ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
Several classes of compounds promote the anhydrous condensation of phenyl chloroformate with itself to give diphenyl carbonate and phosgene (or its elements). The compounds in question act either as true catalysts (recoverable unchanged) or as reagents. Salts of magnesium and zinc, particularly the chlorides, belong to the catalytic class. Useful reagents included metal oxides (magnesium, zinc, and calcium) and alkali and alkaline earth metal carbonates, sulfites, bicarbonates, and bisulfites. High molecular weight aromatic polycarbonates were obtained by analogous reactions starting with difunctional chloroformates. Self-condensation of bisphenol-A dichloroformate in the presence of magnesium chloride afforded the polycarbonate with a reduced viscosity 0.2. The use of magnesium oxide allowed the preparation of polycarbonates having reduced viscosities in the useful plastic range (0.45 and higher).
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1965.070091010
