Synthesis and physico-chemical study of halogenated aromatic cardo polysulfonates

155-161Poly(R, R′, 4, 4′-cyclohexylidene diphenylene-2, 4-toluene disulfonate) (PS-3: R=R′=C1 and PS-4: R=CH3 and R′=C1) have been synthesized by interfacial polycondensation technique by using water-chloroform (4:1 v/v) as an interphase, alkali (0.12 mol) as an acid acceptor and cetyl trimethyl ammonium bromide as an emulsifier. The reaction time and temperature are 3½ h and 0ºC, respectively. The structure of PS-3 and PS-4 are supported by IR and NMR spectral data. The intrinsic viscosities of the said polymers are determined in different solvents at three different temperatures 30, 35 and 40ºC. The calculated and experimental (floatation method) densities are found in good agreement with small fractional free volume. PS-3 and PS-4 possess excellent resistance to hydrolytic attack against water, acids, alkalis and salt, moderate tensile strength (15.6-17.0 N/mm2), excellent volume resistivity (1.1 to 3.9 1015 Ω cm), high electric strength (33.9-32.9 kV/mm) and low dielectric constant (1.36), good thermal stability (360ºC and 340ºC) and high Tg (143.5oC and 134.3ºC). DSC and DTA endo/exothermic transitions have supported physico-chemical changes. No change in tensile strength is observed but volume resistivity has increased 1.5 to 54.2 times, while electric strength has increased 2.5 to 3.5 times upon introducing methyl and chlorine groups alone or in combination. The improvement in volume resistivity and dielectric constant is due to cancellation of partial charges present on the polymer molecules