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Renewable environmentally friendly polysaccharides and their composites have been critically reviewed for biodegradable food packaging applications.

A two-step strategy to improve the thermoplasticity of bamboo powder (BP) by the combination of hydrothermal pretreatment (BP-LHW) and propargyl modification (BP-PB/BP-LHW-PB) in a heterogeneous system was developed in this research. It was observed that the hydrothermal pretreatment has a positive impact on the alkyne-functionalized BP-LHW, resulting in substantial change including the etherification of BP-LHW with propargyl bromide, breaking of crystalline phase of the cellulose fraction. Besides, the modified sample is significantly changed in the apparent morphology and reduced in the thermal stability and glass transition temperature (Tg). The Tg is attributed to the increase of free volume due to the increase of propargyl concentration in the modified samples. These results revealed that the combination of propargyl group into pretreated BP is an efficacious way to ameliorate the thermoplasticity. Notably, the thermoplasticity of BP-LHW-PB with high concentration of propargyl is significantly enhanced compared to BP-PB, which is owed to the enhanced molecular mobility resulting from the reduced interaction forces between the cellulose molecular. Herein, the application way that the building a "clickable" alkyne platform in BP to obtain multifunctional materials will be broadened in bamboo-based materials. The bio-based material with improved thermoplasticity was prepared by grafting propargyl bromide onto bamboo powder.

Natural chemicals obtained from the renewable resources were widely used in the modification of plant fibers. In this report, in order to develop thermoplasticity of materials, the bamboo powder (BP) after hydrothermal pretreatment (BP-LHW) was efficiently modified with natural rosin acid (BP-LHW-RA) by esterification reaction under heterogeneous condition. The results indicate that the modified BP-LHW-RA presents a strong peak at 1743 cm−1 in the FT-IR spectra, which attributed to the –C = O vibration of the ester group formed by the reaction between rosin acid and the BP-LHW, confirming that BP-LHW was successfully grafted with rosin acid. The C1/C3 ratio of BP-LHW-RA increased 1.35 times as compared with BP-LHW in XPS analysis. Meanwhile, the crystallization index of BP-LHW-RA decreased by 4.62%, and its surface became smooth and full. Moreover, the glass transition temperature of BP-LHW-RA was 200 °C. The work presents a green and feasible route to prepare bio-based materials with desired thermoplasticity by grafting natural rosin onto biomass substrate. The bio-based material with desired thermoplasticity was prepared by grafting natural rosin onto bamboo powder.

Lignin is the second most abundant biopolymer and the main source of aromatic structures on the earth. As a by-product of cellulose in the paper pulp production, lignin has rather low added-value applications. Sub-micro and nano- lignin materials maybe open promising high added-value applications. These new fields have brought about renewed interest for lignin. In this paper, the current developments of sub-micro and nano-lignin materials were reviewed. The synthetic routes between sub-micro and nano- lignin materials were summarized. All the different shapes, microstructures, and properties of these sub-micro and nano- lignin materials were compared with that of conventional lignin. The future trend toward micro- and nanostructured lignin-based materials is also suggested. It is expected that the small size of sub-micro and nano-lignin materials displays great progress, which are promising applications of various fields in the near future.