Intra and intermolecular relaxations 2,3-dihydroxypropyl methacrylate and 2-hydroxyethyl methacrylate hydrogels

Semi-interpenetrating polymer networks based on polyurethane and poly(2-hydroxyethyl methacrylate): Dielectric study of relaxation behavior

“…2) allowed us to observe five relaxation mechanisms. In order of increasing temperature: c-relaxation process is observed in the temperature range of À135 to À60°C, this relaxation masks a very weak relaxation phenomenon in the temperature domain of -100°C/-75°C-so called bsw-relaxation process [35][36][37][38]. As the temperature increases, a b-relaxation mechanism appears displayed in Fig.…”

Steady-state diffusion of water through soft-contact-lens materials

“…A few studies report measurements of kinetic sorption/desorption [23][24][25][26][27] of water or steady-state water fluxes [8,28] driven by a water-activity gradient through a SCL.…”

Preparation of New Amphiphilic Liquid-Crystal Diblock Copolymers Bearing Side-on Cholesteryl Mesogen and Their Self-aggregation

“…为了进一步拓展该系列胆固醇液 晶嵌段大分子的生物材料应用, 本组最近报道了具有自 由羟基的聚甲基丙烯酸羟乙酯(PHEMA)为亲水性嵌段 两亲胆固醇液晶嵌段功能大分子, 有趣地发现液晶嵌段 的相转变温度(T LC-I )高于胆固醇液晶均聚物, 揭示亲水 嵌段氢键网络的存在, 可能在嵌段共聚物微相分离的过 程中诱导液晶的有序取向与排列 [13] . 另一方面, 重复单 元侧基含有双羟基的聚甲基丙烯酸甘油酯(PGMA)具有 更优异的亲水性和生物相容性, 大量的羟基可共价偶联 药物或生物活性分子, 同时已经在隐形眼镜、水凝胶、 药物输送载体等领域得到关注与应用 [14,15] , 并进一步拓 展其作为生物相容性人工肾滤过膜材料的应用 [16] . 在本组已有相关工作的基础上, 为了进一步研究阐 明亲水嵌段中多羟基官能团的存在、氢键网络密度对胆 固醇液晶嵌段功能大分子聚集行为、液晶相结构与转变 及其溶液自组装的影响规律, 本文新采用生物基甘油为 合成出发原料, 以缩酮保护的甲基丙烯酸丙酮缩甘油酯 (SMA)和含有胆固醇液晶元的甲基丙烯酸亚己基胆固 醇酯(MA6Chol)作为共聚单体, 通过顺序可逆加成-断 裂链转移聚合(RAFT)反应和去保护反应 [17,18] , [19] .…”