Polychloroprene Rubber

Polychloroprene Rubber

 

a light-yellow synthetic rubber that is a polymer of chloroprene, with the general formula [—CH2—CCl=CH—CH2—]n. The density of polychloroprene rubbers varies from 1.20 to 1.24 g/cm3, and the molecular weight ranges from 100 × 103 to 200 × 103. The glass-transition temperature is –40°C, the volume electrical resistivity, 4.4 × 106 ohm· m, the electric strength, 23 megavolts/m, and the dielectric constant, 6.4 to 6.7.

Polychloroprene rubbers are characterized by a number of specific properties, determined by the presence of chlorine atoms in the macromolecules. These properties include resistance to oil, gasoline, ozone, and heat; incombustibility; and the ability to vulcanize through the addition of metallic oxides, for which purpose mixtures of ZnO and MgO are used in industry. Polychloroprene rubbers crystallize upon stretching, and consequently those that are uncompounded are most durable. When polychloroprene rubbers are compounded, their durability decreases in certain cases, but other valuable properties, such as tear strength and resistance to gasoline, usually improve.

Polychloroprene rubbers are synthesized industrially by polymerization in an aqueous emulsion. They are mainly used in the production of industrial rubber products, primarily conveyor and other types of belts and various hoses. They are also used in the production of wire and cable insulation and protective coatings. Polychloroprene rubber adhesives and chloroprene latexes are also important in industry.

The annual world production of polychloroprene rubbers amounts to approximately 400,000 tons. The most common trade names are Nairit in the USSR and Neoprene in the USA.

REFERENCES

Entsiklopediia polimerov, vol. 3. Moscow, 1977.
See also references under RUBBER, SYNTHETIC.
References in periodicals archive ?
Contract awarded for 45180362-rubber pad 240x160x18 mm made of polychloroprene rubber compound grade ~f~ confirming to properties as laid down in clause no.
MTT-80 acts as a vulcanization accelerator to polychloroprene rubber, chlorinated or brominated butyl rubber.
Candidate polymers include a polybutadiene /styrene copolymer, an ethylene propylene diene rubber, an acrylic rubber, a polychloroprene rubber, a polyurethane, a fluoro-rubber and a butyl rubber.
Besides, halogenated grade butyl rubber, unlike the normal butyl rubber grades, can be used in blend with natural rubber or synthetic rubbers such as nitrile rubber (NBR), styrene-butadiene rubber (SBR), polychloroprene rubber (CR), ethylene-propylene rubber (EPDM), or butadiene rubber (BR).
For industry and construction products as well as for the modification of materials, other types are preferred, for example ethylene propylene diene rubber (EPDM) or polychloroprene rubber (OR).
Flex-Lag Adhesives are also environmentally friendly, comprised of a polychloroprene rubber in a solvent base that is free of chlorinated hydrocarbons.
A South American client recently partnered with Dynasol to develop a solvent-based, sprayable adhesive formula to replace an adhesive formula based in Polychloroprene rubber.
The new Aqua RN8 cable has a special polychloroprene rubber outer sheath making it safe for permanent use in water.
Plastic materials: Chlorinated polyethylene (CPE), chlorinated polyvinylchloride (CPVC), chlorosulfonated polyethylene (CSPE), polychloroprene rubber (CR)
The limestone process is considered more environmentally-friendly, according to the company, and the firm uses it exclusively in all its polychloroprene rubber products.
Chapter 4 analyzes demand for rubber split by the types styrene butadiene rubber (E-SBR and S-SBR), polybutadiene rubber (BR), ethylene propylene diene rubber (EPDM), butyl rubber (IIR), acrylonitrile butadiene rubber (NBR), polychloroprene rubber (CR) and polyisoprene rubber (IR).