本研究係採用改質紅麻植物纖維添加入聚乳酸基材中,另外再添加多壁奈米碳管熔融混摻後,對複合材料整體性能的探討與研究。其中纖維先經兩種不同矽烷偶合劑(3‐glycidoxypropyltrimethoxysilane, 代號OX)與(vinyltriethoxy silane, 代號Vi)改質,結果顯示以OX改質之效果較佳,在添加30wt%之OX改質紅麻纖維與1wt%奈米碳管時,複合材料之拉伸強度最佳,提升了84%;而添加40wt%改質紅麻纖與1wt%奈米碳管時,複合材料之耐衝擊強度最佳,提升了156%,熱變形溫度也提升122%。從XRPD、DSC分析與等溫結晶動力學之探討得知,紅麻纖維與奈米碳管的添加能改變聚乳酸的結晶型態與增快其結晶速率。SEM分析可以觀察到經由偶合劑改質可使紅麻纖維與聚乳酸間相容性提升。電性質分析中,含30wt% OX改質紅麻纖維與1wt%奈米碳管之複合材料,其表面電阻為3.47x109 Ω,可達到抗靜電等級。結果顯示,聚乳酸添加改質紅麻植物纖維與多壁奈米碳管,能增進聚乳酸之熱性質、機械性質、電性質,使複合材料應用範圍更廣泛,並對環境較為友善。
In this study, the chemically modified kenaf fibers (KF), and an acid-treated multi-walled carbon nanotubes (MWCNTs) were added into polylactic acid (PLA) matrix. Moreover, the fibers were pre‐treated by two kinds of coupling agent (3-glycidoxypropyltr-imethoxysilane, code: OX, and vinyltriethoxy silane, code: Vi). The results showed that the reinforcing effects of OX modified fibers were better than those of Vi modified ones. The tensile strength of PLA was increased about 84% when 30wt% of OX modified KF and 1wt% of MWCNTs were added. The impact strength and heat deflection temperature were increased about 156 and 122%, respectively, when the composite reinforced with 40wt% of OX modified KF and 1wt% of MWCNTs. The analysis of XRPD, DSC and isothermal crystallization kinetics showed that the crystalline behavior of PLA can be changed and accelerated with the addition of modified KF and MWCNT. SEM analysis showed that the compatibility between PLA and KF was improved after coupling agent modification. The results of electrical properties test showed that the surface resistivity of the composite containing 30wt% of OX modified KF and 1wt% of MWCNTs was 3.47x109 Ω, which can reach the anti-static purpose. These results show that the thermal, mechanical and electrical properties of PLA can be improved by the addition of modified KF and MWCNTs. Moreover, this type of reinforced PLA would be more environmental friendly than the artificial additive-reinforced one.