Polybutylene succinate thermo-coated corn husk as laminar reinforcement for crosslinked tapioca starch composite foams

Abstract

Tapioca starch laminated composite foams were prepared from glyoxal crosslink-tapioca starch and polybutylene succinate (PBS) using corn husks as reinforcement by compression molding technique. Corn husk content was fixed at 1% of crosslinked starch. Both sides of corn husk were treated with silane coupling agents, tetraethoxy silane (TEOS) at 10% and thermo-coated with PBS films at different concentrations (1%, 3% and 5%) by molding at 160 °C. Effect of PBS thermo-coated corn husks on foam morphology, water resistance and mechanical properties were investigated. The SEM micrographs of coated composite foams showed a relatively smooth surface of composite but more cracks were observed as increasing PBS concentration due to thermal degradation of PBS during compressing molding. It was found that impact strength and water resistance of laminar composite foams were increased in thermo-coated with PBS films. Crosslinked tapioca starch laminar composite foams with 3% PBS coated corn husk showed the highest impact strength and water resistance. Thermo-coated method was able to apply to prepare coated PBS on crosslinked tapioca starch laminar composite foams, however thermal degradation of PBS occurred especially at a high concentration which results in poor properties of starch laminar composite foams.