Effect of a small variation in percentage of sulfur on rubber vulcanization: temperature profiles, state of cure

Small variations in sulfur as a vulcanizing agent have been proved to have a significant effect on rubber vulcanization. This problem has important consequences in the industry, because it is difficult to keep a constant value of % sulfur in the small samples taken from a larger amount of blended rubber, owing to the un-ideal distribution of sulfur throughout the mass. The effect of 0.2 and 0.4 variation in % sulfur around the average value of 2 % on the temperature profile developed through 2 cm thick rubber sheets was studied, as well as the profile of the extent of the cure. The time taken for the extent of cure to reach selected values was calculated at different points in the sheet for all cases, and was correlated with the variation in temperature at the sheet midplane