Premium
Gel in polyethylene
Author(s) -
Mortimer George A.,
Wade Dennis E.,
Arnold Lloyd C.
Publication year - 1968
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.1968.070120607
Subject(s) - polyethylene , polymer , polymerization , ethylene , materials science , polymer chemistry , homogeneous , phase (matter) , chemical engineering , chemistry , organic chemistry , catalysis , thermodynamics , composite material , physics , engineering
A quantitative test for the presence of gel (insoluble polymer) in polyethylene is described. A number of experiments were performed by using the test and on the polymers separated by the test. It is concluded that gel is crosslinked polyethylene in the form of discrete particles of significant size, the large ones, probably weighing up to at least 10 mg. Some crosslinks are broken by treatment with solvents above 200°C., and much of the gel is thus rendered permanently soluble. Gel is also insoluble in the reaction medium in which it is produced. Thus, even if the ethylene–polyethylene phase relationships would predict a homogeneous reaction, the reaction must be hetero‐geneous if gel is present. Therefore, kinetic treatments of ethylene polymerization which do not consider phase separation when gel is found in the reaction product are oversimplified.