Ethylene-methacrylic acid blends

The ionic aggregates present in an ionomer act as physical crosslinks and drastically change the polymer properties. The blending of two ionomers enhances the compatibility via ion-ion interaction. The compatibilisation of polymer blends by specific ion-dipole and ion-ion interactions has recently received wide attention [93-96]. FT-IR spectroscopy is a powerful technique for investigating such specific interactions [97-99] in an ionic blend made from the acid form of sulfonated polystyrene and poly[(ethyl acrylate - CO (4, vinyl pyridine)]. Datta and co-workers [98] characterised blends of zinc oxide-neutralised maleated EPDM (m-EPDM) and zinc salt of an ethylene-methacrylic acid copolymer (Zn-EMA), wherein Zn-EMA content does not exceed 50% by weight. The blend behaves as an ionic thermoplastic elastomer (ITPE). Blends (Z0, Z5 and Z10) were prepared according to the following formulations [98] ... 

Nucrel . [DuPont DuPont UK] Ther-m(f lastic ethylene methacrylic acid copolymos f( r extrusion into sheet, film, and coatings, for inj. molding, blow molding, thennoforming blend-able with other materials f[Pg.258]

Blends of ethylene-methacrylic acid or ethylene-acrylic acid copolymers with PE (Formion ) show either dispersed or co-continuous morphologies. They have outstanding fuel and oil resistance, adhesion to glass and metals, and ease of foaming. The blends are injection molded into bumper end caps, bumper mb strips, fender stone guard, extmded into products such as carpet heel pad and window trim. Moldings can also be foamed for bumper guards. 

When injecting blends of ethylene-methacrylic acid or ethylene-acrylic acid copolymer with PE (Formion ), it is recommended to keep full water cooling of hopper and throat and ensure that the rear zone temperature does not exceed 190°C to prevent bridging. 

Commercial ionomers are ethylene-methacrylic acid copolymers and terpolymers in which the carboxylic acid moiety is partially neutralized with sodium or zinc, to promote interchain ionic bonding. Ionomers exhibit excellent low temperature toughness, chemical resistance and adhesion. However they lack in stiffness and heat resistance. Hence ionomer blends with polyolefins such as polyethylene have been developed which, upon reinforcing with suitable fillers, seem to give a unique combination of high strength, excellent low temperature toughness, and moderate stiff-... 

The grafting functionalization of a poly(vinylidene fluoride) powder by y-irradiation was achieved by Valenza et aL The amoimt of grafted meth-acrylic acid onto poly(vinylidene fluoride) (PVDF) powder was 19.7 w%. The grafted polymer was then blended at different ratios with an ionomer based on ethylene-methacrylic acid copolymer, partially neutralized (Surlyn 9970). Nongrafted PVDF and this ionomer are highly immiscible. The functionalization of the PVDF with methacrylic acid allows to compatibilize both... 

Compatibilized blends of ethylene-methacrylic acid copolymer and PS were prepared by Kim et al. (1998) through addition of S-co-4-vinylpyridine. Similarly, blends of poly(isobutyl methacrylate) were compatibilized with poly(styrene-co-methacrylic acid) using poly(isobutyl methacrylate-co-2-(A, A -dimethylamino) ethyl methacrylate) or poly(isobutyl methacrylate-co-4-vinylpyridine) (Habi and Djadoun 1999). Turcsayii (1995) has reported compatibilized blends of PE-g-(N-vinylimidazole) with acrylic acid-modified PP. 

LDPE/PA6 blends with ethylene-methacrylic acid copolymer Na salt ionomer as compatibilizer Thermal stability of blends using TGA TGA measurements demonstrated an improvement in thermal stability when iratomer was added Labor et al. 2004... 

Fig. 10.66 HDPE-polyamide-6 (20 wt%) blend with compatibilizer ethylene-methacrylic acid copolymer neutralized with metal ions (5 wt%). Injection-molded flexural bar in the skin zone as viewed under SEM (Xavier and Pendyala 2008)...

PE was blended with ethylene-methacrylic acid copolymer, 80 wt% ionomer, and ethylene-vinyl acetate, 10 wt% EVAc, for films with high toughness, stiffness, and impact resistance ... 

