A new diacid containing optically active functional groups, N,N 0 -(4,4 0 -diphthaloyl)-bis-L-leucine diacid (3), was synthesized and used in a preparation of a series of poly(amide-imide)s (PAIs) by direct polycondensation with various aromatic diamines in N-methyl-2-pyrrolidinone (NMP). All polymers derived from diacid (3) were highly organosoluble in the solvents like N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, g-butyrolactone, cyclohexanone, and chloroform at room temperature or upon heating. Inherent viscosities of the PAIs were found to range between 0.34 and 0.61ÁdL g À1 . All the PAIs afforded flexible and tough films. The glass-transition temperatures of these PAIs were recorded between 212 and 2378C by differential scanning calorimetry, and the 10% weight loss temperatures were ranging from 372 to 3938C and 336-3728C under nitrogen and air, respectively. The polyimide films had a tensile strength in the range of 63-88 MPa and a tensile modulus in the range of 1.2-1.7 GPa. Optically active PAIs exhibited specific rotations in the range of À10.588 to À38.708.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.