對位聚苯乙烯與液晶聚酯之反應增容摻合研究

Abstract

在本研究中對位聚苯乙烯( Syndiotactic Polystyrene , sPS )和液晶高分子(Liquid Crystalline Polymer，LCP)利用押出機做熔融摻合，並以Styrene-Glycidyl Methacrylate copolymer(SG)作為sPS與LCP聚摻合系統的相容劑。我們期待在加入少量的主鏈型液晶高分子即能提升摻合物的機械強度，SG的加入可增加兩相間的相容性，並且觀察液晶高分子與相容劑對整個系統的影響。由SEM作形態學觀察，可以很明顯地看出SG可以有效地降低sPS/LCP摻合物間的界面張力，增加界面黏著力，使LCP分散相粒徑減小，也較為均勻，同時改善sPS與LCP間的相容性，然而過量的SG卻會阻礙液晶纖維形成，最後導致LCP形成小滴狀顆粒。因此，在本研究sPS/LCP增容摻合系統中機械性質並沒有達到要求的性能。

In this study, styrene-glycidyl methacrylate random copolymer (SG) is used to function as a reactive compatibilizer for the blends of liquid crystalline polymer (LCP) with syndiotactic polystyrene (sPS). The epoxy functional groups that present in the SG copolymer can react with the terminal groups of the LCP, carboxyl and hydroxyl, at interface to produce the desirable SG-g-LCP copolymer during melt processing. These in situ-formed copolymers tend to distribute along the interface, so as to reduce the interfacial tension in the melt and to enhance the interfacial adhesion in the solid state. SEM micrographs, perpendicular to the flow direction of inject-molded specimens, show that the domain size of the dispersed LCP particles has the tendency to reduce with the increase of SG content in the compatibilized sPS/LCP blends, an indication of improvement of compatibility between LCP and sPS. However, the amounts of SG in these compatibilized sPS/LCP blends are excess and result in the reduction of the number of in situ-created LCP fibrils, eventually leading to the formation of LCP droplet domain. Therefore, the mechanical properties of the sPS/LCP blends compatibilized by SG with the quantity employed in this study do not achieve a satisfactory performance.