Preparation and Properties of Low Density Polyethylene/Organo-clay Nanocomposite

In this study, low density polyethylene/organo-clay nanocomposites were prepared by melt blending. Thermal property, structure, and morphology of the LDPE/organo-clay nanocomposites were investigated. When the composition ratios of the compounds of LDPE/PE-g-MA/organo-clay were 90/10/1~10 (w/w/w), X-ray diffractograms of LDPE/organo-clay nanocomposites revealed that the intercalation of polymer chains lead to increase the spacing between clay layers. TEM microphotographs showed that LDPE was intercalated into organo-clay. TGA performed under air atmosphere demonstrated a great increase in thermal stability of the LDPE/organo-clay nanocomposties. The maximum decomposition temperature of LDPE/organo-clay nanocomposite was increased about $80^{\circ}C$ compared with pure LDPE. When the organo-clay contents were 1.0~5.0 wt%, the LOI values were increased with increasing the organo-clay content, but in the case of the contents more than 5.0 wt%, the LOI values were not increased any more.

저밀도 폴리에틸렌 나노복합재료의 제조 및 특성

본 연구에서는 용융법에 의한 저밀도폴리에틸렌 나노복합재료를 제조하였으며, 구조변화, organo-clay의 분산정도, 열적 특성 및 난연 특성을 조사하였다. LDPE/PE-g-MA/organo-clay의 조성비가 90/10/1~10 (w/w/w)일 때, XRD 분석 결과 clay 층간간격이 증가함을 알 수 있었으며, TEM을 이용하여 organo-clay의 분산을 관찰하였는데, 대체적으로 organo-clay가 일정한 방향성을 가지며 잘 분산되어 있음을, 즉 삽입형(intercalation) 나노복합체가 형성되었음을 확인할 수 있었다. 또한 LDPE 나노복합재료의 분해온도가 순수한 LDPE에 비해 약 $80^{\circ}C$ 정도 상승함으로써 열적특성이 현저히 증가함을 알 수 있었고, organo-clay 5.0 wt% 범위 내에서 organo-clay의 함량이 증가함에 따라 LOI가 증가함을, 그 이상에서는 더 이상의 LOI 증가를 보이지 않음을 알 수 있었다.