Facile synthesis of branched poly(methyl methacrylate)s

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.