Positron annihilation lifetime studies of free volume changes in polycarbonate under static tensile deformation

Autor: Robert Simha, A. M. Jamieson, M. Y. Ruan, H. Moaddel, J. D. McGervey
Rok vydání: 1992
Předmět:
Zdroj: Macromolecules. 25:2407-2411
ISSN: 1520-5835
0024-9297
DOI: 10.1021/ma00035a018
Popis: It is found that, for well aged bisphenol A polycarbonate (PC), the fractional free volume h increases with strain up to a level of 4%, after which no further change in h occurs. This behaviour is consistent with literature observations of strain-enhanced rejuvenation of the mechanical properties of polycarbonate. Upon long-term room-temperature annealing of a PC specimen held at 3% strain, it is found that h gradually decreases to levels below the initial value, suggesting a strain-induced reactivation of physical ageing, and hence a closer approach to the equilibrium density
Databáze: OpenAIRE