Enzyme-treated Wheat Straw-based PVOH Bio-composites: Development and Characterization

Valorization of lignocellulosic waste residues in the development of potential biodegradable composites has been of recent research interest. Recent research has shown that wheat straw can be used as a reinforcement material for the synthesis of novel polyvinyl alcohol (PVOH)based composites. However, certain pretreatment methodology needs to be used for the selective removal of the lignin component. The de-lignification of native wheat straw was performed using an in-house isolated ligninolytic consortium. The bio-composites were developed using the de-lignified wheat straw along with PVOH as the matrix phase and glycerol as a plasticizer via a compression molding technique. In this study, a structural analysis by Fourier transform infrared spectroscopy (FT-IR) showed that the enzymatic treatment led to noticeable changes in the chemical structure of the materials used. A dynamic mechanical analysis (DMA) of the composites revealed an increase in the tensile strength of the sample from 46.1 MPa +/- 0.1 MPa to 53.0 MPa +/- 0.9 MPa, upon the addition of the plasticizer. Also, there was a noticeable increase in the tensile modulus of composites from 2,130 MPa to 4,520 MPa, respectively. Topographical features of the newly synthesized PVOH-based bio-composites were observed using scanning electron microscopy.