Reinforcing and toughening of polyurethane by chemically modified Konjac glucomannan nanocrystal

Konjac glucomannan (KGM) nanocrystal obtained from native KGM by sulfuric acid hydrolysis was modified by using benzoyl chloride, and the improvement of hydrophobicity was confirmed by contact angle measurements. The chemically modified KGM nanocrystals with nanosize smaller than 100 nm, which confirmed by TEM, were used as fillers to prepare polyurethane nanocomposites. The morphology, thermal stability, and mechanical properties of the polyurethane nanocomposite films were investigated by means of SEM, TGA, and tensile testing. It is worth noting that the obtained KGM/PU nanocomposites showed simultaneous enhancements both in strength and elongation. The synergistic interaction between the fillers and the matrix played an important role in the improvement of mechanical properties. POLYM. COMPOS., 38:1447–1453, 2017. © 2015 Society of Plastics Engineers