Fire‐retardant synergy of tris(1‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidinyl)phosphite and aluminum hypophosphite/melamine hydrobromide in polypropylene

Abstract

Fire-retardant synergy of tris(1-methoxy-2,2,6,6-tetramethyl-4-piperidinyl) phosphite (NORPM) and aluminum hypophosphite (ALHP)/melamine hydrobromide (MHB) in polypropylene (PP) was researched by limiting oxygen index (LOI) measurement, vertical burning test, and cone calorimetric test (CCT). The results reveal that NORPM, together with ALHP/MHB, has an exceptional fire-retardant synergy in PP. For the FR-PP containing 1.0 wt% of ALHP and 1.5 wt% of MHB, combining NORPM in 0.20 wt% concentration can make its LOI value increases from 19.0% to 26.1%, the fire-retardant efficiency (EFF) increases from 0.48 to 3.07, synergistic efficiency (SE) is as high as 2.18, the vertical combustion rating can be improved from none to UL 94 V-2, fire performance index (FPI) increases from 58.7 to 84.9, and various heat release parameter values are reduced markedly. NORPM induces the synergy with ALHP/MHB primarily by the mechanisms as follows: active free radicals formed through the decomposition of NORPM, such as CH 3 , CH 3 O, nitro radicals and amino radicals, together with PH 3 and HBr, trap active radicals (HOÁ) for combustion. Consequently, the reaction chain of combustion is terminated, which makes gaseous phase fire retardancy more efficient.

Fire‐retardant synergy of bis(1‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidinyl)sebacate and melamine hydrobromide/aluminum diethylphosphinate in polypropylene

“…SEM images of the residues in CCT ADEP can cleave into diethylphosphonic acid 24,30. However, it was established that ADEP cracked neither into PH 3 nor into volatile products such as diethylphosphonic acid in this study, indicating that ADEP is thermally stable and mainly cracked into nonvolatile substances.…”

“… 19 Bis(1‐octyloxy‐2,2,6,6‐tetramethyl‐4‐piperidinyl)sebacate exhibits good light stabilization and good fireproofing synergy with brominated phosphate in PP fiber, which could pass the FMVSS 302 test when the loading of the brominated phosphate and Tinuvin NOR123 was 2 wt% and 1 wt%, respectively 20 . Wu et al established that bis(1‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidinyl)sebacate (NORSM) and tris(1‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidinyl)phosphite (NORPM) exhibited a good fireproofing synergy with tri(tribromophenyl) cyanurate/Sb 2 O 3 in high‐impact polystyrene 21,22 and MHB/ALHP in PP 23,24 …”

“…20 exhibited a good fireproofing synergy with tri(tribromophenyl) cyanurate/ Sb 2 O 3 in high-impact polystyrene 21,22 and MHB/ALHP in PP. 23,24 Although ALHP/MHB/NORSM and ALHP/MHB/NORPM exhibit good fire retardation in PP, they have significant environmental and safety problems because of released hypertoxic PH 3 when ALHP is heated. 5 Aluminum diethylphosphinate (ADEP) exhibits exceptional thermal stability and fire retardation, and no PH 3 is produced during its thermal decomposition; thus, it is safe.…”

Smoke suppression, flame retardancy, and fire toxicity of polypropylene containing melamine salt of pentaerythritol phosphate halloysite

“…The absorption peaks at 606 and 2325 cm −1 are referred to SiOP. [ 3,6,11 ] The FTIR spectrum of MPPH manifests an absorption band at 3419 cm −1 for primary amine. A new characteristic wide and intense absorption band appeared at 3154 cm −1 , and a medium narrow one at 1399 cm −1 are ascribed to NH + .…”

“…The band at 1671 cm −1 is assigned to phosphoric acid ester. [ 6,11 ] The Peak at 1246 cm −1 is referred to PO and the absorption bands at 954 and 1037 cm −1 point out to POC. [ 29 ] The absorption peaks at 612 and 2305 cm −1 are attributed to SiOP, and the band at 766 cm −1 is attributed to AlOP.…”