ABSTRACT

In this research, the silk fibers that were successfully extracted from silk cocoons using Na₂CO₃ were treated with silane coupling agent (3-aminopropyl)trimethoxysilane. The silane treated and untreated silk fiber reinforced epoxy composites were fabricated using the hand lay-up technique. The effects of fiber loading and the presence of silane coupling agent on the mechanical, morphological, thermal, void fraction, and water absorption properties of the silk fiber reinforced epoxy composites were studied. Fourier transform infrared (FTIR) analysis confirmed presence of silane group on the surface of fiber. The void fraction and water absorption increased with increasing fiber loading for both untreated and silane-treated composites. However, the silane-treated composites displayed lower increment of both void fraction and water absorption in comparison to the untreated samples suggesting better properties. The impact, flexural and tensile properties of the treated composites exhibited better property enhancement compared to the untreated samples with optimum fiber loading was observed at 30 wt%. The presence of this coupling agent also increased the thermal properties of the composites in general. The morphological studies revealed good interfacial compatibility between fiber and matrix in the presence of silane coupling agent which consistent with the enhancement observed for impact properties.

摘要

在这项研究中，使用Na ₂ CO ₃从蚕茧中成功提取了蚕丝纤维用硅烷偶联剂（3-氨基丙基）三甲氧基硅烷处理。硅烷处理和未处理的丝纤维增强环氧复合材料均采用手工铺层技术制造。研究了纤维负载量和硅烷偶联剂的存在对丝纤维增强环氧复合材料的机械，形态，热，空隙率和吸水性能的影响。傅里叶变换红外（FTIR）分析证实了纤维表面上存在硅烷基。对于未处理和硅烷处理的复合材料，空隙率和吸水率均随纤维含量的增加而增加。然而，与未处理的样品相比，经硅烷处理的复合材料显示出较低的空隙率和吸水率增量，表明具有更好的性能。影响，与未处理的样品相比，经处理的复合材料的弯曲和拉伸性能表现出更好的性能增强，在30 wt％的条件下观察到最佳的纤维负载。通常，这种偶联剂的存在还提高了复合材料的热性能。形态学研究表明，在存在硅烷偶联剂的情况下，纤维与基质之间具有良好的界面相容性，这与观察到的冲击性能增强相一致。