Cm. Cheng et al., DEFORMATION OF RUBBER-TOUGHENED POLYCARBONATE - MACROSCALE ANALYSIS OF THE DAMAGE ZONE, Journal of applied polymer science, 52(2), 1994, pp. 177-193
Two commercial core-shell rubbers were used as impact modifiers for po
lycarbonate (PC). Specimens with a single semicircular edge notch were
stretched uniaxially in order to study the prefracture damage evoluti
on of blends under a triaxial tensile stress state. The irreversible d
eformation of modified PC included a cavitation mechanism in addition
to the three shear modes of unmodified PC. At the macroscopic level, t
he cavitation condition could be described by a mean stress concept. T
he corresponding critical volume strain for cavitation in PC blends wa
s determined to be independent of rubber content but differed for the
two impact modifiers. The critical volume strain for cavitation was us
ed as an index of cavitation resistance for the impact modifiers. The
effect of rubber content and temperature on Izod impact strength of th
e PC blends was also reported. From the relationship between the cavit
ation resistance and the Izod impact strength, it was proposed that im
pact modifiers with a higher cavitation resistance impart better tough
ness to blends with PC. (C) 1994 John Wiley & Sons, Inc.