Aromatic and brominated aromatic homopolycarbonates were synthesized by the two-phase phase-transfer-catalyzed polycondensation of bisphenols with trichloromethyl chloroformate at 25" C. The infrared spectra, inherent viscosity, x-ray diffraction, volubility, contact angle, differential scanning calorimetry, thermogravimetric analysis, and limiting oxygen index (LOI) of all polycarbonates were measured. Polycarbonates of moderate or large molar mass with inherent viscosities up to 0.77 dL/g were obtained in high yields with tetrabutylammonium bromide (TBAB) as a catalyst, sodium hydroxide as a base, and l,2-dichloroethane as solvent. The brominated polycarbonates have good flame retardency, as indicated by LOI values. The x-ray diffraction diagram showed that all polycarbonates were semicrystalline. The polycarbonate (PC-2) based on bisphenol S has greater crystal-Iinity than the others because of the sulfonyl group, which has a small van der Waals radius. The incorporation of the bromine atoms (PC-4-PC-6) on the ring decreased the crystallinity. Almost all polymers were soluble in DMF, pyridine, and phenol, but insoluble in acetone and rn-cresol. Volubility increased remarkably with bromine substitution. The contact angles of polycarbonates (PC-l-PC-3) lie in the of range 82 to 97 degrees greater than that of brominated polycarbonates (PC-4-PC-6). The nettability of the homopolycarbonate based on bisphenol S is greater than that of polycarbonates derived from bisphenol A and bisphenol AF. T. of polycarbonates lies in the range 141-206"C, although T. of polycarbonate based on bisphenol S was not detected. T~of brominated polycarbonates was remarkably greater than that of unbrominated polycarbonates.
These polymers obtained from aromatic bisphenols lost no mass helow 341"C, but 10% loss of mass was recorded above 396ยฐC in nitrogen. (C1 1997