聚对苯二甲酸乙二酯熔融共缩聚的研究进展—共聚组分化学结构对性能和应用的影响

The progress in study of melt copolycondensation of poly(ethylene terephthalate)—effect of chemical structure of comonomers on properties and applications

论述了共聚组分柔性和刚性的化学结构对共聚酯性能及应用的影响。柔性和刚性共聚组分均破坏PET规整性,降低分子间作用力,故导致熔点降低。柔性组分有利于链段活动,θg下降。直链柔性组分以分子柔性作用为主,故结晶速度加快。柔性取代烷基二醇则因取代基的位阻作用而结晶速度减慢。大多数刚性组分因其分子结构阻碍链段活动使θg升高。所有刚性组分共聚酯的结晶速度均减慢,甚至共聚酯可为无定形结构。不同性能的共聚酯可用于不同的应用领域。

This article review the research works published in recent years. The effect of chemical structure of comonomers on properties and applications of PET eopolyesters is described. Two kinds of structure of comonomeric units are considerated：flexible and rigid. Comonomers including flexible and rigid all disturb the regularity of PET macromolecular chain, so the acting force between moleculars of PET is decresaed, as a result the melt temperature θg decreased. All flexible eomomers are favour of movement of chain segment, so the θg of this kind of copolyesters decreases. The flexible comonomers promote the crystallization of obtained copolyester, so the crystallization rate in- creases. The crystallization rate of eopolyesters obtained from substituted glycols decreases due to hindered effect of substituted groups. The θg of a great majority of copolyesters obtaine from rigid comonomeric units increases. The crystallization rate of all copolyesters from rigid units decreases, even amorphous structure can be obtained. The copolyesters with different properties can be used in different applications.