Akademik Veri Yönetim Sistemi
JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY, cilt.38, ss.559-576, 2001 (SCI-Expanded)
In this work, phenylisocyanate was polymerized in bulk and in a solution of THF by the complex base (CB), NaNH2/(CH3)(3)CONa catalyst under vacuum. The percent yield for bulk polymerization at -20 degreesC first increased with a slow rate reaching 32% conversion in 3 hours, then with a greater rate up to 86% in 6 hours. However, at 0 degreesC the yields were relatively smaller and not very reproducible. The product obtained was a high molecular weight polymer, insoluble in most solvents, and partially crystalline. The polymerization in THF at -20 degrees gave 58% conversion in 9 hours with a high rate first, then a slower rate. The polymer samples were characterized by fractionation, FT-IR, DSC, NMR, TGA, and X-ray powder diffraction. The polymer samples in the solution polymerization contained trimer and oligomeric components. No glass transition temperature was observed at the temperature interval studied.