Water-resistant cellulose films coated with polyurethane-acrylamide grafted konjac glucomannan

The water-soluble coating, including the semi-interpenetrating polymer networks (IPNs) formed by polyurethane (PU) with acrylamide grafted konjac glucomannan (KGM), was prepared and coated to the regenerated cellulose film that was prepared from 7 wt.-% ramie cellulose cuoxam to give water-resistant films. The structure and properties of the coated films were studied by infrared, differential thermal analysis, transmission electron microscopy, ultraviolet, and tensile strength test. It was shown that there was strong interaction between the regenerated cellulose (RC) film and the semi-IPN coating layer at the interface, where covalent bonds and hydrogen bonds formed between -NCO groups in the coating and -OH groups in the RC film. The tensile strength and water resistances evaluated from the mechanical parameters of the coated films were much higher than those of the uncoated films.