Macroscopic volume changes of PVF2 undergoing uniaxial tension and creep

Uniaxial tension and creep tests were performed on apolar cristalline PVF2 at room temperature and above the high glassy transition temperature (T-g = 40 degrees C and T-g' = 60 degrees C), for different strain-rates (tension) or applied stresses (creep). Volume changes were simultaneously measured to study cavitation damage occuring in this polymer when strained. Damage mechanisms were explicated. Influence of experimental conditions such as strain-rate or temperature was studied: onset of cavitation is delayed and volume changes more pronounced when molecular motions in amorphous phase are hindered, for lower temperature or higher strain-rates. This work brings elements for a better comprehension of PVF2 global mechanical behaviour as damage is very linked to yield or creep studies. (C) 1999 Kluwer Academic Publishers.