Study on the life expectancy of storage and ageing for rubber vulcanizates

Summary

In this paper the relationship of the ageing time to the tensile strength and the ultimate elongation of rubber vulcanizates was derived from the combination of ageing kinetics with the molecular theory of ultimate tensile strength of elastic networks, basing on the micro-structure model of rubber vulcanizates. According to this relation, a new simple method for determining the coefficients (α₄) of ageing time and the ageing rate constants (k ₄) of rubber vulcanizates from the data of the extension tests was proposed. The accelarated ageing experiments of Butadiene-acrylonitrile Rubber (BAR) vulcanizates were carried out at the range of temperature 70–110°C in a given period of 1–100 days, and the molecular parameters were determined by using this new method. It is shown that the experimental results are consistent to the theory.