cross-propagation

https://doi.org/10.1351/goldbook.15393
Propagation reaction in a copolymerization in which a chain carrier, bearing at its active end a monomer unit of one kind, reacts with a monomer molecule of another kind.
Note: The recommended symbol for the rate constant of cross-propagation in a binary copolymerization is \(k_{ij}\) , in which \(i\) and \(j\) refer to (a) the type of terminal monomer unit of the chain carrier and (b) the reacting monomer molecule, respectively.
Source:
PAC, 2008, 80, 2163. (Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization (IUPAC Recommendations 2008)) on page 2172 [Terms] [Paper]