Synthesis and characterization of poly(amide imide)s containing cyclohexylidene moieties with bulky substituents

Novel poly(amide imide)s (PAI) containing alkyl-substituted cyclohexylidene moieties were synthesized by conventional polycondensation of trimellitic anhydride chloride with novel aromatic diamines followed by chemical imidization using acetic anhydride and pyridine. The inherent viscosities of the resulting PAIs are relatively high and range from 71 to 112 mL g^–1. The prepared PAIs show excellent thermal stability and good solubility. The glass transition temperatures (T_g) measured by DSC are observed in the range of 312–342°C. Furthermore, all the polymers are readily soluble in less hygroscopic organic solvents like cyclohexanone, γ-butyrolactone as well as aprotic polar solvents.