A hyperbranched P/N/B-containing oligomer as multifunctional flame retardant for epoxy resins
writer：Huo SQ, Sai T, Ran SY, Guo ZH, Fang ZP*, Song PA*, Wang H.
keywords：Epoxy resin; Hyperbranched oligomer; Fire safety; Mechanical properties; Dielectric performances.
source：期刊
specific source：Composites Part B, 2022.4, 234: 109701
Issue time：2022年
Flame-retardant epoxy resins (EPs) with superior optical, mechanical and dielectric properties are highly desired in high-tech industries. In this work, a multifunctional hyperbranched additive (BDHDP) was synthesized for EPs. Our results showed that BDHDP catalyzed the curing of epoxy resin because of its tertiary amine and hydroxyl. At a low addition (< 3.0 wt%), BDHDP increased the glass-transition temperature and maintained the transmittance of epoxy thermoset. As expected, BDHDP improved the mechanical robustness and toughness, and reduced the dielectric constant and loss of EP because of the rigid phosphaphenanthrene groups and intra-molecular cavities. Moreover, BDHDP retarded the heat release and smoke generation during the combustion of the EP matrix. Adding 1.5 wt% of BDHDP increased the UL94 rating to V-0, and reduced the total smoke production by 16.4%. Hence, this study offers an effective method to create transparent EP thermosets with outstanding mechanical, dielectric and fire-retardant properties via incorporating a P/N/B-containing hyperbranched oligomer.