Synergistic effect on flame retardancy and thermal behavior of polycarbonate filled with α‐zirconium phosphate@gel‐silica

Abstract

A new kind of flame retardant (ZS) with layered a-zirconium phosphate disks (a-ZrP) as the core and inorganic flame retardant (gel-silica, GS) to shield solid acid sites on the surface of a-ZrP as the shell, was synthesized via a facile method. The incorporation effects of ZS with silicone resin on the thermal properties and flame retardance of PC composites were investigated. The presence of ZS could improve the thermal stability of PC matrix. With the addition of ZS contents increased to 3 wt %, the limiting oxygen index (LOI) of the composite was 32.3% and the vertical burning (UL-94) test reached a V-0 rating. However, with more contents of ZS, the LOI value decreased, and without the GS layer, the LOI value was decreased significantly as well. The synergism between the a-ZrP core and gel-silica shell, also with the silicone resin were found. Based on these results, the flame-retardant mechanism was proposed.

Flame‐retardant behavior of a phosphorus/silicon compound on polycarbonate

“…However, PC flame retardancy is often required in many fields, especially in electronic applications. Although some organic halogen compounds can provide better solutions for flame‐retarding PC, worries about the environmental problems of organic halogen compounds drive researchers to pay increasing attention to the more efficient halogen‐free flame retardants …”

Mechanistic Aspects of Condensed- and Gaseous-Phase Activities of Some Phosphorus-Containing Fire Retardants

“…The structural features of char residues can be deduced from observing the relevant signal intensities in the Raman spectra [ 11 , 18 , 19 ]. In the present study, we recorded the Raman spectra from representative char residues where the intensities of the graphitic ( G band, associated with the vibrations of plane terminal glass carbons’ unorganized carbon structure) and amorphous ( D band, owing to an E 2 g vibrational mode of graphitic sp 2 bonded carbon atoms’ graphitic layered structure) were compared [ 11 ].…”

A phosphorous/nitrogen/silicon containing diphenylphosphoramide silicon oil toward effective flame retardancy for polycarbonate with comparable mechanical properties

“…To extend the further application, many efforts have been devoted to improving the flame retardancy of PC 5–10 . From the perspective of ecological and environmental protection, the majority of the present works focus on the development of halogen‐free flame retardants 11–15 …”

“…[5][6][7][8][9][10] From the perspective of ecological and environmental protection, the majority of the present works focus on the development of halogen-free flame retardants. [11][12][13][14][15] Organophosphorus flame-retardants are considered to be one of the most promising candidates for replacing halogen flame retardants due to their high efficiency, low smoke, and no corrosive gas. 16 Nitrogen-containing compounds can act as both char-forming agent and foaming agent for phosphorus-containing intumescent flameretardants, it thus promotes the strong expansion to form a protective carbon layer and also release incombustible gas such as ammonia.…”