Accession Number : ADA028872

Title :   Polyphosphazene Wire Coverings.

Descriptive Note : Final rept. 31 Mar 75-30 Mar 76,


Personal Author(s) : Reynard,Kennard A. ; Vicic,John C.

Report Date : JUN 1976

Pagination or Media Count : 47

Abstract : A 2:3 ((C6H5O)2PN- (4-C2H5C6H4O)2PN)n copolymer was selected from several candidates for compounding studies to develop fire-retardant electrical wire insulation. All formulations prepared did not contain halogen either in the polymer or in the filler system employed. A filler system based on silane-treated hydrated alumina, magnesium hydroxide, and dicumyl peroxide proved to be very effective. Formulations based on this recipe gave: (1) tensile strength and elongations greater than 1000 psi and 100%, respectively; (2) dielectric constants less than 4.5 (at 100 kHz); (3) dielectric strengths greater than 800 volts/mil; (4) NBS smoke densities of 65 and 22 in the flaming and nonflaming modes, respectively; and (5) Limiting Oxygen Index values in the range of 34-40. Samples were submitted for an evaluation of flame spread index and a value of 11 was obtained for the only sample tested to date. These values met or exceeded contract goals with the exception of the elongation, which was somewhat low, but within acceptable limits. Other formulations gave lower dielectric constant and higher elongation, but there was some sacrifice in smoke density values.

Descriptors :   *Inorganic polymers, *Elastomers, Thermal stability, Mechanical properties, Phosphazene, Copolymers, Electrical insulation, Fire resistant coatings, Tensile properties, Physical properties, Synthesis(Chemistry), Polymerization, Performance tests, Aging(Materials), Crosslinking(Chemistry), Plastics

Subject Categories : Polymer Chemistry
      Elastomers and Rubber

Distribution Statement : APPROVED FOR PUBLIC RELEASE