EVA

EVA plastics Copolymers of elhene and vinyl acetate (vinyl elhanoaie). 

The systems of such type have been developed of all last 10 years. We shall bring some characteristics of one of the last development within the framework of European BRITE project, carried out in LETT This 3D cone-beam tomograph is referred to as EVA Bench or Equipment for Voludensimetry Analysis. It is oriented on NDT of industrial products from ceramics and other composites. One of the main task of this tomograph is achievement of high resolution at study of whole internal volume of researched object. For test sample of the size 10mm spatial resolution in 50mm was obtained [14]. 

LETI. 3D cone-beam X-ray Tomograph EVA ( Equipment for Volumedensitometry Analysis) Bench, 1996. 

EVA descriptors were proposed by Ferguson et al. [Ah, 47]. The EVA descriptor (EigenVAlue) extracts structural information from infrared spectra. The eigenva-... 

The mechanism of the Hantzsch s synthesis was studied at a very early stage by several authors. The intermediates were generally assumed to be open-chain a-thioketones, but in a series of papers by Murav eva and Schukina (470, 490) the isolation of hydroxythiazolines from the reaction between a-haloketones and a variety of thioureas was reported. 

INFRARED TECHNOLOGY AND RAMAN SPECTKOSCOPY - INFRARED TECHNOLOGY] (Vol 14) EVA. See Ethylene-vinyl acetate. 

Pentaerythritol in rosin ester form is used in hot-melt adhesive formulations, especially ethylene—vinyl acetate (EVA) copolymers, as a tackifier. Polyethers of pentaerythritol or trim ethyl ol eth an e are also used in EVA and polyurethane adhesives, which exhibit excellent bond strength and water resistance. The adhesives maybe available as EVA melts or dispersions (90,91) or as thixotropic, one-package, curable polyurethanes (92). Pentaerythritol spko ortho esters have been used in epoxy resin adhesives (93). The EVA adhesives are especially suitable for cellulose (paper, etc) bonding. 

HDPE, high density polyethylene PP, polypropylene EVA, ethylene—vinyl alcohol SMC, sheet-molding compound ERP, fiber-reinforced plastic LDPE, low density polyethylene PE, polyethylene BMC, bulk mol ding compound TPE, thermoplastic elastomer. 

Ethylene vinyl acetate copolymer (EVA) forms a soft, tacky film with good water-vapor barrier but very poor gas-barrier properties. It is widely used as a low temperature initiation and broad-range, heat-sealing medium. The film also serves for lamination to other substrates for heat-sealing purposes. 

In order to increase the solubiUty parameter of CPD-based resins, vinyl aromatic compounds, as well as other polar monomers, have been copolymerized with CPD. Indene and styrene are two common aromatic streams used to modify cyclodiene-based resins. They may be used as pure monomers or contained in aromatic steam cracked petroleum fractions. Addition of indene at the expense of DCPD in a thermal polymerization has been found to lower the yield and softening point of the resin (55). CompatibiUty of a resin with ethylene—vinyl acetate (EVA) copolymers, which are used in hot melt adhesive appHcations, may be improved by the copolymerization of aromatic monomers with CPD. As with other thermally polymerized CPD-based resins, aromatic modified thermal resins may be hydrogenated. 

Ethylene vinyl acetate (EVA) polymers are used in thermoplastic and thermosetting jacketing compounds for apphcations that require flame retardancy combined with low smoke emission during the fire as well as the absence of halogen in the composition. 

In West Europe, a similar pattern of evolution began ia the 1960s with informal meetings and was formalized ia 1967 when the European Chemical Marketing Research Association (ECMRA) became a division of the European Association for Industrial Marketing (EVAE). EVAE was later renamed the Eederation of European Marketing Research Association (EEMRA) and has about 500 members of which about 300 are ECMRA members. 

Fig. 10. Preparation and morphology of toughened PVC (a) secondary PVC grain (50—250 flm) (b) modified PVC with coherent primary grain (ca 1 -lm) (220). CPE = chlorinated polyethylene EVA = ethylene—vinyl acetate copolymers ABS = acrylonitrile—butadiene—styrene MBS = methyl...

Vinyl Acetate—Ethylene Copolymers. In these random copolymers, the ratio of ethylene to vinyl acetate (EVA) is varied from 30—60%. As the vinyl acetate content increases, the oil and heat resistance increases. With higher ethylene content the physical strength, tensile, and tear increases. The polymers are cured with peroxide. The main properties of these elastomers include heat resistance, moderate oil and solvent resistance, low compression set, good weather resistance, high damping, exceUent o2one resistance, and they can be easily colored (see Vinyl polymers, poly(VINYL acetate)). 

Bayer, USI, and DuPont are U.S. suppHers. There is an estimated 2300—4000 t/yr of EVA used in the United States. Uses include automotive electrical system components, eg, ignition cable, footwear, weatherstripping, and misceUaneous O-rings and seals for industrial appHcations. 

Fig. 2. U.S. consumption of vinyl acetate, where represents PVAc I, poly(vinyl alcohol) (PVA) A, ethylene—vinyl acetate (EVA) O, PVB , EVOFl ...

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