K. Furusawa et al., ADSORPTION BEHAVIOR OF END-FUNCTIONALIZED POLYMERS MODIFIED BY IMINIUM ION, Colloid and polymer science, 272(12), 1994, pp. 1514-1520
In order to clarify the end-functionalization effect of polymers modif
ied by iminium ion, a model compound with a modified chain end was pre
pared by directly reacting n-butyllithium with N-methyl-2-pyrrolidone
and then quenching by the addition of methanol. It is shown that the m
odel compound includes the iminium ion group and that the adsorption b
ands in the IR-spectra of the chemically modified polymer were similar
to those of model compound. The adsorption behavior of end-functional
ized polystyrene(PS-X) and diblock copolymer of PS and polybutadiene(P
B) which were modified by iminium ion(PS-PB-X), were examined over a w
ide range of molecular weights of these polymers. It is evident that t
he amount of adsorption increased significantly by the end-functionali
zation and this trend was especially strong in the low molecular weigh
t polymers (M(W) less than or equal to 10(5)). The preference for the
end-functionalized polymer was also examined by competitive and sequen
tial adsorption experiments between different molecular weight species
. It is shown that a prefered adsorption of PS-X with low molecular ma
ss is pronounced over the adsorption of PS or PS-X with high molecular
weight and in the combination of high and low molecular weight specie
s of PS-X, a special enhancement of total adsorption can be observed.
This enhancement is based on a combination of different adsorption lay
ers formed by these two molecular weight species.