EFFECT OF PHYSICAL AGING ON PHENOLPHTHALEIN POLYETHERSULFONE POLY(PHENYLENE SULFIDE) BLEND .1. MECHANICAL-PROPERTIES/

The effect of physical aging at 210 degrees C on the mechanical proper ties of phenolphthalein polyether sulfone (PES-C) and a PES-C/poly(phe nylene sulfide) (PPS) blend, with 5% content of PPS, were studied usin g DMA, tensile experiments, an instrumented impact tester, and SEM obs ervations. The blend shows good mechanical properties in comparison wi th the corresponding PES-C. The mechanical properties of both material s exhibit characteristics of physical aging, with only the aging rate of the blend relatively slower, which should be attributed to the cons traint effect of PPS particles and the good interfacial adhesion. The morphology of the PPS phase in the blend did not change with aging tim e. The principal role of PPS particles is to induce crazes, which diss ipate energy, under applied loading; thus, the blend shows good toughn ess. On the other hand, the multiple crazing mechanism depends on the molecular mobility or structural state of the matrix. (C) 1996 John Wi ley & Sons, Inc.