I. Capek et al., Dispersion copolymerization of polyoxyethylene macronomer and styrene 4. Solution properties of polystyrene-graft-polyoxyethylene copolymers, J POL SC PC, 37(16), 1999, pp. 3087-3097
Citations number
29
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
The graft copolymers (polystyrene-graft-polyoxyethylene) (PSt-graft-PEO) we
re prepared by the radical dispersion copolymerization of methacryloyl (MA)
-terminated PEO macromonomer and styrene. By means of size-exclusion chroma
tography, liquid chromatography at the critical adsorption point, and light
scattering, the molecular weight parameters and the solution properties of
PSt-graft-PEO were investigated. The apparent average molecular weight and
the molecular weight distribution (MWD) of graft copolymers were found to
decrease with increasing molecular weight of PEO-MA macromonomer. This decr
eased molecular weight was attributed to the chain transfer to PEO unit and
increased contribution of the solution polymerization. The broad MWD varie
d with the ratio of the polymerization in the continuous phase and the poly
mer particles. The number of PEO grafts per PSt backbone decreased with inc
reasing molecular weight of the PSt-graft-PEO copolymer, which was attribut
ed to the intramolecular association of PEO segments. The intrinsic viscosi
ty or the coil size of graft copolymer molecules varied with temperature as
a result of the dehydration of PEO segments. (C) 1999 John Wiley & Sons, I
nc.