One pot synthesis and characterization of novel poly(ether ester) mutiblock copolymers containing poly(tetramethylene oxide) and poly(ethylene terephthalate)
One pot synthesis and characterization of novel poly(ether ester) mutiblock copolymers containing poly(tetramethylene oxide) and poly(ethylene terephthalate)
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DOI：
10.1039/c3py00932g
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发表时间：
2014
影响因子：
4.6
通讯作者：
Weichun Huang;Yingbo Wan;Jianying Chen;Qiaozhen Xu;Xiaohong Li;Xiaoming Yang;Yaowen Li;Y. Tu-Y.-T
中科院分区：
文献类型：
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作者：
Weichun Huang;Yingbo Wan;Jianying Chen;Qiaozhen Xu;Xiaohong Li;Xiaoming Yang;Yaowen Li;Y. Tu-Y.-T
以聚四氢呋喃（PTMO）为大分子引发剂，通过一锅法熔融聚合环状低聚对苯二甲酸乙二醇酯（COET），合成了聚对苯二甲酸乙二醇酯-嵌段-聚四氢呋喃多嵌段共聚物（PET-b-PTMO-b-PET）x。采用二维和一维核磁共振（2D和1D-NMR）技术，包括1H-13C杂原子单量子相干（HSQC）和1H-1H相关谱（COSY），对多嵌段共聚物的结构和绝对分子量进行了表征和揭示。结果表明，COET在15 min内完全消耗，嵌段共聚物的分子量随反应时间线性增加。在聚合动力学研究的基础上，提出了两步聚合机理：第一步是在PTMO大分子引发剂作用下，COETs开环聚合生成PET-b-PTMO-b-PET三嵌段共聚物，第二步是三嵌段共聚物原位缩聚生成（PET-b-PTMO-b-PET）x多嵌段共聚物。用粘度计和凝胶渗透色谱（GPC）对共聚物的结构进行了表征。与PTMO均聚物相比，这些多嵌段共聚物显示出改进的热稳定性，以及分别通过热重分析和差示扫描量热法显示出的来自PTMO和PET链段的双晶性质。
We demonstrate here a novel method to synthesize poly(ethylene terephthalate)-block-poly(tetramethylene oxide) multiblock copolymers (PET-b-PTMO-b-PET)x by the one pot melt polymerization of cyclic oligo(ethylene terephthalate)s (COETs) using poly(tetramethylene oxide) (PTMO) as a macroinitiator. Two-dimensional and one-dimensional nuclear magnetic resonance (2D and 1D-NMR) techniques, including 1H–13C Heteronuclear Single Quantum Coherence (HSQC) and 1H–1H Correlation Spectroscopy (COSY), have been used to characterize and reveal the multiblock copolymer structures and absolute molecular weights. It was found that the COETs were consumed completely within 15 minutes, and the molecular weights of the block copolymers increased linearly with reaction time. Based on the polymerization kinetic studies, a two-stage polymerization mechanism is proposed: the ring-opening polymerization of COETs by a PTMO macroinitiator to PET-b-PTMO-b-PET triblock copolymers at the first stage, followed by the in situ condensation polymerization of triblock copolymers to (PET-b-PTMO-b-PET)x multiblock copolymers at the second stage. The structures of the multiblock copolymers are further characterized and confirmed by viscometry and gel permeation chromatography (GPC). These multiblock copolymers show improved thermal stability when compared to PTMO homopolymers, and double crystalline properties from PTMO and PET segments, as revealed by thermogravimetric analysis and differential scanning calorimetry, respectively.