Structural Differences in Masticated and Unmasticated Raw Rubber Mixtures and Vulcanizates, and Their Significance from a Practical Point of View

Abstract

Abstract The use of latex in certain branches of the rubber industry is even today looked upon with a great deal of skepticism in technical circles. This point of view rests not so much on ignorance of actual progress in this field as on the still prevalent idea that a mixture of latex and fillers can never give a useful product and one comparable in quality with a raw rubber mixture. This belief is based on the fact that latex is a decidedly heterogeneous system, since the rubber in latex is distributed throughout in the form of individual particles. In spite, however, of this current belief there is now satisfactory evidence to show that products made from latex mixtures without mastication of the rubber are superior in almost all their physical properties to products made from raw rubber in the conventional way. This superiority is in evidence particularly in the higher tensile strength and elasticity and in the incomparably better resistance to tearing. The experiments to be described, which are based in part on work already published elsewhere and on still unpublished investigations of Miss Hünemörder and the author, will serve to make clear the theoretical basis on which these facts rest and will furthermore indicate a few points which in our opinion are worthy of special consideration in the preparation of latex mixtures.