Premium
Modelling copolymerization kinetics
Author(s) -
O'Driscoll Kenneth
Publication year - 1992
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19920530107
Subject(s) - reactivity (psychology) , monomer , copolymer , polymerization , kinetics , polymer , work (physics) , chemistry , polymer chemistry , kinetic energy , reaction rate , thermodynamics , materials science , chemical engineering , organic chemistry , catalysis , physics , medicine , alternative medicine , pathology , quantum mechanics , engineering
The composition and rate behavior of free radical copolymerizations is usually described by the Mayo‐Lewis (ML) model and the associated reactivity ratios, r 1 and r 2 . Particularly with respect to rate, a number of systems have been found to be poorly described by the simple ML model and the penultimate unit effect (PUE) model has been suggested as an explanation. A small but significant amount of work has been done with small model analogues of polymer chains and with ESR which has established the chemical feasibility of a PUE. This paper reviews recent work with pulsed laser polymerization kinetic measurements which are successfully described in terms of a modified PUE. It is concluded that the strength of the PUE correlates inversely with the monomer reactivity ratio product, r 1 r 2 . The effect is important for rate, but not for composition.