Poly(vinyl alcohol) (PVA) was blended with 10,20,30,40, and 50 wt % of starch with and without crosslinking by solution casting process. The solution-casted films were dried and tested for physicomechanical properties like tensile strength, tensile elongation, tensile modulus, tear and burst strengths, density, and thermal analysis by differential scanning calorimetry (DSC). These PVA/starch films were further characterized for moisture content; solubility resistance in water, 5% acetic acid, 50% ethanol, and sunflower oil; and swelling characteristics in 50% ethanol and sunflower oil. The crosslinked PVA/starch composite films show significant improvement in tensile strength, tensile modulus, tear and burst strengths, and solubility resistance over the uncrosslinked films. Between the crosslinked and uncrosslinked films, the uncrosslinked films have higher tensile elongation, moisture content, moisture absorption, and swelling over the crosslinked films.

Crosslinked poly(vinyl alcohol) was blended with 10, 20, 40, and 50 wt % starch by a solution-casting process. The solution-cast films were dried, and then their physicomechanical properties including tensile strength, tensile elongation, tensile modulus, tear strength and density, and burst strength and density were tested. Thermal analysis was performed by differential scanning calorimetry. A moisture analysis of the PVA/starch films was performed and their moisture content determined. Also investigated were the films'resistance to solubility in water, 5% acetic acid, 50% ethanol, and sunflower oil and their swelling characteristics in 50% ethanol and sunflower oil. The prepared PVA/starch blends showed significant improvement in tensile modulus and in resistance to solubility in water, 5% acetic acid, and 50% ethanol.

Nanocomposites of poly(vinyl alcohol) (PVA) with Mg-Al layered double hydroxides (LDHs) were prepared with different compositions, viz., 2, 4, 6, and 8 wt %, of LDH, by solution-intercalation method. The effect of LDH contents on thermal, physicomechanical, and morphological property of PVA films were investigated. Differential scanning calorimetric analysis reveals that LDH layers promote a new crystalline phase for PVA. The tensile analysis of PVA/LDH nanocomposites indicates reduction in tensile strength and modulus with change in LDH concentration and moisture. The microstructure analysis by optical microscopy and scanning electron microscopy demonstrates exfoliation and dispersion of LDHs in the PVA matrix in a disorderly fashion. The primary focus of the present investigation is to explore the potential of LDHs as nanofiller in a polyhydroxy polymer without surface modification.

A series of sodium alginate (SA) and starch blends, namely 100/0, 90/10, 80/20, 70/30, and 60/40, were processed into films by solution casting process and the obtained SA/starch blends have been characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). DSC analysis shows single glass transition temperature (T g ) up to 30 wt % starch content in the blend, indicating the compatibility and interaction between SA and starch molecules. The TGA reveals the reduction in thermal stability of SA/starch with increase in starch content. FTIR analysis demonstrated the existence of specific intermolecular interactions between carbonyl groups of SA and hydroxyl groups of starch. The morphological analysis by SEM shows the homogeneous distribution of starch in the SA matrix.

To determine the possibility of using sugarcane bagasse (SCB) waste as reinforcing filler in the thermoplastic polymer matrix, SCB-reinforced polypropylene (PP) composites were prepared. The PP and SCB composites were prepared by the extrusion of PP resin with 5, 10, 15, and 20 wt % of SCB filler in a corotating twin screw extruder. The extruded strands were cut into pellets and injection molded to make test specimens. These specimens were tested for physicomechanical properties such as tensile, flexural, Izod, and Charpy impact strengths, density, water absorption, and thermal characteristics, namely, heat deflection temperature (HDT), melt flow index, and thermogravimetric analysis. It was found that the flexural strength increased from 23.66 to 26.84 MPa, Izod impact strength increased from 10.499 to 13.23 Kg cm/cm, Charpy impact strength increased from 10.096 to 13.98 Kg cm/cm, and HDT increased from 45.5 to 66.58C, with increase in filler loading from 5 to 20% in the PP matrix. However, the tensile strength and elongation decreased from 32.22 to 27.21 MPa and 164.4 to 11.20% respectively.