General interpretation of intrinsic viscosity – temperature data and application to solutions of polytetrahydrofuran

The general form of the variation of In [η] with temperature which results from the excluded‐volume theories of FLORY, KURATA‐STOCKMAYER‐ROIG, PTITSYN, and FIXMAN, is examined. On the basis of these theories a new analysis of ln [η]T versusT data is presented, which enables both d ln 〈r2〉0/dT and the Ψ‐temperature to be evaluated. The procedure has been applied to polytetrahydrofuran in a large number of solvents, and the applicability of excluded‐volume theories to these systems is discussed.