Accession Number : ADA006328

Title :   Polyphosphazenes: Thermomechanical Transitions.

Descriptive Note : Technical rept. Jul 74-Mar 75,

Corporate Author : PRINCETON UNIV N J DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Connelly,T. M. ; Gillham,J. K.

Report Date : MAR 1975

Pagination or Media Count : 30

Abstract : The dynamic mechanical behavior (approximately 1 Hz) of: four linear phosphazene homopolymers with structure (NPX2)n, where X = Cl, OCH2CF3, OCH2C3F7 and OCH2C3F6CHF2; two copolymers with mole ratios of the alkoxy substituents OCH2CF3/OCH2C3F7 and OCH2CF3/OCH2C3F6CHF2 approximately 1/1; and two physical blends with overall compositions approximating those of the copolymers, was examined between -180 and 250C in an inert atmosphere using a fully automated torsional braid apparatus. Crystal/melt, crystal/crystal, glass and glassy-state transitions are documented on the basis of the thermomechanical experiments. In addition to the assignment of transition temperatures, the noteworthy findings include the narrow range of values of the glass transition temperatures of the four homopolymers, the increasing slope of the modulus versus temperature in the glassy state with increasing size of the substituent, the presence of a transition immediately above Tg for the copolymers, and the incompatibility of the blends.

Descriptors :   *Thermomechanics, *Inorganic polymers, Crystals, Mechanical properties, Solid phases, Phase transformations, Glass, Mixtures, Temperature, Phosphorus compounds, Nitrogen compounds

Subject Categories : Polymer Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE