Polyepichlorohydrin rubbers

Uses Modifier for elastomers, adhesives, fibers reactive diluent for epoxies reactive intermediate for coatings sizing/finishing agent for fiberglass silane intermediate in elec, coatings stabilizer of chlorinated compds., vinyl resins, rubber defoamer comonomer for polyepichlorohydrin rubber, unsat. polyester resins, and crosslinked PU elastomers curing system additive in bisphenol A-epichlorohydrin epoxies for food-contact articles... 

Some specialty elastomers are used in mature markets, such as nitrile rubber and polychloroprene. Others such as polyepichlorohydrin rubber have not found their... 

Polyepichlorohydrin and poly(propylene oxide) rubbers have been discussed recently (82). World usage of polyepichlorohydrin rubber is 20-22 million pounds (9-10,000 metric tons) per year and has a growth rate of 7-8 percent per year. It is used mainly in the automotive industry, where advantage is taken of polyepichlorohydrin s excellent ability to withstand ozone and heat and its good air- and oil-permeability characteristics. Worldwide demand for poly(propylene oxide) rubber is about 1-2 million pounds (450-900 metric tons) per year. This rubber is effective in high-performance tubing applications that need both high-temperature resistance and the properties of natural rubber. Poly (propylene oxide) rubbers have upper use-temperature limits of 145°C, compared to 110°C for natural rubber. 

Vernon J. Kylhngstad and Clark J. Cable, Lead-ETU Free Curing Polyepichlorohydrin Rubber Compounds, Zeon Chemicals publication PH 500.1, presented at the Specialty and High Performance Rubber Conference, September 9-12, 1992, RAPRA Technology Limited, Shawhuty, Shropshire, England. 

Vulcanisation can be effected by diamines, polyamines and lead compounds such as lead oxides and basic lead phosphite. The homopolymer vulcanisate is similar to butyl rubber in such characteristics as low air permeability, low resilience, excellent ozone resistance, good heat resistance and good weathering resistance. In addition the polyepichlorohydrins have good flame resistance. The copolymers have more resilience and lower brittle points but air impermeability and oil resistance are not so good. The inclusion of allyl glycidyl ether in the polymerisation recipe produces a sulphur-curable elastomer primarily of interest because of its better resistance to sour gas than conventional epichlorhydrin rubbers. 

Polyisobutylene rubber Butyl rubber Halobutyl rubber Polyepichlorohydrin Polypropylene Polypropylene oxide... 

Sequence distribution studies on several types of rubber by 13C-NMR technique have been reported. Some of the more recent reports include silicone rubbers [28-30], SBR [31], acrylonitrile-butadiene rubber (NBR) [32,33], polyurethane [34,35], polyepichlorohydrin [36], ethylene-norbonene [37] and ethylene-propylene rubber [4, 16, 25, 38-44]. The NMR studies on EPDM have been carried out extensively, because it is one of the important parameters, which control the physical properties of the elastomer. For example, ethylene sequence can influence the crystallisation kinetic and melting behaviour of the rubber [38]. 

FIGURE 9.17 Dependence of productivity and separation factor /3p C6H5CH3/H2O of membranes based on various rubbery polymers on the glass transition temperature of the polymer (pervaporation separation of saturated toluene/water mixture, T = 308 K) (1) polydimethyl siloxane (2) polybutadiene (3) polyoctylmethyl siloxane (4) nitrile butadiene rubber with 18% mol of nitrile groups (5) the same, 28% mol of nitrile groups (6) the same, 38% mol of nitrile groups (7) ethylene/propylene copolymer (8) polyepichlorohydrin (9) polychloroprene (10) pol3furethane (11) polyacrylate rubber (12) fluorocarbon elastomer. (From analysis of data presented in Semenova, S.I., J. Membr. Sci., 231, 189, 2004. With permission.)... 

Most compounders use a combination of physical and chemical antiozonants and achieve excellent protection in this way. For more severe ozone-resistance problems, there are, of course, a number of specialty elastomers that are saturated and therefore completely ozone-resistant ethylene/propylene rubber, chlorinated and chlorosulfonated polyethylene, ethylene/vinyl acetate, ethylene/acrylic esters, butyl rubber, SEES, plasticized PVC, butyl acrylate copolymers, polyepichlorohydrin and copolymers, polyetherester block copolymer, polyurethane, and silicone. 

