丙烯酸(N-甲基全氟己烷磺酰胺基)乙酯与MMA梯度共聚物的合成与表征

通过电子转移再生催化剂的原子转移自由基聚合(ARGET ATRP)研究了甲基丙烯酸甲酯(MMA)和丙烯酸(N-甲基全氟己烷磺酰胺基)乙酯(C₆SA)的共聚可控性及单体的反应活性, 利用Kelen-Tüdos法测得MMA和C₆SA的表观竞聚率分别为r(MMA)=1.42, r(C₆SA)=0.34. 在此基础上, 考察了聚合过程中共聚物组成和表面能的变化. 共聚物的凝胶渗透色谱法(GPC)曲线呈现严格的单峰分布, 分子量随着转化率的增加而增加, 且分布较窄(多分散系数PDI<1.3), 共聚反应表现出"活性"聚合的特征. 静态接触角测试结果显示, 共聚物表面能随着转化率的增加而降低, ¹H NMR结果显示, C₆SA链节的含量随着分子链的增长而增加, 分子链由开始时的MMA为主导转变为后期的C₆SA为主导, 表明形成了梯度共聚物.

Synthesis and Characterization of Gradient Copolymer Composed of [N-Methyl-perfluorohexane-1-sulfonamide] Ethyl Acrylate and MMA

The controllability of copolymerization as well as the monomer relative reactivity for activators regenerated by electron transfer atom transfer radical polymerization(ARGET ATRP) [N-Methyl-perfluorohexane-1-sulfonamide] of ethyl acrylate(C6SA) and methyl methacrylate(MMA) in anisole was studied, the reactivity ratios were calculated by Kelen-Tüdos method, which got the apparent reactivity ratios, rMMA=1.42 and rC6SA=0.34. The copolymer compositions and the corresponding PMMA-grad-C6SA film surface properties during the "living" copolymerization were observed. The synthesis of MMA and C6SA via ARGET ATRP showed "living" polymerization characteristics, the gel permeation chromatography(GPC) traces of the copolymers presented the distribution were unimodal and polydispersity index(PDI<1.3) throughout the reaction, the Mn of the obtained copolymers increased with comonomer conversion. The static contact angle measurements showed that the surface energy of copolymer was decreased with the growth of the conversion. The compositions of samples during copolymerization were determined by 1H NMR, which showed the content of C6SA segments increased with the growth of copolymer chains. The increase of the cumulative composition of C6SA segments along the copolymer chain demonstrated that the gradient copolymer composed of C6SA and MMA was synthesized via ARGET ATRP.