Radical-initiated copolymers of styrene and p-formylstyrene, 1. Solution copolymerization and characterization

Kinetics of solution homopolymerization of p-formylstyrene

1 System name: 4-vinylbenzaldehyde.

(A) and copolymerization with styrene (S) have been examined at 60°C in N,N-dimethylformamide with 2,2′-azoisobutyronitrile as initiator. For p-formylstyrene, k_p/k = 0,135 L^1/2 · mol^?1/2 · s^?1/2 was estimated from the plot of monomer consumption versus time, i.e. a value greater than that for styrene (K_p and K_t are the rate constants of propagation and termination and termination, respectively). Reactivity ratios have been determined to be r_A = 3,0 and r_S = 0.2, indicating the reactivity of p-formylstyrene to be higher than that of styrene. Moreover, from initial copolymerization rates, the cross termination factor was calculated and found to depend upon the copolymer composition. Some solution properties of the homo- and copolymers have been analysed: solubility of (co)polymers, their molecular weight and its distribution (by gel permeation chromatography), and their composition and monomer sequence distribution (using ¹H and ¹³C NMR spectroscopy).