Influence of carbon black/silica ratio on the physical and mechanical properties of composites based on epoxidized natural rubber

The aim of the present paper is to investigate how carbon black/silica ratio influences the curing characteristics, mechanical and dynamic properties of composites based on epoxidized natural rubber (Epoxyprene 25). The data obtained show that the composites, containing carbon black and silica at a 30:40, 20:50, and 10:60 ratio have the best complex of parameters (cure characteristics, mechanical and dynamic properties). That is probably due to the intermingling of carbon black and silica particles what leads to the formation of hydrogen bonds between the silanol groups of silica particles. As a result, silica particles aggregate less and the filler disperses better in the rubber matrix. On the other hand, the presence of a silane coupling agent and the polar character of epoxidized natural rubber predetermine the stronger polymer-filler interaction.