CAJ | 학술논문

采用直接酯化法,通过改变对苯二甲酸( PTA)与2,5-呋喃二甲酸( FDCA)的摩尔比,制备了一系列聚对苯二甲酸-2,5-呋喃二甲酸乙二醇共聚酯( PEFT)。运用1 H-NMR和13 C-NMR测试手段研究PEFT共聚酯的链结构。通过观察PEFT共聚酯链上乙二醇单元中氢原子和碳原子的化学位移及相应的4种信号的强度变化,计算出共聚酯的数均序列长度(L),无规度值(B)和共聚物的组成。通过Yamadera 和Murano公式计算所得共聚酯无规度值 B 均接近于1,说明 PEFT 共聚酯为无规共聚物；PEF-block-PET 嵌段共聚物 B 为0.577,PEF-blend-PET共混物的B为0；差示扫描量热仪(DSC)测试结果表明,0PEFT共聚酯均有一个玻璃化温度,进一步说明了PEFT共聚酯为无规共聚物。其中PTA：FDCA的摩尔比为1：1时,即PEFT-50,B值最大,基于1 H-NMR谱图计算得B=1.012,13 C-NMR谱图计算得B=1.028。上述结果表明,2,5-呋喃二甲酸与对苯二甲酸在与乙二醇的亲核取代反应中活性相近。
채용직접지화법,통과개변대분이갑산( PTA)여2,5-부남이갑산( FDCA)적마이비,제비료일계렬취대분이갑산-2,5-부남이갑산을이순공취지( PEFT)。운용1 H-NMR화13 C-NMR측시수단연구PEFT공취지적련결구。통과관찰PEFT공취지련상을이순단원중경원자화탄원자적화학위이급상응적4충신호적강도변화,계산출공취지적수균서렬장도(L),무규도치(B)화공취물적조성。통과Yamadera 화Murano공식계산소득공취지무규도치 B 균접근우1,설명 PEFT 공취지위무규공취물；PEF-block-PET 감단공취물 B 위0.577,PEF-blend-PET공혼물적B위0；차시소묘량열의(DSC)측시결과표명,0PEFT공취지균유일개파리화온도,진일보설명료PEFT공취지위무규공취물。기중PTA：FDCA적마이비위1：1시,즉PEFT-50,B치최대,기우1 H-NMR보도계산득B=1.012,13 C-NMR보도계산득B=1.028。상술결과표명,2,5-부남이갑산여대분이갑산재여을이순적친핵취대반응중활성상근。
A series of poly(ethylene terephthalate-Co-ethylene 2,5-furandicarboxylate) (PEFT) copolyesters were synthesized with different terephthalic acid (PTA) /2,5-furandicarboxylic acid (FDCA) molar ratios by direct esterification method. In order to investigate their chain structures, 1 H-NMR and 13 C-NMR spectra of these copolyesters were recorded. The average length ( L) , the degree of randomness ( B) and composition of copolyesters were calculated from the intensities of four kinds of signals, which corresponding to the chemical shifts of hydrogen and carbon atoms in ethylene glycol unit in PEFT copolyesters chains. It was shown that the degree of randomness B of all purified copolyesters reached to 1 by the formula of Yamadera and Murano, which indicated that they were random copolymers. Comparatively, the PEF-block-PET of B value was 0. 577, and the PEF-blend-PET of B value was 0 . It was also consistent with the previous results of differential scanning calorimeter ( DSC) that each of the PEFT copolyesters had only one glass transition temperature and the copolyesters were random copolymers. The randomness B of PEFT-50 was the greatest of all, the value was 1. 012 based on the result of 1 H-NMR, and the value was 1. 028 based on the result of 13 C-NMR. Furthermore, the results above displayed that the activity of 2,5-furandicarboxylic acid and terephthalic acid was similar in this nucleophilic substation reaction with ethylene glycol.