azeotropic copolymerisation

https://doi.org/10.1351/goldbook.15381
Binary copolymerization in which the two monomer reactivity ratios, \(r_{12}\) and \(r_{21}\) are not both equal to unity yet the copolymerization forms a copolymer with its molar ratio of monomer units equal to the molar ratio of monomers in the monomer feed.
Notes:
  1. An azeotropic polymerization occurs at only one specific molar ratio of monomers in the feed.
  2. Although, in its equality of copolymer and monomer-feed compositions, an azeotropic polymerization has the same feature as an ideal binary copolymerization in which \(r_{12} = r_{21} = 1\), it is not an ideal copolymerization as it has \(r_{12} r_{21} \neq 1\).
Source:
PAC, 2008, 80, 2163. (Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization (IUPAC Recommendations 2008)) on page 2166 [Terms] [Paper]