(2-Chloro-2-alkoxycarbonyl)ethyl acrylates with methyl, dodecyl, perfluoroalkyl, siloxane, oligooxyethylene, and mesogenic ester substituents were synthesized as inimers for self-condensing vinyl polymerization (SCVP) to produce hyperbranched polyacrylates. The inimers were polymerized by atom transfer radical polymerization under a variety of conditions to produce soluble polymers with broad polydispersities (up to PDI = 5.24) characteristic of hyperbranched polymers, although the isolated polymers had narrower polydispersities. The molecular weight distribution was followed as a function of time and inimer conversion for the polymerization of the mesogenic inimer. The first-order inimer conversion was linear with time. The buildup of a hyperbranched structure during the SCVP was confirmed by comparison of the error in the GPC(PSt)-determined molecular weights of the mesogenic polymer with those of the corresponding linear, three-arm star, and comb architectures.
该研究通过开发新型Inimers(一种具有不同取代基的改性
丙烯酸酯单体),成功实现了自缩合
乙烯聚合(SCVP),制备了一系列超支化聚
丙烯酸酯。这些Inimers具有多种功能化取代基,包括甲基、
十二烷基、
全氟烷基、
硅氧烷、寡聚氧
乙烯以及介晶取代基。研究采用了原子转移自由基聚合(ATRP)技术,在不同条件下进行聚合,成功制备了具有广泛分子量分布(最高PDI=5.24)的可溶性超支化聚合物,尽管分离出的聚合物分子量分布较窄。通过对具有介晶Inimer的聚合过程进行分析,发现Inimer的转化率与时间呈线性关系,这表明在SCVP过程中形成了明确的支化结构增长特性。通过对比介晶聚合物与对应线性、三臂星型以及梳状结构聚合物在凝胶渗透色谱(
GPC,使用聚
苯乙烯为标样)测定下的分子量误差,进一步证实了超支化结构的形成。