DYNAMIC MECHANICAL PROPERTIES AND FRACTURESURFACE MORPHOLOGIES OF CORE-SHELL RUBBER (CSR)TOUGHENED EPOXY AT LIQUID NITROGEN (LN2)TEMPERATURES

摘要

The dynamic mechanical properties and fracture surface morphologies were evaluated for arncommercial epoxy resin toughened with two types of core-shell rubber (CSR) toughening agentsrn(Kane Ace~? MX130 and MX960). The impact resistance (R) was evaluated by the resultingrnbreaking energy measured in Charpy impact tests conducted on an instrumented drop tower. Thernresulting fracture surface morphologies were examined using Scanning Electron Microscopyrn(SEM). Fractographic observations of the CSR toughened epoxy tested at ambient temperature,rnshowed a fracture as characterized by slender dendrite textures with large voids. The increasingrnnumber of dendrites and decreasing size of scale-like texture with more CSR particlesrncorresponded with increased R. As the temperature decreased to Liquid Nitrogen (LN_2), thernfracture surfaces showed a fracture characterized by a rough, torn texture containing many riverrnmarkings and deep furrows.