A new strategy for the simultaneous modeling of molecular weight distributi
on (MWD) and degree of branching distribution (DBD) for such branched polym
ers as bimodal low-density polyethylene is presented, based on the Galerkin
h-p finite element package PREDICI, a commercial code. The key problem of
how to address a bidimensional distribution is successfully solved by using
so-called reduced or pseudo distributions. The branching distribution per
chain length is modeled by moment equations, thus yielding distributions of
branching moments over chain length. No closure relationships are required
. The MWD/DBD curves obtained are the most probable ones for the given reac
tion mechanisms and kinetic data. Simulated MWD and DBD curves are compared
to experimental data from gel permeation chromatography and light scatteri
ng; the agreement found is good in general and excellent in one case. The b
imodal MWD of the autoclave low-density polyethylene (ldPE) IUPAC Alpha cou
ld be reproduced well. It is finally shown that the shapes of MWD and DBD a
re highly sensitive, quantitative measures for random scission.