Synthesis and Characterization of Thermally Curable Benzoxazine‐Functionalized Polystyrene Macromonomers

Abstract

Abstract Summary: Thermally curable benzoxazine ring‐containing polystyrene macromonomers were synthesized and characterized. 1,4‐Dibromo‐2,5‐bis(bromomethyl)benzene and 1,4‐dibromo‐2‐(bromomethyl)benzene were used as initiators in the atom transfer radical polymerization of styrene. The resulting polymers were used in combination with 3‐aminophenylboronic acid hemisulfate, for a Suzuki coupling. The obtained polymers, with amino groups in the middle or end of the chains, were reacted with formaldehyde and phenol to yield benzoxazine ring‐containing macromonomers. In addition to the glass transition temperature of the polystyrene segment observed at ca. 105 °C, differential scanning calorimetry thermograms exhibit an exotherm at ca. 276 °C corresponding to the oxazine thermal polymerization. Both macromonomers undergo thermal curing with the formation of thermosets having polystyrene segments. Structure of the benzoxazine‐functionalized polystyrene. magnified image Structure of the benzoxazine‐functionalized polystyrene.