High impact polystyrene (HIPS) nanocomposites with organically modified montmorillonite (organoclay) via in situ polymerization were synthesized, and the effects of organoclay incorporation on material properties were investigated. Organoclays having a reactive group, vinylbenzyltrimethyl clay (VBC) and octadecylvinylbenzyldimethyl clay (ODVC), were prepared by the ion-exchange reactions of sodium montmorillonite with vinylbenzyltrimethyl ammonium chloride (VBTMAC) and octadecylvinylbenzyldimethyl ammonium bromide (ODVBDAB), respectively, and a commercial organoclay, Cloisite® 10A (C10A), was used for comparison. It was confirmed that the X-ray diffraction (XRD) peak of the nanocomposites prepared by ODVC disappeared, which indicates the exfoliation of silicate layers. On the contrary, the XRD peak of the nanocomposites prepared by C10A shifted to lower angle, indicative of the intercalation of polymer chains into silicate layers. Rheological properties such as storage modulus and complex viscosity increased with increasing organoclay.

직접 중합법으로 내충격성 폴리스티렌(HIPS)과 유기화 점토로 구성된 나노복합재료를 합성하여 점토 첨가에 따른 물성을 조사하였다. 반응성 작용기를 갖는 유기화 점토인 vinylbenzyltrimethyl clay(VBC)와 octadecylvinylbenzyldimethyl clay(ODVC)를 sodium montmorillonite와 계면활성제인 vinylbenzyltrimethyl ammonium chloride(VBTMAC)와 octadecylvinylbenzyldimethyl ammonium bromide(ODVBDAB)의 이온교환으로 각각 제조하였고 상용화된 유기화 점토인 Cloisite® 10A(C10A)를 비교를 위해 사용하였다. ODVC로 제조한 나노복합재료의 경우 X-선 회절(XRD) 피크가 사라진 것으로 보아 실리케이트 층이 박리된 것을 알 수 있었고, C10A로 제조한 나노복합재료의 경우 XRD 피크의 각도가 작은 쪽으로 이동하는 것으로 보아 실리케이트 층에 고분자 사슬이 층간 삽입된 것을 알 수 있었다. 저장탄성률과 복소점도로 나타낸 유변물성은 유기화 점토의 함량이 증가할수록 증가하였다.

Keywords: high impact polystyrene; nanocomposites; organoclay; montmorillonite