On the Relation between Creep and Rupture of Unplasticized Polyvinyl Chloride

Abstract

We have studied on a relation between minimum creep rate and time duration to rupture of unplasticized polyvinyl chloride.
Although it has been shown by many reports on metals that they are reciprocally proportional to each other, we have recognized through our experiment that the relation is as follows;
t_r=M/(ε_min)^θ,
where t_r is time duration to rupture, ε_min is minimum creep rate, M and θ are coefficients which change their values depending on testing temperatures, two ranges of ε_min and conditions of heat treatment of specimens.
Values of coefficient θ for normal specimens become larger than 1 in the lower range of minimum creep rate, though it is almost equal to 1 in the higher range in which time duration to rupture is approximately proportional to reciplocals of minimum creep rate. For the specimens kept at 60°C for 5 days, no range is recognized where the value of θ is almost equal to 1.
A master rupture curve of normal specimens is drawn in the range of temperature -10 to 40°C, derived from the formula proposed by the authors in the preceding paper and from the above mentioned parameters.