In Vietnam, two students have developed a plastic bag replacement from cassava flour. Nguyen Cam Binh Minh and Nguyen Cam Kieu Khanh, students at Hue High School for the Gifted, developed a material using 100 ppm silver nano solution, pure polyvinyl alcohol powder, cassava starch and 99 percent glycerol. The starchy material can then be flattened into film to make biodegradable bags with tensile strength.
“One year ago, when making banh bot loc (a small, clear-looking, chewy tapioca dumpling), I accidentally discovered that the finest flour could create a thin film with tensile strength. I thought of flattening starch into thin film,” Khanh tells Vietnam.net.
PVA creates “pockets” to create tensile strength. Glycerol helped increase starch processing capabilities.
Tests show that the material has good antibacterial capability against E. coli and Salmonella bacteria and is biodegradable. Vietnam uses at least 90 million plastic bags daily.