Polymer ( IF 4.6 ) Pub Date : 2017-09-19 , DOI: 10.1016/j.polymer.2017.09.042 Leandro G. Aguiar , Juliana O.V. Moura , Thiago R. Theodoro , Turibio G.S. Neto , Vinícius M.P. Lopes , Joslaine R. Dias
The production of polymeric resins through free-radical copolymerization is an interesting procedure from an economic standpoint; however, its mathematical representation is of great complexity. In the present study, modeling tools were used to describe the copolymerization of styrene with ethylene glycol dimethacrylate (EGDMA) beyond the gel point. Balance of species and sequences, method of moments, and numerical fractionation technique were applied in the model's kinetic description. Diffusion effects were also taken into account. The concept of elementary gel structures (EGSs) was used in order to predict textural properties of polymer particles, such as specific surface area and swollen gel volume. Suspension copolymerizations were carried out in the presence of toluene/heptane mixtures, and data on these reactions were used to assess the model's predictability. Reactivity parameters showed similarities to styrene/divinylbenzene systems. Agreement between the model and experimental data improved when diffusion effects were considered. The fitted apparent coiling factors for dry particles were found in the range of 0.368–0.406, and a linear correlation was obtained between this parameter and toluene fraction (a good solvent), being consistent with the pore formation phenomenon.
中文翻译:
通过乙烯基/二乙烯基共聚模型预测树脂的结构性能
从经济角度看,通过自由基共聚生产聚合物树脂是一种有趣的方法。但是,其数学表示非常复杂。在本研究中,使用建模工具描述了苯乙烯与乙二醇二甲基丙烯酸酯(EGDMA)超过胶凝点的共聚反应。在模型的动力学描述中采用了物种和序列的平衡,矩量法和数值分馏技术。还考虑了扩散作用。使用基本凝胶结构(EGSs)的概念是为了预测聚合物颗粒的质地特性,例如比表面积和溶胀的凝胶体积。悬浮共聚是在甲苯/庚烷混合物的存在下进行的,这些反应的数据用于评估模型的可预测性。反应性参数显示与苯乙烯/二乙烯基苯体系相似。当考虑扩散效应时,模型和实验数据之间的一致性得到改善。拟合得到的干燥颗粒的表观卷曲系数在0.368–0.406范围内,并且该参数与甲苯分数(一种良好的溶剂)之间存在线性相关性,与孔隙形成现象一致。