Effect of Microfibrillated Cellulose Loading on Physical Properties of Starch/Polyvinyl Alcohol Composite Films

The starch/polyvinyl alcohol (PVA)/ microfibrillated cellulose (MFC) composite films were prepared using solution casting method after adding MFC into starch/PVA blend matrix.The effects of MFC content on the mechanical properties of starch/PVA composite films were investigated.As MFC content increases,the elongation at break and tensile strength increase firstly and then decrease.When the content of MFC is 2wt%,the tensile strength is 26.6 MPa and reaches the maximum.Through Fourier transform infrared (FTIR),scanning electron microscopy (SEM),X-ray diffraction (XRD) and thermogravimetric analysis (TGA),good dispersion of MFC in starch/PVA matrix at the loading of 2wt%,lower crystallinity of the starch/PVA/MFC films in comparison with starch/PVA blend and the effect of glass transition temperature increasing with MFC content from 0.5wt% to 4wt% can be found observed.And,incorporating MFC does not change the composition and crystal structure of the starch/PVA composite films.Thus,the reinforcing mechanism for the improvement of mechanical properties is attributed to the homogeneous dispersion of MFC with large aspect ratio,good compatibility and interfacial interactions between starch/PVA blend matrix and MFC.