A double‐click strategy for the synthesis of P and N‐containing hydrolytically stable reactive flame retardant for photocurable networks

Abstract

The use of modern chemical routes and the development of innovative material designs bring smart solutions to the problems in materials science and open up new horizons for future research. In this work, we utilized from two click reactions to prepare a P and N‐containing reactive flame retardant. The para‐fluoro groups of bis(pentafluorophenyl)phenyl phosphine oxide were converted to azides and then the obtained compound was reacted with propargyl acrylate via copper‐catalyzed azide‐alkyne cycloaddition reaction. The effect of the synthesized monomer (10%, 20%, and 30%) on the mechanical, thermal, and flame retardancy properties of an aliphatic polyurethane acrylate was investigated. The newly synthesized monomer led to a slight decrease in double bond conversion percentages, an increase in tensile strength of the photocured samples, and a decrease in the elongation at break values. The glass transition temperatures increased with the increasing amount of the flame retardant monomer as well as the limiting oxygen index (LOI) values. When the flame retardant ratio was 30% in the formulations, almost a 25% enhancement was realized in the LOI values.

New Horizon in Phospha-Michael Reaction: Ultrafast Double Addition of P–H Bond-Bearing Nucleophiles to Electron-Deficient Triple Bonds and Its Use for Functional Monomer Synthesis and Polymer Modification

“…Both T 1 and T 2 temperatures reduced when the Allyl-DPP percentage was increased to 20%, reflecting the early degradation characteristic of Allyl-DPP, but in turn, the char yield boosted and increased to almost 15%. This higher thermal stability of the FRDPP series can be attributed to the early degradation behavior of the Allyl-DPP monomer, which leads to the early formation of high carbonaceous char that impedes the transfer of heat, and thus the thermal stability increases. − FRDPP3 also displayed a relatively higher char yield at 600 °C and moderate T 1 and T 2 temperatures.…”

How Do Phosphorus Compounds with Different Valence States Affect the Flame Retardancy of PET?

“…However, the change of structure leads to differences in the valence state of phosphorus, which further affects the proportion of flame-retardant mechanisms in the condensed and gas phases [14][15][16]. Therefore, studying the effects of flame retardants with different phosphorus valence states on the flame-retardant properties of PET composites helps to guide the design and synthesis of highly efficient flame retardants.…”