Role of bulky α‐substituent in free‐radical polymerization and copolymerization of methyl α‐(alkoxymethyl)acrylates

Methyl α‐(alkoxymethyl)acrylates were prepared from methyl α‐(bromomethyl)acrylate in 80–90% yield. The monomers homopolymerize fast to yield low‐molecular‐weight polymers. The monomers bearing a linear alkoxymethyl group except for the ethoxymethyl group are characterized by a relatively low ceiling temperature. The rate constants for propagation kp and termination kt of methyl α‐(butoxymethyl)acrylate were evaluated to be kp = 298 dm3 · mol−1 · s−1 and kt = 8 · 106 dm3 · mol−1 · s−1 at 60°C, respectively. The α‐(alkoxymethyl)acrylates are more reactive than methyl methacrylate toward polystyrene radical, except for the α‐(dodecyloxymethyl)acrylate which is slightly less reactive, indicating that an increase in the reactivity by the electron‐withdrawing character of the alkoxy group prevails over the steric hindrance against addition of the polymer radical, except for the large dodecyloxymethyl group.