Properties of Starch‐Based Nanocomposites with Starch‐Coated ZnONP Obtained by Flat‐Die Extrusion

• Published in: Starch - Stärke Vol. 75; no. 7-8
• Main Authors: Quintero‐Borregales, Lucía M., Guz, Lucas, Goyanes, Silvia, Famá, Lucía
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.07.2023
• Subjects: antibacterial activity; Biodegradation; Bioplastics; cassava starch nanocomposites; Composts; E coli; eco‐friendly synthesis; Environmental perception; Extrusion coating; Extrusion dies; Extrusion rate; flat die extrusion; Food industry; Food packaging; Food packaging industry; Hydrophobicity; Mechanical properties; Modulus of elasticity; Moisture content; Moisture effects; Nanocomposites; Nanoparticles; Nanotechnology; Starch; Water content; Zinc oxide; zinc oxide nanoparticles
• ISSN: 0038-9056; 1521-379X
• DOI: 10.1002/star.202200190

Fast‐growing environmental concern has made nanotechnology surge as an enhancer of eco‐friendly materials. In this research, biodegradable and active nanocomposites are developed from thermoplastic starch films with the incorporation of different concentrations of zinc oxide nanoparticles eco‐friendly synthesized with starch (ZnONP) (0, 0.5, 1, 2, and 5 wt.%) by flat‐die extrusion. ZnONP at 2 and 5 wt.% enhances Young's modulus (E), strain at break (εb), and tensile toughness (T), and decreases the water solubility (WS) and moisture content (MC), also inhibiting the growth of Escherichia coli. Additionally, with 5 wt.% of nanofiller, a hydrophobic material with UV‐A and UV‐B shielding is also achieved. Furthermore, all films are fully biodegraded in vegetal compost at around 4 weeks. The results show that ZnONP can be a very promising alternative as a reinforcing and active agent for preparing new starch‐based nanocomposites for the food packaging and coating industry. Starch‐ZnONP extrusion research finds cracks due to nanofiller‐matrix incompatibility. This paper aims to demonstrate that when the nanoparticles are synthetized with the matrix material, this problem is overcome.