Neoprene Polychloroprene

Neoprene is the generic name for polymers of chloroprene (2-chIoro-1,3-butadiene), first manufactured by Du Pont in 1931. There are many types of solid and latex neoprene. 

Scrape the surface with a sharp blade to remove gross layers of wax, sulfur, and other compounding ingredients that may have floated to the surface  

Solvent-wipe with ethyl, isopropyl, or methyl alcohol, MEK, or toluene 

Solvent-wipe again as in step 2 to remove particles 

This process is often applied to pr are for bonding with flexiblized epoxy adhesives. It has 

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Neoprenes. Of the synthetic latices, a type that can be processed similarly to natural mbber latex and is adaptable to dipped product manufacture, is neoprene (polychloroprene). Neoprene latices exhibit poor initial wet gel strength, particularly in coagulant dipped work, but the end products can be made with high gum tensile strength, oil and aUphatic solvent resistance, good aging properties, and flame resistance. There are several types of neoprene latex, available at moderately high (ca 50 wt %) and medium soHds content. Differences in composition between the types include the polymer s microstmcture, eg, gel or sol, the type of stablizer, and the total soHds content (Table 22). 

Elastomers Solutions of NR have been used for laminating textiles for over a century. The Macintosh raincoat, invented in 1825, consisted of two sheets of cotton adhered by an inner layer of natural rubber. SBR is used as an adhesive in carpet backing and packaging. Neoprene (polychloroprene) may be blended with a terpene or phenolic resin and used as a contact adhesive for shoes and furniture. 

Ethylenethiourea has a wide variety of uses in addition to vulcanization, a principal application since 1948. The curing process converts most of the ETU to other compounds, but traces of it are still found in the rubbers. Neoprene (polychloroprene) is found largely in automotive parts, wire and cable insulation, construction and adhesives. Consumer products containing neoprenes include container seals (e.g., aerosol dispensers) and shoes. It is also an intermediate in the manufacture of antioxidants, dyes, fungicides, insecticides, pharmaceuticals, synthetic resins, and a constituent of plating baths. 

Elastomers include natural rubber (polyisoprene), synthetic polyisoprene, styrene-butadiene rubbers, butyl rubber (isobutylene-isoprene), polybutadiene, ethylene-propylene-diene (EPDM), neoprene (polychloroprene), acrylonitrile-butadiene rubbers, polysulfide rubbers, polyurethane rubbers, crosslinked polyethylene rubber and polynorbomene rubbers. Typically in elastomer mixing the elastomer is mixed with other additives such as carbon black, fillers, oils/plasticizers and accelerators/antioxidants. 

The 1950s were known for the explosive development and growth in elastomers. DuPont Company developed a whole range of synthetic elastomers such as neoprene (polychloroprene), Hypalon (chloro-... 

Chloroprene is used to produce neoprene (polychloroprene rubber). In 1986 worldwide production caps- cilics of neoprene were the following ... 

A bodied, or more viscous, solvent may be required by certain joint designs and for producing airtight or watertight seals. These are made by dissolving usually 5%-15% of polystyrene by weight in a solvent. Solvent-based contact cements provide the strongest bond between polystyrene and wood. These adhesives all have a neoprene (polychloroprene) base and a ketonic-aromatic solvent system. 

Apart from the rather expensive and inferior methyl rubber produced in Germany during World War I, the first industrial production of synthetic rubbers took place in 1932, with polybutadiene being produced in the USSR, from alcohol derived from the fermentation of potatoes, and neoprene (polychloroprene) being produced in the USA from acetylene derived from coal. In 1934 the first American car tyre produced from a synthetic rubber was made from neoprene. In 1937 butyl rubber, based on polyisobutylene, was discovered in the USA. This material has a lower resilience than that of natural rubber but far surpasses it in chemical resistance and in having a low permeability to gases. The chemical structures of these materials are shown in fig. 6.10. 

Midgley, C.A. and Rea, J.R., Styrene-butadiene rubber adhesives. In Skeist, I. (Ed.), Handbook of Adhesives, 3rd edn. Van Nostrand Reinhold, New York, 1990, pp. 227-234. Guggenberger, S.K., Neoprene (polychloroprene)-based solvent and latex adhesives. In Skeist, 1. (Ed.), Handbook of Adhesives, 3rd edn. Van Nostrand Reinhold, New York, 1990. 

In the hot-melt type, two principal polymer types are used polyolefin and ethylene co-polymer based and polyester and polyamide type. In the solvent-based type, the most prominent are neoprene (polychloroprene)-based solvent and latex types, and polyvinyl acetate emulsions. For pressure-sensitive adhesives, the most favored are acrylic adhesives and butyl rubber/polyisobutylene types. 

These alloy adhesives are thermosetting phenolic resins blended with neoprene (polychloroprene) rubber. They are available in solvent solutions in toluene, ketones, or solvent mixtures, or as unsupported or supported films. The supporting medium may be glass or nylon cloth. Neoprene-phenolic adhesive may be used to bond a variety of substrates such as aluminum. 

Neoprene paint n. Paint based upon pigmented solutions of the proprietary synthetic rubber neoprene (polychloroprene rubber), a vulcanizing agent being added before use. 

The amount of excess caustic in Neoprene polychloroprene liquid dispersions is approximately 0.1%. The liquid dispersions are, however, very basic having pH near 12. While not corrosive in animal tests, eye protection and skin protection are essential in areas where personnel exposure is possible because of possible irritation. 

Some dry polychloroprene types have been shown to have low oral toxicity rates. Human patch test for several dry types showed no skin reactions (142). The FDA status of Neoprene polychloroprene is described in the literature (143). 

Both natural and synthetic rubbers are used as elastomeric linings. The most commonly used synthetic elastomers are NBR (acrylonitrile-butadiene), Hypalon (chlorosulfonated polyethylene), EPDM (ethylene-propylene-diene monomer), EPT (ethylene-propylene-diene terpolymer), SBR (styrene-butadiene), and neoprene (polychloroprene). A maximum use temperature of nS F/SOX is typical. 

The commercial development of Neoprene (polychloroprene) by du Pont followed that of Thiokol by only a few years, and this turned out to be the second synthetic rubber to be developed in the USA, because it was far superior to natural rubber in oxidation and solvent resistance. However, it is not being included in this review, since it is "outperformed" by both Thiokol and nitrile rubber. The latter is actually the most commonly used solvent-resistant rubber today. 

While progress was erratic until about the 1930 s, synthetic elastomers were not only born, but expanding technically. It is perhaps notable that the first few products of the synthetic elastomer industry s resurgence then brought forth elastomers which offered environmental resistances vastly superior to natural products. Most notable of these were Thiokol (polysulfides) in 1929, neoprene (polychloroprene) in 1931, Buna N (copolymers of butadiene and acrylonitrile) in 1937, and butyl (copolymer of isobutylene and isoprene) in 1940. Many more were to follow. 

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