The effect of zirconium phosphonate with different functional groups on the structure and properties of chitosan film: THE EFFECT OF INTERFACIAL INTERACTION ON THE CHITOSAN COMPOSITE

Three types of zirconium phosphonate (org-ZrP) with different functional groups (-COOH, -SO3H, -NO2) were prepared first and then added into chitosan (CS) matrix, respectively. The effect of these functional groups on structure, morphologies, and mechanical properties of chitosan films was investigated. The Fourier transform infrared spectroscopy revealed that org-ZrP had intensely interacted with chitosan in the composites because of introducing functional groups on the fillers. The composite films filled with zirconium sulfophenylphosphonate exhibited the best mechanical properties among the three org-ZrP fillers. These differences of reinforcement effect appeared to be caused by the difference of interfacial interactions between the org-ZrP fillers and matrix. The stronger the interfacial interactions are, the better the reinforcement effect is. In addition, the moisture uptake (Mu) of CS/org-ZrP-n composite films depended on the hydrophilic property of functional groups. It was found that zirconium nitrophenyl phosphonate showed the best moisture barrier property due to its poor absorbability for water molecules. Copyright (C) 2014 John Wiley & Sons, Ltd.