A Novel P/N/Si-Containing Vanillin-Based Compound for a Flame-Retardant, Tough Yet Strong Epoxy Thermoset

• Published in: Polymers Vol. 15; no. 10; p. 2384
• Main Authors: He, Siyuan, Chi, Cheng, Peng, Chaohua, Zeng, Birong, Chen, Yongming, Miao, Zhongxi, Xu, Hui, Luo, Weiang, Chen, Guorong, Fu, Zhenping, Dai, Lizong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.05.2023; MDPI
• Subjects: Curing; epoxy resin; Epoxy resins; Fire prevention; Fire protection; Fire safety; Fireproofing agents; flame retardant; Flame retardants; Impact strength; Mechanical properties; Nanomaterials; Nitrogen; NMR; Nuclear magnetic resonance; Phosphorus; Silicon compounds; Storage modulus; strength and toughness; synergistic effect; Toughness; Vacuum distillation; Vanillin; China; United States > US; Germany; epoxy resin; flame retardant; vanillin; strength and toughness; synergistic effect
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym15102384

It is still extremely challenging to endow epoxy resins (EPs) with excellent flame retardancy and high toughness. In this work, we propose a facile strategy of combining rigid-flexible groups, promoting groups and polar phosphorus groups with the vanillin compound, which implements a dual functional modification for EPs. With only 0.22% phosphorus loading, the modified EPs obtain a limiting oxygen index (LOI) value of 31.5% and reach V-0 grade in UL-94 vertical burning tests. Particularly, the introduction of P/N/Si-containing vanillin-based flame retardant (DPBSi) improves the mechanical properties of EPs, including toughness and strength. Compared with EPs, the storage modulus and impact strength of EP composites can increase by 61.1% and 240%, respectively. Therefore, this work introduces a novel molecular design strategy for constructing an epoxy system with high-efficiency fire safety and excellent mechanical properties, giving it immense potential for broadening the application fields of EPs.