Methyl methacrylate free radical addition polymerisation

Diethyl vinyl phosphate can be co-polymerised with styrene, methyl methacrylate or acrylonitrile monomers by free radical addition, using benzoyl peroxide (12.84). Alternating or block-type polymers are presumably possible. 

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... 

Latex with hydroxyl functionalised cores of a methyl methacrylate/butyl acrylate/2-hydroxyethyl methacrylate copolymer, and carboxyl functionalised shells of a methyl methacrylate/butyl acrylate/methacrylic acid copolymer was prepared by free radical polymerisation. The latex was crosslinked using a cycloaliphatic diepoxide added by three alternative modes with the monomers during synthesis dissolved in the solvent and added after latex preparation and emulsified separately, then added. The latex film properties, including viscoelasticity, hardness, tensile properties, and water adsorption were evaluated as functions of crosslinker addition mode. Latex morphology was studied by transmission electron and atomic force microscopy. Optimum results were achieved by introducing half the epoxide by two-step emulsion polymerisation, the balance being added to the latex either in solution or as an emulsion. 8 refs. 

Water is the ideal solvent from the cost and pollution viewpoints, but it is a non-solvent for many surface coating polymers. It will ssolve a small number of homopolymers, notably those derived from acrylamide, acrylic acid, itaconic acid, vinyl methyl ether, vinyl pyrrolidone and vinyl sulphonic acid, but none of these homopolymers forms flexible films of use in the coatings industry. While copolymers of acrylic or methacrylic acids with acrylate esters are generally insoluble in water, their salts are soluble when the acid content is over 5% (for hydrophilic monomers) and 12% (for hydrophobic monomers). Such polymers can be prepared in solution, or in emulsion, but not in aqueous solution. This is because the acrylate esters are insoluble in water. The acid is copolymerised in the un-ionised form because the ion is unreactive to free radicals. In emulsion polymerisation, care has to be taken to avoid homopolymerisation of the acrylic or methacrylic acid in the water phase. Suppression of homopolymerisation requires a low concentration of acid throughout the polymerisation process. This can be achieved by using a long reaction period and slow addition of monomer mixture, or by careful pH buffer selection. 

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