COPOLYMERIZATIONS OF METHYL ALPHA-BROMOACRYLATE, 2-BROMOETHYL METHACRYLATE AND 2,3-DIBROMOPROPYL METHACRYLATE WITH VINYLTRIACETOXYSILANE

Radical copolymerizations of methyl α-bromoacrylate, 2-bromoethyl methacrylate and 2,3-dibromopropyl methacrylate with vinyl triacetoxysilane (VTAS) were carried out in bulk at 60 ± 0.1° using azobisisobutyronitrile as initiator. The compositions of low conversion copolymers were determined by silicon estimation. The monomer reactivity ratios as calculated by the Kelen-Tüdős graphical method, the Fineman-Ross and the Intersection methods have been compared. The introduction of bromine at the α-position of the acrylate enhances the tendency towards cross propagation, i.e. k11 k12 decreases. Thermal degradation studies reveal that bilactone formation is more favourable in poly(methyl α-bromoacrylate); in copolymers with VTAS, the weight loss for lactone formation decreases with increase in silane concentration due to random distribution of silane units in the polymer chain. The influences of the silicon comonomer on properties of copolymers (such as solubility, molecular weight and thermal behaviour) were studied. © 1990.