Terpolymer thermoplastic diene

Organic peroxides are used in the polymer industry as thermal sources of free radicals. They are used primarily to initiate the polymerisation and copolymerisation of vinyl and diene monomers, eg, ethylene, vinyl chloride, styrene, acryUc acid and esters, methacrylic acid and esters, vinyl acetate, acrylonitrile, and butadiene (see Initiators). They ate also used to cute or cross-link resins, eg, unsaturated polyester—styrene blends, thermoplastics such as polyethylene, elastomers such as ethylene—propylene copolymers and terpolymers and ethylene—vinyl acetate copolymer, and mbbets such as siUcone mbbet and styrene-butadiene mbbet. 

Han S.J., Lohse D.J., Radosz M., and Sperling L.H. Thermoplastic vulcanizates from isotactic olypro-pylene and ethylene-propylene-diene terpolymer in supercritical propane Synthesis and morphology. Macromolecules, 31, 5407, 1998. 

Medintseva, T.I., Dreval, V.E., Erina, N.A., and Prut, E.V., Rheological properties thermoplastic elastomers based on isotactic polypropylene with an ethylene-propylene-diene terpolymer, Polym. Sci. A, 45, 2032, 2003. 

By rapid expansion of supercritical propane solution (RESS), and isobaric crystallisation (ICSS), isotactic polypropylene and ethylene-butylene copolymers were precipitated from the supercritical solution. The RESS process produced microfibres with a trace of microparticles, while the ICSS process produced microcellular products. Improvement in thermal stability was achieved by first synthesising a thermoplastic vulcanisate from polypropylene and ethylene-propylene-diene terpolymer from a supercritical propane solution, followed by RESS. 28 refs. 

The choice of date range is arbitrary. The number of journal articles for each year was obtained from a search of electronic version of English-based polymer and polymer-related journals using the keywords polyolefin and blends. Within polyolefin keyword, the subkeywords used in the search were polyethylene (PE, LLDPE, LDPE, HDPE, UHMWPE, PE, etc.), polypropylene (PP, iPP, sPP, aPP, etc.), polybutene-1, poly-4-methylpentene-l, ethylene-diene monomer, ethylene-propylene-diene terpolymer, ethylene propylene rubber, thermoplastic olefins, natural rubber (NR), polybutadiene, polyisobutylene (PIB), polyisoprene, and polyolefin elastomer. For the polyolefin blends patent search, polymer indexing codes and manual codes were used to search for the patents in Derwent World Patent Index based on the above keywords listed in the search strategy. 

A very important thermoplastic elastomer is comprised of a blend of polypropylene (PP) with an ethylene-propylene-diene (EPDM) terpolymer. This latter material is, of course, a crosslinkable thermoset rubber ... 

Nowadays commercial mixtures of bitumens with uncured synthetic elastomers are produced, e.g. ethylene-propylene-diene terpolymers (EPDM), styrene-butadiene sequence copolymers (SBS), and ethylene-acrylic ester-acrylic acid terpolymers (AECM). Mixtures with some thermoplastics are also commercial products, e.g. polyethylene (PE), ethylene-propylene copolymers (EPM), alpha-olefinic copolymers, atactic polypropylene (aPP), and ethylene-vinyl acetate copolymers (EVA). 

The EP thermoplastic elastomers are distinguished from the crossUnked analogues, which are not thermoplastics since reforming is impossible. A very important thermoplastic elastomer is comprised of a blend of an EP copolymer with an ethylene-propylene-diene (EPDM) terpolymer. This latter material is, of course, a crosslinkable thermoset however, these materials can be processed as thermoplastics if the crosslinkable component is present at low enough concentration to be present as an isolated phase. Melt-processing causes the formation of chemical bonds within the isolated rubber phase, a process called dynamic vulcanization. A commercial example of this type of material is Santoprene [4] manufactured by Advanced Elastomer Systems. Other blends of noncrosslinkable TPEs with crosslinkable materials are used commercially. These materials are classified as elastomer blends and are the subject of Chapter 12. 

