ring-opening copolymerization 

https://doi.org/10.1351/goldbook.R05395
A copolymerization which is a ring-opening polymerization with respect to at least one monomer.
Source:
PAC, 1996, 68, 2287. (Glossary of basic terms in polymer science (IUPAC Recommendations 1996)) on page 2308 [Terms] [Paper]