LDPE PRODUCTION IN TUBULAR REACTORS. COMPREHENSIVE MODEL FOR THE PREDICTION OF THE JOINT MOLECULAR WEIGHT-SHORT (LONG) CHAIN BRANCHING DISTRIBUTIONS

DIETRICH, MAIRA L; SARMORIA, CLAUDIA; BRANDOLIN, ADRIANA; ASTEASUAIN, MARIANO

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

AMER CHEMICAL SOC

Año: 2019 vol. 58 p. 4412 - 4424

0888-5885

Good control on molecular properties, and in consequence on end-use properties, is very important for low-density polyethylene (LDPE) manufacturers. However, the connection between the architecture of polymer chains and the kinetic mechanism and polymerization conditions is still a subject of study. In this work we present a comprehensive model of the polymerization of ethylene in high-pressure tubular reactors. In addition to the usual predictions of conversion, temperature profiles and average molecular properties, this model also provides bivariate distributions such as molecular weight-long chain branching distribution and molecular weight-short chain branching distribution of LDPE produced under different operating conditions. The 2D probability-generating function technique is applied to obtain the bivariate distributions. This is a deterministic technique that allows the calculation of the distributions without any prior assumption of their shape.