Study of using aluminum hypophosphite as a flame retardant for low‐density polyethylene

Abstract

Aluminum hypophosphite (AHP) was first used to improve the flame retardance of low‐density polyethylene (LDPE). The flame‐retardant properties of LDPE composites were investigated by the limiting oxygen index, vertical burning test (UL‐94), microscale combustion calorimetry, and cone calorimeter tests. The results showed that the incorporation of AHP could improve the flame retardancy of LDPE dramatically, the limiting oxygen index of LDPE containing 50 phr AHP reached 27.5%, and the UL‐94 could pass V‐0 rating. The cone calorimeter test results indicated that PP/AHP composite exhibited superior performance, and the heat release rate and the total heat release of composites were significantly reduced. In addition, the strength of the char was improved with the load of AHP increased. The structure of the char was researched by Fourier transform infrared spectrometry (FTIR) and scanning electron microscope‐energy dispersive spectrometer, and the results revealed that AHP promoted the formation of compact char layer. The TG‐FTIR analyses proved that AHP could react with LDPE to reduce the production of olefin in gas phase. Moreover, the structure of P–O–C was found, and the effective mechanism of AHP in LDPE composites was also hypothesized in this work.

Preparation and characterization of polyamide 6 fibre based on a phosphorus-containing flame retardant

“…However, by reacting with the decamethylene diamine which has the electron-donating group, electron cloud density of P-O-C in DDP increased and the absorption peak of P-O-C moved to 1023 cm À1 . 23,[30][31][32] The FTIR spectra of PA6 and FRPA6-5 have been shown in Fig. 2.…”

“…The peaks at 7.64-8.53 (e) ppm, 3.48 (g) ppm, 3.24 (h) ppm and 1.62 (f) ppm account for the chemical shis of H on the diphenyl and methylene of DDP. To further conrm the chemical structure, 31 P-NMR spectra of DDP (deuterated DMSO as solvent) and FRPA6-5 were observed and shown in Fig. 4.…”

Synergistic effect between phosphorus tailings and aluminum hypophosphite in flame‐retardant thermoplastic polyurethane composites

“…The temperature of the maximum weight loss rate (T max ) of neat TPU is 420°C and that of the TPU/25AHP composite is 322°C, corresponding to the dramatic peak in DTG curves. The reduced degradation temperature of the TPU/AHP composites is mainly due to the decomposition of AHP at low temperature . Additionally, the T 5% , T 10% , and T max values of the samples with AHP and PT are also lower than those of neat TPU, as shown in Table .…”

Flame retardancy and smoke suppression of silicone foams with microcapsulated aluminum hypophosphite and zinc borate

“…With the high thermal and chemical stabilities, good mechanical, and environmental friendly properties, aluminum hypophosphite (AHP) has attracted much attention over the decades . Gu et al found the addition of AHP to poly (lactic acid) (PLA) could markedly increase the LOI values.…”