Preparation of phosphorus‐containing phenolic resin and its application in epoxy resin as a curing agent and flame retardant

Abstract

For the sake of improving the flame retardancy of epoxy resin (EP), a novel phosphorus‐containing phenolic resin (PPR) synthesized in our group instead of conventional phenolic resin (PR) was used to cure EP in the present research. The curing processes and the corresponding crosslinking structure and mechanical performance were investigated by differential scanning calorimeter and dynamic mechanical thermal analysis. Because of the introduction of flame‐retarding elements including P and Si, PPR exhibited higher charring capacity in the condensed phase, which is helpful to construct a char layer of higher quality. Correspondingly, PPR‐cured EP displayed remarkably improved flame retardance as compared to conventional PR‐cured EP through the related evaluations including limiting oxygen index, vertical burning test, and microscale combustion colorimeter. As a multifunction agent, it is believable that PPR possesses potential commercial value to prepare flame‐retardant EP with high performance.

Intrinsic flame‐retardant epoxy resin composites with benzoxazine: Effect of a catalyst and a low curing temperature

“…The UL 94 rating decreased to V‐1 and no rating when average curing temperature increased and, furthermore, without MI. Such an improvement was very remarkable in comparison with results reported in the literature, as shown in Figure . The increased effectiveness of EBM–LT with the addition of MI and the further effectiveness at a lower curing temperature were evidenced by the LOI increment value of 10.3 and the UL 94 V‐0 rating, which exceeded most reported composites.…”

Preparation of highly efficient flame retardant unsaturated polyester resin by exerting the fire resistant effect in gaseous and condensed phase simultaneously

“…The pyrolysis behavior of PPMPNG, pure UPR, and UPR-15 (FR-UPR) thermosets was investigated by Py-GCMS analysis. According to our previous work, 24 the pyrolysis products of PPMPNG mainly included vinylidene (1), 1,3-butadiene (2), piperazine derivative (3,4), and methylphosphonic acid derivative (5,6), as shown in Table 4. Some pyrolysis products such as vinylidene (1), 1,3-butadiene (2), and piperazine and its derivative (3,4) could occur cross-linking and charring.…”

“…On the basis of the consideration of environmental safety and human's health, a series of halogen‐free flame retardants including phosphorus‐containing, aluminium trihydroxide, montmorilloneite, layer double hydroxide, boric‐containing, and intumescent flame retardant (IFR) have been proposed to enhance the flame retarded properties of UPR materials. Among these flame retardant additives, the IFR system exhibited superior charring and dripping inhibition capability accompanied with low production of toxicity substances .…”

Activated carbon spheres (ACS)@SnO2@NiO with a 3D nanospherical structure and its synergistic effect with AHP on improving the flame retardancy of epoxy resin

“…However, its flammability and the emission of a large amount of smoke and hazardous gases during combustion limit its applications. Significant effort has been undertaken by the academic and industrial community to improve the fire safety of EP resin …”

“…These properties make EP resin suitable for an extensive range of applications in the adhesive, laminating, potting, and coating areas.However, its flammability and the emission of a large amount of smoke and hazardous gases during combustion limit its applications.Significant effort has been undertaken by the academic and industrial community to improve the fire safety of EP resin. [1][2][3] The addition of a flame retardant to a polymer is an effective method to improving its flame retardancy. Li et al 4 successfully synthesized a polyphosphoric acid piperazine flame retardant (PPAP) containing nitrogen and phosphorus using polyphosphoric acid and piperazine and used it as an additive for flame-retardant EP resin thermosets.…”