Recent Developments in Synthetic Rubber Latex

Abstract
Progress has proceeded at a good rate since the close of the Government Program in the spring of 1955. Improved latexes have been made, and the technology of manufacture and of application has advanced. Also progress has been made in fundamental latex research. Some of the newer latexes representing the more important advances are those involving functonal groups derived from the use of unsaturated monomers such as those containing amino groups and carboxy groups in the polymerization system, those from solid rubbers by the solvent emulsion technique, and those of higher solids content including the agglomerated latexes giving 68 per cent minimum solids at low viscosity. Some of the applications of greatest growth are : 1. Carpet backing involving both sulfur curing and so-called self-curing (noncured) elastomer latexes. The latter obtain strength from polar groups including functional (carboxyl) groups and/or fairly high styrene content. 2. Foam sponge backed carpets. In 1954 it was suggested that synthetic rubber latexes would have a permanent place in our economy. This has now come to pass, and natural latex is decreasing in volume compared to total synthetic rubber latex consumption. It now appears that by forming a latex from cis polyisoprene (synthetic natural rubber) and adding it to our list of latexes, that our country could probably become independent of the natural product.