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With appropriate choice of reaction composition and conditions, copolymerisation of methyl methacrylate and ethylene glycol dimethacrylate using Cu-based ATRP or GTP methodologies yields soluble branched polymers in facile one-pot reactions.

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Soluble, branched methyl methacrylate copolymers have been prepared via facile, one-step, batch solution free-radical polymerisations taken to high conversion. Methyl methacrylate has been copolymerised with the brancher, ethylene glycol dimethacrylate, using a chain transfer agent to inhibit gelation. Soluble branched copolymers containing unreacted double bonds have been produced and characterised by SEC and H-1 NMR spectroscopy. It has been shown that the level of branching depends on the monomer concentration, the monomer/chain transfer agent feed ratio and the conversion. It appears that branching arises through the reaction of one vinyl group of the brancher to produce polymer chains containing pendent double bonds in the first instance, followed by the reaction of the unreacted pendent double bonds with additional monomer units or other growing chains

Branched poly(methyl methacrylate)s have been prepared using conventional solution phase free radical polymerization of methyl methacrylate (MMA) in the presence of a branching divinyl comonomer with appropriate levels of dodecanethiol (DDT) chain transfer agent added to inhibit gelation. The branching comonomers employed were five ethylene glycol dimethacrylates with varying lengths of PEG chains, divinylbenzene (DVB), and ethylene glycol diacrylate (EGDA). Soluble branched polymers were obtained in good yield with a MMA/brancher mole ratio up to 100/15. The minimum mole ratio of DDT required to avoid gelation was evaluated. The isolated polymers were characterized by elemental analysis to determine the level of DDT incorporated, by 1H NMR spectroscopy, to determine the molecular composition and in particular the level of brancher incorporated (both as a branch unit and as a pendant functionality), and by double detection SEC in order to evaluate the level of branching. The differing behaviors of the branchers are discussed with a focus on a comparison of ethylene glycol dimethacrylate (EGDMA), EGDA and DVB. The latter brancher has been shown to produce the most regularly branched material with the smallest molar mass distributions. In general, however, the latter are broad or very broad.