Open Access

ARTICLE

Development of Flame Retardant Composite Based on Glucose-Citric Acid-Based Resin Reinforced by Walnut Shell Powder

Zhenzhou Wang¹, Rui Luo¹, Wenqing Yang¹, Seng Hua Lee^2,*, Wei Chen Lum³, Longjiang Liu⁴, Xiaojian Zhou¹, Jun Zhang^1,*

1 Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products, Southwest Forestry University, Kunming, 650224, China
2 Department of Wood Industry, Faculty of Applied Sciences, Universiti Teknologi MARA Pahang Branch Jengka Campus, Bandar Tun Razak, 26400, Pahang, Malaysia
3 Department of Bio and Natural Resource, Faculty of Bioengineering and Technology, Universiti Malaysia Kelantan, Jeli, 17600, Kelantan, Malaysia
4 School of Chemical Engineering, Yunnan Vocational College of National-Defense Technology, Yunnan Open University, Kunming, 650223, China

* Corresponding Authors: Seng Hua Lee. Email: ; Jun Zhang. Email:

Journal of Renewable Materials 2025, 13(6), 1229-1249. https://doi.org/10.32604/jrm.2025.02024-0073

Received 26 December 2024; Accepted 27 February 2025; Issue published 23 June 2025

Abstract

Highly flame-retardant bio-based composites were prepared in this study. Firstly, glucose-citric acid (GC) resin was synthesized through the interaction of glucose and citric acid derived from agricultural and forestry sources. Polyvinyl alcohol (PVA) served as a toughening agent, whereas walnut shell powder (WSP) functioned as a filler in the formulation of a thermosetting bio-based GC-PVA-WSP (GCPW) composite with GC resin. The findings demonstrated that boric acid increased the limited oxygen index (LOI) value of GCPW to 33%, while simultaneously diminishing its total smoke production (TSP) by 99.9%, and achieving a flame retardant index (FRI) of 5.04. In addition, the incorporation of WSP enhanced the compressive strength of the GCPW composite to 9.15 MPa. Concurrently, the GCPW composite demonstrates excellent hydrophobic properties, with a thermal conductivity as low as 0.086 W/m·K.

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