ポリウレタン／キチン系複合材料の開発

Abstract

A novel functional composite by combining chitin and polyurethane elastomers was developed. Diisocyanates were reacted with polymer glycols at 80°C in a nitrogen atmosphere to form NCO-terminated prepolymers. Various amounts of chitin powder were added to a prepolymer with catalyst and mixed thoroughly. Then the reaction mixtures were molded by a press at 70-90°C for 1-7hr. After synthetic conditions were examined, it was found that the proper range of the amount of chitin, the optimum time, temperature, and pressure required for pressure-molding were 60wt%, 4hr, 90°C, and 30MPa, respectively. After screening several polymer glycols and diisocyanates, poly(oxytetramethylene) glycol and hexamethylene diisocyanate were found to be suitable for compatibility with chitin. Swelling, thermal property, tensile property, SEM, and water sorption of polyurethane/chitin composites were measured. The composites were brittle, but the wet composites became elastomeric. The composites had good humid-breathing function.