Polyfunctional monomers, grafting solution

UV- or y-radiation-induced grafting of cellulose films with styrene in methanol solution was significantly enhanced in the presence of H2SO4, lithium salts, urea, and other organic compounds and polyfunctional monomers... 

The new additives are polyfunctional monomers, which are exemplified by divlnylbenzene (DVB) and trlmethylol propane triacrylate (TMPTA) and are used in concentrations of 1% (v/v). When these polyfunctional monomers are added to the monomer solution, the results show that the gamma ray grafting of styrene in methanol to polyethylene is enhanced to a comparable degree to that of inclusion of acid (Table VII). The polyfunctionality of DVB and TMPTA is obviously Important in these reactions, since the number of grafting sites in the system is potentially enhanced by the Increase in... 

Mechanistically, it is important to note that the presence of polyfunctional monomers in the grafting solution does not lead to a uniform enhancement in grafting. Instead, increased yields of copolymer are only observed at specific monomer concentrations. In the present experiments, polyfunctional monomers appear to have a dual function, namely to enhance the copolymerisation and also cross-link the grafted polystyrene chains. Such monomers have previously been used to extensively cross-link linear polymer chains. 

Solvent resistant laminates for printed circuits were manufactured by coating of copper foil with a solution of PPO, BPA/DC, bis(4-maleimidophenyl) ether and Zn octoate in toluene the coated foil was laminated with PPO-impregnated glass fabric [47]. Similar result was achieved by the modification of PPO with polyfunctional cyanates or maleimides, liquid polybutadiene and a polymerization catalyst [48], A solvent and heat resistant composition for printed circuits consists of copoly [(2,6-dimethylphenylene)-(2,3,6-trimethylphenylene)]oxide, maleic anhydride grafted poly-1,2-butadiene, bis(4-maleimidophenyl)methane, BPA/DC and toluene. BPA/DC prepolymer may be used instead of the monomer [49]. 

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