Chemical modification of pullulan by isocyanate compounds

The modified pullulan derivatives having N-phenylurethane and N-hexyluretha ne groups in the side-chain (PI-PL and HI-FL) have been synthesized by the reactions of pullulan with phenyl isocyanate (PIC) and hexyl isocyanate (HI C), respectively. The structure of the derivatives was characterized by gel permeation chromatography, IR and H-1 NMR spectroscopy. From the measureme nt of differential scanning calorimetry of PI-FL and HI-FL with various deg rees of addition (DA) in the range of 0-3, it was revealed that both the de rivatives showed a clear glass transition temperature (T-g), which decrease d with the increasing DA of PIC and HIC. The pullulan derivatives were wate r-resistant and had good solubility in general organic solvents. (C) 2000 E lsevier Science Ltd. All rights reserved.