Polyvinyl alcohol Biodegradable Foams Containing Cellulose Fibres

The preparation of polyvinyl alcohol (PVOH) based foams containing pulp cellulose fibres and microfibrillated cellulose (MFC) fibre is reported, aiming at the realization of sustainable "green-composites." Foams were obtained through an eco-friendly preparation method able to generate a pore structure by entrapping air into the polymer/filler aqueous dispersion during a high-speed mixing. The effect of pulp cellulose fibres (Bc1000) and MFC on foam microstructure, water vapor absorption behavior, and mechanical properties was studied. The addition of small amount of MFC (1-5-wt%) induced a progressive decrease of the average cell diameter and an increase of the cell density; whereas Bc1000 cellulose fibres affected the cell shape and regularity of PVOH based foams. A reduction of the water vapor absorption in PVOH/MFC and PVOH/Bc1000 was recorded with respect to neat PVOH foam, in particular for foams containing pulp cellulose fibres. Finally, both MFC and Bc1000 increased the Young modulus and the compression deflection of PVOH based foams.