PROP: an in situ cascade polymerization method for the facile synthesis of polyesters
PROP: an in situ cascade polymerization method for the facile synthesis of polyesters
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DOI：
10.1039/c7py00068e
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发表时间：
2017-03
影响因子：
4.6
通讯作者：
Tu Yingfeng
中科院分区：
文献类型：
--
作者：
Zhu Xiang;Gu Jiali;Li Xiaohong;Yang Xiaoming;Wang Lian;Li Yongjin;Li He;Tu Yingfeng
我们在这里提出了一种原位级联缩聚-偶联开环聚合（PROP）方法，可以轻松合成传统缩聚方法难以合成的相对较高分子量的聚酯。该方法是在研究1,3-丙二醇β位具有不同侧烷基链的三种聚对苯二甲酸丙二醇酯（PTT）类似物的熔融聚合过程中开发的，即聚（对苯二甲酸2-甲基-1,3-丙二醇酯）（PMPT）、聚（对苯二甲酸新戊二醇酯）（PNT）和聚（对苯二甲酸2-甲基-2-丙二醇酯） (PMPPT)，使用二醇引发剂从其相应的环状低聚酯得到。动力学研究表明，该体系在早期阶段遵循开环聚合机制，形成二醇末端官能化聚酯，而随后，聚酯之间在高单体转化率区域开始缩聚。受有机化学中“多米诺骨牌反应”概念的启发，上述原位级联聚合过程归属于“多米诺骨牌聚合”方法。研究了这些聚酯的结构-性能关系。结果表明，在丙二醇链段侧面引入烷基链可通过改善链刚度来提高聚酯的 Tg，因为模量较高的聚酯表现出较高的 Tg，但气体阻隔性能随着引入更多或更长的烷基链而降低。我们的 PROP 方法提供了一种简便的方法来合成具有官能团的聚酯和共聚酯，在材料科学中具有潜在的应用。
We present here an in situ cascade polycondensation-coupling ring-opening polymerization (PROP) method for the facile synthesis of polyesters with relatively high molecular weights that are hard to synthesize by traditional condensation polymerization methods. The method was developed during our studies on the melt polymerization of three poly(trimethylene terephthalate) (PTT) analogues with different lateral alkyl chains at the β-position of 1,3-propanediol, i.e., poly(2-methyl-1,3-propylene terephthalate) (PMPT), poly(neopentylene terephthalate) (PNT) and poly(2-methyl-2-propyl-1,3-propylene terephthalate) (PMPPT), from their corresponding cyclic oligoesters using diol initiators. Kinetic studies suggest that the systems follow the ring-opening polymerization mechanism at the early stages to form diol end-functionalized polyesters, while, subsequently, condensation polymerization starts between the polyesters at high monomer conversion regions. Inspired by the “domino reaction” concept in organic chemistry, the above in situ cascade polymerization process is attributed to a “domino polymerization” method. The structure–property relationship of these polyesters was investigated. It shows that the introduction of alkyl chains on the lateral side of propanediol segments increases the polyesters’ Tg by improving the chain stiffness, as those with higher modulus exhibit higher Tg, yet the gas barrier properties decrease with more or longer alkyl chains introduced. Our PROP method affords a facile way to synthesize polyesters and copolyesters with functional groups for potential application in materials science.