Molecular Weight Dependence of the Glass Transition Temperature in Sodium Phosphate Polymers

摘要

It is shown that an inorganic ionic polymer (sodium polyphosphate) exhibits the same type of glass transition temp. versus average chain length behavior as non-ionic organic polymers. If the chain ends resemble the terminal units, specifically in terms of the number of anions per phosphorus atom, the material is entirely analogous in its behavior to the organic materials, as shown, for instance, by the applicability of the Gibbs-DiMarzio theory. By contrast, if the terminal units possess two anions per phosphorus atom, a profound change in behavior is observed. (Author)