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Biodegradable cellulosic pulp foams with robustness and water resistance are urgently needed in nowadays to replace petroleum-based plastic foams for environmental sustainability. In this work, a facile protocol to fabricate robust poly-lactic acid (PLA) coated cellulose foams (PCCF) was developed through a combined water-based foaming and PLA melt-coating process using pulp as the raw material. In the synthesis, the so-called PLA coating was realized through melting PLA powders dispersed between fibers by an in-situ heating and post cooling process. Performance tests revealed that the incorporation of PLA coating significantly enhances mechanical strength, water stability, and biodegradability of the synthesized PCCF samples compared with conventional cellulosic foams. Specifically, the low-density PCCF were observed with mechanical strength up to 81.24 kPa, high water stability, and more than 95% degradation in 56 days. As the fabrication process is simple and pulp is highly cost competitive, our proposed synthesis strategy makes the PCCF a promising substitute for petroleum-based plastic foams at large-scale production., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In contemporary life, plastic, a kind of petroleum carbon source, has been produced and used in varieties of applications. However, the vast consumption of petroleum-based plastic and the burning of agricultural wastes make the environmental problems increasingly severe. Furthermore, a large number of lignocellulosic resources (such as corncob and wheat straw) are often wasted and burned, which will aggravate the environmental damage. In this paper, we use unbleached corncob and wheat straw pulp to fabricate the lignin-containing cellulose bio-composites (LCBs) to reduce non-renewable energy consumption and utilize agricultural wastes. The LCBs were obtained by a direct manufacturing process in benzyltrimethyl ammonium hydroxide (BzMe 3 NOH) aqueous solution under mild conditions, constituting an entwined composite structure of cellulose micro/nano-fibers. This unique micro/nano-structure provides bio-composites with the outstanding mechanical performance of 96.7 MPa and a high haze of 90.1%. Meanwhile, with the inherent lignin, the LCBs could filter over 81.8% UV-C. As the raw material used is pure natural lignocellulose, the bio-composites prepared have innate environmental friendliness. With exceptional mechanical strength, UV-shielding property, and innate environmental friendliness, the LCBs are possible and potential substitutes for traditional petroleum-based plastic that is easily aging or non-biodegradable., (Copyright © 2022 Elsevier B.V. All rights reserved.)