In order to investigate the polymerization of β-vinyl-β-propiolactone derivatives, α-phenyl-β-vinyl-β-propiolactone and α-methyl-α-phenyl-β-vinyl-β-propiolactone were synthesized and their radical and thermal polymerization behavior were investigated.
These two monomers were prepared by cyclization of corresponding β-hydroxy acid with p-toluene sulfonylchloride and pyridine as condensing agent. Polymerization was redically initiated with azobisisobutyronitrile(AIBN), benzoylperoxide(BPO) and dibutylperoxide(DTBP) as initiators and thermally at 120℃ in neat or in solution.
For all cases, the structure determined by H-NMR and IR spectra of monomers and polymers indicated that both monomers underwent ring-opening polymerization acompannied with decarboxylation.
The best result was obtained for bulk polymerization of α-methyl-α-phenyl-β-vinyl-β-propiolactone with DTBP, where conversion was 60%. In solution polymerization, the higher conversion was obtained in chlorobenzene.
This is the first example of ring-opening polymerization acompannied with carbon dioxide extrusion in the molecule.
