New Types of Transformation Products of Rubber

Abstract

Abstract In the present paper, a few observations are described which were made in the last few months by Philipp and one of the present authors (Posnansky). When a solution of silver nitrate in a mixture of acetone and water, which is a satisfactory solvent for silver nitrate and at the same time has a sufficiently strong swelling action, is allowed to react with crude rubber in the form of films prepared from latex, products are obtained whose properties depend on the concentration of the solution, on the time of reaction and on the temperature, and differ fundamentally from the properties of the original rubber. When highly purified latex is used for preparing the films, the already familiar reducing action of rubber on silver nitrate does not take place, and colorless or white films are obtained, within which considerable quantities of inorganic substances are embedded. Determinations of the silver contents of these products showed values up to 18 per cent of silver, corresponding to approximately 37 per cent of silver nitrate, the actual percentage depending on the time that the reaction was allowed to continue. That a very strong addition reaction takes place becomes evident, for example, by the fact that when a similar latex film is swollen in a silver perchlorate solution of the same concentration, only 2.5 per cent of silver, i. e., less than one-seventh as much as with silver nitrate, was found in the end product, which, moreover, gave no indication that any fundamental changes had taken place, such as are described below for the reaction between rubber and silver nitrate.