CHDM改性PTT共聚酯合成及表征

Synthesis and characterization of CHDM modified PTT copolyesters

以1,4-环己烷二甲醇(CHDM)为改性单体对聚对苯二甲酸1,3-丙二醇酯(PTT)进行改性合成研究,通过常规PTT熔融缩聚工艺,改变1,3-丙二醇(PDO)和CHDM两种二元醇的比例,加入对苯二甲酸,在5L反应釜中合成了一系列CHDM改性PTT共聚酯聚对苯二甲酸1,3-丙二酯-1,4-环己烷二甲酯共聚酯(PTTG)。采用乌氏黏度计、核磁共振氢谱仪、差示扫描量热仪以及热台正交偏光显微镜等测试方法表征了所合成共聚酯样品的基本结构和结晶行为。研究结果表明,改性单体CHDM的增加,破坏PTT分子链规整性,合成共聚酯的性能有所变化,CHDM投入量的提升,共聚酯的玻璃化转变温度逐渐升高,熔融温度下降,结晶温度降低,球晶直径逐渐减小,结晶能力逐渐降低。

A series of 1,4-cyclohexanedimethanol(CHDM)modified poly(propylene terephthalate)(PTT)poly(1,3 propanediol-1,4-cyclohexanedimethane)copolyesters(PTTG)were synthesized through general polycondensation process by changing the molar ratio of 1,3-propanediol(PDO)and CHDM using terephthalic acid in a 5 L polycondensation reactor.The basic structure and crystallization behavior of the copolyesters were characterized by Ubbelohde viscometer,1H NMR,differential scanning calorimeter and orthogonal polarizing microscope.The results showed that the molecular chain regularity of PTT polyester was destroyed and the properties of copolyester were changed with the addition of the third monomer CHDM.With the increase of the amount of CHDM,the glass transition temperature of the copolyester increased and the melting temperature decreased gradually.At the same time,the crystallization temperature and the crystalline ability decreased,the spherulite diameter decreased with the increase of CHDM content.