Brittle Points of Natural and Synthetic Rubber Stocks

Abstract

The slow-bend brittle point test does not have the same practical significance as the Bell Telephone Laboratories brittle point test because most rubber articles which are exposed to low temperatures in service are required to withstand fairly rapid flexing. If the slow-bend brittle point test were used as a criterion of the cold resistance of these rubber articles, it might qualify the rubbers for a lower temperature than they could safely withstand in service. The brittle point test developed by the Bell Telephone Laboratories is simple and sensitive. It is believed that this test may advantageously be used to study all cold resistance problems where damage to the rubber itself and not increase in stiffness is the first consideration.

New Rubber Peptizers and Coatings Derived from Guayule Resin (Parthenium argentatum Gray)

“…In the field of industrial applications for the resin of guayule, the literature does not report any significant studies limiting their scope to report general observations of the possible degrading effects and the lowering of the mechanical properties caused by the resin upon guayule rubber (Morris et al, 1942a(Morris et al, ,b, 1943; Hauser andle Beau, 1942, 1943a,b; Place andClark, 1945, 1946).…”