低密度聚乙烯與聚丙烯奈米複合材料微細發泡射出成型機械/熱性質之探討

本研究將探討嫁接馬來酸酐（MA）之低密度聚乙烯（LDPEgMA）、聚丙烯（PPgMA）以蒙脫土（MMT）複合材料母粒以及利拿機混鍊進行製備成LDPEgMA/MMT、PPgMA/MMT以及PPgMA/DCP/MMT奈米複合材料，進而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，並在製程參數穩定下，藉由改變奈米黏土的含量（0~9wt%）進而對機械性質（拉伸、衝擊）、熱性質（DSC、TGA）、氣泡微結構特性（SEM）、奈米結構特性（XRD）、結晶性質（TEM）以及流變性質之測試。結果指出，機械性質方面，LDPEgMA/MMT、PPgMA/MMT以及PPgMA/DCP/MMT奈米複合材料會隨著奈米黏土含量增加而提高拉伸強度的趨勢。發泡結構特性方面，以PPgMA/MMT奈米複合材料擁有較佳的氣泡尺寸與氣泡密度。熱性質方面顯示出，三種製備方式下皆能在熔點（Tm）和裂解溫度（Td）都有增加的趨勢，證明添加奈米黏土有助於Tm點和Td點的提升。在奈米結構特性方面，XRD顯示出以PPgMA/MMT奈米複合材料較能撐開其層間距離，皆可轉變為插層型奈米複合材料，而在TEM也證實奈米黏土的分散型態，結果可與XRD相符。在流變性質方面，黏度係數是會隨著奈米黏土含量增加而提升，而MA可使PP降低其黏度係數增加其流動性，LDPE反而會增加其黏度係數。

關鍵字

聚烯烴；奈米複合材料；超臨界流體微細發泡射出成型；流變

並列摘要

Maleated LDPE and PP were compounded in a twin-screw extruder in different montmorillonite (MMT) loadings. The LDPEgMA and PPgMA nanocomposites were then molded by conventional and microcellular injection molding process. The effect of MMT contents on the mechanical, thermal, rheological and foaming properties was investigated. The results showed that LDPEgMA and PPgMA nanocomposites (up to 9 wt. % MMT loading) have better tensile strength than their neat counterpart both on conventional and microcellular injection molding process. In addition to the mechanical properties, the Polyolfins nanocomposites also have better foaming property (i.e., cell size and cell density) than their neat counterpart. The addition of MMT also improved the thermal stability of the Polyolfins material. XRD results showed that as MMT loading is increased, so is the D-spacing of the Polyolfins nanocomposites. The addition of MMT increases the viscosity of the nanocomposites. However, the viscosity of maleated LDPE is lower than that of the neat LDPE. Shear shinning effect is observed at high shear rate both on the LDPEgMA and PPgMA nanocomposites.