本文選題：原子轉(zhuǎn)移自由基聚合　切入點(diǎn)：甲基丙烯酸-N　出處：《天津科技大學(xué)》2015年碩士論文

【摘要】：本文首先以2-溴代異丁酸乙酯(EBIB)為引發(fā)劑,以溴化亞銅(CuBr)(或溴化亞銅與溴化銅混合物)為催化劑、五甲基二乙烯三胺(PMDETA)為配體、甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)為單體,采用原子轉(zhuǎn)移自由基聚合(ATRP)法在水溶液中制備了一系列不同聚合度的均聚物PDMAEMA。以聚乙二醇單甲醚(PEG)和2-溴異丁酰溴(BIBB)為原料,制備大分子引發(fā)劑PEG-Br。接著,以CuBr為催化劑、PMDETA為配體、DMAEMA為單體,采用ATRP法在水溶液中制備了一系列不同DMAEMA鏈段長度的聚乙二醇單甲醚-聚甲基丙烯酸-N,N-甲氨基乙酯嵌段共聚物(PEG-b-PDMAEMA)。GPC、紅外、核磁等測試手段表明均聚物和共聚物都具有預(yù)期結(jié)構(gòu),相對分子質(zhì)量符合預(yù)期設(shè)計(jì)且相對分子質(zhì)量可控。紫外可見分光測試手段表明了均聚物PDMAEMA和嵌段共聚物PEG-b-PDMAEMA都具有溫度敏感性。由1H-NMR得到的動力學(xué)數(shù)據(jù)表明,均聚物PDMAEMA和嵌段共聚物PEG-b-PDMAEMA的聚合過程均符合一級動力學(xué)反應(yīng)特性,說明這一反應(yīng)體系具有較好的可控性。本文利用紫外-可見分光光度計(jì)對產(chǎn)物溫敏性的研究表明,聚合物溶液濃度越高,其最低臨界溶解溫度(LCST)越低；DMAEMA鏈段越長,PDMAEMA和PEG-b-PDMAEMA的LCST均隨之降低；并且將DMAEMA鏈段長度相同的PDMAEMA和PEG-b-PDMAEMA的LCST進(jìn)行對比發(fā)現(xiàn),均聚物PDMAEMA由于沒有PEG親水段,其LCST均低于相應(yīng)嵌段共聚物的LCST。通過調(diào)節(jié)這些因素得到了LCST在人體溫度附近的質(zhì)量分?jǐn)?shù)為1.0wt%的嵌段聚合物PEG-b-PDMAEMA300，該產(chǎn)物有望成為藥物運(yùn)輸?shù)牧己幂d體。本實(shí)驗(yàn)是在30℃水溶液環(huán)境下進(jìn)行的ATRP反應(yīng),反應(yīng)條件溫和,故可以應(yīng)用在生物醫(yī)藥領(lǐng)域中。嵌段共聚物PEG-b-PDMAEMA不僅具有親水性,還具有顯著的溫度敏感性,且其LCST范圍在37.4℃C-40.8℃,與人體體溫相近,在醫(yī)藥高分子領(lǐng)域中具有廣闊的發(fā)展與應(yīng)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，

本文編號：1678741