Preparation and Performance of Pueraria lobata Root Powder/Polylactic Acid Composite Films

Shuang Zhao¹, Shenglan Chen², Shuan Ren¹, Gang Li³, Ke Song^1,4, Jie Guo^1,4, Shima Liu^1,4, Jian He^1,4, Xianwu Zhou^1,4,*
1 Key Laboratory of Hunan Forest Products and Chemical Industry Engineering, Jishou University, Zhangjiajie, 427000, China
2 Central South Inventory and Planning Institute of National Forestry and Grassland Administration, Changsha, 410000, China
3 School of Civil Engineering and Architecture, Jishou University, Zhangjiajie, 427000, China
4 College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
* Corresponding Author: Xianwu Zhou. Email: zhouxianwu@jsu.edu.cn
(This article belongs to this Special Issue: Polylactide Based Biopolymeric Systems)

Journal of Renewable Materials https://doi.org/10.32604/jrm.2023.026066

Received 13 August 2022; Accepted 26 October 2022; Published online 14 November 2022

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Abstract

Petroleum-based materials, such as plastic, are characterized by adverse environmental pollution; as a result, researchers have sought alternative degradable plastics that are environmentally friendly, such as polylactic acid (PLA). PLA has shown great potential to replace petroleum-based plastics. In this study, seven different samples of unmodified Pueraria lobata root powder (PRP) with different contents (i.e., 0, 5, 10, 15, 20, 25, and 30 wt%) and three different modified PRPs (i.e., treated with NaOH, NaOH-KH-550, and Formic) were used to reinforce polylactic acid (PLA) via solution casting process. These prepared PRP/PLA composite films were characterized using SEM, FTIR, UV-visible spectra analysis, TG, DSC, weight loss measurement (wt%), and mechanical measurements. The results showed that the PRP modified with KH-550 (PRPK) intensified the interaction in the interface region between the PRP and the PLA matrix, thus increasing the tensile strength (54.5 MPa), elongation at break (2.8%), and Young’s modulus (3310 MPa) of the PRPK/PLA biofilms. Contact angle measurement showed that the PRP treatments contributed to the hydrophobicity of films. The transparency of PRP-10/PLA film at λ₈₀₀ was 11.09%, and its UVA and UVB transmittance were 3.28 and 1.16, respectively. After blending PLA with PRP, the PRP/PLA composite films exhibited excellent biodegradability. In summary, PRPK improved the mechanical properties of PLA and prevented the films from ultraviolet light, suggesting that PRPK-5/PLA film could be used as packaging materials.