Degradable bio-based fluorinated epoxy resin with excellent flame-retardant, dielectric, hydrophobic, and mechanical properties

• Published in: Advanced composites and hybrid materials Vol. 6; no. 4
• Main Authors: Wang, Zhimin, Hou, Guixiang, Xie, Jianqiang, Zhang, Zengping, Zhang, Xiangkai, Cai, Jiajin
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.08.2023
• Subjects: Ceramics; Chemistry and Materials Science; Composites; Glass; Materials Engineering; Materials Science; Natural Materials; Polymer Sciences; Epoxy thermosets; Biomass; Dielectric; Fluorinated; Fire safe; Degradable
• ISSN: 2522-0128; 2522-0136
• DOI: 10.1007/s42114-023-00704-6

One of the trendiest subjects is the production of multifunctional polymers with hydrophobicity, fire resistance, dielectric characteristics, degradability, and recyclability from renewable resources. They can be used to create composites with improved performance as well as composites that are recyclable. In this study, the bio-based fluorinated Schiff base SA-BTB prepared in previous work was reacted with epichlorohydrin to produce the bio-based fluorinated epoxy resin N, N′-(2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-dial) bis (1-(3,5))-dimethoxy-4-(oxirane-2-ylmethoxy)phenyl)methenamine (SA-BTB-EP), which was reacted with 4,4′-methylenedianiline (DDM) to acquire SA-BTB-EP/DDM. It was found that the storage modulus and carbon residue of SA-BTB-EP/DDM increased by 42.5% and 4.79 times, respectively, in comparison to DGEHBA/DDM after curing. Additionally, the presence of fluorine enhanced the material’s dielectric and hydrophobic properties. In frequencies below 5 MHz, the SA-BTB-EP/DDM system exhibited a lower dielectric constant and dielectric loss compared to the DGEHBA/DDM system. The mechanical properties and water contact of SA-BTB-EP/DDM proved to be significantly superior to those of DGEHBA/DDM. Due to the inclusion of a Schiff base structure in SA-BTB-EP, cured fluorinated epoxy resins also demonstrated a higher limiting oxygen index (LOI), a lower total heat release rate (THR), and a reduced peak heat release rate (pk-HRR) when compared to DGEHBA/DDM. Subsequently, the combustion mechanism was examined using combined TG-IR technology, and the acid-catalyzed degradation of Schiff base epoxy resins was explored. This study highlights the potential of SA-BTB-EP as a composite matrix and presents an environmentally friendly approach for creating bio-based fluorinated materials. Graphical Abstract