Arylene ether phosphine oxide homopolymers were prepared via nucleophilic aromatic substitution polycondensations of bis(4-ftuorophenyl)phenyl (or methyl) phosphine oxide with various aromatic bisphenols in the presence of a weak base and an aprotic dipolar solvent. These thermoplastic materials with Tg values in the range of about 200°C-285°C showed 5% weight loss in air around 500°C with substantial amounts of char yield at 800°C, which was related to their excellent' self-extinguishing characteristics relative to other engineering thermoplastics. Additionally, the presence of phosphorus in the char after such high temperature heating implied that these materials should also be resistant to aggressive oxygen plasma environments. Indeed, these systems showed extremely low amounts of etching in oxygen plasma when compared with other engineering polymers. The presence of phosphorus residues after either burning or etching with oxygen plasma could play crucial roles in areas of commercial importance and aerospace applications.

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Hydrolytically stable phosphorus-containing monomers, such as 4,4'-bis(fluoro-pheny1)methylphosphine oxide (BFPMPO), 4,4'-bis(hydroxyphe1nyl)methylphosphine oxide (BOHPMPO), and 4,4-bis(hydroxyphenyl)phenylpliosphine oxide (BOHPPO), were synthesized and used in nucleophilic aromatic Substitution polycondensation to prepare poly(ary1ene ether phosphine oxide) engineering thermoplastics. The synthesis and characterization of these novel polymers are described. It was determined that by incorporating the phosphine oxide moiety into the polymer backbone, certain properties of the resulting poly(ary1ene ether) were substantially improved, such as an increase in Tg, thermal stability in air, modulus, and char yield compared with control poly(ary1ene ether su1fone)s. The :high char yields obtained for these polymers in air along with observed intumescence indicates that these materials have improved fire resistance. Preliminary cone calorimetry measurements support this conclusion.

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Polypyrrole was deposited on polyester yarns by vapour phase polymerization technique. Ferric chloride was used as an initiator. In order to determine the effect of the initiator concentration on polymerization process, four different initiator concentrations (0.2, 0.4, 0.6 and 0.8 mol/l) were used. The effect of the initiator in terms of tensile properties, electrical resistivities and morphological properties of the yarns was investigated. The polypyrrole deposited polyester yarns were then weaved in a handloom to form fabric for the investigation of surface resistivity and electromagnetic shielding effectiveness. Scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared analyses illustrated that polypyrrole has penetrated into the yarn structure and the highest polypyrrole deposition was obtained at the initiator concentration of 0.6 mol/l. Also, the highest electromagnetic shielding effectiveness value and the lowest surface resistivity were obtained at this concentration.

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