Understanding copolymerisation kinetics for the design of functional copolymers via free radical polymerisation

Determining the monomer sequence distribution of copolymers is important when correlating copolymer molecular structure (random, gradient etc. ) to macroscopic/material properties. We report here the relative monomer reactivities for the copolymerisation of methyl methacrylate (MMA) with functional monomers – poly(ethylene glycol) methyl ether methacrylate (PEGMEM M n 500 g mol −1 ), acetonide-protected dopamine methacrylamide (ADMA), methacrylic acid (MAA) and glycidyl methacrylate (GMA) – to provide information on monomer sequence distribution and compositional drift. Reactivity ratios were calculated, using non-linear least squares regression analysis, in the cases of the free radical copolymerisation of MMA with (i) PEGMEM ( r MMA = 1.17 r PEGMEM = 0.62) and (ii) ADMA ( r MMA = 2.21 r ADMA = 0.17). Additionally, monomer feed depletion as a function of total monomer conversion was monitored by 1 H NMR spectroscopy for a series of batch co- and terpolymerisations. This approach offers detailed insight into monomer compositional drift and copolymerisation kinetics. Such information provides a platform for the design of copolymers with specific desired properties e.g. adhesion, solubility or interfacial activity.