Preparation of organic–inorganic intumescent flame retardant with phosphorus, nitrogen and silicon and its flame retardant effect for epoxy resin

Abstract

According to the requirement of fire life cycle assessment (LCA), chitosan ethoxyl urea phosphate (CEUP), an organic–inorganic intumescent flame retardant (IFR) containing phosphorus, nitrogen, and silicon, was synthesized by the reaction of chitosan, phosphorus pentoxide, and urea. FTIR, 1H NMR, SEM, and XRD were employed to characterize the compounds. As a result, CEUP was successfully prepared with higher thermal stability, favorable to enhance fire resistance. Combined with OMMT, the organic/inorganic IFR was applied as EP flame‐retardant agents. The combustion behavior of EP composite was investigated by LOI, UL‐94, CCT, SEM, TGA, and TG‐IR. It was observed that using 15% CEUP and 3% OMMT (EP3), LOI value reached 34.8% and passed the UL‐94 V‐0 rating, while THR and TSP of EP composite reduced 65 and 72% compared with pure EP. The char residue of EP composite was up to 22.4%. The thermal decomposition mechanism was traced from 100 to 600°C by TG‐IR. It was suggestive that CEUP decomposition commenced at 100°C to create phosphoric acid and sublimation of urea occurred at 300°C. EP3 exhibited a strong thermal stability, namely even at 600°C, the volatile substances were detectable. Dense and expanded carbon layer was confirmed in SEM images.

Toughening, highly thermostable, and flame retardant polylactic acid enabled by polyphosphazene microsphere

“…After the polymerization reaction among HCCP and DDS was completely finished, the synthesized CP‐DDS microsphere exhibited a broad absorption at about 2 θ = 20° corresponding to the amorphous phase, and no crystalline peaks were observed. These results indicated that CPDDS microsphere had a highly cross‐linked structure that correlated to its high thermal stability 36 …”

Synthesis of a bio‐based piperazine phytate flame retardant for epoxy resin with improved flame retardancy and smoke suppression

“…As for PA, a wide peak at around 3335 cm −1 is owing to stretching vibration of ─OH. The signal at 1120 cm −1 is associated with P═O stretching, 31 while absorption peaks located at 1019 and 891 cm −1 are respectively corresponding to symmetric stretching and asymmetric vibration of P─O(H) 32 . For PIPT, the intensity of ─OH peak at around 3335 cm −1 is significantly reduced in comparison with that of PA.…”

Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

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