Freely Moldable Modified Starch as a Sustainable and Recyclable Plastic.

Efficiently preparing a starch-based plastic with moisture insensitivity and toughness is a challenge to improve the high-value utilization of polysaccharide resources. Herein, a sustainable, recyclable starch-based plastic was prepared in a facile and eco-friendly way. First, starch acetoacetate (SAA) with different degrees of substitution (DSs) was synthesized by transesterification. Then, the SAA film was obtained through a solvent-free hot-pressing method. Notably, SAA with different DSs exhibited various glass transition temperatures (109-140 °C), and SAA with high DS (>0.84) was insoluble even after boiling in water for 1 h. Also, the maximum fracture strength of SAA film up to 15.5 MPa and a maximum elongation at break up to 30% were reached . In addition, the starch-based plastic film retained the original mechanical properties after three cycles of hot processing. In consideration of the facile preparation process, this protocol provided a new avenue for developing sustainable and recyclable starch-based plastics.

High strength holocellulose paper from bamboo as biodegradable packaging tape.

As the fast-growing of package business in express delivery industry, replacing traditional scotch tapes with degradable materials has attracted extensive attention. Herein, holocellulose paper (H-paper) was prepared by an efficient delignification and papermaking process from bamboo. The structure and properties of resultant holocellulose fibers and H-paper were characterized and compared with those from other pulping methods, such as Kraft pulping, enzyme treated, sulfite and alkaline sulfite process. The yield of holocellulose pulp (55%) increased by about 10% compared with that of other fibers. Compared to that of Kraft paper (38 MPa), the strength of H-paper increased by nearly 60% at similar density, reaching a maximum of 65 MPa. The total transmittance of H-paper was about 20% higher than Kraft paper. Moreover, H-papers displayed high mechanical properties, good printability, and degradability, which was important for the application as paper tape.

Holocellulose nanofibrils assisted exfoliation of boron nitride nanosheets for thermal management nanocomposite films.

High-quality boron nitride nanosheets (BNNSs) were exfoliated via eco-friendly holocellulose nanofibrils (HCNFs) assisted ultrasound treatment in water. The resultant H-BNNSs possessed high yields (23.4%), few surface defects, a high aspect ratio (~134), and excellent dispersibility in water (Zeta potential, -53.5 mV). Furthermore, H-BNNSs were functionalized by liquid metal (Gallium, Ga) dominated interface engineering and assembled with cellulose fibers into Ga@H-BNNSs filled nanocomposite films. Owing to the well-designed interface engineering, the obtained nanocomposite films exhibited outstanding integrated performance, especially excellent in-plane thermal conductivity (11.78 W m-1 K-1), and had great potential in the thermal management of flexible electronics.