Hypalon is a chlorosulfonated

polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including b ...

(CSPE)

synthetic rubber A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About 32-million metric tons of rubbers are produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubb ...

(CSM) noted for its resistance to chemicals, temperature extremes, and

ultraviolet light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiatio ...

. It was a product of DuPont Performance Elastomers, a subsidiary of

DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...

. Hypalon as it is now known in the marine industry today is a remarketed version of the old Hypalon using an additional layer of neoprene (cr) so the new chemical formulation is csm/cr.

Chemical structure

Polyethylene is treated with a mixture of chlorine and sulfur dioxide under UV-radiation. The product contains 20-40% chlorine. The polymer also contains a few percent chlorosulfonyl (ClSO₂-) groups. These reactive groups allow for

vulcanization Vulcanization (British: Vulcanisation) is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to includ ...

, which strongly affects the physical durability of the products. An estimated 110,000 tons/y were produced in 1991.

Discontinuance

DuPont Performance Elastomers announced on May 7, 2009, that it intended to close its manufacturing plant in

Beaumont, Texas Beaumont is a coastal city in the U.S. state of Texas. It is the seat of government of Jefferson County, within the Beaumont– Port Arthur metropolitan statistical area, located in Southeast Texas on the Neches River about east of Houston ( ...

, by June 30, 2009. This was DPE's sole plant for CSM materials. The company was therefore exiting the business for Hypalon and its related product, Acsium.Dupont Hypalon operations have ceased.
The plant closure was delayed until April 20, 2010, in response to customer requests.

References

{{DuPont Elastomers Brand name materials