Interaction between an Adamantane End-Capped Poly(ethylene oxide) and a β-Cyclodextrin Polymer

Abstract

A novel route to the formation of large aggregates, with associated rheological enhancement, is provided by formation of inclusion complexes between a telechelic polymer and a second polymer containing appropriate receptor groups. The main focus of this paper describes such complexes between an adamantane end-capped poly(ethylene oxide) (PEO) ( M w = 10 4 gmol - 1 ) with a polymer of β-cyclodextrin ( M w = 3.5 × 10 4 gmol - 1 ) as studied by light scattering. There is a pronounced broadening of the width of the particle size distribution with increasing concentration of end-capped polymer, accompanied by a strong increase in the average relaxation time. Viscosity enhancement in the system was measured on the same samples. Newtonian behavior was observed in the shear rate range 0.017−90 s - 1 . Light scattering experiments (static and dynamic) were also made on the telechelic PEO itself. Light scattering shows the presence of a slowly relaxing component which dominates the scattering and this reflects large structures (radius 80 nm) created by interchain association to form a loose network, albeit at low concentration. Static and time-resolved fluorescence experiments show that there is no detectable tendency for “micellization” of the adamantane groups.