Chlorinated polyethylene elastomer

There have been some attempts to develop chlorinated polyethylene elastomers. The rubbers possess such attractive properties as very good oil, heat, flame, ozone, and weathering resistance and are also available in a convenient powder form. In spite of being marketed at competitive prices, the chlorinated polyethylene rubbers (designated as CM rubbers by ASTM) took... 

The moderate random chlorination of polyethylene suppresses crystallinity and yields chlorinated polyethylene elastomer (CPE), a rubber-like material that can be crosslinked with organic peroxides. The chlorine (Cl) content is in the range of 36 to 42%, compared to 56.8% for PVC. Such elastomer has good heat and oil resistance. It is also used as a plasticizer for PVC. They provide a very wide range of properties from soft/elastomeric too hard. They have inherent oxygen and ozone resistance, resist plasticizers, volatility, weathering, and compared to PEs have improved resistance to chemical extraction. Products do not fog at high temperatures as do PVCs and can be made flame retardant. 

CPR. [DuPont] Chlorinated polyethylene elastomer for wire and cable industry. 

Chlorinated polyethylene elastomer (CPE) has been produced by the introduction of chlorine atoms onto the polyethylene backbone in order to reduce the crystallization ability of polyethylene. In addition, the enhancement in resistance to hydrocarbon oil, heat and weathering is also achieved. To gain desired properties of the final products, CPE has been blended with many polymers, including polyvinyl chloride, styrene-acrylonitrile and polyurethane. Compared to NR, CPE is relatively expensive and therefore the blending of CPE/NR is one of methods to reduce the production cost of the final products requiring CPE properties. Some researchers from Thailand are working with this kind of blend. ... 

Of much longer commercial standing than the chlorinated polyethylene elastomers are the so-called chlorosulphonated polyethylenes (designated as CSM Rubbers) marketed by Du Pont since 1952 under the trade name Hypalon. These are essentially chlorinated polyethylenes which in addition possess a small amount of —SO2CI side chains to provide a useful cure site. Whilst most rubbers are shrouded in anonymity as far as the general public is concerned these speciality materials have a merited excellent and enviable reputation with outdoor pursuit enthusiasts with uses in such areas as groundsheets and inflatable dinghies. 

Chlorinated polyethylene-elastomers exhibit good weathering and ozone resistance because of their saturated structure [83]. 

R.R. Blanchard, Compounding Chlorinated Polyethylene Elastomers for High Temperature Service, Advances in Synthetic Rubbers and Elastomers Science and Technology, Tech-nomic Publishing Co., Inc., 1973, pp. 1 13. 

L.E. SoUherger and C.B. Carpenter, Chlorinated Polyethylene Elastomers—A Comprehensive Characterization, presented at a meeting of the Ruhher Division, American Chemical Society, Toronto, Canada, May 7-10, 1974. 

Chlorinated polyethylene elastomer (CPE) is one of the alternatives of the PDMS. Extraoral maxillofacial prostheses have been fabricated with silicone elastomer for 50 years, with few improvements. A controlled, randomized, prospective, double-blind, single-crossover, multicenter, phase 111 clinical trial was performed by Kiat-Amnuay et al. to determine the noninferiority of CPE to silicone elastomer [46]. For this purpose, 42 patients were randomly assigned to wear a custom-made prosthesis fabricated from both materials for four months and asked to rate their satisfaction (0 = not satisfied, 10 = completely satisfied). Of the 28 patients who completed the study, 68% had used silicone prostheses previously. Overall, patients rated the silicone prosthesis higher than CPE (difference 2.2, 95% confidence interval [Cl] 0.9 to 3.6, P =. 017). Previous users had a stronger preference for silicone (difference 3.3, 95% Cl 1.7 to 4.9, P =... 

Natural mbber comes generally from southeast Asia. Synthetic mbbers are produced from monomers obtained from the cracking and refining of petroleum (qv). The most common monomers are styrene, butadiene, isobutylene, isoprene, ethylene, propylene, and acrylonitrile. There are numerous others for specialty elastomers which include acryUcs, chlorosulfonated polyethylene, chlorinated polyethylene, epichlorohydrin, ethylene—acryUc, ethylene octene mbber, ethylene—propylene mbber, fluoroelastomers, polynorbomene, polysulftdes, siUcone, thermoplastic elastomers, urethanes, and ethylene—vinyl acetate. 

Chlorinated polyethylene (CPE) has excellent o2one, oil, and heat resistance. In addition chlorinated polyethylene has replaced chloroprene elastomers. CPE has a lower specific gravity than chloroprene compounds and produces compounds that are similar to CR in properties but with lower costs. In addition, due to high levels of chlorine in the polymer, the flame resistance of the compounds of CPE are high. 

Maxillofacial polymers include the chlorinated polyethylenes, polyethemrethanes, polysiloxanes (see Elastomers), and conventional acrylic polymers. These are all deficient in a number of critical performance and processing characteristics. It is generally agreed that there is a need for improved maxillofacial polymers that can be conveniently fabricated into a variety of prostheses (218,227,228). 

Elurocaibon elastomers Acrylic elastomers Polyurethanes Polyethylene Chlorinated polyethylene Poly(vinyl chloride)... 

Thermoplastic elastomers—chlorinated polyethylene (CPE), chlorylsulfonated polyethylene (CSPE)... 

Plastics and elastomers Degrades chlorinated polyethylene, neoprene, nitrile rubber, polysulfide, polyurethane... 

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

At room temperature, PE is a semi-crystalline plastomer (a plastic which on stretching shows elongation like an elastomer), but on heating crystallites melt and the polymer passes through an elastomeric phase. Similarly, by hindering the crystallisation of PE (that is, by incorporating new chain elements), amorphous curable rubbery materials like ethylene propylene copolymer (EPM), ethylene propylene diene terpolymer (EPDM), ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene (CM), and chlorosulphonated polyethylene (CSM) can be prepared. 

Within the family of polyolefins there are many individual families that include low density polyethylenes, linear low density polyethylenes, very low polyethylenes, ultra low polyethylenes, high molecular weight polyethylenes, ultra high molecular weight polyethylenes, polyethylene terephthalates, ethylene-vinyl acetate polyethylenes, chlorinated polyethylenes, crosslinked polyethylenes, polypropylenes, polybutylenes, polyisobutylene, ionomers, polymethylpentene, thermoplastic polyolefin elastomers (polyolefin elastomers, TP), and many others. 

Fig. 7a-c. Phase contrast microscope pictures of a blend of ethylene-vinyl acetate copolymer (40% vinyl acetate) with chlorinated polyethylene (43 % chlorine) before and after phase separation. Since both polymers are elastomers the mobility is quite high. The original pictures are coloured red and green. These black and white pictures have enhanced contrast to make the phase separation clear... 

Impact modifiers are rubbery additives that improve the resistance of materials. Proper compatibility between the phases is essential. This is often achieved with graft and block copolymers. Most impact modifiers are elastomers such as ABS, BS, methacrylate-butadiene-styrene, acrylic, ethylene-vinyl acetate, and chlorinated polyethylene. 

A second family of ionic elastomers based on the sulfonation of chlorinated polyethylene was also introduced in the early 1950 s by E. I. du Pont de Nemours Co., Inc. Curing these materials with various metal oxides gives rise to a combination of ionic and covalent crosslinks, and these elastomers are commercially available under the trade name Hypalon. 

T. Crisenza, et al., Direct 3D visualization of the phase-separated morphology in chlorinated polyethylene/nylon terpolyamide based thermoplastic elastomers, Macromol Rapid Commun. 33 (2) (2012) 114—119. 

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