【作者】 姚利辉；

【导师】 唐宁； 邬金才；

【作者基本信息】 兰州大学 ， 无机化学， 2012， 博士

【摘要】 进入21世纪,高分子材料已经在国民经济的各个部门和人们的日常生活中发挥了极其重要的作用。然而高分子材料在给人们带来生活便利、提高生活品质的同时,也给人类生存的环境造成难以估量的破坏作用。随着石油资源的日益短缺以及环境中的白色污染不断加重,人们迫切地寻求清洁、安全和可循环的替代材料。近年来,生物降解高分子材料的研究发展十分迅速,并开始在农业、包装材料和服装纤维以及生物医药等领域取得广泛的应用。其中尤其是聚酯,如聚丙交酯(PLA)、聚乙交酯(PGA)、聚ε-己内酯(PCL)以及它们之间的共聚物[如共聚乙交酯-丙交酯(PLGA)]等,是公认的优良的可生物降解高分子材料。因此,本论文以席夫碱钠和锌配合物为催化剂,研究了它们对环酯开环聚合合成聚酯的催化作用。本论文分为以下四部分：一、主要介绍了近些年环酯开环聚合的研究概况。二、合成并表征了两个Salen [N,N’-双(3,5-二叔丁基亚水杨基)-1,3-丙二胺]钠配合物和一个Salen锌的配合物。两个Salen钠配合物(1和2)能够催化L-丙交酯开环聚合,而Salen锌的配合物(3)则基本不能催化L-丙交酯开环聚合。两个Salen钠配合物展现了不同的催化活性：配合物(1)的催化活性比配合物(2)要高得多。L-丙交酯开环聚合所得的短链聚酯是环状的聚乳酸,而所得的长链聚酯就是环状和直链的聚乳酸混合物。三、合成和表征了四个席夫碱锌的配合物。席夫碱[(E)-2-(((2-(二甲基氨基)乙基)亚氨基)甲基)-6-甲氧基苯酚]锌苄氧基配合物(4)能够活性而可控地引发L-丙交酯开环聚合。实验结果表明,当苯环上酚氧的邻位取代基是给电子的甲氧基时,聚合速率会明显地下降。聚合动力学研究证实,聚合反应对单体和引发剂都是一级反应。席夫碱[2-{(Z)-[(呋喃基-2-甲基)亚氨基]甲基}-苯酚]锌配合物(5)和席夫碱2-{(Z)-[(呋喃基-2-甲基)亚氨基]甲基}-6-甲氧基苯酚]锌配合物(6)基本不能催化L-丙交酯开环聚合,但能催化三亚甲基碳酸酯在甲苯中100℃下进行开环聚合。四、合成及表征了三个席夫碱钠的配合物。在尝试合成席夫碱[2-{(Z)-[(呋喃基-2-甲基)亚氨基]甲基}-6-甲氧基苯酚]钠烷氧基配合物时,意外地得到了一个桥环化合物。所得到的席夫碱钠配合物NaL5(7)的晶体结构中存在钠氧键形成的立方体,并具有较好的空气稳定性。催化环酯开环聚合的初步研究结果发现,它对于不同的环酯具有不同的催化活性；虽然催化的活性很高,但是聚合的可控性不好。更多还原

【Abstract】 Polymer materials play an important role in each department of the national economy and our life after 21 century. However, polymer materials not only improve our life, but also have done greatly harmful to our environment. With the increasingly shortage of the petroleum resources and serious White Pollution in the environment, the clean, safe and renewable polymers are urgently sought for us. In the last few years, biodegradable polymers are rapid developed, due to their applications in agriculture, packaging materials, garment and fiber, biomedical and pharmaceutical devices. The most excellent biodegradable polymer materials are polyesters, such as polylactide(PLA), polyglycolide(PGA), polycaprolactone (PCL) and their copolymers (PLGA). Therefore, studies on the ring opening polymerization of cyclic esters by Schiff base sodium and zinc complexes to obtain polyesters are presented in this paper.This paper can be divided into four parts as follows:1. A brief review of ring opening polymerization of cyclic esters in the last few years was given.2. Two Salen [N, N-bis(3,5-di (tert-butyl)salicylaldimine)-1,2-propylenediamine] sodium complexes and one Salen zinc complex were synthesized and characterized. The two Salen sodium complexes(1 and 2) are used as the effective catalysts in the ring opening polymerization(ROP) of L-lactide(L-LA), but the zinc complex(3) is almost not able to catalyze the ROP of L-LA. The two Salen sodium complexes show different catalytic activity:complex(1) is more active than complex(2). The obtained polymer is mainly cyclic PLA for a short PLA chain, but a mixture of cyclic and linear PLA for a long PLA chain.3. Four Schiff base zinc complexes were synthesized and characterized. The Schiff base [(E)-2-(((2-(dimethylamino)ethyl)imino)methyl)-6-methoxyphenol] benzyloxy zinc complex(4) is an efficient initiator for the ring opening polymerization(ROP) of L-lactide(L-LA) in a living and controlled fashion. Experimental results show that the introduction of an electron donor methoxy at ortho-phenoxy substituent leads to a decrease of the polymerization rate. In addition, it is found that the polymerization reaction proceeds with a first-order rate in both monomer and initiator in the kinetic study with the ROP of L-LA. The two Schiff base [(E)-2-(((furan-2-ylmethyl)imino) methyl)phenol] and (E)-2-(((furan-2-ylmethyl)imino)methyl)-6-methoxyphenol] zinc complexes(5 and 6) are almost not able to catalyze the ROP of L-LA, but can catalyze the ROP of trimethylene carbonate(TMC) in toluene at 100℃.4. Three Schiff base sodium complexes were synthesized and characterized. While trying to synthesize Schiff base [(E)-2-(((furan-2-ylmethyl)imino)methyl)-6-methoxy phenol] sodium alkoxy complexes, a bridged bicyclic compound is unexpectedly obtained. Schiff base sodium complex(7) has a cube of Na-O bond in its crystal structure and is a well air-stable complex. Preliminary experimental results of the ring opening polymerization(ROP) of cyclic esters show that its different catalytic activity has been displayed when this sodium complex(7) catalyzes the ROP of different cyclic esters. The catalytic activity is high, but the polymerization is not controlled fashion.更多还原