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

Abstract

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), 1H-NMR and 13C-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, 1H-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 ( Tg) between 130 and 160°C.