Characterisations of cassava starch and poly(butylene adipate‐co‐terephthalate) blown film with silicon dioxide nanocomposites
Danaya Phothisarattana, Nathdanai Harnkarnsujarit
Abstract
Summary Films with high permeability are necessary for the packaging of agricultural products that respire to avoid anoxic conditions. This research developed and characterised bioplastic nanocomposite films with enhanced permeation and increased strength. Thermoplastic starch (TPS) was compounded with silicon dioxide (SiO 2 ) and blended with poly (butylene adipate‐co‐terephthalate) (PBAT) to produce bioplastic PBAT/TPS blend films via blown‐film extrusion. Different SiO 2 contents (0.5%–1%) were dispersed in the matrices, causing interaction via hydrogen bonding with the TPS phase. SiO 2 at 1% significantly improved melting of the polymer blends, giving increasing amorphous ratios of the polymeric films. Microstructures and surface topography indicated voids between incompatible components and porous structures that improved permeation. Increasing SiO 2 content linearly enhanced oxygen and water vapour permeability by up to 39% and 16%, respectively. Tensile strength and elongation at break increased and decreased up to 40% and 32%, respectively, indicating increased rigidity due to adding solid nanoparticles to 1%. Migration phenomena of the film components, that is molecules with diol structures and silicon compounds depended on types of simulant and microstructures that induced swelling and release of the compounds. Film permeabilities increased, thereby facilitating air and humidity flow through the packaging.