J. Phys. IV France
Volume 03, Numéro C4, Septembre 19934th International Workshop on Positron and Positronium Chemistry
|Page(s)||C4-275 - C4-278|
J. Phys. IV France 03 (1993) C4-275-C4-278
Investigation of polymer deformation by positron annihilationS.J. WANG, C.L. WANG and B. WANG
Department of Physics, Wuhan University, Wuhan 430072, China
Positron lifetimes in polytetrafluroethylene (PTFE) and polyethylene (PE) have been measured as a function of residual deformation [MATH]. For PTFE, the variation of o-Ps intensity shows a three-stage processes : the elastic region ([MATH]), plastic-f low region ([MATH]) and strain-strengthening region ([MATH]). The changes of free-volume hole size and concentration suggest the separation, scission and orientation of segments. For PE, the o-Ps parameters are sensitive to the elastic and plastic regions. Particularly, the hole concentration decreases linearly with [MATH], which indicates the crystallization during deformation.
© EDP Sciences 1993