TROUSER TEARING OF A MODEL NATURAL RUBBER TIRE BELTVULCANIZATE. PART 3: EFFECT OF DEFORMATIONDURING ANAEROBIC AGING

摘要

The effect of test rate and cure time on the trouser tear strength of a model NR tire belt vulcanizate was discussed previously. Specimens had thick legs and a thin (intended) tear path. Particular attention was paid to the type (steady, stick-slip) and locus of tearing. We now employ trouser tear test pieces that were held at fixed extension ratio λ_0 perpendicular to specimen length while they were anaerobically aged for 48 h at 120 ℃. After aging, specimens were released and retracted to λ_r before they were torn apart at 23℃. When aging had taken place without pre-extension = 1), specimens remained strong and tearing was knotty, but tearing became steady and easy when test pieces had been sufficiently extended during aging.