Premium
A theoretical interpretation of reactivity ratio products in copolymers formed from two fractions differing in composition
Author(s) -
Floyd S.
Publication year - 1987
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.1987.070340719
Subject(s) - reactivity (psychology) , copolymer , monomer , polymer , polymer chemistry , chemistry , ethylene , materials science , organic chemistry , catalysis , medicine , alternative medicine , pathology
Reactivity ratio products for ethylene‐propylene copolymerization over catalysts with two sites differing in incorporation and/or reactivity ratio product have been theoretically derived. It is shown that combination of the polymer fractions resulting from two sites can lead to large dyadic reactivity ratio products as determined by nuclear magnetic resonance. The dyadic reactivity ratio product is calculated at several different monomer ratios in the reactor, and compared to the reactivity ratio product obtained from a least‐squares fit of the copolymerization equation. When the polymers are compositionally heterogeneous, the reactivity ratios derived from kinetic measurements are not meaningful.