Cornejo-Bravo J M, Siegel R A
Department of Pharmacy, University of California, San Francisco 94143-0446, USA.
Biomaterials. 1996 Jun;17(12):1187-93. doi: 10.1016/0142-9612(96)84939-8.
Copolymers of N, N-diethylaminoethyl methacrylate (DEA) and methyl methacrylate (MMA) were synthesized in ethanolic solution and characterized in terms of reactivity ratios, densities and water vapour sorption. For the reaction conditions studied the copolymerization is essentially random. Polymer densities, determined by centrifugation in a density gradient, range from 1.10 for pDEA to 1.13 for p(DEA/MMA) 52/48 mol%. Flory-Huggins chi parameters were determined by isopiestic water vapour sorption, and were found to depend on both the comonomer ratio and the water content. An exceptionally strong dependence of chi on water content (or equivalently, polymer volume fraction) suggests that Flory-Huggins theory is not the proper theory to apply, especially for the polymers with the highest MMA content. Analysis of the data in terms of the Zimm-Lundberg cluster theory reveals that as the polymer becomes more hydrophobic and glassy with increased MMA, the sorption becomes more nonuniform in the polymer.
在乙醇溶液中合成了甲基丙烯酸N, N -二乙氨基乙酯（DEA）与甲基丙烯酸甲酯（MMA）的共聚物，并通过竞聚率、密度和水蒸气吸附对其进行了表征。在所研究的反应条件下，共聚反应基本是无规的。通过在密度梯度中离心测定的聚合物密度，对于聚DEA为1.10，对于p(DEA/MMA) 52/48摩尔%的共聚物为1.13。通过等压水蒸气吸附测定了弗洛里 - 哈金斯相互作用参数χ，发现其取决于共聚单体比例和水含量。χ对水含量（或等效地，聚合物体积分数）具有异常强烈的依赖性，这表明弗洛里 - 哈金斯理论并非适用的恰当理论，特别是对于MMA含量最高的聚合物。根据齐姆 - 伦德伯格簇理论对数据进行分析表明，随着聚合物随着MMA含量增加变得更加疏水和玻璃态，聚合物中的吸附变得更加不均匀。
