原位合成纳米SiO2增强阴离子聚酯型上浆剂及其对碳纤维复合材料层间剪切强度的影响

采用溶胶-凝胶法, 在侧链带有羧基的线性不饱和聚酯中加入正硅酸乙酯(TEOS), 使TEOS在酸性条件下发生水解反应, 原位合成纳米SiO₂增强阴离子型聚酯乳液(SEAPE). 利用傅里叶变换红外光谱(FTIR)仪、 激光粒度分析仪和冷冻扫描电子显微镜(Cryo-SEM)对SEAPE进行分析与表征. 将SEAPE与聚乙二醇单油酸酯润滑剂、 非离子型表面活性剂FC-4430及抗氧剂1010进行复配, 原位制备纳米SiO₂增强阴离子型聚酯乳液上浆剂(SEAPEs), 用扫描电子显微镜(SEM)、 视频动态接触角测量仪、 X射线能谱(EDS)仪和纤维强力仪对SEAPEs上浆后碳纤维的表面形貌、 表面能、 碳纤维(CF)表面元素及碳纤维增强不饱和聚酯(UPR)复合材料(CF/UPR)的层间剪切强度(ILSS)进行测试与表征. 结果表明, 当TEOS添加质量分数为5%时, SEAPEs上浆后的碳纤维有效增强了其与UPR的结合强度, CF/UPR复合材料的ILSS达到40.03 MPa, 与市售环氧树脂型上浆剂上浆后碳纤维增强UPR复合材料相比, ILSS提高90.1%. SEAPEs中原位生成的纳米SiO₂分散均匀, 乳液储存稳定, 上浆后SiO₂均匀吸附在碳纤维表面, 增加碳纤维表面能, 改善碳纤维与树脂间的浸润性, 可有效提高碳纤维增强不饱和聚酯树脂复合材料的ILSS.

In situ Synthesis of Nano-sized Silica Enforced Anionic Polyester Sizing Agent and Its Effect on ILSS of Carbon Fiber Composites ?

Nano-sized silica enforced anionic polyester sizing agent(SEAPs) were synthesized by in situ synthetic technologies. SEAPs was analyzed and characterized by Fourier transform infrared spectroscopy(FTIR), laser particle size analyzer and cryo scanning electron microscope(SEM). The carbon fiber sized by SEAPs was studied with SEM, dynamic contact angle meter and energy dispersive spectroscopy(EDS). The surface morphology, surface energy, surface elements of carbon fibers and interlaminar shear strength(ILSS) of the sized carbon fibers and its reinforced unsaturated polyester composites were tested. The testing results showed that when the mass fraction of TEOS was 5%, the optimal ILSS of carbon fiber reinforced unsaturated polyester composite was obtained, which was 90% higher than that of carbon fibers composites after sizing with commercial epoxy resin sizing agent. In situ synthesized nano-SiO₂ formed core-shell micelle with anionic polyester and nano-sized SiO₂ is evenly adsorbed on the surface of carbon fibers after sizing, increasing the surface energy of carbon fibers and improving the wettability between carbon fibers and unsaturated polyester, which can effectively enhance the ILSS of carbon fibers composites.