Vulcanization kinetics of low‐protein natural rubber with use of a vulcameter

Abstract

Abstract Kinetics of vulcanization of low‐protein natural rubber (LPNR) was studied with the use of a vulcameter. In the induction period of vulcanization, the time t 0 of LPNR is longer than that of natural rubber (NR), and the temperature dependences of the time t dis and the rate constant $ k^{1/\alpha}_1 $ of LPNR are greater than that of NR. Both the curing periods of LPNR and NR (except 170°C for LPNR) consist of two stages. The first stage follows first‐order reaction. The rate constant k 2 of LPNR in the first stage is substantially the same as that of NR at the same temperature, and so is the activation energy E 2 . The second stage (end stage of the curing period) does not follow first‐order reaction, and the calculated reaction order n is in the range of 0.67–0.73. Both rate constants of LPNR (except 170°C) and NR at the same temperature are approximately the same, and so is the activation energy E 3. The whole process of curing period for LPNR at 170°C follows n = 0.7 order reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007