【作者】 杨伟；

【导师】 陈明清；

【作者基本信息】 江南大学 ， 应用化学， 2006， 硕士

【摘要】 本文首先研究了甲基丙烯酸叔丁酯的原子转移自由基聚合特点。分别以对氯甲基苯乙烯和α-溴代丙酸乙酯为引发剂,联二吡啶和N,N,N′,N″,N″-五甲基二亚乙基三胺为配位剂,在氯化亚铜的催化作用下,使甲基丙烯酸叔丁酯(tBMA)进行本体聚合。用凝胶渗透色谱(GPC)跟踪聚合物的相对分子质量变化,发现不同引发剂与配位剂对聚合反应速率有明显的影响,比较了四种不同体系下的反应规律。通过改变引发剂与单体的摩尔配比(1:50-1:150),可将聚甲基丙烯酸叔丁酯(PtBMA-X)的相对分子质量控制在5×103～2×104范围内,并保持其相对分子质量分布≦ 1 .2。同时用傅里叶红外光谱(FTIR)、核磁共振氢谱(1H-NMR)对产物的结构进行了表征,结果表明所得聚合物PtBMA-X的结构明确,为目标产物。进而以PtBMA-Br作为大分子中间体,使其末端的Br原子与甲基丙烯酸进行亲核取代反应,从而在聚甲基丙烯酸叔丁酯末端引入C=C双键,得到了甲基丙烯酸封端的疏水性大分子单体MAA-PtBMA,通过核磁共振谱的峰面积,计算了大分子单体的双键导入率。通过优化条件,可将双键的导入率提高到90%以上,并研究了大分子单体的聚合特性,表明其具有较强的聚合能力。将所合成的聚甲基丙烯酸叔丁酯大分子单体MAA-PtBMA在无水乙醇溶剂中与苯乙烯进行分散共聚,制备得到了单分散性的高分子微球,初步考察了该类大分子单体在分散共聚中的作用。同时,在交联剂存在条件下也初步尝试用聚甲基丙烯酸叔丁酯大分子单体与丙烯酰胺在无水乙醇溶剂中,制备交联的聚丙烯酰胺功能性微球,为进一步开拓该类大分子单体的应用奠定了基础。探索性研究了大分子链之间进行亲核取代反应制备接枝聚合物,并初步研究了该类接枝聚合物在溶剂中的自组装行为。更多还原

【Abstract】 In this paper, bulk atom transfer radical polymerization (ATRP) of tert-butylmethacrylate (tBMA) was first studied. P-chloromethylstyrene (CMSt) and ethyl-2-bromo-propionate (EPN-Br) were selected as initiators, 2,2’-bipyridyl (bpy) and N,N,N′,N″,N″-Penta-methyldiethylenetriamine (PMDETA) as ligand, with CuCl as catalyst. Poly(tert-butyl methacrylate) with a halogen atom end group PtBMA-X was synthesized by bulk ATRP at 85oC. It was found that initiator and ligand can clearly affect polymerization rate of tBMA monomer based on measurement of molecular weight of PtBMA-X under different initiator/ligand system by using gel permeation chromatography (GPC). The polymerization regulations under different system were compared. The number average molecular weight (Mn) of PtBMA-X could be controlled in a range from 5×103 to 2×104 g/mol by varying the ratio of monomer to initiator(1:50 to1:150), and distribution of molecular weight (Mw/Mn ) kept low than 1.20. The 1H-NMR chemical shifts in parts per million (ppm) were recorded from 0.00 ppm using tetramethylsilane as an internal reference. It was found that obtained PtBMA has a specific structure.Further more, the poly(tert-butyl methacrylate) macromonomer (MAA-PtBMA) with a C=C double end group was successfully prepared by the nucleophilic substitution of halogen atom to methacrylic acid. The introduction rate of double bond could be calculated through the peaks’area of 1H-NMR, the result was high to above 90%. Then, the polymerizations of macromonomers were reseached.Polymeric microspheres were prepared by dispersion copolymerization with macromonomer and styrene in ethanol. In the dispersion copolymerization system, macromonomer make the role of dispersant and co-monomer, the regulation was primary studied. Other more, we attempt to prepare cross-linked PtBMA-PAm microspheres, and the more regulation need be more research.The nucleophilic substitution between polymer chains was discussed. The graft polymers were synthesized and its self-assemble in dissolve was researched. Keywords tert-butyl methacrylate; atom transfer radical polymerization; macromonomer; microsphere更多还原