Effects of aluminum hydroxide on mechanical, water resistance, and thermal properties of starch-based fiber-reinforced composites with foam structures

Abstract

Despite the large demand, the current biomass composites still exhibit problems of low mechanical properties, strong hydrophilicity, and poor thermal resistance, which limit biomass composites' application fields. Facing these problems, starch-based fiber-reinforced composites with foam structures were fabricated by hot pressing and foaming process, for the first time. In these composites, the corn starch serves as matrix while the sisal fiber acts as skeleton. Aluminum hydroxide (ATH) has been added to alter microstructures. To identify microstructure and material composition changes induced by ATH, scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy have been performed. Experimental results show that an appropriate ATH content can improve composite's ultimate tensile strength by as much as 37%. Molecular dynamic simulations were performed to understand ATH effects on tensile properties at an atomic level. In addition to tensile properties, the addition of ATH is also beneficial to improve the compressive properties, water resistance and thermal stability of starch-based fiber-reinforced composites, making the composite a potential candidate to replace traditional packaging materials. Therefore, this investigation will benefit the current packaging industry in that sustainable utilization of packaging materials can be realized.

Keywords

• Biomass composite
• Hot pressing and foaming
• Mechanical property
• Water resistance
• Thermal stability
• Molecular dynamics