Chlorinated rubber, bonding agents

Chlorinated rubber is also an effective bonding agent. It can be used for bonding neoprene, nitrile and natural rubbers to metals. Phenol formaldehyde resins have been used alone or in conjunction with chlorinated rubbers, but curing time is lengthy. 

Uses Bonding agent for bonding rubber doughs, sol n. coatings, and solv.-based dips to a variety of syn. textiles, rec. for adhesives, esp. those based on polychloroprene and on chlorinated rubbers Properties Dk. bm. low vise, liq. dens. 1070 kg/m (20 C) 54% act. Toxicoiogy Harmful by inh. irritating to skin, eyes, and respiratory tract may cause sensitization by inh. 

Nitrile rubber is used preferably for contact adhesives with improved plasticizer resistance. Polyisobutylene is used in pressure-sensitive adhesives. Butyl rubber is sometimes added to pressure-sensitive and hot-melt adhesives, although it is mainly used in sealing compounds. Epoxy resins and reactive (meth)acrylate adhesives (reactive adhesives) are modified with polychloroprene, butyl, and nitrile rubber. Chlorinated rubber is added in small quantities to contact adhesives and also to rubber-to-metal bonding agents for improving the adhesion properties. 

Nowadays, rubber-metal composites are produced with bonding agents in which the polymer base is usually a halogenated polymer, for example, a mixture of chlorinated and brominated polybutadiene. After the film of bonding agents applied to the metal component has dried, the metal component is bonded to the rubber mixture during the vulcanization process. 

The Germans developed several arsenical-based warfare chemical agents circa 1917 (Goldman and Dacre, 1989). The allies, on the other hand, developed Lewisite (2-chlorovinydichloroarsine), adamsite (diphenylaminechloroarsine), methyldichloroarsine, and arsine. Lewisite is soluble in organic solvents it is readily absorbed by rubber, paint, varnish, and porous materials. There are labile chlorine atoms, bivalent arsenic, carbons, and multiple bonds that make it quite reactive. Some of its reactions are due to nucleophilic substitution by water, hydrogen sulfide, thiols, and acid salts. 

Several chlorinating agents have been used for SBR soles bonding. Acidified sodium hypochlorite aqueous solutions have been used successfully (O Table 51.1) and the mechanism of chlorination has been established (Vukov 1984), which consists in the formation of H2CIO which produces chlorine chlorine is added to double C=C bond in the rubber producing chlorinated hydrocarbon moieties and some cross-linking. 

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