- 學位論文
超臨界流體微細發泡射出成型對聚烯烴彈性體蒙脫土奈米複合材料機械與熱性質之研究
Effect of Organoclay and Preparation Method on the Mechanical/Thermal Properties of Microcellular Injection Molded TPO-Clay Nanocomposites
摘要
本研究主要是探討聚烯烴彈性體(TPO)/蒙脫土奈米複合材料以兩種不同製備方式(利拿機與雙螺桿押出機)進行混鍊，之後再利用傳統射出成型與超臨界流體微細發泡射出成型製成符合美國材料與試驗協會(ASTM)的標準式片。在實驗的過程中，將使用氮氣(N2)作為發泡劑，並在製程參數保持恆定下，觀測改變蒙脫土的添加含量(0 wt% ~ 9 wt%)對高分子奈米複合材料之機械性質(拉伸、衝擊、耐磨耗)、熱性質(DSC、TGA)、發泡微結構特性(SEM)與奈米結構特性(XRD、TEM)之影響性。結果顯示，在傳統射出方面，兩種製備方式在機械性能(拉伸與衝擊)方面皆非常相近，都會隨著蒙脫土含量的增加而上升之趨勢；而在耐磨耗性能的部份，則以雙螺桿押出機製備的奈米複合材料擁有較好的耐磨性，相信這應該是雙螺桿在混鍊時產生的高剪切力造成加工硬化效應所引起的。在發泡特性方面，以利拿機混鍊方式，具有較好的氣泡尺寸與氣泡密度分佈，故其衝擊性能優於雙螺桿押出機所混鍊的複合材料。在熱性質方面，證明添加適量的蒙脫土的確能有效的提高基材之熔融溫度(Tm)與熱裂解溫度(Td)，使其整體的熱穩定性有所提升。在XRD測試方面，則顯示聚烯烴彈性體(TPO)/蒙脫土奈米複合材料是屬於插層型奈米複合材料。而在TEM測試方面，則可驗證蒙脫土的分散型態，並與XRD試驗做個完美的比對。
並列摘要
Thermoplastic olefin elastomers (TPO)/MMT nanocomposites prepared by kneader and melt compounding methods were used in this study. The organoclay TPO nanocomposites were then injection molded by conventional and microcellular methods. Nitrogen was used as the blowing agent. The effect of organoclay content and preparation methods on the mechanical/thermal properties was investigated. The results showed that the mechanical properties increased as the clay content increased both for kneader and melt compounding process. The foaming by kneader had better cell density than that of melt compounding and cell size decreased as the clay loading increased. The addition of MMT also improved the thermal stability of the TPO/clay nanocomposites. The XRD results showed that the nanocomposites having intercalated layered structure..