Elastomeric alloy-thermoplastic

Rader C.P. and Abdou Sabet S., Two phase elastomeric alloys. Thermoplastic Elastomers from Rubber Plastic Blends (De S.K. and Bhowmick, A.K., eds.), Ellis Horwood, London, 1990, 159. 

Most TPEs fall in one of six categories, listed in order of increasing cost and performance styrenic block copolymers, polyolefin blends (TPOs), elastomeric alloys, thermoplastic polyurethanes (TPUs), thermoplastic copolyesters, and thermoplastic polyamides [3]. 

Vulcanized elastomeric alloys (EA) are TPEs composed of mixtures of two or more polymers that have received a proprietary treatment. Elastomeric alloy-thermoplastic vulcanizates (EA-TPVs) are a category of TPEs made of a rubber and plastic polymer mixture in which the rubber phase is highly vulcanized. The plastic phase of an EA-TPV is a polypropylene, and the rubber phase is an ethylene-propylene elastomer. 

Considerable improvements in properties result, compared to RRPP, if cross-linking/curing is introduced into the rubber particles. PR modified, rubber compounds. Such materials may be known as dynamically crosslinked polyolefin elastomer or TPO-XL or, as a d5mamically vulcanized material or, as an elastomeric alloy (EA) or, as an elastomeric alloy thermoplastic vulcanizate (EA-TPV). If enough plastic is present (say 50%), the compound can still be easily processed by thermoplastic techniques. 

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)... 

SCH02] ScHOLZ H., POtschke P., Michael H., et al., Morphology and mechanical properties of elastomeric alloys fi-om rubber crumb and thermoplastics , Kautschuk Gummi Kunststoffe, vol. 55, no. 11, pp. 584-589,2002. 

Thermoplastic elastomers (TPEs) continue to grow in commercial importance. These materials combine the functional properties of comparable thermoset elastomers with the fabrication advantages of thermoplastics. As a class, TPEs comprise several types of materials such as elastomeric alloys (EAs), styrenic block copolymers, copolyesters, and thermoplastic polyurethanes. 

In contrast to the rigid TPOs described above, low-modulus/flexible grades of TPO blends are also produced commercially. In flexible TPOs, the rubber content can be as high as 60 %, and in some cases, the dispersed rubber may also be partially cross-linked during the mixing without losing the thermoplastic character of the matrix. However, the latter type of dynamically vulcanized elastomeric alloys or thermoplastic vulcanizate rubbers (TPVs) are considered as a separate class of elastomeric materials and hence will be discussed under elastomer blends. On the other hand, the soft TPO blends discussed here contain a low-modulus olefln copolymer elastomer as the major component with some polypropylene added to impart melt processability. 

Thermoplastic elastomer, TPE Elastomer/thermoplastic blend, TEO Elastomeric alloy, EA TEO EA... 

Chattopadhyay S., Chaki T.K., and Bhowmick A.K., New thermoplastic elastomers from poly(ethyle-neoctene) (engage), poly(ethylene-vinyl acetate) and low-density polyethylene by electron beam technology structural characterization and mechanical properties. Rubber Chem. TechnoL, 74, 815, 2001. Roy Choudhury N. and Dutta N.K., Thermoplastic elastomeric natural rubber-polypropylene blends with reference to interaction between the components. Advances in Polymer Blends and Alloys Technology, Vol. 5 (K. Finlayson, ed.), Technomic Publishers, Pensylvania, 1994, 161. 

Commercially important elastomeric thermoplastic alloys are dynamically vulcanized blends of polypropylene with high volume fractions of EPDM, polybutadiene rubber, nitrile rubber, and butyl rubber (Santoprene , Vyram , Geolast and Trefsin ) all currently sold by Advanced Elastomer Systems, a joint venture of Monsanto and Exxon. Another recent member of the commercial dynamically cured elastomeric thermoplastic alloys is the blend of PVC and a crosslinked ethylene copolymer (Alcryn , DuPont). The current consumption of all the elastomeric thermoplastic alloys in the USA is over 23 kton/y, with the EPDM/PP blend (Santoprene ) assuming about 90% of the market share. 

This term is usually used to apply to all adhesives other than natmal adhesives (i.e., elastomeric, thermoplastic, thermosetting, and alloys). All structural adhesives are synthetic. 

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