as higher catalytic activity,lessvalue about b in the PET product, steady catalytic properties, easy to storage andtransportation, less dosage( containing 20 ppm) based on weight of terephthalicacid and equal to 1/15 weight of antimony catalyst. The inherent quality of its PETchips is better than that of Sb2O3 catalyst and equal to that of Sb(Ac)3 andSb2(EG)3 catalyst. The thermal stability and spin-able of PET chips aresatisfactory. Finally, the industrial semi-continuous polymerization processes using themultiphase titanic catalysts on 5000t/a production line and spinning test of PETchips on 6000t/a line were proceeded. It was shown that the complexed catalyst ofmultiphase titanic catalyst with Sb2O3 was suitable to current semi-continuouspolymerization processes and the quality of its PET chips was better than that ofprevenient antimony catalyst. The chips were suitable to fiber spinning productionline. The fully winding ratio and production yield of fiber spinning wereimproved. The quality of fiber was getting advance. It was indicated that the newcatalyst has favorable prospects on industrial application and would bringconsiderable economic & social benefits in the future.