Cellulose nanofiber reinforced starch membrane with high mechanical strength and durability in water.

Single-use plastic become a post-consumer waste and create a big problem for the society and the environment. Polysaccharides are the potential replacement of single-use plastics, however lack of mechanical strength and water durability restrict their applications. In this study, we prepared a cellulose nanofiber reinforced starch membrane, which had adequate mechanical strength and durability in water. TEMPO-oxidized cellulose nanofiber (TCNF) was blended with three different types of modified starch: hydroxypropyl starch (HPS), acetyl starch (AS) and acetyl oxidized starch (AOS), respectively. It was demonstrated that the TCNF/starch membrane exhibited reduced swelling in water and enhanced mechanical strength in wet condition compared to TCNF or starch membrane because hemiacetal bonding was formed between TCNF and starch. TCNF/HPS membrane showed the highest wet tensile modulus (7 MPa) with the minimum swelling in water. Therefore, the TCNF reinforced HPS membranes may be served as potential substitutes for petrochemical plastic packaging.