Synthesis of ultra high-molecular-weight polycarbonate

Solid-state thermal polymerization of isolated Bisphenol A type macrocyclic oligocarbonates was carried out. The ring-opening polymerization progressed without any catalyst. Dimer (c-2mer) could be completely converted to the corresponding aromatic polycarbonate by heating at 300 °C for 10 min. In case of trimer (c-3mer), a small part of c-3mer remained unpolymerized even after heating for 30 min at 300 °C and complete conversion of tetramer (c-4mer) could not be achieved even in 120 min. Although the c-4mer exhibited much lower reactivity than c-2mer and c-3mer, its conversion was drastically improved by the addition of the c-2mer. The lower reactivity of the larger oligomer may be due to slower initiation of the larger ring. The ultra high-molecular-weight polymers (M w > 1,000,000) were soluble in chloroform.