https://doi.org/10.1351/goldbook.15416
Empirical equations expressing the monomer reactivity ratios in a binary radical copolymerization, \(r_{12}\) and \(r_{21}\), in terms of the empirical parameters \(Q\) and \(e\) for the two monomers, namely, \(\rm{Q}_{1}\), \(\rm{Q}_{2}\), \(\rm{e}_{1}\), and \(\rm{e}_{2}\), with\(r_{12} = (Q_{1}/Q_{2})\exp [-{e_{1}}(e_{1} - e_{2})]\) and \(r_{21} = (Q_{2}/Q_{1}) \exp [-{e_{2}}(e_{2} - e_{1})]\)
Notes:
- Although the parameters are empirically derived, the parameter \(Q\) is considered to be a measure of the stabilization by conjugation of a monomer and the radical derived from it, while the parameter \(e\) is considered to be a measure of the polar effects of substituents on the monomer and the radical derived from it.
- The Q-e scheme is known also as the Alfrey–Price scheme.