POLYMERS OF CARBONIC-ACID .3. THERMOTROPIC POLYCARBONATES DERIVED FROM 4,4'-DIHYDROXYBIPHENYL AND VARIOUS DIPHENOLS

Starting from 4,4-dihydroxybiphenyl and bis(trichloromethyl) carbonate as condensing reagent various copolycarbonates were prepared by the interfacial condensation method. Hydroquinone, methylhydroquinone, chlorohydroquinone, phenylhydroquinone, 4,4-dihydroxydiphenyl ether, 4,4-dihydroxybenzophenone, Bisphenol A, 4,4-dihydroxydiphenyl sulfide, and 4,4-dihydroxydiphenyl sulfone were used as comonomers. Furthermore, copolycarbonates with an alternating sequence were prepared from 4,4-dihydroxybiphenyl as models for 13C NMR sequence analyses. The copolycarbonates were characterized by elemental analyses, inherent viscosities, 13C NMR sequence analyses, DSC measurements, microscopy with polarized light, and thermogravimetric analyses. All copolycarbonates are amorphous materials with glass transition temperatures (T°C. A nematic melt was found for copolycarbonates containing methylhydroquinone, chlorohydroquinone, 4,4-dihydrodiphenyl ether, and 4,4-dihydroxybenzophenone. Ternary copolycarbonates consisting of 4,4-dihydroxybiphenyl, methylhydroquinone, and 4,4-dihydroxydiphenyl ether or 4,4-dihydroxybenzophenone are soluble in aprotic organic solvent, and tough films could be cast from their solutions in dichloromethane. © 1990, American Chemical Society. All rights reserved.