THE EXTENSION OF THE RESTRICTED PENULTIMATE SCHEME OF BINARY COPOLYMERIZATION TO TERNARY-SYSTEMS

The so-called ''restricted'' penultimate scheme of binary copolymerization - first presented by Fukuda et al. - is extended to ternary systems without introducing extra parameters not inherent in the three binary systems which form the ternary systems. The crucial assumption is that the restricted penultimate effect is only dependent (1) on the type of monomer forming the terminal radical and (2) the monomer replacing this type of monomer in the penultimate unit, but is independent of the monomer to be added. Accordingly, the scheme is fully described by quantities taken from the binary copolymerizations forming the ternary system. This general principle is still valid when the number of different monomers in the copolymerization system is even increased beyond three. Comparison between predicted values of the phenomenological propagation constant ($) over bar k(p) with the few experimental data available for terpolymerization systems indicates a satisfactory agreement.