The co-continuous structure and the final rheological properties of an immiscible polymer blend are generally controlled by not only the viscoelastic and interfacial properties of the constituent polymers but also by the processing parameters. For example, the effect of plasticizer on co-continuity development in blends based on polypropylene and ethylene-propylene-diene-terpolymer (PP/EPDM), at various compositions, was studied using solvent extraction. The results showed more rapid percolation of the elastomeric component in the presence of plasticizer. However, the same fuUy co-continuous composition range was maintained, as for the non-plasticized counterparts (Shahbikian et al. 2011). It was also shown that the presence of nanoclay narrows the co-continuity composition range for non-plasticized thermoplastic elastomeric materials (TPEs) based on polypropylene and ethylene-propylene-diene-terpolymer and influences their symmetry. This effect was more pronounced in intercalated nanocomposites than in partially exfoliated nanocomposites with improved clay dispersion. It seems that the smaller, well-dispersed particles interfere less with thermoplastic phase continuity (Mirzadeh et al. 2010). A blend of polyamide 6 (PA6) and a co-polyester of... 

Synonyms N,N -dibutyl-thiourea N,N-dibutylthiourea N,N -di-n-butylthiourea i,3-dibutyl-2-thiourea 1,3-dibutylthiourea Uses accelerator for mercaptan-modified chloroprene rubber activator for ethylene-propylene-diene terpolymers and natural rubber antidegradant for natural rubber latex and thermoplastic styrene-butadiene rubber A... 

The high diffusion speed of small molecules (even under nearcritical conditions) in comparison with ordinary solvents and the dissolution selectivity of such systems can be used in the extraction of low-molecular organic products out of amorphous polymeric materials. Some results for acrylonitrile containing (co-) polymers/blends and thermoplastic polymers like ethylene-propylene-diene terpolymers are reported. 

EPDM is a terpolymer produced from ethylene, propylene, and a diene monomer that is usually 5-ethylidene-2-norbornene (ENB), see Eigure 3.12. Good EPDM properties are attainable because the stereospecific Ziegler-Natta catalysts and the newer metallocene-type catalysts are used in the polymerization of these elastomers. Much proprietary knowledge is applied with the latest catalysts to help the EPDM producers achieve a competitive advantage in the marketplace. Today, about 20% of all EPDM goes into the production of TPOs (thermoplastic olefins) or TPVs (thermoplastic vulcanizates), mainly for nontire automobile uses. (About 13% of EPDM production is used in TPO manufacture while about 7% is consumed in TPV production.)... 

Ethylene-Propylene-Diene Terpolymer (EPDM) is used for weather protection, tire sidewalls and coverstrips, wire, cable, mechanical goods, sheeting, hoses, tubing, and plastics modification and TPO. EPDM can be modified with silicone to reinforce high temperature performance of silicone and mechanical and physical strength of EPDM. Maleated EPDM (0.5 to 1.0%) is used to toughen nylon (impact modifier of nylon) and polyester thermoplastics (impact modifier for polycarbonate and polyester/carbonate alloys, PVC). Typical EPDM recipes are... 

Polyurethane elastomers (some TUP, thermoplastic polyurethane) These terpolymers can be used uncured for most applications however, selected grades can be eross-linked to enhance properties. As a family these elastomers are tough and wear resistant. They have excellent chemical resistance and flexibility. They can have excellent clearity. Applieations include cable jackets. Automotive fascia, connectors, fittings, and many, many more. Ethylene-Propylene-Dlene Terpolymers (EPDM) These terpolymers typically contain a few percent of a diene such as hexadiene. This material is easy to fabricate and then is usually heat-treated at 125"C to 175 C to induce crbss-linking. The physical properties are much different after crosslinking. Commonly, they are heavily formulated for applications which include wire jacketing systems, automotive hoses, and roof sheeting. 

Chloroprene rubber or, polychloroprene rubber Chlorotrifluoroethylene ethylene copolymers Cis-polyisoprene or, cis-l,4-polyisoprene Coumarone indene resins Diallyl phthalate Diallyl isophthalate Dough molding compound Elastomeric alloy melt processable rubber Elastomeric alloy thermoplastic vulcanizate Epichlohydrin rubber Epoxy or, epoxide Epoxy or, epoxide, with glass fiber Ethyl cellulose Ethylene acryic acid Ethylene propylene diene monomer (an EPR terpolymer)... 

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