PP/PE熔体流动速率比与共混体系力学性能的关系

CORRELATION BETWEEN THE MECHANICAL PROPERTIES AND THE MELTING FLOW RATE RATIO OF PP/PE BLENDS

选择不同熔体流动速率(MFR)的乙-丙共聚型聚丙烯(PP)和聚乙烯(PE),分别配混出一系列不同熔体流动速率比(R_M=MFR_(PP)/MFR_(PE))的共混体系。深入探讨了共聚PP/PE共混体系的力学性能与PP和PE间R_M的关系。结果表明,在适宜的R_M范围內,PE能对乙-丙共聚型PP具有良好增韧增强效果。在0<R_M<25范围内,共混体系表现出脆-韧转变特征。大多数共混体系在5.0<R_M<15范围內的拉伸屈服强度、冲击强度、断裂伸长率和弯曲强度均有明显提高,体系综合力学性能最优。R_M>25后,体系性能劣化。

A series of PP ( propylene - ethylene copolymer) /PE ( high density polyethylene) blends with different melting flow rate ratio (RM=MFRpp/MFRPE ) were obtained by matching PP and PE with different melting flow rates (MFR). The correlations between the mechanical properties and the RM of PP/PE were investigated. It showed that within some range of RM, PP could be remarkably toughened and strengthened by PE. For 0 < RM< 25, the resulting blends exhibited the behavior of ductile-brittle transition. The tensile strength, the bending strength, the elongation at break and the notched impact strength of the most blends were all improved significantly when 5.0 <RM< 15, and the blends had the optimum combined property. At high RM values (RM>25) , the performance deteriorated.