基于悉尼酮—马来酰亚胺点击化学环状聚合物的制备及研究

发布时间：2018-02-14 08:52

本文关键词： 环状聚合物悉尼酮马来酰亚胺 SMDC 自组装　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：环状聚合物由于没有端基减少了分子链间的缠结,与相应的线状前驱体相比表现出诸多特异的性质,是具有特殊结构的聚合物。近年来,越来越多的高分子工作者都对环状结构和性能之间的关系表现出极大的兴趣。然而,由于合成及后续的分离提纯困难,目前已经用于环状聚合物制备方法的报道还不多。线状聚合物两末端基团的"Click"反应即两端基间的耦合反应是线状聚合物的关环方法之一。目前已经用于关环反应中的高效耦合反应有:叠氮和炔之间的"1,3-偶极环化加成"反应、"Diels-Alder"(4+2)环加成反应、"Thiol-ene"加成反应等。这些用于制备环状聚合物的分子间或分子内的成环反应通常需要很稀的浓度条件,实验往往需要借助蠕动泵进行,分子间关环反应需严格控制线状聚合物和偶联剂小分子的投料比,催化剂的使用又使得反应后处理会比较麻烦并且减少了关环产物的产量。因此,找到一种更容易和更简便有效的合成环状聚合物的方法尤为重要。本论文利用悉尼酮(sydnone)与马来酰亚胺(maleimide)间特有的双环加成反应(SMDC)合成环状聚合物。通过分子设计制备了亲水性的单环聚环氧乙烷(c-PEO)和两亲性的蝌蚪形聚合物(l-PCL-c-PEO99-l-PCL)。将悉尼酮与马来酰亚胺间的SMDC反应引入到环状聚合物的合成中,会有以下优点:降低偶联剂小分子的官能团浓度,其浓度为常见分子间关环偶联剂小分子的一半,减少了分子间副反应的发生;对环状聚合物的制备无需采用蠕动泵的滴加方式可以一次投料且无需严格控制反应物投料比;反应不需催化剂,后处理的纯化过程简单。具体研究内容简述如下:(1)对聚环氧乙烷的两端的羟基进行改性修饰,使其两端均以马来酰亚胺基团封端,然后利用悉尼酮与马来酰亚胺间的1,3-偶极双环加成反应(SMDC),制备了两种不同分子量的亲水性单环聚合物,并系统探讨了反应时间、温度、浓度对单环聚合物制备的影响。聚合物样品的化学结构和分子量通过1HNMR、GPC、MALDT-TOF MS进行表征测试。(2)以羟基封端的聚环氧乙烷为原料,通过分子设计制备了以马来酰亚胺封端并含有两个活性羟基的聚环氧乙烷长链为线状前驱体,然后利用悉尼酮与马来酰亚胺基团间SMDC反应进行关环。随后分别通过线状前驱体与单环上的羟基与己内酯单体进行开环聚合反应(ROP)制备了带有不同链段长度的聚己内酯的两亲性蝌蚪形聚合物l-PCL-c-PE099-l-PCL(e1-4)和两亲性嵌段共聚物PCL-b-PEO99-b-PCL(f1-4),聚合物的化学结构和分子量通过1H NMR、GPC、MALDT-TOF MS进行表征。通过TEM对两亲性的蝌蚪形聚合物和嵌段共聚物的自组装行为进行了初步研究。此外还通过DSC对比研究了线状前驱体、单环及蝌蚪状共聚物和嵌段共聚物的热性能。
[Abstract]:Due to the absence of terminal group, the cyclic polymer has many special properties compared with the corresponding linear precursor, and it is a polymer with special structure in recent years, because it has no terminal group to reduce the entanglement between molecular chains, so it shows many special properties compared with the corresponding linear precursor. More and more polymer workers have shown great interest in the relationship between ring structure and properties. However, due to the difficulty of synthesis and subsequent separation and purification, At present, there are few reports on the preparation of cyclic polymers. The "Click" reaction of two terminal groups of linear polymers, that is, the coupling reaction between the two ends of linear polymers, is one of the methods for closing the rings of linear polymers. At present, it has been used to close the rings of linear polymers. The highly efficient coupling reactions between azide and acetylene include the "1o _ 3-dipolar cycloaddition" reaction, the "Diels-Alder" -42) cycloaddition reaction, the "Thiol-ene" addition reaction, etc. These intermolecular or intramolecular cyclization reactions for the preparation of cyclic polymers usually require very thin concentration conditions. The experiment often needs to be carried out by peristaltic pump and the feeding ratio of linear polymer and small molecule of coupling agent should be strictly controlled by intermolecular closed loop reaction. The use of the catalyst makes the post-treatment more troublesome and reduces the production of the annular products. It is particularly important to find a more convenient and effective method for the synthesis of cyclic polymers. In this paper, cyclic polymers are synthesized by using the unique bicyclic addition reaction between Sydney ketone sydnoneand maleimide and SMDC. Hydrophilic monocyclic poly (ethylene oxide) (c-PEO) and amphiphilic tadpole shape polymer (l-PCL-c-PEO99-l-PCL) were prepared. The SMDC reaction between Sydney ketone and maleimide was introduced into the synthesis of cyclic polymers. It has the following advantages: reducing the concentration of functional groups of small molecules of coupling agents, which is half the concentration of common intermolecular coupling agents, reducing the occurrence of intermolecular side reactions; For the preparation of cyclic polymer without the use of peristaltic pump dripping method can be used once without strictly controlling the feed ratio of reactants; the reaction does not require catalyst. The purification process is simple. The specific research contents are as follows: 1) the hydroxyl groups at both ends of poly (ethylene oxide) are modified so that both ends are capped by Maleimide groups. Then two kinds of hydrophilic monocyclic polymers with different molecular weights were prepared by using 1 ~ 3- dipolar bicyclic addition reaction between Sydney ketone and Maleimide. The reaction time and temperature were discussed systematically. The influence of concentration on the preparation of monocyclic polymers. The chemical structure and molecular weight of the polymer samples were characterized by 1HNMR-GPC-MALDT-TOF MS. Poly (ethylene oxide) with Maleimide capped and two active hydroxyl groups as linear precursors was prepared by molecular design. Then the SMDC reaction between Sydney ketone and Maleimide group was used to close the ring, and then through the ring-opening polymerization of hydroxyl group and caprolactone monomer on the linear precursor and monocycle respectively, the polyether with different segment length was prepared. The amphiphilic tadpole polymer l-PCL-c-PE099-l-PCLL1-4) and the amphiphilic block copolymer PCL-b-PEO99-b-PCLLf1-4 were characterized by 1H NMRGPC-MALDT-TOF MS. The self-assembly of amphiphilic tadpole and block copolymers was carried out by TEM. In addition, the linear precursors were compared by DSC. Thermal properties of monocyclic, tadpole and block copolymers.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631

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