Melt-blended polysulfone (PSF) and poly(phenylene sulfide) (PPS) are n
otch sensitive. A significant improvement in the notched Izod impact t
oughness occurs when at least 10 wt% of a shell-core rubber modifier i
s incorporated into the blend. At rubber modifier levels above 15 wt%,
the notched Izod impact strength was essentially retained upon anneal
ing at 160-degrees-C for 2 h, while below 15 wt% of rubber modifier, t
he notched Izod impact strength decreases after annealing under the sa
me conditions. Izod impact fracture surface morphology was studied usi
ng scanning electron microscopy (SEM). Fracture surfaces without a rub
ber modifier exhibit cavitation around the dispersed phase, i.e. PPS.
On the other hand, fracture surface morphology of the rubber toughened
blends with the same PSF/PPS composition show no cavitation surroundi
ng the dispersed phase. Blend morphology was also studied using transm
ission electron microscopy (TEM).