Rubber/silane reactions and grafting rates investigated by liquid-state NMR spectroscopy

Abstract Interactions between butadiene rubber (BR) and polysulfide silane (TESPT) were studied by liquid state NMR spectroscopy. 1 H, 13 C and DOSY spectra highlighted the presence of pre-crosslinking and grafting reactions in BR/TESPT blends mixed with dump temperatures between 155 and 180 °C. Pre-crosslinking induced by the sulfur release of TESPT was evidenced at high temperature. The grafting rate of silane on BR chains was quantified thanks to deconvolution of 1 H NMR signals of crude blends and 1 H spectra analysis of blends after extraction of non-grafted silane. These two methods showed similar values of grafting rates and demonstrated the influence of the dump temperature on BR/silane reactions.

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