Temperature Stability of the Heat Fluctuation Mechanism of Breakdown of Polymer Fibres

Full Durability Isotherm of Polymer Fibres

“…The material constants τ 0 , U 0 , and γ can be considered to be constant in a certain range of stresses and temperatures corresponding to a certain mechanism of failure. Numerical processing of experimental data on the long-term strength for a number of polymers (PMMA and polyvinyl acetals) in a wide test temperature range from -200 to +50°C, conducted by the present authors in a previous study [4], showed the presence of sudden changes in U 0 and V a β on transition through the brittle point. Therein lies the problem of temperature instability of the heat fl uctuation mechanism of failure of unoriented polymers.…”

“…In constructing the theory of the full curve of the durability isotherm of oriented polymer fi bres, experimental data on the time dependence of strength at different test temperatures for polyethylene, polypropylene, cellulose triacetate, and nylon-6 fi bres [4] were analysed beforehand.…”

“…,(4), and (7) make it possible to calculate the important parameters for the theory of durability and the limiting characteristics of the process of failure, namely[2]: is the surface energy and q is the temperature coeffi cient.…”