以对氯甲基苯乙烯(CMS)作为活性单体,CuCI/2,2’-联吡啶(bpy)为催化体系,用原子转移自由基聚合(ATRP)法,在120℃下,通过改变n(CuCl):n(CMS)配比,合成具有不同支化度的超支化聚对氯甲基苯乙烯(h—PCMS),分别考察了催化剂与单体的配比、溶剂极性、用量等因素对所合成的h—PCMS的组成结构、相对分子质量分布指数和转化率的影响。再分别以具有不同支化度的h—PCMS作为大分子引发剂,引发第二单体甲基丙烯酸甲酯(MMA)聚合,制得以超支化大分子h—PCMS为核,以聚甲基丙烯酸甲酯(PMMA)为臂的星型多臂共聚物h—PCMS—b—PMMA。借助红外光谱(FT-IR)、核磁共振氢谱(^1H—NMR)、凝胶渗透色谱(GPC)等技术对所制得的聚合物进行表征。本研究的特点是运用先核后臂的方法来合成具有精确分子结构参数的星型多臂共聚物,为进一步深入研究其结构与性能的关系提供了物质依据,更重要的是提供了合成具有复杂但结构可控的多元共聚物的新思路。
A hyperbranched polymers( h -PCMS) with different branching degree was pre- pared with chloromethylstyrene (CMS) as both a reactive monomer and a highly efficient initia- tor,at 120℃ under nitrogen and in the presence of CuC1/2,2' -bipyridine(bpy) as catalyst, through varying the mole ratio of CuC1 to CMS by atom transfer radical polymerization (AT- RP). The influence of the polarity and quantity of the solvent and the mole ratio of CuC1 to CMS on the structure of h - PCMS and molecular weight distribution as well as coversion was studied. Then, a second monomer, MMA,was initiated and polymerizaed by using h - PCMS as a macroinitiator to produce star - shaped dobby block copolymers, h - PCMS - b - PMMA, in which the core was h - PCMS and the arm was PMMA. The resulting products were characterized by FT -IR, 1H -NMR and GPC. The study was focusing on a process of core -first - arm - later to prepare a star - shaped muhiarm copolymer with defined structure, which provided a foundation for further investigate the relationship between structure and performance and a multipolymer with a controled structure.