Epoxidized natural rubber: Exploring the potential of an old elastomer

A study was carried out to evaluate the efficiency of dodecyl succinic anhydride as a curing agent for a commercial grade of natural rubber that had been epoxidized to approximately 50 %mol (ENR50). It was shown that the maximum achievable gel content for this system is about 87 - 88 %wt due to the presence of non-functionalized species. The incorporation of unmodified natural rubber in the mix reduced the gel content in direct correlation with the dilution of the epoxidized component. Mixing the system, even under "mild" thermal conditions induces rapid gelation due to the high functionality of ENR50. The catalytic effect of N,N-Dimethylbenzylamine was confirmed by both thermal analysis and the curometer evaluations. A quantitative analysis of the latter data has shown that mixing under severe conditions can lead to an increase in reactivity in the subsequent curing step. © 2014 AIP Publishing LLC.