Premium
Polymerization of olefins through heterogeneous catalysis. XV. The influence of pressure in the solution copolymerization of ethylene
Author(s) -
Jaber Isam A.,
Ray W. Harmon
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070500203
Subject(s) - copolymer , dispersity , ethylene , polymerization , polymer chemistry , catalysis , molar mass distribution , chemistry , materials science , organic chemistry , polymer
The high‐temperature solution homopolymerization of ethylene and copolymerization with 1‐hexene using highly active TiCl 4 /MgCl 2 ‐supported catalyst was studied. Experiments with pressure variations in the range 100–400 Psig were carried out at 185°C and for 10 min polymerization time. Both peak initial rate of polymerization and the catalyst productivity in homo‐ and copolymerization were found to increase steadily with increasing reactor pressure. Higher polymerization rates arose in copolymerization compared to homopolymerization, especially above 200 Psig total pressure. In both cases, the reaction order with respect to ethylene concentration was close to two. The number‐average molecular weight was found to be almost independent of pressure, whereas in copolymerization, the weight‐average molecular weight was observed to decrease from about 200,000 to 120,000 over the range of pressure studied. The polydispersity index in copolymerization was found to decrease steadily from 8 to about 4 with increasing pressure. © 1993 John Wiley & Sons, Inc.