聚氯乙烯押出結構發泡之研究

Abstract

自 1980 年起，塑膠結構發泡產品開始成為一種新的趨勢，它不但較為經 濟、質輕、提供適當的機械性質以及理想的表面品質之外更符合環保的要 求。如今，結構發泡產品已經成為取代木質材料的主要建材。在以往的研 究中， 我們致力於 ABS 之押出結構發泡產品加工的研究，但是對一般的 用途而言，ABS 這種材質的價格太高而不易被接受， 因此我們用以往 ABS 的研究基礎轉而研究成本較低且較為普遍使用的 PVC 押出結構發泡 產品之製程。本研究藉由變更不同的材料配方如：改變發泡劑的濃度、不 同的加工助劑與濃度、 不同的成核劑與濃度、 及不同的耐衝擊改質劑 （ ABS、CPE、MBS 橡膠）與濃度，並改變模頭溫度來探討對發泡產品的 整體密度、耐衝擊強度、發泡結構及韌性╱脆性轉變溫度（ DBTT ）之影 響，以使產品達到最佳化的目的。實驗結果顯示，對高發泡比例產品而言 ，較高發泡劑濃度、較高的模頭溫度，相對形成皮層較薄、較大氣泡尺寸 、較低整體密度及較低耐衝擊強度的成品；對較低發泡比例產品而言，較 高的發泡劑濃度、較高的模頭溫度及較低的耐衝擊改質劑濃度，可以形成 較低整體密度及較低耐衝擊強度的成品。對加工助劑而言，增加加工助計 分子量及濃度均能使高和低發泡產品的整體密度下降而耐衝擊強度上升。 本研究經由調整配方及加工條件， 已經加工出密度約達 0.5 左右且收縮 現象得以消除之產品，以達到取代木材的目的。 Since 1980, applying sturctural foam products to commerical uses has become a trend as these products not only possess proper mechanical properties and desirable surface quality, they are also economical, light weight and environmentally friendly. Presently, structural foam products have replace natural wood as the major constructuction materials. Previous investigations focused on the studies on the processing of extruded structural foam with acrylonitrile-butadiene-styrene terpolymer(ABS) as the processing material. But for general purposes, the cost of ABS is too high to be accepted for popular uses. therefore, this study aimed at investigating the structural foam extrusion using a cheaper and more widely used material-polyvinylchloride( PVC), based on the previous sudies on ABS structrual foam. In this study, the effect of varying die temperature and material formulation(such as using different concentrations and kinds of processing aids, nucleation agents and impact modifiers, including terpolymer of methylacrylate-butadiene-styrene, chlorinated polyethylene, and ABS) on the bu;k density, impact strength, foam structrue and ductile-brittle transition temperature(DBTT) of the foam product was studied to optimize the product quality.