本實驗主要探討的是有無接枝馬來酸酐(MA)之乙烯-醋酸乙烯酯(EVA、EVAgMA)以微米級絹雲母製備成絹雲母/乙烯-醋酸乙烯酯複合材料,利用傳統射出成型與超臨界流體微細發泡射出成型製作ASTM 之拉伸和衝擊標準試片,藉由改變雲母(Mica)的含量(0、1、3、5、7、9、12、15wt%)探討對機械性質、熱性質、氣泡結構以及流變性質之影響。結果顯示,EVA/Mica與EVAgMA/Mica傳統和發泡試片之抗拉強度皆隨著Mica比例增加呈現上升的趨勢。而EVAgMA/Mica在15wt%過多的雲母含量導致團聚現象而造成抗拉強度的下降,此現象可與TEM的微結構可互相印證。XRD方面藉由觀察半高寬的特性,可發現EVAgMA/Mica的結晶強度比EVA/Mica還強。DSC方面,證實添加雲母會降低材料的結晶。TGA方面,證實添加雲母可提高材料的熱裂解溫度。流變性質方面EVAgMA/Mica的平均黏度都比EVA/Mica還高,而DMA方面也證實了EVAgMA有較大的黏彈性係數。在發泡方面EVAgMA/Mica的發泡尺寸比EVA/Mica還要小,而且密度也較高。證明EVA架接馬來酸酐(MA)作為雲母填充料是良好介面相溶劑。
In this study, with and without maleic anhydride(MA) grafted ethylene vinyl acetate (EVA) of different mica contents of EVA/mica composites were prepared. The EVA/mica and EVAgMA/mica composites were then molded by conventional and microcellular injection molding process. The effects of mica loading on the mechanical, thermal, foaming and rheological properties were investigated. The results showed that EVAgMA/mica composites have better tensile strength than that of EVA/mica composites. The addition of mica (up to some certain loadings) also increased the tensile strength of the composites, but decreased the impact strength of EVA/mica and EVAgMA/mica composites. TGA results showed with the addition of mica increased the degradation of EVA/mica and EVAgMA/mica composites. The MA grafted EVA helped the composites to develop smaller cells than that of EVA/mica composites on the foaming process. Rheological results showed an increase in the viscosity with the addition of mica. The viscosity increase for the EVAgMA/mica composites was greater than that of EVA/MA composites.