In-situ SAXS study and modeling of the cavitation/crystal-shear competition in semi-crystalline polymers: Influence of temperature and microstructure in polyethylene

摘要: Abstract This study focuses on the first occurrence of either cavitation or crystal shear in relation to temperature and microstructure during tensile drawing polyethylene. Four high density polyethylenes covering a range crystallinity have been thermally treated generate different microstructures displaying large thickness from 8 29 nm. The testing spanned domain 25–100 °C. In-situ SAXS measurements synchrotron performed capture initiation parallel with stress-strain measurements. Depending strain onset proved be before after yielding associated homogeneous localized regimes respectively. transition between two can defined by critical value lamella at each temperature. A physical modeling based activated nucleation process has developed for predicting macroscopic stress generation cavities as well one initiating shearing. accounts both effects yielding. It allows describing successfully delayed apparition increasing decreasing thickness. observation complete disappearance is also predicted model more relevant aspects shortcomings are discussed conclusion.