The Research Of The Preparation Of PTT And New Type Copolyesters

In this paper, the different viscosity (molecular weight) polymers of PTT (Poly trimethylene terephthalate) were synthesized by the way of direct esterification-prepolycondensation-the block polycondensation.In the method, we use PTA(p-phthalic acid) and1.3-PDO(1,3-propanediol) as the substrates and the type of Ti(IV) and Sb (II) as catalysts. through optimizing the reaction condition including the ratio of substrates, the amount of catalysts, the temperature of prepolycondensation and the time of polycondensation we got the optimal reaction condition. In this period of experiment, the viscosity0.83dl/g of PTT has been synthesized. And comparing references now available, this viscosity (molecular weight) is better than the majority.On the basis of the optimal condition of synthesizing PTT (Poly trimethylene terephthalate) in hand, for an environmental, economical and facile substrate,we use1,2-PG(1,2-propanediol) instead of1.3-PDO(1,3-propanediol) partly and synthesized a series of different ratio (0:1;1:3;1:2,;1:1;1:0.5;1:0.25) of1.3-PDO and1,2-PG.from this way, we get different viscosity of copolyesters (0.11dl/g;0.14dl/g;0.25dl/g;0.45dl/g;0.58dl/g;0.65dl/g) and with the help of1H NMR and DSC for samples their properties and crystallinity has been tested.On the basis of the experimental results of second part. another environmental, economical and facile substrate diethylene glycol were used instead of1,2-PG for synthesizing copolyester. synthesized a series of different ratio (0:1;1:1;1:0.333;1:0.25) of1.3-PDO and Diethylene glycol. And also from this way, we get different viscosity of copolyesters (0.23dl/g;0.46dl/g;0.63dl/g;0.80dl/g) and with the help of1H NMR and DSC for samples their properties and crystallinity has been examined. This part of work has not been reported yet, this is a first trial。...