Reactivity ratios in copolymerizations involving allyl methacrylate

Abstract

The copolymerizations of allyl methacrylate (AMA) with methyl methacrylate (MMA) and of AMA with N -vinyl-2-pyrrolidone (VP) have been effected in bulk by γ-irradiation to various stages of fractional conversion θ extending over a wide span of θ. Addition of n-heptane isolated the crosslinked copolymer. FT i.r. analysis on the supernatant solution yielded the composition of unreacted monomer mixture, which was used in conjunction with θ and the composition of initial feed to determine the reactivity ratios ( r ) via an iterative procedure involving a simplex algorithm, yielding AMA(1) MMA(2) r 1 = 1.55 ± 0.16, r 2 = 0.99 ± 0.19 and AMA(1) VP(2) r 1 = 1.408 ± 0.074, r 2 = 0.401 ± 0.044. For the system AMA VP , analysis of crosslinked copolymer (via nitrogen analysis) was also possible and manipulation of the data by three modern procedures afforded good agreement with the values of r 1 and r 2 obtained by analysis of monomer mixture alone.