Figure 1 Polymer interpretation chart. PAI, polyamideimide PC, polycarbonate UP, unsaturated polyester PDAP, diarylate phtalate resin VC-VAc, vinyl chloride-vinyl acetate copolymer PVAc, polyvinyl acetate PVFM, polyvinyl formal PUR, polyurethane PA, polyamide PMA, methacrylate ester polymer EVA, ethylene-vinyl acetate copolymer PF, phenol resin EP, epoxide resin PS, polystyrene ABS, acrylonitrile-butadiene-styrene copolymer PPO, polyphenylene oxide P-SULFONE, poly-sulfone PA, polyamide UF, urea resin CN, nitrocellulose PVA, polyvinyl acetate MC, methyl cellulose MF, melamine resin PAN, polyacrylonitrile PVC, polyvinyl chloride PVF, polyvinyl fluoride CR, polychloroprene CHR, polyepichlorohydrin SI, polymethylsiloxane POM, polyoxy-methylene PTFE, polytetrafluoroethylene MOD-PP, modified PP EPT, ethylene-propylene terpolymer EPR, ethylene-propylene rubber PI, polyisoprene BR, butyl rubber PMP, poly(4-methyl pentene-1) PE, poly(ethylene) PB, poly(butene-l). (Adapted from Ref. 22, p. 50.)...

Synthetic rubbers are produced as commodities. Polybutadiene, polybutylene, polychloroprene and polyepichlorohydrin are examples of elastomeric homopolymers. Copolymeric rubbers comprise poly-(butadiene-co-styrene), poly(butadiene-co-acryloni-trile), poly(ethylene-co-propylene-co-diene), and poly-(epichlorohydrin-co-ethylene oxide). The unsaturated group in the comonomer provides reactive sites for the crosslinking reactions. Copolymers combine resilience with resistance to chemical attack, or resilience in a larger temperature range, and thermoplastic-like properties. There are several studies in the literature describing the preparation of blends and composites of elastomers and conductive polymers. A description of some significant examples is given in this section. 

More recently Crosbie and Philips [85,86] investigated the toughening effect of several reactive liquid rubbers (carboxyl terminated butadiene-acrylonitrile, vinyl terminated butadiene-acrylonitrile, hydroxyl terminated polyether, polyepichlorohydrin) and an unspecified experimental reactive liquid rubber developed by Scott Bader Ltd. on two different polyester resins a flexibilized isophthalic-neopentyl glycol polyester resin, PVC compatible and an epoxy modified polyester resin, which is preaccelerated. The results of these studies are summarized as follows ... 

Although not strictly the subject matter of this book, work is briefly reviewed next on the application of non mass spectrometric Py-GC methods in the determination of polymer structure. This information is inclnded in the hope, when necessary, that chemists will be able to adapt these methods by including a mass spectrometric detailed information on polymer structure acrylates [63, 105-107], rubbers [63, 108-110], PVC [63,111-115], aliphatic polyhydrazides [116], polyoxamides [116], polyamides [117], polyether imides [118], methacrylamide [119], aromatic aliphatic polyamides [117], polyurethanes [120], chitin graft poly(2-methyl 2-oxazolone) [121, 122], polyxylyl sulfide [123-126], epoxy resins [127], polyethylene oxalate [128], polytetrafluoroethylene [129], polyvinylidene chloride [129], polyepichlorohydrin, fluorinated ethylene-propylene copolymer [129], polyvinyl fluoride [129], polyvinylidene [129], fluoride [129], SBR copolymer [129] and styrene-isoprene copolymer [130]. 

Because of the aliphatic chlorine atom, base-catalyzed initiation of epichlorohydrin to relatively high polymer is not practical. Coordinate polymerization is used with the Vandenberg Catalyst, as will be discussed in Section III. Polyepichlorohydrin is used commercially as an oil-resistant rubber. 

Polyepichlorohydrin copolymer or terpolymer compounds can provide vibration dampening comparable to natural rubber (NR), but at an extended temperature range. This characteristic makes polyepichlorohydrin compounds a good choice for suspension mounts and impact absorbers, which must operate at higher temperatures than practical for natural rubber. Typical data are shown in Figures 7.3 and 7.4. 

A few polymers cannot be cross-linked with peroxides. These polymers have a high degree of branching or many side groups. In these polymers, such as butyl rubber, polyepichlorohydrin homo- and copolymers as well as polypropylene, the addition of peroxides causes chain scission and softening rather than cross-IinMng. 

The Handbook of Specialty Elastomers was conceived as a single reference source for the rubber compounder with some experience in designing parts in the rubber industry. The definition of specialty elastomers referenced in this publication is heat, oil, fuel, and solvent-resistant polymers that include polychloroprene (CR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluoroelastomer (FKM), polyacrylate (ACM), ethylene acrylic elastomer (AEM), polyepichlorohydrin (CO, ECO), chlorinated polyethylene (CPE), chlorosulfonated polyethylene (CSM), ethylene vinyl acetate (EAM), and thiokol (T). 

Poly (tetrafluoroethylene), PMMA, rubber hydrochloride, polyepichlorohydrin fluorinated ethylene-propylene copolymer, polyvinyl fluoride, polyvinylidene fluoride styrene butadiene copolymer Temperature programmed, pyrolysis MS - - - [45]... 

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