Synthesis and performance of star-shaped aluminum phosphinate flame retardant

Abstract

A star-shaped aluminum dimethyl(2,2-dimethyl-1,3-propylene)bis(oxy)bicarbonylethyldiphos phinate (AlCP) was synthesized by esterifying reaction between 2-methy-2,5-dioxo-1,2-oxaphospholane (OP) and neopentyl glycol following by neutralizing with aluminum hydroxide. The structure and composition were confirmed with FTIR, 1 H NMR, 31 P NMR and X-ray fluorescent spectroscopy. AlCP begins to decompose at 370°C, matching the initial decomposition temperature of PBT. It endows PBT with desired flame retardancy and anti-dripping property and shows good compatibility with PBT. When the total filler loading is kept at 17, 15-13 mass% AlCP combining with 2-4 mass% MC can make the PBT passing the UL 94 V0 rating and eliminating dripping. In addition, the AlCP has a little influence on the mechanical properties of PBT. The tensile strength and notched impact strength of PBT containing 17 mass% AlCP only reduce by 5.6 and 4 %, respectively, comparing to the pure PBT. The SEM photographs show that AlCP has a good compatibility with PBT. Microcombustion calorimeter, TG-FTIR and SEM results show that AlCP can depress the heating release and promote char forming during combustion and acts mainly in the condensed phase.

Flame-Retardant Thermoplastic Polyether Ester/Aluminum Butylmethylphosphinate/Phenolphthalein Composites with Enhanced Mechanical Properties and Antidripping

“…Compared to inorganic compounds, the organic compounds showed better compatibility with TPEE. Some benzene or hetero-ring-rich compounds such as novolac [ 31 ], Belta-cyclodextrin [ 32 ], and triazine-containing compounds [ 33 ] have high-char-forming ability and good compatibility with TPEE. This is because benzene is a key component of residual charring, and benzene-rich compounds can effectively improve the charring performance of composites, thereby enhancing flame retardancy.…”