聚醚酰亚胺耐热大分子偶联剂增强增韧石英纤维/含硅芳炔复合材料

设计并制备了一种新型乙炔基封端聚醚酰亚胺大分子偶联剂(BDA-K),探究了其对石英纤维(QF)/含硅芳炔(PSA)复合材料界面增强增韧的效果.在常温下,加入大分子偶联剂的复合材料层间剪切强度、弯曲强度和缺口冲击强度分别提高了54.1%,59.0%和23.8%;在250℃时,层间剪切强度和弯曲强度保留率分别达到89.0%和89.6%,500℃时保留率分别达到63.3%和67.9%.傅里叶变换红外光谱和X光电子能谱分析结果表明,BDA-K参与PSA的交联固化,与QF发生有效化学键合;热重分析(TGA)结果表明,由于BDA-K的分子结构中引入耐热官能团酰亚胺环等,使其大分子偶联剂的T_(d5)达到489℃;扫描电子显微镜(SEM)结果表明,柔软的大分子层提供了适中的界面结合,使强度和韧性都得到提高.

Reinforcement and Tougheness of Quartz Fiber/Silicon-containing Arylacetylene with Heat-resistant Polyetherimide Macromolecular Coupling Agent

A novel acetylene-terminated polyetherimide macromolecular coupling agent ( BDA-K ) was designed and synthesized, and its effects on the interfacial reinforcement and toughness of the quartz fiber (QF) reinforced silicon-containing aryl-alkyne(PSA) matrix composites were investigated. The interlaminar shear strength( ILSS) , flexural strength and notched impact strength increased by 54. 1％, 59. 0％ and 23. 8％compared with those of untreated at room temperature. The retention of ILSS and flexural strength reached 89. 0％ and 89. 6％ at 250 ℃ and 63. 3％ and 67. 9％ at 500 ℃, respectively. The FTIR and XPS spectra indicate that BDA-K takes part in PSA curing and effective chemical bonds form between BDA-K and QF. Owing to the introduction of heat-proof groups i. e. the imide rings to BDA-K backbone, TGA results reveal that the value of Td5 is up to 489 ℃. The interphase morphologies by SEM show that soft and moderate macromolecule layers constructed between the matrix and the fiber treated with BDA-K, which improves the mechanical strength and toughness of the QF/PSA composites.