The dependence of the chain branching degree on molecular weight: Fractal analysis

Abstract

The fractal analysis methodology allows the clear structural identification of both chemical and physical factors controlling a chain branching degree. The effective number of branching centers per one macromolecule m is controlled by four factors: polymer molecular weight, MW, maximal 'chemical' density of reactive centers, cch, dimension of non-screening surface of macromolecular coil, du, and its fractal dimension, D. The presented research allows the determination of the critical value, Dcr = 1.10, the lower of which branching degree is equal to zero (i.e., branching does not occur).