Effect of silane treatment on tensile strength, moisture absorption and thermal property of unidirectional woven mat enset fibers reinforced polypropylene composite

The aim of this paper is to study the effect of bis [3(triethoxysilyl) propyl] tetrasulfide (Si69) and 3-Glycidoxypropyl trimethoxy silane (GPS) on the properties of unidirectional enset fiber reinforced Polypropylene (PP) composite. For this purpose, enset fiber was weaved into the mat and treated with 1.5 wt% Si69 and 5 wt% GPS after which it was used to reinforce PP composites through the film stacking method followed by the compression molding. Fabricated composites were characterized by their tensile, thermal, water absorption, image of the fracture surface, and FTIR spectroscopy properties. Among the developed unidirectional reinforced PP composite, the surface-treated enset-woven mat with 1.5wt% Si69 gave the highest tensile strength with an increase of 267.1%, and 36.9% from untreated enset random (EvRa) and unidirectional fiber-reinforced PP composite (EvUnt) respectively. Moreover, 1.5 wt% Si69-treated enset fiber unidirectional reinforced PP composite reduced equilibrium water uptake percentage by approximately two folds, and thermal performance also improved by 12.9% from EvUnt composite. Notably, both silane treatment of enset fibers and composites increased elongation at break compared to EvUnt. Altogether, 1.5wt% Si69-treated enset fiber unidirectional reinforced polypropylene composite achieved a remarkable improvement of property and can be used for high mechanical and long-term performance applications.

本研究旨在探讨双[3-(三乙氧基硅基)丙基]四硫化物（bis[3(triethoxysilyl) propyl] tetrasulfide，Si69）与3-缩水甘油醚氧基丙基三甲氧基硅烷（3-Glycidoxypropyl trimethoxy silane，GPS）对单向埃塞俄比亚芭蕉纤维（enset fiber）增强聚丙烯（PP）复合材料性能的影响。为此，将埃塞俄比亚芭蕉纤维织制成纤维毡，分别采用1.5 wt%的Si69与5 wt%的GPS对其进行表面改性，随后通过薄膜叠层法结合模压成型工艺制备纤维增强聚丙烯复合材料。对所制备的复合材料，分别从拉伸性能、热稳定性能、吸水率、断口形貌以及傅里叶变换红外光谱（FTIR）等方面进行表征分析。在所制备的单向增强聚丙烯复合材料中，经1.5wt% Si69表面改性的埃塞俄比亚芭蕉纤维编织毡增强复合材料的拉伸性能最优，其拉伸强度相较于未处理的恩塞特无序纤维增强聚丙烯复合材料（EvRa）与未改性单向纤维增强聚丙烯复合材料（EvUnt）分别提升了267.1%与36.9%。此外，经1.5 wt% Si69改性的埃塞俄比亚芭蕉纤维单向增强聚丙烯复合材料的平衡吸水率较EvUnt复合材料降低了约一倍，热稳定性能也提升了12.9%。值得注意的是，对埃塞俄比亚芭蕉纤维及复合材料进行硅烷改性后，其断裂伸长率均高于未改性的EvUnt复合材料。综上，经1.5wt% Si69改性的埃塞俄比亚芭蕉纤维单向增强聚丙烯复合材料的综合性能得到显著提升，可应用于对力学性能与长期服役性能要求较高的场景。