Synthesis of Monofunctional Metathesis Polymers

Significance

Ring-opening olefin metathesis polymerization (ROMP) of monomer 1 was initiated with Grubbs’ catalyst and allowed to achieve 60% conversion, followed by the addition of dioxepine monomer 3 or 4. Treatment of diblock copolymer 5 or 6 with HCl cleaved the acetal groups and led to decomposition of the second polymer block, thus affording the polymers 7 with the monofunctionalized (hydroxyl group) chain ends. The reaction can be conducted in the presence of residual monomer, yields narrow molecular weight distributions and allows the presence of functional groups in the monomer structure. Polymers 2, 5-7 were characterized by NMR spectroscopy, gel permeation chromatography (GPC) as well as MALDI-TOF mass spectrometry.