Synthesis and Characterization of Novel Chiral Poly(imide-urethane) Derived from N,N′-(4,4′-carbonyl-diphthaloyl)-bis-(L-phenylalanine)diol with Different Diisocyanates

N,N′-(4,4′-carbonyl-diphthaloyl)-bis-(L-phenylalanine)diol (p4) as novel chiral diol was prepared from L-phenylalaninol (2) and 4,4′-carbonyldiphthalic dianhydride (3) in dry acetic acid under refluxing conditions in high yield and characterized with Fourier transform infrared (FTIR), 1 H-NMR and 13 C-NMR. The step-growth polymerization of this novel chiral diol (p4) containing an imide group and a chiral group with different diisocyanates in dry N-methylpyrrolidinone (NMP) was conducted under conventional heating conditions. The resulting new optically active polymers were obtained in good yields and their inherent viscosities ranged between 0.18 and 0.29 dL g —1 . The polymers were characterized with FTIR, 1 H-NMR, differential scanning calorimetry and thermogravimetric analysis. These polymers are soluble in aprotic-polar solvents such as N, N-dimethylacetamide, NMP, N, N-dimethylformamide, dimethyl sulfoxide and sulfuric acid. Thermogravimetric analysis showed that the 10% weight loss temperature under air atmosphere were more than 265°C and glass transition temperature ( T g ) between 130 and 160°C.