含半不稳定边臂配体的钛配合物催化丙交酯聚合

发布时间：2018-02-24 20:06

  本文关键词： 聚乳酸 丙交酯 催化剂 开环聚合 含半不稳定边臂的希夫碱配体 钛配合物　出处：《材料导报》2017年14期 　论文类型：期刊论文

【摘要】：聚乳酸类材料作为可生物降解性材料具有广阔的应用前景。设计、合成了6种含半不稳定边臂的希夫碱配体L1—L6,并与钛酸四异丙酯络合合成相应的6种配合物C1—C6,配合物的结构和化学组成经元素分析、红外测试确定。将其作为催化剂催化丙交酯开环聚合,以催化剂C1为考察对象,系统研究了催化剂用量、温度、时间对聚合反应的影响,发现当单体与催化剂配比为2 000,温度为160℃,反应24h时,聚合产率最高,达90.35%,聚合物分子量达8.41×104。在上述优化条件下,比较了催化剂C1—C6的活性,结果表明催化剂活性按以下顺序递减:C6C4C3C1C2C5,同时,催化剂中心金属钛原子周围位阻相对稍小,配体中含配位能力较弱的半不稳定O边臂均有利于提高催化剂的活性。
[Abstract]:Polylactic acid materials as biodegradable materials have broad application prospects. Six Schiff base ligands L1-L6 with semi-unstable edge arms were synthesized and complexed with tetraisopropyl titanate to form six corresponding complexes C1-C6. The structure and chemical composition of the complexes were analyzed by elemental analysis. The effects of the amount of catalyst, temperature and time on the polymerization of lactide were systematically studied by using the catalyst C1 as the object of investigation, which was used as catalyst to catalyze the ring-opening polymerization of lactide. It was found that when the ratio of monomer to catalyst was 2 000, the temperature was 160 鈩，

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