Toughening of polyamides by the in situ generation of elastomeric phases
Toughening of polyamides by the in situ generation of elastomeric phases
复制标题
通过原位生成弹性体相增韧聚酰胺
DOI：
10.1007/s003960000316
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发表时间：
2000
影响因子：
2.4
通讯作者：
J. E. Mark
中科院分区：
文献类型：
--
作者：
Y. W. Park;J. E. Mark
用两种硅烷偶联剂对一种商业化的Trogamid聚酰胺（一种芳香“尼龙”）进行了改性。在环氧硅基剂的情况下，硅烷作为侧链掺入，与样品在50-60℃下反应3天，三乙二胺为催化剂。相反，异氰化硅基化合物只被添加到聚酰胺端基（羧酸和胺基）。聚酰胺-环氧复合材料与双官能硅烷连接，然后干燥成薄膜。在较低的环氧硅烷含量下，它们表现出一些改善的最终性能，包括韧性。特别是在120℃退火后，试样的抗拉强度得到了很大的提高。同时，增加双官能团硅烷的用量可以提高材料的最大伸长率，但以降低拉伸强度为代价。另一方面，Trogamid异氰基硅基材料表现出与原位水解四乙氧基硅烷生成的二氧化硅增强聚酰胺相似的性能。具体来说，这些复合材料的抗拉强度略有增加，但代价是韧性下降。虽然不可能同时改善任何一种复合材料的所有机械性能，但有可能确定一次至少使其中一种或两种性能最大化的条件。因此，研究结果为如何优化一类重要的聚酰胺的性能提供了指导。
Samples of a commercial Trogamid polyamide (an aromatic “nylon”) were modified with two silane coupling agents. In the case of the epoxysilyl agent, the silane was incorporated as a side chain by reacting it with the sample at 50–60 °C for 3 days, with triethylenediamine as catalyst. In contrast, an isocyanatosilyl compound was added only to the polyamide end groups (carboxylic acid and amine groups). The polyamide–epoxy composites were linked with a difunctional silane and were then dried into films. They exhibited some improved ultimate properties, including toughness, at the lower epoxysilane contents. In particular, the tensile strengths of the samples that were annealed at 120 °C were greatly improved. Also, the maximum extensibility was increased by increasing the amount of difunctional silane, but at the cost of decreased tensile strengths. The Trogamid isocyanatosilyl materials, on the other hand, showed properties similar to those of polyamides reinforced with silica generated in situ by the hydrolysis of tetraethoxysilane. Specifically, the tensile strengths of these composites increased slightly, but at the cost of decreased toughness. Although it was not possible to improve all the mechanical properties of either type of composite simultaneously, it was possible to identify the conditions for maximizing at least one or two of them at a time. Thus, the results provided guidance on how to optimize the properties of an important class of polyamides for any particular application.