【摘要】 利用凝胶渗透色谱(GPC)、差示扫描量热法(DSC)、J积分法和动态力学分析(DMA)等研究了聚乙烯管材专用料的分子量分布和共聚单体对其结晶行为、断裂韧性和耐蠕变性能的影响。结果表明,相对于单峰分子量分布的共聚聚乙烯而言,双峰分子量分布的均聚聚乙烯结晶度从54.5%增加到60.9%,断裂韧性从5.85 kJ/m2提高到6.67 kJ/m2。此外,拉伸性能和耐蠕变性能也得到提高。更多还原

【Abstract】 The effects of molecular weight distribution(MWD) and co-monomer on crystal behavior,fracture toughness and creep resistance properties of polyethylene(PE) pipe extrusion special material were studied through gel permeation chromatography(GPC),differential scanning calorimetry(DSC),J-integration method and dynamic machanical analysis(DMA).The experimental results show that compared to PE copolymer with unimodal MWD,the crystallinity of PE homopolymer with bimodal MWD is increased from 54.5% to 60.9%,and the JIC value is improved from 5.85 kJ/m2 to 6.67 kJ/m2,which means that fracture toughness is enhanced.The melting temperature of PE homopolymer is higher than that of PE copolymer.Furthermore,tensile properties and creep resistance performance are also improved.更多还原