In situ synchrotron small angle X-ray scattering investigation of structural formation of polyethylene upon micro-injection molding

摘要: Abstract A customized micro-injection molding apparatus with a pair of diamond windows in the filling cavity was specifically designed to simulate extreme processing conditions inherent practical micro-molding process. This setup combined synchrotron radiation allows real-time investigation multi-scale structural development during manufacturing process, which enables evaluation flow-induced crystallization features for range polymeric materials. In this study, evolution high density polyethylene at nanoscale investigated by situ small angle X-ray scattering technique under injection molding. The respective parameters kebab lamellae (including long period, and average thickness crystalline amorphous phase) shish formation (such as radius gyration, length, misorientation shish) were extensively analyzed from resulting data. growth crystals found exhibit two-step behavior: melting thin crystallites followed recrystallization process occur onset whereas an annealing-induced perfectioning is activated later stage. spite initial decrease length radius, there overall increase structure times, can be attributed partially oriented chains onto longitudinal surface existing shish. results acquired unique combination provide effective means predict modulate morphology final products polymers.