Premium
Prediction of the Bivariate Molecular Weight‐Long Chain Branching Distribution in High‐Pressure Low‐Density Polyethylene Autoclaves
Author(s) -
Krallis Apostolos,
Pladis Prokopis,
Kiparissides Costas
Publication year - 2007
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.200700005
Subject(s) - bivariate analysis , branching (polymer chemistry) , polyethylene , polymer , molar mass distribution , joint probability distribution , mathematics , chain (unit) , grid , population , materials science , thermodynamics , statistical physics , statistics , physics , geometry , composite material , demography , astronomy , sociology
Abstract In the present study a population balance approach is described to follow the time evolution of bivariate molecular weight‐long chain branching (MW‐LCB) distributions in high pressure low density polyethylene autoclaves. The model formulation is based on a sectional grid method, the so‐called fixed pivot technique (FPT). According to this method, the ‘live’ and ‘dead’ polymer chain populations are assigned to a selected number of discrete points. Then, the resulting dynamic discrete‐continuous molar species equations for ‘live’ and ‘dead’ polymer chains are solved at the specified grid points. It is shown that a very good agreement exists between theoretical results and experimental data which proves the capability of the FPT method in calculating the joint MW‐LCB distribution for branched polymers.