FORMATION OF MICROPOROUS STRUCTURE UPON D RAWING POLY(ETHYLENE-TEREPHTHALATE) IN WATER

Drawing of PET in water was found to produce crazed materials with a w ell-developed microporous structure. Preliminary swelling PET was show n to increase critical rate, above which drawing of amorphous samples in water was accompanied by necking. Upon drawing of semicrystalline P ET in water, crazing was observed at all strain rates used (0.0025 - 2 .5 min-1). The development of crazes was related to local plasticizati on of the stressed polymer with water. The substitution of water with dilute solutions of long-chain surfactants was shown to increase a cri tical strain, above which crazes experience collapse, from 50 - 70 to 150 - 200%.