A Study on Processing-Structure-Property Relationships of Extruded Carbon Nanomaterial-Polypropylene Composite Films

Abstract

??? ??????????????? ????????????????????? ????????? ????????????????????? ???????????? ????????? ???????????? ???????????? ??? ??????????????? ?????? ????????? ????????? ??????????????? ?????? ????????? ???????????????. ????????????????????? ????????????????????? ???????????? ??????????????? ?????? ??????????????? ?????????????????? ??????(<700 ??m)??? ????????????????????? ????????? ??? ??????????????? ?????? ????????? ?????? ???????????? ???????????????. ??????????????? ????????? ??????????????? ???????????? ?????? differential scanning calorimetry??? ???????????????. ????????? ????????? ??????????????? ????????? ????????? ??? ?????? ?????????????????? ????????? ???????????????, ?????? ??? ?????? ??????????????? ?????? ??????????????? ??????????????? ????????? ???????????????. ????????????????????? ?????????????????? ????????? ????????? ????????? ????????? ???????????? ???????????????, ?????? ?????? ???????????? ?????? ???????????? ?????? ???????????????. ??????, ??????????????? ?????? ????????? ???????????? ??????????????? ?????? ?????????????????? ??????????????? ????????? ???????????? ???????????????. Polypropylene films reinforced with multi-walled carbon nanotubes and exfoliated graphite nanoplatelets were fabricated by extrusion, and the effects of filler type and take-up speed on the mechanical properties and microstructure of composite films were investigated. Differential scanning calorimetry revealed that the addition of carbon nanomaterials resulted in increased degree of crystallinity. However, increasing the take-up speed reduced the degree of crystallinity, which indicates that tension-induced orientations of polymer chains and carbon nanomaterials and the loss of degree of crystallinity due to rapid cooling at high take-up speeds act as competing mechanisms. These observations were in good agreement with tensile properties, which are governed by the degree of crystallinity, where the C-grade exfoliated graphite nanoplatelet with a surface area of $750m^2/g$ showed the greatest reinforcing effect among all types of carbon nanomaterials used. Scanning electron microscopy was employed to observe the carbon nanomaterial dispersion and orientation, respectively.clos