Effects of biomass additives on mechanical strength and water resistance of corn starch straws

To explore a biomass material for significantly improving mechanical strength and water resistance of corn starch straws, lotus root powder, wheat flour and bamboo powder were chosen to study and compare the structure and performances of starch straws. Corn starch straws (CS), corn starch/lotus root powder straws (CSL), corn starch/wheat flour straws (CSW) and corn starch/bamboo powder straws (CSB) were prepared by thermoplastic extrusion. The results showed that CSW had the strongest hydrogen bonding interactions among starch straws. CSW had the largest FTIR 1047/1022 cm−1 ratio and relative crystallinity, indicating the highest degree of short- and long-range order and the highest crystallization melting temperature (298 °C). The relaxation time of all corn starch/additive straws decreased, indicating that stronger chain segment interactions. CSL had the highest flexural strength (81.72 MPa). CSL had the lowest water absorption value after soaked in water at 70 °C, whereas CSW had the lowest water absorption value after soaked in water at 4 and 25 °C. CSL was suitable for hot drinks, while CSW was more suitable for cold drinks. The outcomes would provide a new theoretical basis for selecting the most appropriate additives from biomass materials to interact with corn starch to improve mechanical properties and water resistance of corn starch straws.