Ethylene glycol dimethacrylate swelling

Third Monomers. In order to achieve certain property improvements, nitrile mbber producers add a third monomer to the emulsion polymerization process. When methacrylic acid is added to the polymer stmcture, a carboxylated nitrile mbber with greatly enhanced abrasion properties is achieved (9). Carboxylated nitrile mbber carries the ASTM designation of XNBR. Cross-linking monomers, eg, divinylbenzene or ethylene glycol dimethacrylate, produce precross-linked mbbers with low nerve and die swell. To avoid extraction losses of antioxidant as a result of contact with fluids duriag service, grades of NBR are available that have utilized a special third monomer that contains an antioxidant moiety (10). FiaaHy, terpolymers prepared from 1,3-butadiene, acrylonitrile, and isoprene are also commercially available. 

Other functionalized supports that are able to serve in the asymmetric dihydroxylation of alkenes were reported by the groups of Sharpless (catalyst 25) [88], Sal-vadori (catalyst 26) [89-91] and Cmdden (catalyst 27) (Scheme 4.13) [92]. Commonly, the oxidations were carried out using K3Fe(CN)g as secondary oxidant in acetone/water or tert-butyl alcohol/water as solvents. For reasons of comparison, the dihydroxylation of trons-stilbene is depicted in Scheme 4.13. The polymeric catalysts could be reused but had to be regenerated after each experiment by treatment with small amounts of osmium tetroxide. A systematic study on the role of the polymeric support and the influence of the alkoxy or aryloxy group in the C-9 position of the immobilized cinchona alkaloids was conducted by Salvadori and coworkers [89-91]. Co-polymerization of a dihydroquinidine phthalazine derivative with hydroxyethylmethacrylate and ethylene glycol dimethacrylate afforded a functionalized polymer (26) with better swelling properties in polar solvents and hence improved performance in the dihydroxylation process [90]. 

The effect of irradiation dose and different polyfunctional monomers(PFMs) at a constant ratio of 10 phr on the physicochemical properties of a PVC formulation used as wire coating was investigated. The PFMs used were trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, pentaerythritol tetraacrylate, triallyl cyanurate and 1,6-hexanediol diacrylate. The properties studied included tensile properties at room and elevated temps., softening temp., swelling characteristics and volume resistivity. 18 refs. 

Later, they reported the photoregulation of the degree of ionization and swelling of poly(methacrylic acid) membrane cross-linked with 1 mol-% ethylene glycol dimethacrylate onto which positively charged p-phenylazophenyltrimethylammonium ions (PTA) were absorbed (Eq. (9)). 

Mention may also be made here of the 2-hydroxyethyl ester of methacrylic acid, which is the monomer used for soft contact lenses. Copolymerization with ethylene glycol dimethacrylate produces a hydrophilic network polymer (a hydrogel). Hydrogel polymers are brittle and glassy when dry but become soft and plastic on swelling in water. 

Monomer 268 was also copolymerized with hydroxyethyl methacrylate and ethylene glycol dimethacrylate as crosslinking agent in a 1/7/2 ratio to lead to the new polymer-supported alkaloid 274 (Scheme 112) [171]. This one was insoluble in all solvents and swelled very well in protic polar solvents. The catalytic activity of chiral polymer 274 was... 

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