CRACK VELOCITY DEPENDENCE OF ELECTRON-EMISSION DURING FRACTURE OF FILLED ELASTOMERS

IN THIS ARTICLE THE AUTHORS EXAMINE THE ELECTRON EMISSION ACCOMPANYING THE FRACTURE OF FILLED ELASTOMERS, WHERE IN PREVIOUS WORK THEY HAVE SHOWN THE EMISSION TO BE INTENSE AND DUEPREDOMINATELY TO INTERFACIAL FAILURE. IN THIS STUDY THEY SHOW THAT THERE IS A STRONG VELOCITY DEPENDENCE ON THE RATE OFELECTRON EMISSION DURING THE PROPAGATION OF A CRACK IN FILLED SILICONE RUBBER AND POLYBUTADIENE FILLED WTIH GLASS BEADS. THIS DEPENDENCE CANNOT BE EXPLAINED BY A SIMPLE PROPORTIONALITY BETWEEN EMISSION RATE AND RATE OF SURFACE AREA PRODUCTION. THE AUTHORS PROPOSE THAT THE CONCENTRATION OF FREE RADICALS PRODUCED BY CRACK PROPAGATION INCREASES RAPIDLY WITH CRACK VELOCITY WHICH IN TURN PRODUCES MORE INTENSE ELECTRON EMISSION BY A CHEMIEMISSION MECHANISM.