Premium
Ring‐opening polymerization of cyclic urethanes and ring‐closing depolymerization of the respective polyurethanes
Author(s) -
Neffgen Stephan,
Keul Helmut,
Höcker Hartwig
Publication year - 1996
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.1996.030170602
Subject(s) - depolymerization , cationic polymerization , polymerization , polymer chemistry , monomer , condensation polymer , ring opening polymerization , materials science , polymer , oxetane , bulk polymerization , chemistry , radical polymerization , composite material
The cationic ring‐opening polymerization of trimethylene urethane (tetrahydro‐2 H ‐1,3‐oxazin‐2‐one) in the melt with methyl trifluoromethanesulfonate as initiator results in poly(trimethylene urethane) in yields of ≈70%. Under the same reaction conditions 2,2‐dimethyltrimethylene urethane (5,5‐dimethyltetrahydro‐2 H ‐1,3‐oxazin‐2‐one) cannot be polymerized. Poly(2,2‐dimethyltrimethylene urethane), however, was obtained via polycondensation polymerization. Both polymers exhibit a uniform microstructure as deduced from NMR spectroscopic analysis. Ring‐closing depolymerization in the melt with dibutyltin dimethoxide or titanium tetraisopropoxide at 140°C results the respective monomers in yields of ≈90%.