利用物理性官能化無官能性高分子聚掺合物進行反應型增容押出之研究

Abstract

利用高分子聚掺製造符合特殊應用需求的新材料是最經濟且迅速的方法。然而大部份的高分子對皆不相容，如果沒有適當的增容則無法得到具備實用價值的高分子聚掺合物。在塑膠工業上最常使用反應型增容的方式來增加不相容高分子對的相容性。但由於大部份的高分子並不含合適的官能基，需要特別的改質後方能進行反應型增容。在本研究中我們提出一種簡便的物理性官能化的方式來改質無官能性高分子，以取代傳統利用化學方式改質無官能性高分子的複雜製程。 所謂的物理性官能化改質無官能性高分子是將特定商品化具有官能性的高分子加入無官能性高分子中以達到賦予官能化的目的。使用此種方式的前提是此特定商品化官能性高分子必須與欲改質的無官能性高分子有良好的相容性。除此之外，如果官能基之間無法反應，尚需另外加入一個能與彼此官能基同時反應的偶合劑。我們成功的利用此種方式增容不相容的PP/PS，Nylon/PPE及PP/mPPO合膠。PP及PS可以利用加入PP-g-MA及SMA共聚物達到物理性官能化改質的目標。另一方面，高分子量PPE及mPPO只具有非常低的反應性﹔但是小分子量PPE具有較其含量高約五倍的phenolic OH末端基。因此藉由小分子量PPE的加入可以有效提高它們的反應性。上述的高分子合膠可以在將各組成物混合後以押出機進行製備。相對於未增容之高分子合膠，使用此方式增容的高分子合膠具備較佳的機械性質、較小的分散相尺寸及較高的熱變形溫度。

Polymer blends have attracted great attentions both industrially and academically because of their flexibility and versatility to create new materials with desired properties from existing polymers. Since most of the interesting polymer blends are immiscible, different compatibilization approaches have been proposed. In the plastics industry, reactive compatibilization is widely adopted to compatibilize immiscible polymer blends. Unfortunately, most of the polymers do not contain suitable functional groups for reactive compatibilization. In this study, we aim to provide a relatively simple method to physically functionalize the non functional polymers for reactive blending, instead of the conventional chemically functionalization methods. Reactive compatibilization of immiscible polymer pairs, containing no suitable functional groups, can be achieved by physically imparting functionality to the constituent polymers with the addition of commercially available functional polymers, which is miscible with each of the constituent polymers, respectively. In addition, a multifunctional reactive coupler able to simultaneously react with both of the functional groups of the physically functionalized constituent polymers is required, if the two functional groups do not mutually react under the processing conditions. The strategy has been proven to be successful in reactive compatibilization of the immiscible PP/PS, Nylon/PPE and PP/mPPO blends. PP and PS can be physically functionalized by addition of PP-g-MA and SMA copolymers, respectively. On the other hand, PPE and mPPO has very limited functionality, but with the addition of a low molecular weight PPE, possessing 5 times higher phenolic OH contents than high molecular weight PPE, the functionality is significantly increased. The reactive compatibilization of the above physically functionalized polymer pairs can be carried out in an extruder, with the addition of a multifunctional epoxy coupler. The resulting PP/PS, Nylon/PPE and PP/mPPO show finer domain size, better mechanical properties and higher HDT, compared to the uncompatibilized ones.