High temperature continuous viscometry coupled with analytic temperature rising elution fractionation for evaluating crystalline and semi-crystalline polymers

摘要

A method and apparatus analyzes a polymer sample to determine the instantaneous intrinsic viscosity and the instantaneous viscosity average molecular weight of the various fractions of the continuous stream of fractionated polymer sample solution. The polymer sample is first precipitated over a cooling temperature gradient to produce a precipitated polymer sample, which is precipitated as a function of its crystallinity, branching configuration or density. The precipitated polymer sample is then eluted over a heating temperature gradient to produce a fractionated polymer sample solution, which is successively measured to produce raw mass detector data and differential pressure data, which data can be stored for subsequent computer analysis. The raw mass detector data is used to produce instantaneous concentration data, and the differential pressure data is used to produce instantaneous specific viscosity data. The instantaneous specific viscosity data for the various fractions is produced using the instantaneous concentration data and the instantaneous specific viscosity data. The instantaneous specific viscosity data is used to produce the instantaneous viscosity average molecular weight of the various fraction.