Reaction-induced phase separation in modified thermosetting polymers
Reaction-induced phase separation in modified thermosetting polymers
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DOI：
10.1007/3-540-61218-1_7
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
Roberto J. J. Williams-Roberto-J.-J.-Williams-2116648663;B. Rozenberg;J. Pascault
中科院分区：
文献类型：
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作者：
Roberto J. J. Williams-Roberto-J.-J.-Williams-2116648663;B. Rozenberg;J. Pascault
热固性聚合物经常用于配方中，包括橡胶、热塑性聚合物或油等，相对于热固性聚合物的用量约为 2-50 wt%。这种额外的组分称为改性剂，最初可能是不混溶的，或者可能在固化过程中发生相分离。最后一个过程，即反应引起的相分离，是本次综述的主题。使用弗洛里-哈金斯方程在两个近似水平上对该过程进行热力学描述，即准二元方法和考虑成分多分散性的多组分处理。由此建立了影响相分离过程的热力学因素。成核与生长（NG）和旋节线分层（SD）被认为是可能的相分离机制。讨论了促进一种或另一种过程的因素。基于热力学和动力学论证对所产生的形态的控制进行了分析。提出了获得增强特定性能的特定形态的想法。
Thermosetting polymers are frequently used in formulations, including rubbers, thermoplastic polymers or oils, etc, in an amount of the order of 2–50 wt% with respect to the thermoset. This extra component, called the modifier, may initially be immiscible or may phase-separate during cure. This last process, i.e the reaction-induced phase separation, is the subject of this review. A thermodynamic description of the process is made, using the Flory-Huggins equation at two approximation levels, i.e. a quasi-binary approach and a multicomponent treatment taking polydispersity of constituents into account. Thermodynamic factors affecting the phase separation process are thus established. Nucleation and growth (NG) and spinodal demixing (SD) are considered as possible phase separation mechanisms. Factors promoting one or the other process are discussed. The control of morphologies generated is analyzed on the basis of thermodynamic and kinetic arguments. Ideas for obtaining particular morphologies enhancing particular properties are put forward.