Sustainable, biodegradable, and recyclable bioplastics derived from renewable carboxymethyl cellulose and waste walnut shell

Yangyang Qian; Changpei Qin; Jianqiang Zhang; Bingfei Shi; Yuan Wei; Chunyu Wang; Jingchao Niu; Shimin Kang; Gang Chen; Yijun Liu

doi:10.1016/j.ijbiomac.2025.140130

Sustainable, biodegradable, and recyclable bioplastics derived from renewable carboxymethyl cellulose and waste walnut shell

Int J Biol Macromol. 2025 Jan 20:140130. doi: 10.1016/j.ijbiomac.2025.140130. Online ahead of print.

Authors

Yangyang Qian¹, Changpei Qin², Jianqiang Zhang³, Bingfei Shi⁴, Yuan Wei⁵, Chunyu Wang⁶, Jingchao Niu⁷, Shimin Kang⁷, Gang Chen⁶, Yijun Liu⁸

Affiliations

¹ College of Tea (Pu'er), West Yunnan University of Applied Sciences, Pu'er 665000, China; Hainan Key Laboratory of Storage & Processing of Fruits and Vegetables, Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China. Electronic address: [email protected].
² College of Tea (Pu'er), West Yunnan University of Applied Sciences, Pu'er 665000, China.
³ School of Biology and Chemistry, Pu'er University, Pu'er 665000, China.
⁴ School of Biology and Chemistry, Pu'er University, Pu'er 665000, China. Electronic address: [email protected].
⁵ School of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan 523000, China; Hainan Key Laboratory of Storage & Processing of Fruits and Vegetables, Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China. Electronic address: [email protected].
⁶ State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China.
⁷ School of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan 523000, China.
⁸ Hainan Key Laboratory of Storage & Processing of Fruits and Vegetables, Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China. Electronic address: [email protected].

PMID: 39842599
DOI: 10.1016/j.ijbiomac.2025.140130

Abstract

Manufacturing water-stable carboxymethyl cellulose (CMC) films as an alternative to commercial plastics is a promising solution to address plastic pollution. In this study, waste walnut shell (WS) was used as a natural lignocellulosic filler, glycerol as a plasticizer, and citric acid (CA) as a crosslinking agent for preparing high-performance CMC-based bioplastics through a one-pot casting method. When WS content was 12 wt%, the obtained CWGA-12 after optimization exhibited excellent mechanical properties (tensile strength ≈18.53 MPa, fracture strain ≈78.11 %), low surface roughness (< 16 nm), high optical transmittance (82.23 %), and superior thermal stability. Moreover, CWGA-12 could not decompose within 7 days of immersion in water, or even after 5 h of continuous stirring at 60 °C, while it could be reused after crushing, dissolving, and re-pouring under alkaline conditions. The alkali-recycled CWGA-12 exhibited a better UV-blocking capacity than before (99.22 % for UVA and 99.95 % for UVB). In addition, our bioplastic also had excellent biodegradability and disappeared completely after 2 days in rainy weather. Thus, our work not only offers an innovative approach to producing petroleum-based plastic substitutes with outstanding water resistance and UV-blocking properties but also paves the way for WS waste's broader applications.

Keywords: Bioplastics; Carboxymethyl cellulose; One-pot casting; UV-blocking; Waste walnut shell.