Mechanical and water resistance performance of physically cross-linked poly(vinyl alcohol) composite with poly(dopamine) modified cellulose nanocrystals

A novel strategy was developed for the construction of physically cross-linked poly(vinyl alcohol)- PVA composite reinforced by poly(dopamine) modified cellulose nanocrystals (PDA@CNCs) with robust mechanical and water resistance property. The PDA@CNC hybrid had improved thermal stability and the rod-like morphology of CNCs was well preserved after the PDA modification. The Young’s modulus, tensile strength and water resistance property of physically cross-linked PDA@CNC/PVA composites were obviously improved compared with the composites without cross-linking. The improved properties of the PDA@CNC/PVA composites were attributed to the destruction of intramolecular hydrogen bond and reconstruction of intermolecular hydrogen bonds as well as ferric ions coordination cross-linking interactions. The excellent mechanical and water resistance property of the developed PDA@CNC/PVA provides a path way for the development of water induced-mechanically adaptive PDA@CNC functional nanocomposites for applications such as direct ink writing in 3D/4D printing.