Effect of the synthesis route on the structure and properties of polyurethane/nitrokonjac glucomannan semi‐interpenetrating polymer networks

摘要: With a synthesis route differing from previous methods, novel semi-interpenetrating polymer networks (semi-IPNs), coded UNK-II, were synthesized by the initial mixing of nitrokonjac glucomannan (NKGM) with castor oil in butanone and subsequent addition toluene diisocyanate (TDI) to begin polymerization reaction presence 1,4-butanediol (BD) as chain extender at 60°C. The results dynamic mechanical analysis, differential scanning calorimetry, ultraviolet spectroscopy indicated that certain degree microphase separation occurred between soft hard segments polyurethane (PU) UNK-II sheets. α-transition temperature, glass-transition heating capacity, tensile strength increased an increase NKGM content, this suggested interaction PU In method, semi-IPN materials (PUNK) TDI, then prepolymer was mixed cured BD extender. PUNK sheets had relatively good miscibility properties. However, for prepared method reported work, mainly played role reinforcement. When content less than 10%, exhibited miscibility, (26–28 MPa), breaking elongation (130–140%), similar those materials. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1948–1954,