Studies of polycyanurates based on phenoxy-substituted cyclic phosphazenes: Synthesis of the monomer and a preliminary study of its thermal properties in binary blends
Hamerton, I, Glynn, S, Hay, JN, Pullinger, MA and Shaw, SJ (2012) Studies of polycyanurates based on phenoxy-substituted cyclic phosphazenes: Synthesis of the monomer and a preliminary study of its thermal properties in binary blends Polymer Degradation and Stability, 97 (4). 679 - 689. ISSN 0141-3910
|PDF - Accepted Version|
Official URL: http://dx.doi.org/10.1016/j.polymdegradstab.2011.1...
The four-step preparation of a new monomer, 1,2,3-tris(4-cyanatophenoxy)-,3′,5,5-tris-phenoxy-2λ5,4λ5,6λ5-[1,3,5,2,4,6]-triazatriphosphinine, is reported. Characterization of the monomer is undertaken using spectroscopic and chromatographic methods and elemental analysis and the data are in agreement with the proposed structure (as a mixture of isomers). The thermal polymerization of the monomer and its behaviour within selected blends containing 2,2-bis(4-cyanatophenyl)propane (AroCy B10) are studied using differential scanning calorimetry. The blends appear to melt sharply at ca. 80 °C onset of polymerization (corresponding to the melting point of the commercial dicyanate) before commencing polymerization directly thereafter. Typical exothermic peak maxima at ca. 135 °C are observed, whilst the cure is apparently concluded by 200 °C under the scanning conditions. On rescan, the cured samples display glass transition values in the region of 160–190 °C, depending on composition with the higher values reflecting increasing amounts of the new material. The cured polycyanurate of the tricyclophosphazene is also analysed using thermogravimetric analysis and displays a mass loss of 5% at approximately 381 °C in air and 366 °C in nitrogen. When 1,2,3-tris(4-cyanatophenoxy)-,3′,5,5-tris-phenoxy-2λ5,4λ5,6λ5-[1,3,5,2,4,6]-triazatriphosphinine is combined with AroCy B10, the cured copolymers (containing between 10 and 30 wt% of the tricyclophosphazene) show disappointing thermal stability with a progressive reduction in the onset of degradation with increasing phosphazine content; this may be a result of incomplete cure.
|Additional Information:||NOTICE: this is the author’s version of a work that was accepted for publication in Polymer Degradation and Stability. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Polymer Degradation and Stability, 97(4), April 2012, DOI 10.1016/j.polymdegradstab.2011.11.004.|
|Divisions:||Faculty of Engineering and Physical Sciences > Chemistry|
|Deposited By:||Symplectic Elements|
|Deposited On:||09 May 2012 12:26|
|Last Modified:||01 Apr 2013 14:33|
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