Ethylene vinyl acetate maleic anhydride

In the case of EVOH being used as an interlayer with polyethylene or polystyrene, it is necessary to use additional adhesive layers such as an ethylene-vinyl acetate-maleic anhydride terpolymer (e.g. Orevac— Atochem). 

Over the past years considerable attention has been paid to the dispersing system since this controls the porosity of the particle. This is important both to ensure quick removal of vinyl chloride monomer after polymerisation and also to achieve easy processing and dry blendable polymers. Amongst materials quoted as protective colloids are vinyl acetate-maleic anhydride copolymers, fatty acid esters of glycerol, ethylene glycol and pentaerythritol, and, more recently, mixed cellulose ethers and partially hydrolysed polyfvinyl acetate). Much recent emphasis has been on mixed systems. 

Important copolymers of styrene are SBR (styrene butadiene rubbers), ABS, a copolymer with butadiene and acrylonitrile, and various copolymers with methacylic and acrylic esters, such as styrene-methyl methacrylate and styrene-methyl acrylate copolymers. Additionally, copolymers formed with one or more of the following monomers also exist ethylene, a-methyl styrene, vinyl acetate, maleic anhydride, and acrylonitrile. 

This is another important and widely used polymer. Nanocomposites have been prepared based on this rubber mostly for flame-retardancy behavior. Blends with acrylic functional polymer and maleic anhydride-grafted ethylene vinyl acetate (EVA) have also been used both with nanoclays and carbon nanotubes to prepare nanocomposites [65-69]. 

Notes EVA, ethylene vinyl acetate LLDPE-MAH, maleic anhydride grafted linear low-density polyethylene COPA, co-polyamide. 

E-VA-MA (ethylene-vinyl acetate copolymer, functionalized with maleic anhydride) Exxelor VA1803 Exxon... 

PP, polypropylene PS, polystyrene HDPE, high-density poylethylene EVA, ethylene vinyl acetate ABS, acrylonitrile-butadiene-styrene SMA, styrene maleic anhydride LDPE, low-density polyethylene LLDPE, linear low-density polyethylene. (From Ref. f)... 

Powder coatings are also formed from ethylene-vinyl acetate copolymers (see Section 3.4). Copolymers of ethylene with maleic acid (anhydride) of low molecular mass are water-soluble, form salts, and undergo cross-linking reactions. 

The simultaneous analysis of concentration and composition in GPC measurements is of significant interest for today s complex polyolefin copolymers. The same IR detector can be used to analyze ethylene-vinyl acetate (EVA) or other functional polyolefin copolymers (with a carbonyl group) as a function of molar mass. All that is needed is to replace the methyl interference filter by a carbonyl region filter. An example of a maleic anhydride-modified PE is shown in Fig. 9, with an IR interference filter measuring at 1,740 cm . ... 

Maleic anhydride oligomer. See Maleic anhydride homopolymer Maleic anhydride/polyethylene copolymer. See Ethylene/MA copolymer Maleic anhydride polymer. See Maleic anhydride homopolymer Maleic anhydride, polymer with ethyl acrylate and vinyl acetate, hydrolyzed CAS 113221-69-5 UN 1760... 

Some spectroscopic evidence for the formation of ionic bonds across adhesive interfaces is as follows. Using reflectance IR, Bistac et al. [24] showed that for an ethylene-vinyl acetate polymer grafted with 1% of maleic anhydride, and bonded to iron or zinc, new absorptions were present which were attributed to carboxylate (-COO ), and their presence coincided with strong adhesion. In an IR study of the bonding of maleic anhydride to naturally oxidised aluminium, Schneider et al [25] showed that the anhydride is hydrolysed in the early stages of adhesion, taking about 1 min on exposure to laboratory air. They suggested that the hydrolysed acid is bonded to two aluminium cations as shown in Fig. 5. 

Graft copolymers between unsatnrated acids, especially acrylic acid and maleic anhydride (MA), and polyolefins (PE and PP) are widely used as surface modifiers and compatibilisers, sometimes in combination with bi-functional coupling agents [46], for talc, calcium carbonate and calcined clays. Such polymer coatings include polypropylene-maleic anhydride [47], polypropylene c/s-4-cyclohexene-l,2 dicarboxylic acid [48], polystearyl or polylauryl acrylate [49], polypropylene-acrylic acid, partially oxidised poly(butane diol) [50] and ethylene-vinyl acetate copolymers [51]. Acid-containing products can react with basic fillers. With most other types, they will simply adsorb on to the mineral surface, but they can form esters with some non-basic metal hydroxyls, notably silanols. 

