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.
Several thermoplastic and thermosetting polymeric materials containing the phenyl phosphine oxide group were prepared and characterized by physical methods. High molecular weight poly(arylene ether)s and polyimides containing the hydrolytically stable bulky phosphine oxide unit were synthesized and found to be soluble materials with moderately high glass transition temperatures. The phenyl phosphine oxide moiety was further incorporated into epoxy and bismaleimide type crosslinked systems. Phosphorus promoted char formation in air was displayed by both the linear and crosslinked macromolecules, leading to improved self‐extinguishability relative to the non‐phosphorus containing analogous polymeric systems.
The synthesis of 14C‐labelled poly(ℓ‐menthyl isopropenyl carbonate) is described. Experimental conditions are included for incorporation of 14C into each of the carbon atoms in the molecule. High pressure liquid chromatography conditions are given for separation and purification of the labelled intermediates.
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