A mathematical model of a thermally initiated thiol-ene polymerization is developed and assessed with experimental data gathered in the polymerization of 2,2’-(ethylenedioxy)diethanol (EDDT) as dithiol and diallyl adipate (DAA) as diene. The model considers the main mechanisms of addition (propagation) and chain transfer reactions by which the thiol-ene polymerization proceeds, but also reaction mechanisms that yield to side products formed by reaction of initiator radicals with ene functional groups and by combination termination reactions. The model predicts in addition to kinetics and molar masses, the molar fractions of all the polymer species produced. Conversions of the ene functional groups are determined by in situ ¹H-NMR, absolute molar masses are determined by size exclusion chromatography with a multiangle light scattering detector (SEC/MALS) and molar fractions of copolymer species are measured by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF). The experimental data are used for estimating some of the rate coefficients of the kinetic scheme. The model predicts reasonably well the effects of the initiator concentration on the kinetics and underestimates the molar masses. On the other hand, the model predicts three of the five species experimentally detected by MALDI-TOF.

中文翻译：

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模拟热引发硫醇-烯聚合的动力学和微观结构

开发了热引发硫醇-烯聚合的数学模型，并利用在聚合 2,2'-(乙二氧基) 二乙醇 (EDDT) 作为二硫醇和己二酸二烯丙酯 (DAA) 作为二烯的聚合中收集的实验数据进行了评估。该模型考虑了硫醇-烯聚合进行的加成（增长）和链转移反应的主要机制，以及引发剂自由基与烯官能团反应和组合终止反应形成副产物的反应机制。该模型除了预测动力学和摩尔质量外，还预测了产生的所有聚合物种类的摩尔分数。烯官能团的转化率由原位确定¹H-NMR，绝对摩尔质量通过具有多角度光散射检测器 (SEC/MALS) 的尺寸排阻色谱法测定，共聚物物质的摩尔分数通过基质辅助激光解吸/电离飞行时间质谱法 (MALDI-TOF) 测量）。实验数据用于估计动力学方案的一些速率系数。该模型合理地预测了引发剂浓度对动力学的影响并低估了摩尔质量。另一方面，该模型预测了 MALDI-TOF 实验检测到的五个物种中的三个。