聚对苯二甲酸-2,5-呋喃二甲酸乙二醇无规共聚酯的合成与表征

SYNTHESIS AND CHARACTERATION OF POLY(ETHYLENE TEREPHTHALATE-co-ETHYLENE 2,5-FURANDICARBOXYLATE)

以对苯二甲酸、2,5-呋喃二甲酸(FDCA)和乙二醇为原料,钛酸四丁酯为催化剂,采用直接酯化法,通过改变对苯二甲酸与2,5-呋喃二甲酸摩尔比合成了一系列高分子量线性聚对苯二甲酸-2,5-呋喃二甲酸乙二醇无规共聚酯(PEFT).运用1H-NMR和13C-NMR表征并确立了共聚酯的结构,XRD结果显示该系列共聚酯在原生态状态下均为无定形聚集态结构,DSC结果表明该系列共聚酯只有一个玻璃化转变温度(73.3～84.2℃),介于PET和PEF之间,随着PEF含量的增加而增大.TGA结果显示该系列聚酯具有良好的热稳定性,起始热分解温度高于390℃,介于PET和PEF之间.拉伸测试结果表明共聚酯的组成对其力学性能有影响,其中PEFT-10,PEFT-70和PEFT-90的力学性能较好,优于PET.

High molecular weight linear poly(ethylene terephthalate-co-ethylene 2,5-furandicarboxylate)(PEFT) was synthesized via direct esterification method based on terephthalic acid,2,5-furandicarboxylic acid(FDCA) and ethylene glycol.Tetrabutyl titanate was used as catalyst.Magnetic resonance spectroscopy(1H-NMR and 13C-NMR) confirmed the expected PEFT structure.The results of X-ray diffraction(XRD) displayed that the PEFT copolyesters were amorphous at original ecology.The results of differential scanning calorimeter(DSC) showed that the PEFT copolyesters had a single glass-transition temperature Tg(73.3~84.2 ℃) and Tg increased continuously with the increase of PEF content.The Tgs of PEFT copolyesters were between that of PET and PEF.The results of thermo gravimetric analysis(TGA) indicated that PEFT copolyesters had excellent thermal stability,although it was slightly lower than that of PET.The PEFT copolyesters were thermally stable up to 390 ℃.The thermal properties of PEFT copolyester were between those of PET and PEF.The results of tensile tests showed that PEFT-10,PEFT-70 and PEFT-90 copolyesters had good mechanical properties compared with PET.The results showed that FDCA could partially replace terephthalic acid to synthesis polyester.