基于自缩合自由基聚合超支化聚合物的制备及表征

与线型聚合物相比,超支化聚合物存在高度支化结构从而使其具有许多突出性能,在很多领域具有广阔的应用前景。以同时含有一个双键和两个原子转移自由基聚合(ATRP)引发点的丙烯酸(2,3-二(2-溴代)丙酰氧基)丙酯单体,通过调节丙烯酸(2,3-二(2-溴代)丙酰氧基)丙酯/丙烯酸正丁酯的物质的量比,以溴化亚铜(CuBr)/五甲基二乙烯三胺(PMDETA)为催化体系,进行原子转移自由基自缩合聚合。所得到聚合物的分子量和支化度分别通过凝胶色谱(GPC)和核磁共振氢谱(~1H NMR)进行表征。结果表明,随着聚合时间,单体转化率,丙烯酸(2,3-二(2-溴代)丙酰氧基)丙酯/丙烯酸正丁酯物质的量比的增加,数均分子量和支化度逐渐增加。

Preparation and Properties of Hyperbranched Polymers Based on the Self Condensation Radical

Comparing with linear polymers,hyperbranched polymers had outstanding properties and broad application prospects in many fields,because of their highly branched structures.Taking acrylic2,3-di(2-bromoisobutyryloxy)]propyl ester containing a double bond and two atom transfer radical polymerization(ATRP)initiating groups as monomer,the atom transfer radical self-condensation polymerization was performed with cuprous bromide(CuBr)/pentamethyl diethylenetriamine(PMDETA)as catalytic system at different mole ratios of 2,3-di(2-bromoisobutyryloxy)ethyl acrylate and n-butyl acrylate.The number average molecular weight and branching degree were characterized by gel chromatography(GPC)and nuclear magnetic resonance(1 H NMR),respectively.The results show that the number average molecular weight and branching degree increase with the increase of polymerization time,monomer conversion,2,3-di(2-bromoisobutyryloxy)ethyl acrylate and n-butyl acrylate mole ratio of comonomer.