Permeability of Organic Polysulfide Resins to Hydrogen

Abstract

Abstract A characteristic of balloon and airship fabrics which is of prime importance is that they shall be gas-tight or nearly so. The inherent tendency of hydrogen and of the more costly gas helium to diffuse through thin membranes of rubber provides the incentive for the study of the behavior of a large number of film-forming materials in a search for a more satisfactory material. Considering all of the requirements involved in this application, the permeability of the group of synthetic polymers which are characterized by elastic extensibility has been of particular interest. The general reaction between organic dihalides with—CH2Cl terminals and inorganic polysulfides yields products which in many cases are characterized as rubber-like. Martin and Patrick suggested that the structure of the polysulfide resins is that of long-chain polymers in which the radicals are connected through disulfide linkages and represented as —R—S—S—R—S—S—R—. According to their hypothesis, any additional sulfur in the material in excess of that required to provide the disulfide linkages is believed to be coördinately linked to the sulfur comprising the disulfide linkages.