The following table gives the reactivity ratios for free radical copolymerization of Styrene with (a) butadiene, (b) acrylonitrile and (c) vinyl acetate. For each of these copolymerizations:
(i) Plot the instantaneous copolymer composition in the complete range of monomeric mixture.
(ii) Calculate the composition of the copolymer formed at low conversions of an equimolar mixture of the two monomers.
(iii) Calculate the comonomer composition required to form a copolymer consisting of 50 mol% styrene repeat units
Monomer A Monomer B rA rB
Styrene; Butadiene 0.78 1.39
Styrene; Acrylonitrile 0.40 0.04
Vinyl Acetate; Styrene 0.01 55