Randomly Branched Polymers. II. Computer Analysis of Gel-Permeation Chromatograms

Abstract

An iterative computer method was proposed for estimating the degree of branching and molecular weight distribution simultaneously from a pair of measurements on intrinsic viscosity and gel-permeation chromatography. The validity of the method as applied to randomly branched polymers was tested by using both fractionated and unfractionated samples of branched polystyrenes. It was experimentally concluded that the average number of branch points per unit molecular weight, λ, can be determined by this method with an accuracy of about 15%, and the weight-average molecular weight with accuracy of about 10%.

Gel permeation chromatography (steric exclusion chromatography)

“…An iteration method, based on deriving intrinsic viscosity of the whole polymer, was described for simultaneously estimating' number of branch points and average molecular weights from GPC data (109). Intrinsic viscosity-GPC methods were used to estimate long chain branching in poly(vinyl alcohol) (139) and polychloroprene (37).…”