Chemical copolymers Acrylonitrile-butadiene elastomers

The vinylidene fluoride(VDF)-hexafluoropropylene(HFP) copolymers are well-known fluorocarbon elastomers which have excellent thermal, oil and chemical stability. Due to their inert structure, curing is more difficult compared with the hydrocarbon elastomers such as styrene-butadiene copolymer, acrylonitrile-butadiene copolymer etc. It is known that two curing recipes described below are practically usable for these fluorocarbon elastomers. 

Methacrylonitrile (1) differs from 2 only in that it has a methyl (CH3) group on the a-carbon atom. It too is widely used in the preparation of homopolymers and copolymers, elastomers, and plastics and as a chemical intermediate in the preparation of acids, amides, amines, esters, and other nitriles. In a study conducted by the NTP in which 1 was administered orally to mice for 2 years, there was no evidence that it caused cancer, although other less serious toxic effects were noted [27]. Because 1 does not cause cancer, but undergoes many of the same nucleophilic addition reactions as 2 at the (3-carbon, it is sometimes used as a safer commercial replacement for 2, such as in the manufacture of an acrylonitrile-butadiene-styrene-like polymer that provides improved barrier properties to gases such as carbon dioxide in carbonated beverage containers. 

Acrylic elastomer Acrylonitrile-butadiene rubber, hydrogenated Polyethylene, ultrahigh m.w. high-density Polynorbornene Polyurethane elastomer, thermoplastic Styrenated diphenylamine , Styrene-ethylene/butylene-styrene block copolymer seals, chemical-resistant Chlorotrifluoroethylene polymer seals, dynamic aerospace Polyfluoroalkoxyphosphazene seals, dynamic industrial Polyfluoroalkoxyphosphazene seals, dynamic military Polyfluoroalkoxyphosphazene seals, high performance Tetrafluoroethylene/perfluoromethylvinyl ether copolymer seals, oil... 

Rubber vulcanization crosslinking was an early chemical modification method. Block and graft methods are also widely used in polymer modification. One of the successful examples of a block copolymer is a thermoplastic elastomer. It is a new material that can be processed like plastic and has elasticity like rubber. Among graft copolymers, the most widely used one is the acrylonitrile butadiene and styrene copolymer... 

Nitrile mbber finds broad application in industry because of its excellent resistance to oil and chemicals, its good flexibility at low temperatures, high abrasion and heat resistance (up to 120°C), and good mechanical properties. Nitrile mbber consists of butadiene—acrylonitrile copolymers with an acrylonitrile content ranging from 15 to 45% (see Elastomers, SYNTHETIC, NITRILE RUBBER). In addition to the traditional applications of nitrile mbber for hoses, gaskets, seals, and oil well equipment, new applications have emerged with the development of nitrile mbber blends with poly(vinyl chloride) (PVC). These blends combine the chemical resistance and low temperature flexibility characteristics of nitrile mbber with the stability and ozone resistance of PVC. This has greatly expanded the use of nitrile mbber in outdoor applications for hoses, belts, and cable jackets, where ozone resistance is necessary. 

Poly(butadiene- (9-acrylonitrile) [9008-18-3] NBR (64), is another commercially significant random copolymer. This mbber is manufactured by free-radical emulsion polymerization. Important producers include Copolymer Rubber and Chemical (Nysyn), B. F. Goodrich (Hycar), Goodyear (Chemigum), and Uninoyal (Paracdl). The total U.S. production of nitrile mbber (NBR) in 1990 was 95.6 t (65). The most important property of NBR mbber is its oil resistance. It is used in oil well parts, fuels, oil, and solvents (64) (see Elastomers, synthetic— nitrile rubber). 

During World War II, several new synthetic elastomers were produced and new types of adhesives (mainly styrene-butadiene and acrylonitrile copolymers) were manufactured to produce adequate performance in joints produced with new difficult-to-bond substrates. Furthermore, formulations to work under extreme environmental conditions (high temperature, resistance to chemicals, improved resistance to ageing) were obtained using polychloroprene (Neoprene) adhesives. Most of those adhesives need vulcanization to perform properly. 

Effect of Molecular Configuration of Elastomer. The extent of the impact and strength improvements of ERL-4221 depends on the chemical structure and composition of the elastomer modifier. The data shown in Table I indicate that the carboxyl terminated 80-20 butadiene-acrylonitrile copolymer (CTBN) is the most effective toughening and reinforcing agent. The mercaptan terminated copolymer (MTBN) is considerably less effective as far as tensile strength and heat distortion temperature are concerned. The mercaptan groups are considerably less reactive with epoxides than carboxyls (4), and this difference in the rate of reaction may influence the extent of the epoxy-elastomer copolymerization and therefore the precipitation of the rubber as distinct particles. 

A material made by blending polymers or copolymers with other polymers or elastomers under selected conditions, e.g., styrene-acrylonitrile copolymer (SAN) blended with butadiene-acrylonitrile elastomer (NBR). A mixture of two chemically different polymers to form a material having properties different from but often comprising those of the original resins. Also see Polymer alloy. Low-molecular-weight polymerization product of allyl monomer, CH2 = CHCH2X, where, for example, X = -OH, -OOCCH3. 

All manufacturing processes for ABS involve the polymerization of styrene and acrylonitrile monomers in the presence of an elastomer (typically polybutadiene or a butadiene copolymer) to produce SAN that has been chemically bonded or grafted to the rubber component termed the substrate. ... 

There are variations in the chemical nature of the carbon black surface. There are carboxyl, phenol, quinone, and other groups on the carbon black surface. Relative measures of the surface oxygen compounds can be obtained from the pH of carbon black suspensions. Polar elastomers, such as polychloroprene and butadiene-acrylonitrile copolymer, appear to interact more strongly with polar surface carbon blacks. 

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