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To improve the wound-healing ability of chitosan, heparin, known to be effective in wound healing, was complexed with water-soluble chitosan (WSC) by chemical reaction. The chemical structure of the water-soluble chitosan–heparin (CH) complex was analyzed, and CH complex formation was confirmed with an FTIR spectrometer. The mechanical and thermal properties of the CH complex were measured by a tensile tester and thermal analyzers (DSC and TGA). Within the heparin content up to ≈470 IU/g in the aqueous CH complex solution, the intrinsic viscosity and tensile strength of the water-soluble CH complex gradually increased, but thermal stability slightly decreased by introducing the heparin into the WSC. When the heparin content was greater than these values (470 IU/g), the water-insoluble CH complex, which is supposed to have a multisubstituted or crosslinked structure, precipitated in the aqueous water-soluble CH complex solution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1784–1789, 2003

Starch-g-polycaprolactone copolymers were prepared by two-step reactions. The diisocyanate-terminated polycaprolactone (NCO–PCL) was prepared by introducing NCO on both hydroxyl ends of PCL using diisocyanates (DI) at a molar ratio between PCL and DI of 2:3. Then, the NCO–PCL was grafted onto corn starch at a weight ratio between starch and NCO–PCL of 2:1. The chemical structure of NCO–PCL and the starch-g-PCL copolymers were confirmed by using FTIR and ¹³C-NMR spectrometers, and then the thermal characteristics of the copolymers were investigated by DSC and TGA. By introducing NCO to PCL (Mn : 1250), the melting temperature (Tm ) was reduced from 58 to 45°C. In addition, by grafting the NCO–PCL (35–38%) prepared with 2,4-tolylene diisocyanate (TDI) or 4,4-diphenylmethane diisocyanate (MDI) onto starch, the glass transition temperatures (Tg 's) of the copolymers were both 238°C. With hexamethylene diisocyanate (HDI), however, Tg was found to be 195°C. The initial thermal degradation temperature of the starch-g-PCL copolymers were higher than that of unreacted starch (320 versus 290°C) when MDI was used, whereas the copolymers prepared with TDI or HDI underwent little change. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 986–993, 2000

Amidoximated chitosan-g-poly(acrylonitrile) (PAN) copolymer was prepared by a reaction between hydroxylamine and cyano group in chitosan-g-PAN copolymer prepared by grafting PAN onto crosslinked chitosan with epychlorohydrine. The adsorption and desorption capacities for heavy metal ions were measured under various conditions. The adsorption capacity of amidoximated chitosan-g-PAN copolymer increased with increasing pH values, and was increased for Cu²⁺ and Pb²⁺ but a little decreased for Zn²⁺ and Cd²⁺ with increasing PAN grafting percentage in amidoximated chitosan-g-PAN copolymer. In addition, desorption capacity for all metal ions was increased with increasing pH values in contrast to the adsorption results. Stability constants of amidoximated chitosan-g-PAN copolymer were higher for Cu²⁺ and Pb²⁺ but lower for Zn²⁺ and Cd²⁺ than those of crosslinked chitosan. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 469–476, 1999