Effect of the core-shell impact modifier shell thickness on toughening PVC
Effect of the core-shell impact modifier shell thickness on toughening PVC
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DOI：
10.1002/pen.20190
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发表时间：
2004-10-01
影响因子：
3.2
通讯作者：
Chang, FC
中科院分区：
文献类型：
--
作者：
Lee, JS;Chang, FC
研究发现，核/壳抗冲改性剂的壳厚度是硬质聚氯乙烯 (PVC) 增韧的最重要因素。当壳厚度大于15.8 nm的临界值时，这些核-壳弹性体颗粒能够在熔融共混后保持结构完整并良好地分散在PVC基质中。然而，壳厚度太厚会导致这些核/壳颗粒的硬核（高模量）并丧失有效抗冲改性剂所需的橡胶性质。因此，这些过粗的颗粒只能充当刚性填料。不如有效的橡胶改性剂。另一方面，当壳厚度小于4.9 nm的临界值时，太薄的壳层在剧烈加工条件下根本无法完全保护和覆盖内部橡胶核，并且这些核壳颗粒往往通过部分暴露的核相互连接形成蜂窝状结构，从而导致增韧效率差。无论粒径如何，只要这些核/壳弹性体的壳厚度在这两个临界值（15.8 nm 和 4.9 nm）之间，它们都显示出高增韧硬质 PVC 的效率。 (C) 2004 年塑料工程师学会。
The shell thickness of a core/shell impact modifier is found to be the single most important factor in the toughening of rigid polyvinyl chloride (PVC). When the shell thickness is greater than a critical value of 15.8 nm, these core-shell elastomeric particles are able to remain structurally intact and well dispersed within the PVC matrix after melt blending. However, too thick a shell thickness results in a hard core (high modulus) of these core/shell particles and loss of the rubbery nature required of an efficient impact modifier. Therefore, these over-thick particles can act only as rigid fillers. not as efficient rubbery modifiers. On the other hand, when the shell thickness is less than the critical value of 4.9 nm, too thin a shell layer is simply unable to fully protect and cover the inner rubbery core during vigorous processing conditions, and these core-shell particles tend to connect with one another through the partially exposed core to form a cellular-like structure, thus resulting in poor toughening efficiency. Regardless of the particle size, as long as the shell thickness of these core/shell elastomers is between these two critical values (15.8 nm and 4.9 nm), they all display high efficiency in toughening rigid PVC. (C) 2004 Society of Plastics Engineers.