Poly , methyl crosslinking reactions

Many other crosslinking reactions are used in commercial applications. A variety of halogen-containing elastomers are crosslinked by heating with a basic oxide (e.g., MgO or ZnO) and a primary diamine [Labana, 1986 Schmiegel, 1979]. This includes poly(epichlorohydrin) (Sec. 7-2b-6) various co- and terpolymers of fluorinated monomers such as vinylidene fluoride, hexafluoropropene, perfluoro(methyl vinyl ether), and tetrafluoroethylene (Sec. 6-8e) and terpolymers of alkyl acrylate, acrylonitrile, and 2-chloroethyl vinyl ether (Sec. 6-8e). 

The formation of tri- and especially tetrasilanes which are already branched (tertiary Si-units) as the first reaction products (described elsewhere [4]) suggests the appearance of intermediate silylene species which could enter in insertion reactions of Si-Si as well as Si-Cl bonds. The tri- and tetrasilanes undergo thermal crosslinking reactions at reaction temperatures of 165-250 °C. In addition dehydrochlorination reactions initiated by acid H-abstraction of methyl groups cause the formation of carbosilane (methylene) units in the polymer framework. Table 1 shows the gross compositions of poly(methylchlorosilanes) which are determined by the reaction temperature. 

When the process involves two competitive reactions, some people prrfer to call those modified polymers interpenetrated polymer networks (IPNs) [5]. The formation of a polyether-urethane network in a loosely crosslinked poly(methyl methacrylate) matrix to increase its toughness can serve as one of the examples. From a general point of view, the analysis of the reaction-induced phase separation is the same (perhaps more complex) for IPNs than for rubber-modified epoxies or for high-impact polystyrene. 

In recent years, crosslinkable polymers have found a wide demand in the areas of interpenetrating polymer networks, non-linear optical materials, macro- and microlithography, and the formation of more thermally and chemically resistant materials. With this in mind, the controlled ROMP of 5-methacryloyl-l-cyclooctene (Scheme 8) was investigated to produce a linear polymer with cross-linkable methacrylate side chains. In addition, the copolymerisation of this monomer with cyclooctadiene (Scheme 9) allowed for the incorporation of a varying number of methacrylate side chains on the polymer backbone [23]. These copolymers were crosslinked through the methacrylate side chains with either thermal or photochemical initiation. Reaction of this multifunctionalised methacrylate polymer with methyl methacrylate under free radical polymerisation conditions led to the formation of AB crosslinked systems of poly(methyl methacrylate). A comparison of the... 

The low chemical and thermal stability of poly(vinyl ketones) leads to a sensitivity to degradation reactions. Poly(methyl isopropenyl ketone) lost water at about 250 °C, to yield glassy, red, non-crosslinked products. It was proposed that an intramolecular aldol... 

Poly(methyl vinyl ether-alt-MA), 316, 621 applications, 443, 450, 621 general properties, 425, 437 Poly(methyl vinyl ketone-alt-MA), 290, 322 Poly(4-methyl-5-vinylthiazole-co-MA), 387 Poly(2,5-norborndiene-co-sulfur dioxide), 362 Poly(octadecene-l-alt-MA), 431, 586 applications, 447, 586 properties, 434, 435 Poly(l,3,6-octatriene-co-MA), 349 Poly(l-octene-alt-MA), 338, 586 Poly(octyl vinyl ether-alt-maleic acid), solution properties, 439 Polyolefins MA containing, 289 MA ene reaction, 160 MA grafted, 477 maleimides in vulcanization, 511 Poly(olefins-co-MA) film properties, 436 process patents, 586 Poly(/ -oxathiene-alt-MA), 388, 412-414 Poly(oxycyclohexene), MA crosslinked, 516 Poly(l,3-pentadiene-alt-MA), 343, 346-348,... 

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