Journal of Polymer Science Part A: Polymer Chemistry, Vol.37, No.14, 2551-2558, 1999
Synthesis and cationic ring-opening polymerization of mono- and bifunctional spiro orthoesters containing ester groups and depolymerization of the obtained polymers: An approach to chemical recycling for polyesters as a model system
A spiro orthoester having an ester moiety, 2-acetoxymethyl-1,4,6-trioxaspiro[4.6] undecane (4) was synthesized, and its cationic polymerization and depolymerization of the obtained polymer (5) were carried out. The monomer 4 underwent cationic polymerization with a cationic catalyst to afford the corresponding poly(cyclic orthoester) 5, The obtained polymer 5 could be depolymerized with a cationic catalyst to regenerate the monomer 4 in an excellent yield. Further, bifunctional spiro orthoesters (6, 8, 9) having diester moieties were synthesized from terephthalic acid, succinic acid, and 1,4-cyclohexanedicarboxylic acid, and their acid-catalyzed reversible crosslinking-decrosslinking was examined. The bifunctional monomer 6 derived from terephthalic acid underwent cationic crosslinking to afford the corresponding network polymer (7), which could be also depolymerized to regenerate the original bifunctional monomer 6,
Keywords:spiro orthoester;2-acetoxymethyl-1,4,6,-trioxaspiro[4.6]undecane;cationic ring-opening polymerization;depolymerization;crosslinking;decrosslinking