【2018-0482】一种含腈基的硅烷偶联剂改性石英纤维/含硅芳炔复合材料

《复合材料学报》优先在线发表论文。

摘  要：设计并合成了一种含有二腈基的硅烷偶联剂DCA（Dicyanide-containing Silane Coupling Agent），FTIR、1H-NMR、13C-NMR表征了其化学结构。将DCA添加到石英纤维(QF)/含硅芳炔(PSA)复合材料体系中，DCA含量为纤维的2.0wt%时，常温条件下改性后的QF/PSA复合材料层间剪切强度和弯曲强度分别提升63.3%和28.1%，250℃时，层间剪切强度（ILSS）和弯曲强度的保留率为83.0%和81.9%，500℃时，保留率分别为54.7%和60.0%。偶联剂DCA固化后热失重5%的温度(Td5)为357.8℃，900℃时残炭率为55.7%。XPS和DSC数据表明，偶联剂DCA在QF/PSA复合材料界面形成化学桥接，其中的腈基在229℃固化，炔基在245℃参与PSA的固化，在PSA与石英纤维间形成强界面层。SEM观察表明，经偶联剂DCA改性后的QF/PSA复合材料的破坏属于韧性断裂。新型偶联剂DCA可显著改善QF/PSA复合材料界面，提高其高温力学性能。

关键词：邻苯二甲腈；硅烷偶联剂；复合材料界面；界面增强

Abstract: A novel dicyanide-containing silane coupling agent (DCA) was synthesized and characterized with FTIR, 1H-NMR and 13C-NMR. After modified by the coupling agent DCA, the interlaminar shear strength (ILSS) and flexural strength of the quartz fiber(QF)/poly(silicon-containing arylacetylene) (PSA) composites increase by 63.3% and 28.1% at room temperature respectively. At 250℃, the retention of ILSS and flexural strength of QF/PSA are 83.0% and 81.9% respectively, as well as 500℃, the retention of ILSS and flexural strength are 54.7% and 60.0% respectively. The decomposition temperature of 5% loss (Td5) of cured DCA is 357.8℃, and its residue rate is up to 55.7% at 900℃. According to DSC analysis, the dicyanide groups cure at about 224℃, and the alkenyl groups copolymerized with PSA at 244℃.The strong interfacial layer form between QF and PSA. XPS analysis shows that DCA could form chemical bonds as the bridges between the matrix and fibers. Confirmed by SEM, the rupture mode of QF/PSA composites modified by DCA on the interface is obviously ductile fracture. DCA can apparently modify the interface of QF/PSA composites and improve its mechanical properties.

Keywords: phthalonitrile; silane coupling agent; composite interface; interface reinforcement

作者：成滨等，华东理工大学材料科学与工程学院，特种功能高分子材料及相关技术教育部重点实验室，上海

通讯作者：扈艳红，华东理工大学材料科学与工程学院，特种功能高分子材料及相关技术教育部重点实验室，上海

全文详见中国知网学术期刊优先数字出版。