Preparation and properties of flame-retardant polyphosphate esters: Low-temperature solution polycondensation of 3,3,′5,5′-tetrabromobisphenol AF and aryl phosphorodichloridates |
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Authors: | Der-Jang Liaw |
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Abstract: | This article describes the syntheses of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with 3,3′,5,5′-tetrabromobisphenol AF (TBPAF) in a chlorinated hydrocarbon solvent under low-temperature conditions. The new polyphosphates obtained were characterized by infrared, 13C and 31P nuclear magnetic resonance spectra, elemental analysis, inherent viscosity, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, limiting oxygen index, contact angle, and molar mass measurement. All of the polyphosphates obtained had high yields, and the inherent viscosities were in the range 0.12 - 0.15 dL g−1. All of the polymers start degrading between 210 and 267°C and had 14 - 26% residual mass at 700°C in nitrogen. Polymer E, having a methoxy group in the side chain phenyl ring, showed better thermal stability than the other polymers. The X-ray diffraction patterns revealed that all of the polyphosphates were amorphous. These polyphosphates had glass transition temperatures between 140 and 154°C. Polymers obtained from TBPAF had excellent flame retardency, as indicated by high limiting oxygen index values in the range of 63 - 68. The water contact angles (θw) of all of the polyphosphates were in the range of 74 - 87°. The contact angles of polymers A and B were larger than those of other polyphosphates that contain more oxygen (polymers C and E) or bromine atoms (polymer D). © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 59–65, 1997 |
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Keywords: | 3,3′ ,5,5′ -tetrabromobisphenol AF LOI thermal stability flame retardancy low-temperature solution polycondensation |
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