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选用形状记忆聚氨酯(SMPU)和正硅酸乙酯(TEOS)为前驱体,固体酸对甲基苯磺酸(PTSA)为催化剂,利用空气中的水分为水解水源,通过溶胶-凝胶法原位制备了形状记忆聚氨酯与二氧化硅(SMPU-SiO2)杂化材料,并将杂化材料应用于芳纶纤维增强的柔性复合材料中,以期改善芳纶纤维与基体的界面性能.同时,针对芳纶纤维表面惰性,与树脂基体界面结合性能不佳的特点,通过磷酸溶液改性芳纶纤维以提高芳纶纤维表面的活性.通过傅立叶红外光谱仪(FTIR)、光电子能谱仪(XPS)、万能试验机、低温热膨胀仪和偏光显微镜等对芳纶纤维的表面基团、单丝强度以及芳纶纤维与SMPU基复合材料的界面性能进行了表征.结果表明,通过磷酸改性后,芳纶纤维表面活性基团有所增加,单丝强度有了一定的提高;经浓度为10 wt%的磷酸溶液处理后的芳纶纤维与SMPU之间的界面剪切强度有所提高;在SMPU中杂化SiO2后,能有效降低SMPU在玻璃化温度附近的热膨胀系数,显著提高了芳纶纤维与基体的界面剪切强度.
Shape memory polyurethane (SMPU) and tetraethyl orthosilicate (TEOS) were used as precursors and solid acid p-toluenesulfonic acid (PTSA) was used as catalyst. The water in the air was used as a source of hydrolyzed water and sol- The shape memory polyurethane and silica (SMPU-SiO2) hybrid materials were prepared and the hybrid materials were applied to the aramid fiber reinforced flexible composites in order to improve the interfacial properties of the aramid fiber and the matrix.At the same time, The surface of the fiber is inert and its bonding property with the resin matrix is not good. The aramid fiber is modified by phosphoric acid solution to improve the surface activity of the aramid fiber. Fourier transform infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS) The mechanical properties of the aramid fibers and the surface properties of the aramid fibers and the interfacial properties of the aramid fibers and the SMPU matrix composites were characterized by X-ray photoelectron spectroscopy (XRD), mechanical testing, low temperature dilatometer and polarizing microscope. The results showed that the aramid fiber The surface active groups increased and the monofilament strength increased to a certain extent. The interfacial shear strength between aramid fiber and SMPU treated with 10 wt% phosphoric acid solution increased. In SMPU medium After of SiO2, SMPU can effectively reduce the coefficient of thermal expansion close to the glass transition temperature, significantly improves the interfacial shear strength aramid fiber and the matrix.