【摘要】 研究选择了HDPE 5种不同粘均分子量样品,分子量范围从8.00×10~4到3.29×10~6.通过应力-应变曲线,缺口试件在拉伸状态下的缺口形状宏观变化观察及SEM观察,以及结晶度测量,研究了PE的拉伸行为,试验表明,NMW-PE(Normol MW-PE)和UHMW-PE不仅在宏观力学性能上存在巨大差异,而且在微观结构和形态上也存在显著的差别。结晶和缠结情况是决定宏观性能差异主要因素,屈服强度的变化主要由结晶度变化决定的,断裂强度的变化主要由缠结因素决定的。形貌上差异也和结晶缠结两个因素紧密相关。更多还原

【Abstract】 Five HDPE samples with different molecular weights from 8.00×10~4 to 3.29×10~6 arechosen. The tensile behaviors of PE are investigated by drawing stress-strain curve,observing the macro-change of notch under the tensile state, SEMobservation and measuring thecrystallinity of the HDPE samples. The experiments show that the NMW-PE and UHMW-PEhave the significant differences not only in macroscopic mechanical properties, but inmicroscopic structures and morphology as well. The macroscopic property differences aremainly determined by crystallinity and entanglement, i.e. the change of yield strength. is mainlydetermined by crystallinity. and the change of breaking strength is mainlydetermined byentanglement. The differences in morphology are also closely related to the crystallinity andentanglement.更多还原