Effect of graphene loading on thermomechanical properties of poly(vinyl alcohol)/starch blend

Polymer nanocomposites based on poly(vinyl alcohol) (PVA)/starch blend and graphene were prepared by solution mixing and casting. Glycerol was used as a plasticizer and added in the starch dispersion. The uniform dispersion of graphene in water was achieved by using an Ultrasonicator Probe. The composites were characterized by FTIR, tensile properties, X-ray diffraction (XRD), thermal analysis, and FE-SEM studies. FTIR studies indicated probable hydrogen bonding interaction between the oxygen containing groups on graphene surface and the OH groups in PVA and starch. Mechanical properties results showed that the optimum loading of graphene was 0.5 wt % in the blend. XRD studies indicated uniform dispersion of graphene in PVA/starch matrix upto 0.5 wt % loadings and further increase caused agglomeration. Thermal studies showed that the thermal stability of PVA increased and the crystallinity decreased in the presence of starch and graphene. FE-SEM studies showed that incorporation of graphene increased the ductility of the composites. 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41827.