Until 2003, Chen s [28], Qu s [29-31], and Hu s [32] groups independently reported nanocomposites with polymeric matrices for the first time the. In Hsueh and Chen s work, exfoUated polyimide/LDH was prepared by in situ polymerization of a mixture of aminobenzoate-modified Mg-Al LDH and polyamic acid (polyimide precursor) in N,N-dimethylactamide [28]. In other work, Chen and Qu successfully synthesized exfoliated polyethylene-g-maleic anhydride (PE-g-MA)/LDH nanocomposites by refluxing in a nonpolar xylene solution of PE-g-MA [29,30]. Then, Li et al. prepared polyfmethyl methacrylate) (PMMA)/MgAl LDH by exfoliation/adsorption with acetone as cosolvent [32]. Since then, polymer/LDH nanocomposites have attracted extensive interest. The wide variety of polymers used for nanocomposite preparation include polyethylene (PE) [29, 30, 33 9], polystyrene (PS) [48, 50-58], poly(propylene carbonate) [59], poly(3-hydroxybutyrate) [60-62], poly(vinyl chloride) [63], syndiotactic polystyrene [64], polyurethane [65], poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] [66], polypropylene (PP) [48, 67-70], nylon 6 [9,71,72], ethylene vinyl acetate copolymer (EVA) [73-77], poly(L-lactide) [78], poly(ethylene terephthalate) [79, 80], poly(caprolactone) [81], poly(p-dioxanone) [82], poly(vinyl alcohol) [83], PMMA [32,47, 48, 57, 84-93], poly(2-hydroxyethyl methacrylate) [94], poly(styrene-co-methyl methacrylate) [95], polyimide [28], and epoxy [96-98]. These nanocomposites often exhibit enhanced mechanical, thermal, optical, and electrical properties and flame retardancy. Among them, the thermal properties and flame retardancy are the most interesting and will be discussed in the following sections. 

Nevertheless, in other cases, a plastidzing effect of the nanopartides has been reported, which leads to a decrease in both the values of Tg and the storage modulus. Artzi et al. [127] reported in EVOH-montmorillonite nanocomposites a decrease of Tg values from 5 wt% of day. The same authors predict two opposing effects on the transition the confined chain mobility owing to interaction buildup, and an increased mobility due to reduction in the crystallinity degree as a consequence of polymer-clay interaction [128]. The addition of a compatibilizer, either maleic anhydride-grafted ethylene-vinyl acetate (EVA-g-MA) or maleic anhydride-grafted linear low-density polyethylene (LLDPE-g-MA), led to a decrease in the Tg values [129]. This 5wt% day content maximum is also described by McAdam et cd. in PA6-day nanocomposites [130]. 

Interactions between a steel surface and an ethylene-vinyl acetate copolymer grafted with maleic anhydride were investigated by FTIR diffuse reflectance spectroscopy. The failed surfaces obtained after a mechanical separation of the polymer/steel assemblies were analysed. A two-step mechanism was proposed the opening of the anhydride cycle by a hydrolysis reaction, leading to the formation of a carboxylic diacid, followed by the reaction of the acid with some oxidised metallic elements present at the metal surface. This study underlines the contribution of FTIR reflectance techniques to the understanding of adhesion mechanisms. 7 refs. 

Copolymers of ethylene vinyl acetate (EVA) grades Evatane 2020 and Evatane 2805 (Arkema) and Sevilen 11306-075 brand of JSC Sevilen (TU 6-05-1636-97) copolymer of ethylene vinyl acetate and maleic anhydride (EVAMA) grades Orevac 9305 and Orevac 9707 (Aikema) were used as the objects of the study. The main characteristics of the polymers are listed in the Table 1. 

Tacticity studies have been conducted on poly(3-methyl-l-butene) [120], poly(p-isopropyl-a-methyl styrene) [121], a-methyl styrene [122], polytetrafluoroethylene [123], polyacrylic acid [124], polymethylvinyl ethers [125], polyacrylonitrile [126, 127], polyvinyltrifluoro acetate [128], polyvinyl alcohol and its ethers [129, 130], isobutene-maleic anhydride [111], isobutene dimethyl fumerate [131], isobutene dimethyl maleate [131], polyacrylonitrile [127], ethylene - vinyl acetate [132-135], polyalkyl vinyl ethers [136, 137], ethyl-2-chloroacetate [133], poly-trans-1,3-pentadiene [138], isotactic-l-butene - propylene [139], butadiene - propylene [140], polybutene [141], polychloroprene [142], ethylene - vinyl chloride [143], chlorinated polyethylene [144, 145], poly-a-methyl styrene [146], styrene acrylic acid [147], a-methyl styrene - methacylonitrile [148], styrene acrylonitrile [149], styrene isobutene [150], poly(p-fluoro-a-methyl styrene) [151], polyarylamide-6 [152], PP - polyamide-6 [152], polystyrene oxide [153], polybutene [154], atraconic anhydride - p-chlorostyrene [155], styrene - maleic anhydride [156, 157], ethylene - vinyl acetate [158], polymethyl vinyl ether [159], propene - carbon monoxide [160], methyl(3,3,3-trifluoropropyl)siloxane [161], poly(diallyldimethyl ammonium chloride) [162], polypropene [163, 164], polyepichlorohydrin [165], maleic anhydride-p-chlorostyrene [166], polymethacrylonitrile [167] and polyvinyl acetate [168]. 

---