双键超支化聚硅氧烷在芳纶纤维表面的原位生长

Study on the in-situ growth of hyperbranched polysioxane with double bonds on the surface of aramid fiber

以显著提升芳纶纤维与橡胶基体之间的界面结合强度为目标,本文开发了一种在芳纶纤维表面原位生长碳碳双键超支化聚硅氧烷的策略:首先借助多巴胺的仿生修饰建立初始层,接着采用迈克尔加成反应接枝氨基硅烷偶联剂创建中间层,最后通过脱水缩合反应实现原位生长。改性前后的芳纶纤维表面形貌和化学结构采用扫描电镜、傅里叶变换红外线光谱分析仪、X射线光电子能谱分析仪及热失重分析仪进行了测试表征。由芳纶纤维增强橡胶基复合材料的H-抽出力测试结果可得,本文采用的改性方法能够提升约66.4%的界面结合强度,其原因主要可以归结为表面粗糙度的提升及纤维束与橡胶共硫化的实现。对比分析发现,聚多巴胺初始层的采用使本改性方法具有较高的普适性和工业应用潜力。

To improve the interfacial performance between aramid fiber and rubber matrix, this paper developed a strategy of in-situ growth of hyperbranched polysiloxane with double bonds onto the surface of aramid fiber. At first, the initial layer on the surface of fiber was established by the biomimetic modification of dopamine, and then,the middle layer was created by the graft of amino silane coupling agent via Michael addition reaction. Finally, the in-situ growth of hyperbranched polysiloxane was realized through the dehydration condensation reaction. The surface morphology and chemical structures of aramid fibers before and after modification were investigated by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. It can be obtained from the results of H pull-out tests of aramid fiber/rubber that the method proposed in this paper can increase the interfacial bonding strength by 66.4%, which can be ascribed to the improvement of surface roughness and the co-vulcanization between fibers and rubber. Furthermore, the graft of polydopamine initial layer makes this modification method have high universality and industrial application potential.