A Comparison Study of Liquid Natural Rubber (LNR) and Liquid Epoxidized Natural Rubber (LENR) as the Toughening Agent for Epoxy

Abstract

Rubber-toughened epoxy resins were prepared using the mechanical stirring method and mo lded into samp les by compression mold ing. The aim of this study is to modify the brittleness of the epoxy matrix by adding discrete rubbery phases to improve the toughness properties. Liquid natural rubber (LNR) and liquid epo xidized natural rubber (LENR) were used as toughening agents in the epoxy resin to co mpare the properties of the modified networks. The mechanical and thermal properties have been studied to observe the effect of the modified epoxy network. It was found that by adding the rubbery phase into epoxy resin, the toughness of the epoxy was imp roved. A composite with 3 wt% of LENR possessed the highest mechanical properties for both flexural and impact properties. The scanning electron micrograph (SEM ) demonstrated the discrete rubbery phases between the epoxy and the rubber particles. The g lass transition temperature shifted to a lower temperature in the dynamic mechanical analysis (DMA) for the rubber-toughened epoxy.