화학공학소재연구정보센터
Polymer Engineering and Science, Vol.59, No.7, 1371-1380, 2019
Effects of SCF content, injection speed, and CF content on the morphology and tensile properties of microcellular injection-molded CF/PP composites
Carbon fiber/polypropylene composite foams were prepared by microcellular injection molding using nitrogen as a foaming agent. The effects of nitrogen content, injection speed, and CF content on the morphology and tensile properties of the composite foams were investigated. A three-layer structure was formed in the microcellular foams: the skin layer was solid, the intermediate layer contained stretched cells parallel to the flow direction, and the core layer consisted of spherical cells. The average cell diameter of the machine direction decreased from 41 to 34 mu m as the nitrogen content increased from 0.5 to 1 wt%, increased from 34 to 43 mu m as the injection speed increased from 50 to 150 mm/s, and decreased from 34 to 25 mu m as the CF content increased from 10 to 30 wt%. Thus, the microcellular structure was improved by increasing the nitrogen and CF content and by decreasing the injection speed. Furthermore, when the CF content increased from 10 to 30 wt%, the Young's modulus of the solids and foams increased by 78% and 113%, respectively. Thus, the Young's modulus of the foams improved by 35% due to the improvement in the cellular structure. POLYM. ENG. SCI., 59:1371-1380 2019. (c) 2019 Society of Plastics Engineers