Synthesis of methyl methacrylate/styrene copolymer bearing a carbomethoxyallyl end group with limited molecular weight by addition‐fragmentation reaction of methyl α‐(bromomethyl)‐acrylate

The synthesis of methyl methacrylate/styrene copolymer bearing overwhelmingly bromine and the 2‐carbomethoxyallyl group (CH2C(COOCH3)CH2) at the α‐ and ω‐termini instead of the fragment of the initiator with reduced molecular weight was investigated by using methyl α‐(bromomethyl)acrylate as chain transfer agent through the addition‐fragmentation mechanism. The molecular weight of the copolymer was effectively decreased with bromomethylacrylate, and the unsaturated end groups quantitatively bound to two types of the monomeric units were differentiated by means of 1H NMR spectroscopy. Equations estimating the reactivities of methyl α‐(bromomethyl)acrylate towards polystyrene and poly(methyl methacrylate) radicals were derived. Methyl α‐(bromomethyl)acrylate was found to be more reactive toward the poly(methyl methacrylate) radical than the polystyrene radical by a factor of 0,62.