A Study on the Synthesis, Curing Behavior and Flame Retardance of a Novel Flame Retardant Curing Agent for Epoxy Resin

Abstract

In this work, a flame retardant curing agent (DOPO-MAC) composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and methyl acrylamide (MAC) was synthesized successfully, and the structure of the compound was characterized by FT-IR and 1H-NMR. The non-isothermal kinetics of the epoxy resin/DOPO-MAC system with 1% phosphorus was studied by non-isothermal DSC method. The activation energy of the reaction (Ea), about 46 kJ/mol, was calculated by Kissinger and Ozawa method, indicating that the curing reaction was easy to carry out. The flame retardancy of the epoxy resin system was analyzed by vertical combustion test (UL94) and limiting oxygen index (LOI) test. The results showed that epoxy resin (EP) with 1% phosphorus successfully passed a UL-94 V-0 rating, and the LOI value increased along with the increasing of phosphorus content. It confirmed that DOPO-MAC possessed excellent flame retardance and higher curing reactivity. Moreover, the thermal stability of EP materials was also investigated by TGA. With the DOPO-MAC added, the residual mass of EP materials increased remarkably although the initial decomposition temperature decreased slightly.

Synergistic flame retardant linear low‐density polyethylene based on piperazine pyrophosphate and melamine cyanurate

“…For L7, porous char residues can be observed, which was resulted from the released inert gases of MCA or pyrolysis products. On the one hand, it destroyed the compactness of the char layer; on the other hand, the released inert gases diluted the oxygen concentration on the surface of the material and thickened the residues as a whole 23,26,27 …”

“…On the one hand, it destroyed the compactness of the char layer; on the other hand, the released inert gases diluted the oxygen concentration on the surface of the material and thickened the residues as a whole. 23,26,27…”

Molecular design and properties of intrinsic flame‐retardant P‐N synergistic epoxy resin

“…To address this issue, a new organic flame retardant containing phosphorus and nitrogen was developed by studying the flame retardant properties of polymers and related mechanisms. [2][3][4][5][6] When a fire occurs, it is not only property damage that ensues but also casualties, making flame retardant research on epoxy resin an essential prerequisite for ensuring its safe and effective use. [7][8][9][10] In recent decades, organohalogen flame retardants have been widely utilized for their low dosage and high efficiency in retarding flames.…”

“…However, the flammability of EP limits its potential applications in structural materials for electronic devices, aircraft, and ground vehicles. To address this issue, a new organic flame retardant containing phosphorus and nitrogen was developed by studying the flame retardant properties of polymers and related mechanisms 2–6 . When a fire occurs, it is not only property damage that ensues but also casualties, making flame retardant research on epoxy resin an essential prerequisite for ensuring its safe and effective use 7–10 …”

Thermal Stability and Flame Retardancy of Epoxy Resin with DOPO‐Based Compound Containing Triazole and Hydroxyl Groups

“…[12][13][14][15] There has been reported that the flame-retardant efficiency of DOPO can be further improved through the molecular design method. [16][17][18] Thereinto, introducing the nitrogen-containing group (such as triazine, [19,20] triazinetrione, [21][22][23] Schiff-base, [24][25][26] and hexachlorocyclotriphosphazene [27,28] ) is a feasible way. The phosphophenanthrene group and nitrogen-containing group can exert a P−N synergistic flame-retardant effect to improve the flame retardancy of epoxy thermosets.…”