Synthesis and characterization of new cardo poly(bisbenzothiazole)s containing cyclohexylidene units

A new diaminobenzenethiol 1,1-bis(4-amino-3-mercaptophenyl) cyclohexane dihydrochloride (BAMPCH · 2HCl) containing the bulky pendant cyclohexylidene group was synthesized from cyclohexanone in three steps. Its chemical structure was characterized by 1H NMR, 13C NMR, MS, FT-IR and EA. Aromatic poly(bisbenzothiazole)s (PBTs) were prepared from the new monomer and five aromatic dicarboxylic acids by direct polycondensation. The inherent viscosities were in the range of 0.78–2.04 dL/g. These polymers exhibited good solubility and thermal stability. Most of the prepared PBTs were soluble in various polar solvents. The decomposition temperatures at 10% weight loss were in the range of 482–518 °C in nitrogen. X-ray diffractograms of PBTs showed that all polymers were amorphous.