Preparation and properties of crosslinked poly(vinyl alcohol)/nanofibrillated cellulose based biocomposite by subcritical water/CO₂ process

Abstract In the present work, for the first time plasticized poly(vinyl alcohol) (PVA)/nanofibrillated cellulose (NFC) based biocomposite was crosslinked by citric acid (CA) using subcritical water/CO₂ process. Presence of sufficient number of ‐OH groups in the backbone of plasticized PVA (p‐PVA) helps to form H bonding with SC‐NFC, which significantly improves the mechanical property of the biocomposite. Further, crosslinking of the same biocomposite helps to achieve hydrogel with superior modulus than that of PVA hydrogel alone. In subcritical medium, plasticized poly(vinyl alcohol)/nanofibrillated cellulose based biocomposite powder gets melted, fused and cross‐linked in a single step process to develop such hydrogel. Crosslinked plasticized poly(vinyl alcohol)/nanofibrillated cellulose based biocomposites were fully characterized in terms of gel content, thermal and chemical properties, morphology, swelling behavior and rheology. Excellent water swollen property, cellular structure and high storage modulus establish the potential of prepared biocomposite based hydrogels for several biomedical applications.