Recent work on crystallinity measurements is reported below sulfur containing ether ketones [14], polyethylene glycol [15], polystyrene (PS) [16, 17], (PC) [18], polyphenylene alkene diyls [19, 20], isotactic polypropylene [20, 21], polyethylene [21, 22], polyimide [23], poly(2,5 bis (4-methoxyphenyl) oxycarbonyl styrene [24], polyazomethine esters [25], PET-polybutylene terephthalate blends [26], polycyclohexyl ethylene copolymers [27], polycaprolactone [28], syndiotactic polystyrene [29, 30], polyvinylidene fluoride-trifluorethylene copolymer [30], polyethers [31], isotactic methyl methacrylate [32], soy protein isolate polymers [33], polyamide 6/66 [34], polytrimethylene-2,6-naphthalate [35, 36], PE like polyesters [37], polycyclohexadiene [38], p-dioxolone, L-lactide - polyethylene glycol copolymers [39], ethylene - methacrylic acid copolymers and ionomers [40]. 

Ali [89] reported the results of a study on a LDPE blend with an ionomer resin based on ethylene-methacrylic acid copolymer (Surlyn 1857 10 wt%), which also contained citric acid (1 wt%) as a blowing agent. The blend, as well as the reference samples of pure LDPE and LDPE/citric acid, were e-beam-irradiated at room temperature with a dose of 40kGy, and the EPR spectra were recorded at different time intervals after irradiation. The septet corresponding to allyl radicals was a dominant spectral component in the initial spectra, the total radical concentration being about 10% higher in the presence of the ionomer due to a contribution of Surlyn-derived radicals. The latter were more stable, such that in the blend the EPR signal was still observed three days after irradiation, whereas in the reference samples the radicals had decayed completely within 3.5 h. 

Poly(urethane)/poly(olefin) blend compositions are compatibi-lized using a zinc ionomer, based upon an ethylene/methacrylic acid/alkyl acrylate polymer, or a maleic anhydride-grafted ethylene oxide poly (olefin) elastomer (45). 

Nevertheless, several conunercial grades of moderate impact strength polyamides have been produced for a long time by simple melt blending with such impact modifiers as ethylene-ethyl acrylate, ethylene-acrylic acid copolymers and ionomers based on zinc neutralized, ethylene-methacrylic acid copolymers [15-16]. However, in the case of the PA-6, the zinc ionomers have been found to be particularly effective as impact modifiers... 

Fig. 11.46 Plot of spherulite radius as a function of time for poly(ethylene oxide) in blends with either ethylene-methacrylic acid or styrene-hydroxy styrene copolymer. With ethylene-methacrylic acid poly(ethylene oxide)/ethylene-methacrylic acid A 80/20, = 52.5 °C X 70/30, = 48 °C. With styrene-hydroxy styrene ...

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. 

Low density poly(ethylene) (LDPE) may have unsatisfactory heat seal properties, as they often do not provide sufficient adhesion between the sealing layers to result in a good adhesive seal for a package. Efforts to improve the heat seal characteristics of LDPE by blending them with other materials, such as ethylene copolymers with methacrylic acid or acrylic acid, have not had universal success. 

PVC can be blended with numerous other polymers to give it better processability and impact resistance. For the manufacture of food contact materials the following polymerizates and/or polymer mixtures from polymers manufactured from the above mentioned starting materials can be used Chlorinated polyolefins blends of styrene and graft copolymers and mixtures of polystyrene with polymerisate blends butadiene-acrylonitrile-copolymer blends (hard rubber) blends of ethylene and propylene, butylene, vinyl ester, and unsaturated aliphatic acids as well as salts and esters plasticizerfrec blends of methacrylic acid esters and acrylic acid esters with monofunctional saturated alcohols (Ci-C18) as well as blends of the esters of methacrylic acid butadiene and styrene as well as polymer blends of acrylic acid butyl ester and vinylpyrrolidone polyurethane manufactured from 1,6-hexamethylene diisocyanate, 1.4-butandiol and aliphatic polyesters from adipic acid and glycols. 

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