温和条件下ATRP法合成温敏性高分子材料

发布时间：2018-03-29 00:23

  本文选题：原子转移自由基聚合　切入点：甲基丙烯酸-N　出处：《天津科技大学》2015年硕士论文

【摘要】：本文首先以2-溴代异丁酸乙酯(EBIB)为引发剂,以溴化亚铜(CuBr)(或溴化亚铜与溴化铜混合物)为催化剂、五甲基二乙烯三胺(PMDETA)为配体、甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)为单体,采用原子转移自由基聚合(ATRP)法在水溶液中制备了一系列不同聚合度的均聚物PDMAEMA。以聚乙二醇单甲醚(PEG)和2-溴异丁酰溴(BIBB)为原料,制备大分子引发剂PEG-Br。接着,以CuBr为催化剂、PMDETA为配体、DMAEMA为单体,采用ATRP法在水溶液中制备了一系列不同DMAEMA链段长度的聚乙二醇单甲醚-聚甲基丙烯酸-N,N-甲氨基乙酯嵌段共聚物(PEG-b-PDMAEMA)。GPC、红外、核磁等测试手段表明均聚物和共聚物都具有预期结构,相对分子质量符合预期设计且相对分子质量可控。紫外可见分光测试手段表明了均聚物PDMAEMA和嵌段共聚物PEG-b-PDMAEMA都具有温度敏感性。由1H-NMR得到的动力学数据表明,均聚物PDMAEMA和嵌段共聚物PEG-b-PDMAEMA的聚合过程均符合一级动力学反应特性,说明这一反应体系具有较好的可控性。本文利用紫外-可见分光光度计对产物温敏性的研究表明,聚合物溶液浓度越高,其最低临界溶解温度(LCST)越低；DMAEMA链段越长,PDMAEMA和PEG-b-PDMAEMA的LCST均随之降低；并且将DMAEMA链段长度相同的PDMAEMA和PEG-b-PDMAEMA的LCST进行对比发现,均聚物PDMAEMA由于没有PEG亲水段,其LCST均低于相应嵌段共聚物的LCST。通过调节这些因素得到了LCST在人体温度附近的质量分数为1.0wt%的嵌段聚合物PEG-b-PDMAEMA300，该产物有望成为药物运输的良好载体。本实验是在30℃水溶液环境下进行的ATRP反应,反应条件温和,故可以应用在生物医药领域中。嵌段共聚物PEG-b-PDMAEMA不仅具有亲水性,还具有显著的温度敏感性,且其LCST范围在37.4℃C-40.8℃,与人体体温相近,在医药高分子领域中具有广阔的发展与应用前景。
[Abstract]:In this paper, 2-bromoisobutyrate (EBIBB) was first used as initiator, cupric bromide (or mixture of cuprous bromide and copper bromide) as catalyst, pentamethyldiethylenetriamine (PMDETAA) as ligand, and N-dimethylaminoethyl methacrylate (DMAEMA) as monomer. A series of homopolymer PDMAEMAs with different degree of polymerization were prepared by atom transfer radical polymerization (ATRP) method in aqueous solution. The macromolecular initiators PEG-Br. were prepared from PEG and BIBB. A series of poly (ethylene glycol monomethyl ether-poly (ethylene glycol) monomethyl ether-poly (N-methacrylate) -N (N-methylaminoethyl methacrylate)) block copolymers (PEG-b-PDMAEMAEMA-GPCs) with different lengths of DMAEMA segments were prepared in aqueous solution by using CuBr as the catalyst and PMDETA as the ligand as monomer. Nuclear magnetic measurements show that both homopolymers and copolymers have the desired structure. The relative molecular weight is in accordance with the expected design and the relative molecular weight is controllable. The UV-Vis spectroscopic results show that both homopolymer PDMAEMA and block copolymer PEG-b-PDMAEMA are temperature-sensitive. The kinetic data obtained from 1H-NMR show that, The polymerization process of homopolymer PDMAEMA and block copolymer PEG-b-PDMAEMA is in accordance with the first-order kinetic reaction characteristics, which indicates that the reaction system has good controllability. In this paper, the temperature sensitivity of the product was studied by UV-Vis spectrophotometer. The higher the concentration of polymer solution is, the lower the minimum critical solution temperature (LCST) is, the longer the DMAEMA segment is, the lower the LCST of PDMAEMA and PEG-b-PDMAEMA is, and the comparison between PDMAEMA and PEG-b-PDMAEMA LCST with the same length of DMAEMA segment shows that the homopolymer PDMAEMA has no PEG hydrophilic segment. The LCST of PEG-b-PDMAEMA300 was lower than that of the corresponding block copolymer. By adjusting these factors, the block polymer PEG-b-PDMAEMA300 with a mass fraction of 1.0 wt% near the human body temperature was obtained. The product is expected to be a good carrier for drug transport. ATRP reaction in aqueous solution at 鈩，

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