阻燃共聚酯的固相缩聚反应特性和动力学分析

Reaction characteristics and kinetics of solid-state polymerization of flame-retardant polyesters

为研究磷系阻燃共聚酯的固相缩聚反应,将不同磷含量的阻燃共聚酯切片,在不同温度和反应时间下进行固相缩聚反应,考察工艺条件及磷含量对磷系阻燃共聚酯黏度的影响。结果表明:固相缩聚能有效减少端羧基含量,且无明显降解副反应发生。在190~210℃内,所有共聚酯的黏度随缩聚时间的延长均呈现明显增长趋势,但其增量随着磷含量的增加而下降。此外,通过建立缩聚反应动力学模型,计算出磷系阻燃共聚酯的反应速率常数和活化能,其中反应速率常数随阻燃剂添加量的增加而减小,而反应活化能增大,说明磷系阻燃剂会阻碍共聚酯的固相缩聚反应。

Solid-state polymerization of flame-retardant polyesters with different contents of phosphorus was studied at different temperatures and reaction times to investigate reaction mechanism.Effects of processing conditions and phosphorus contents on intrinsic viscosity were studied.The results show that solid-state polymerization can effectively reduce end carboxyl group contents with no obvious degradation side reactions.At 190-210℃,all polyesters show significant intrinsic viscosity increase with the increase of polymerization time,while the increment rate decreases with the increase of phosphorus content.Additionally,based on the established reaction kinetics model,the reaction rate constant and activation energy of solid-state polymerization were determined.With the increase of flame retardant content,the reaction rate constant decreases while the activation energy increases,which indicates that the addition of phosphorus-flame retardants has an inhibitory effect on the solid-state polymerization of polyesters.