Ethylene Vinyl Alcohol Copolymer EVOH

One of the PVA derivatives extensively used in this field is ethylene-vinyl alcohol copolymer (EVOH). Their blends with different polyolefins are also effective as oxigen barrier materials. 

These discoveries provided the technology base for commercialization efforts of starch-based plastics by the Novon division of the Warner-Lambert Company.157,158 The thermoplastic compositions were based on blends of destructurized starch and various hydrophilic polymers, such as ethylene-vinyl alcohol copolymers (EVOH). Hydrophobic polymers and additives, such as plasticizers and lubricants, could also... 

EVA-copolymers are used as sealants. With vinyl acetate contents ranging from 15-40 % these copolymers are particularly applicable for the production of hot melts because of their good compatibility with fillers and other plastics. Ethylene vinyl alcohol copolymer (EVOH) is a plastic with exceptional barrier properties. It is manufactured by saponification of EVA. 

A series of ethylene-vinyl alcohol copolymers (EVOH) with different comonomer contents were studied by both solution state and soUd-state high-... 

There are two polymers used in a maj ority ofhigh barrier food packages copolymers containing polyvinylidene chloride (Saran ) and ethylene-vinyl alcohol copolymer (Eval, Selar-OH ). Packages in which either polyvinylidene chloride or ethylene-vinyl alcohol copolymer (EvOH) provide the barrier are invariably multilayer since neither of these materials offers the properties required to make a good monolayer structure. There are advantages and disadvantages associated with each of these materials, and the... 

Hydrolysis of EVA copolymers yields ethylene-vinyl alcohol copolymers (EVOH). EVOH has exceptional gas barrier properties as well as oil and organic solvent resistance. The poor moisture resistance of EVOH is overcome by coating, coextrusion, and lamination with other substrates. 

Polyamide (PA) powders are generally precipitated from solution. Ethylene-vinyl alcohol copolymer (EVOH) powders are precipitated by hydrolyzing ethylene-vinyl acetate copolymer solutions. 

A widely popular container or carton used to store liquid or solid food is coated/laminated with various barrier and sealant materials, for example, a high-density polyethylene (HOPE), a heat seal-able polymer material such as low-density polyethylene (LDPE), or a heat-sealable barrier material such as an ethylene vinyl alcohol copolymer (EVOH), which can emit unwanted odors created during extrusion coating or package converting/sealing. 

Material Family ETHYLENE VINYL ALCOHOL COPOLYMER (EVOH) ... 

Thermoplastic starch and ethylene-vinyl alcohol copolymer (EVOH) copolymer systems, depending on the processing conditions, starch type and copolymer composition, can generate a wide variety of morphologies and properties [89-98], Different microstructures have been observed as a function of different hydrophylicity of the synthetic copolymer from a droplet-like to a layered one [92], An in-depth description of this aspect will be presented in section 2.4.6. 

Deng, P.Y., Liu, M.H., Zhang, W.X., Sun, J.Z. Preparation and physical properties of enhanced radiation induced crosslinking of ethylene-vinyl alcohol copolymer (EVOH). Nucl. Instrum. Meth. Phys. Res. B 258, 357-361 (2007)... 

Recently, it was shown that ethylene-vinyl alcohol copolymer (EVOH) fibers constituting a fabric, formed small bone-like apatite crystallites on their surfaces in an SBF, when they were modified with a silane coupling agent and a CaO—Si02 gel on their surfaces, as shown in Figure 14.1.2f [61]. The same polymer also formed bonelike apatite on its surface in an SBF, when it was modified by a titania gel on its surface, and treated in hot water around 80°C to precipitate anatase [62]. 

Rapid developments are being made in the area of oxygen barrier enhancement of ethylene vinyl alcohol copolymer (EVOH) coextrusions in order to increase the shelf-life of such foods. Technology is advancing in two directions barrier improvement in the cup or tray coextrusion, and the replacement of double-seaming with heat-sealed or adhesively sealed lidding of the cups. 

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