Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemical Technology

1 1999

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: synteza poliakrylowęglanów

Sortuj według:

Ogranicz wyniki do:

Synthesis of polyarylocarbonates from dimethyl carbonate and bisphenol A

Wasilewski J., Tkacz B., Krueger A., Krakówka B., Dejnega M., Poskrobko J.

Polish Journal of Chemical Technology

1999

Vol. 1, nr 1

45-49

Polycarbonates were obtained in the conventional two-stage reaction. In the first stage low molecular weight prepolymer was synthesised and then the prepolymer was condensed to polycarbonate. Transesterification and condensation of the prepolymer was carried out with potassium borohydride as a catalyst. The synthesis of polycarbonate from dimethyl carbonate and bisphenol A with the addition of 0.05-0.20 mol/molBPA diphenyl carbonate was carried under the same conditions. Polycarbonate was obtained with the addition of diphenyl carbonate characterised by molecular weight (Mw) which is 2-3 times higher than the polymer, which was obtained only from dimethyl carbonate and bisphenol A. On the grounds of this study we came to the conclusion, that the addition of diphenyl carbonate to the reaction mixture in stage I helps condensation of the low molecular weight oligomers in stage II.