Novel intumescent flame retardants: synthesis and application in polycarbonate

Abstract

SUMMARY Novel phosphorus‐containing and nitrogen‐containing intumescent flame retardants, bis‐aminobenzyl spirocylic pentaerythritol bisphosphonate (BASPB) and arylene‐N,N′‐bis(2,2‐dimethyl‐1,3‐propanediol phosphoramidate) (ABDPP), were synthesized, and their structures were characterized with Fourier transform infrared spectroscopy and 1H and 31P nuclear magnetic resonance. The phosphorus compounds were used to impart flame retardancy to polycarbonate (PC). Combustion behaviors and thermal degradation properties of the flame‐retarded‐PC composites were assayed by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter test, and thermogravimetric analysis. PC/5 wt.% BASPB and PC/5 wt.% ABDPP composites passed UL‐94 V‐0 rating; their LOI values were 35.5% and 34.7%, respectively. Scanning electron microscopy revealed that the char properties had crucial effects on the flame retardancy. The mechanical properties and water resistance of the PC/BASPB and PC/ABDPP composites were also measured. After water resistance test, PC/5 wt.% BASPB and PC/5 wt.% ABDPP composites kept V‐0 rating, and the mass loss was only 1.0%. Copyright © 2012 John Wiley & Sons, Ltd.

In situ polymerization of flame retardant modification polyamide 6,6 with 2‐carboxy ethyl (phenyl) phosphinic acid

“…When the CEPPA addition is up to 6 wt %, the residue char reaches 4.07%, which is the highest value among all of the samples. The data are consistent with the results of the vertical burning and LOI tests, which can be explained by the idea that the phosphorus‐containing monomer firstly was dissociated into small molecules during combustion and then reacted with compounds containing CHO bonds and formed more stable compounds containing PO bonds such as phosphate . The more stable compounds can cover the samples to promote the char formation and then inhibit oxygen from the flaming zone.…”

“…It can be seen that pure PA66 has absorption peaks at 3302.8, 1638.3, and 1536.5 cm −1 assigned to NH, CO stretching and the combined absorption of both δ N‐H and ν C‐N , respectively, and the absorption peaks at 2861.1 and 2938.6 cm −1 are ascribed to CH 2  stretching . For those FR‐PA66 samples, it is observed that new peaks at 1125.2 cm −1 and 1038.5 cm −1 correspond to PO stretching and PN stretching, respectively, suggesting that CEPPA monomer has been introduced to the main chain of copolymer, as expected.…”

“…The data are consistent with the results of the vertical burning and LOI tests, which can be explained by the idea that the phosphoruscontaining monomer firstly was dissociated into small molecules during combustion and then reacted with compounds containing CH O bonds and formed more stable compounds containing P O bonds such as phosphate. 1,11,25 The more stable compounds can cover the samples to promote the char formation and then inhibit oxygen from the flaming zone. All these indicate that the flame retarded copolymer chains can lower the decomposition temperature and promote the char residue formation, and hence enhance the thermal stability at a high temperature range and improve the flame retardance of PA66.…”

Intumescence: Tradition versus novelty. A comprehensive review

“…In a study by Zhao and co-workers[270] two phosphorus-containing and nitrogen-containing intumescent flame retardants, bis-aminobenzyl spirocylic pentaerythritolbisphosphonate (BASPB) and arylene-N,N'-bis(2,2-dimethyl-1,3-propanediolphosphoramidate) (ABDPP), were synthesized and melt-blended with PC. Formulations containing 7wt.-% turned out to give a remarkable increase of PC LOI value (from 28.1 to 36.8 and 35.9% for PC, PC+7wt.-% BASPB and PC+7wt.-% ABDPP, respectively) enabled PC composites able to pass V0 UL94 classification.…”

Flammability and mechanical properties of poly(styrene–butadiene–styrene) copolymer–containing intumescent flame retardants

“…In the recent decades, intumescent flame retardants (IFRs) have been extensively studied in the field of flame retardancy of plastics. [9][10][11][12][13][14] The IFR system generally consists of three components, an acid source, for example, ammonium polyphosphate (APP) and melamine phosphates, a carbon source, such as pentaerythritol (PER) and starch, and a blowing agent, for example, melamine (MEL). There are some publications on the research of IFR in rubbers.…”