聚對苯二甲酸乙酯與聚苯乙烯反應增容聚摻之研究

Abstract

因為 SMA 在 PET/PS 摻合物中對其機械性質及相界面黏著性的改善無法達到預期的效果，所以一種多官能基的環氧樹脂與 PPI 分別被選擇在 PET/PS/SMA 的聚摻系統中作為微量的反應型偶合劑，成為一個四組成的聚摻系統。經由形態學、流變測試、熱性質測試及機械性質測試的結果發現環氧樹脂與 PPI 均對原本的 PET/PS/SMA 系統有類似補強的作用而提高其物理機械性質，但是這兩種偶合劑所造成的結果仍有某種程度上的不同。在以環氧樹脂作為偶合劑的系統中，其抗張性、抗折性和耐衝擊性均隨著環氧樹脂含量的增加而上升，然而在有 PPI 存在的系統中，在高含量下這些性質的提升似乎被限制住。這個現象可由環氧基與異氰酸酯基不同的反應行為來解釋，環氧基在摻合物中能反應生成強的共價鍵結而改善相容性，但對 PPI 而言在高溫下因為異氰酸酯基與羥基的逆反應及自我環化反應的發生，使得 PPI 作為相容劑的改善效果減弱。

Since the improvement of mechanical properties and interfacial adhesionbased on the addition of styrene maleic anhydride random copolymer (SMA)was not as good as expected in the blends of PET/PS, a multi-functionalepoxy resin and polymethylene polyphenyl isocyanate (PPI) were selectedrespectively as a trace reactive coupler in the polyblends of PET/PS/SMAto be a four-component blending system. The morphologies, rheologies,thermal, and mechanical properties were investigated, and it was disco-vered that both of these two couplers enhanced the physicomechanical properties as reinforcing effect compared with the non-coupled compo-sitions. But the results caused by the epoxy resin and PPI were differentin some degree. Tensile, flexural, and impact properties increased ob-viously with increasing the contents of epoxy resin, whereas the raisingof these properties seemed to be limited with the prsence of high PPIcontained. This phenomenon can be explained in terms of the different reaction behavior between epoxide and isocyanate groups. A strong bond-ing was created by the epoxide group to increase the compatibility in the blends, but the inversion reaction between isocyanate and hydroxyl groups and the self-cycling reaction of PPI occurred at high temperatureso that the promoting effects of PPI were reduced.