Accession Number : AD0635586

Title :   MOLECULAR FLOW AND LANTHANUM CATALYZED BOND INTERCHANGE IN SODIUM PHOSPHATE POLYMERS.

Descriptive Note : Technical rept.

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY

Personal Author(s) : Eisenberg, Adi ; Saito,Shogo

Report Date : JUN 1966

Pagination or Media Count : 31

Abstract : It is observed that sodium phosphate polymers, in which some of the Na(+) ions have been replaced by La(+++) ions, are subject to both simple molecular flow and to bond interchange in the glass transition region. These two relaxation mechanisms are separated, and their relative contributions to the shear viscosity are calculated. It is shown that the bond interchange mechanism is subject to an activation energy of ca. 50 Kcal, while that of the molecular flow is of the order of 200 Kcal at Tg + 30C; the latter is of the WLF form. It is further shown that the La(+++) ions act as crosslinks, at least at low concentrations, and that the bond interchange occurs at the site of the La(+++) ions, rather than at random along the polymer chain. (Author)

Descriptors :   (*INORGANIC POLYMERS, *PHOSPHATES), (*SODIUM COMPOUNDS, PHOSPHATES), (*LANTHANUM, CATALYSIS), MOLECULAR PROPERTIES, VISCOELASTICITY, RHEOLOGY, CHEMICAL BONDS, HEAT OF ACTIVATION, CROSSLINKING(CHEMISTRY)

Subject Categories : Polymer Chemistry
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE