Hypalon is the Du Pont trade name for a familyof chlorosulfonated polyethylenes prepared bytreating polyethylene with a mixture of chlorineand sulfur dioxide, whereby a few scatteredchlorine and sulfonyl chloride groups are introducedinto the polyethylene chain. By this treatment,polyethylene is converted to a rubberlikematerial in which the undesirable degree ofcrystallinity is destroyed but other desirableproperties of polyethylene are retained. Theoutstanding chemical stability of Hypalon results from the complete absence of unsaturationin the polymer chain. Hypalon has extreme resistance to ozone.Its chemical resistance to strong chemicals,such as nitric acid, hydrogen peroxide, andstrong bleaching agents, is superior to any ofthe commonly used rubbers. These vulcanizatesalso have good heat resistance, mechanicalproperties, and unlimited colorability. Typicalapplications include white sidewall tires and avariety of sealing, waterproofing, insulating,and molded items.
