Preparation and characterization of flame retardant and proton conducting boron phosphate/polyimide composites

Catalytic pyrolysis and flame retardancy of epoxy resins with solid acid boron phosphate

“…Boric acid was provided by Sinopharm Chemical Reagent Co., Ltd. Boron phosphate (BP, the ratio value of B/P is 1.0, which was evaluated using X-ray photoelectron spectroscopy) powder was prepared from the reaction between boric acid and phosphoric acid, according to the procedure reported elsewhere [27].…”

“…Upon addition of BP to EP, three additional peaks were observed before heating: the peak at 623 cm À1 and the broad band at 1072 cm À1 can be assigned to the bending vibrations and , respectively, and the peak at 920 cm À1 is assigned to BeO stretching vibrations [27]. In comparison with EP-0, the intensity of the band between 3200 and 3600 cm À1 of EP-3 quickly decreased at 300 C, which confirms the TGA-FTIR evidence that the dehydration of epoxy occurred at a lower temperature in the presence of BP.…”

“…BP is an active catalyst in the dehydration of alcohols [20], and has also been used as an additive in glass and ceramic production [21,22]. In recent years BP has been used as flame retardant additive in different polymer systems such as polyamide [23,24], polypropylene [25], polyurethane [26] and polyimide [27] due to its low cost, low toxicity, low evolution of smoke and its effectiveness. However, to the best of our knowledge, very little is known about the detailed mechanism for improving flame retardancy in polymer matrices, and there are no published studies on catalytic flame retardant effects due to the solid acid character of BP.…”

Phosphonium modified clay/polyimide nanocomposites

“…BTDA-ODA films were prepared from poly (amic acid), according to [13]. In order to synthesis poly(amic acid) (PAA) solutions, ODA(0.01 moles) was firstly put into a flame dried three-neck flask containing 16 mL of DMF under a nitrogen purge.…”

“…BTDA/ODA-modified clay polyimide films were prepared, according to [13]. 3 wt % modified clay containing composite film was prepared by adding appropriate amount of modified clay to the PAA which was prepared as described above.…”