Transparent low-flammability epoxy resins using a benzoguanamine-based DOPO derivative

Abstract

We successfully prepared a highly effective flame-retardant additive called hsalbenzoguanamine phosphaphenanthrene (HDPD) through salicylaldehyde and nitrogen-rich benzoguanamine. The introduction of HDPD into epoxy resin (EP) sharply enhanced the flame retardancy of EP/HDPD thermosets. The introduction of 6 wt% HDPD into EP succeeded in reaching the V-0 rating. Limited oxygen index results revealed the high flame-retarding performance of HDPD. Cone calorimeter test data revealed that heat and smoke released from EP/6 wt% HDPD thermoset were significantly restrained. In addition, EP/6 wt% HDPD thermoset demonstrated excellent transmittance and mechanical strength. The transmittance of EP/6 wt% HDPD was assessed from 520 to 800 nm. The results showed that transmittance of EP/6 wt% HDPD were nearly 90% of the control group.

Enhance the fire safety of epoxy resin using ammonium polyphosphate flame retardant with the sandwich structure containing catalytic carbon formation function

“…Therefore, it is crucial to improve the flame retardant properties of EP, which requires the incorporation of flame retardants to improve their fire safety performance. [6][7][8] Since halogenated flame retardants are more environmentally harmful, phosphorus-containing flame retardants have become the most popular class. 9 Among them, ammonium polyphosphate (APP) is a common phosphoruscontaining complex flame retardant, 10,11 which usually forms an intumescent flame retardant (IFR) system together with other flame retardants by providing an acid source and a gas source.…”

“…For example, composites used in the aerospace industry need to meet excellent self‐extinguishing capability off fire. Therefore, it is crucial to improve the flame retardant properties of EP, which requires the incorporation of flame retardants to improve their fire safety performance 6–8 . Since halogenated flame retardants are more environmentally harmful, phosphorus‐containing flame retardants have become the most popular class 9 .…”

Synergistic flame retardant effect of cerium‐based DOPO derivative and intumescent flame retardants in polypropylene

“…DOPO derivatives exhibits good thermal stability and high flame retardant efficiency trapping free radicals in the gas phase and promoting the formation of a char layer in the condensed phase 17–19 . Recently, DOPO derivatives have been extensively studied in epoxy resins, and significantly improve flame retardant without degrading the optical, thermal, dielectric and mechanical properties of epoxy resins 20–23 . Moreover, DOPO derivatives also showed excellent flame retardancy to PP.…”

“…[17][18][19] Recently, DOPO derivatives have been extensively studied in epoxy resins, and significantly improve flame retardant without degrading the optical, thermal, dielectric and mechanical properties of epoxy resins. [20][21][22][23] Moreover, DOPO derivatives also showed excellent flame retardancy to PP. For example, Dong et al 24 studied the synergistic flame retardant effect of 9,10-dihydro-9-oxygen-10-phosphophenanthrene-10-oxide (DOPO) immobilized silica (SiO 2 -DOPO) nanoparticles in PP/IFR system.…”

High performance flame-retardant organic–inorganic hybrid epoxy composites with POSS and DOPO-based co-curing agent

“…4,5 In recent years, as a substitute for halogen ame retardants, DOPO and its derivatives have exhibited remarkable achievements for halogen-free ame-retarded epoxy resin. [6][7][8][9][10] However, the weak bond of phosphorus-containing groups that introduced into the epoxy matrix reduces the crosslinking density and consequently brings negative effects on thermal and mechanical properties of cured epoxy resin. 11,12 It is still worthy to develop a high-performance epoxy resin which combines with the excellent ame retardancy, thermal and mechanical properties.…”