Interfacial equilibrium and dynamic properties of telechelic poly(ethylene oxide) end-capped by alkyl groups
Year: 2003
Type: dissertation
Abstract: Poly(ethylene oxide) end-capped with alkyl groups at both ends belongs to so called �telechelic polymers (TP)� and is widely used in industry as a rheology modifier in water-born coatings, in adhesives and sealants. Despite the fact that this polymer is used in heterogeneous systems in all industrial applications, its interfacial properties are not very well understood. We used the Surface Forces Balance (SFB) with shear capability to study the properties of thin layers of TP adsorbed to solid substrates from toluene and aqueous solutions. The equilibrium and dynamic forces in polymer layers were studied as a function of the nature of the solvent and the molecular architecture of the polymer. Our results show that in organic solvents providing good solvency conditions for poly(ethylene oxide) and alkyl groups the polymers adsorb as monolayers, whereas from aqueous solutions they form multilayers with properties of weak gels. The shear properties of these surface gels were studied as a function of confinement and shear velocity. The results reveal the lubrication effect of the surface gels similar to that observed for polymers in good solvency conditions. In addition, the adsorbed layers show a noticeable shear thinning effect.
Source: TSpace (University of Toronto)
Author: Chestakova, Alexandra
Language: English
Subfield: Surfaces, Coatings and Films
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7133030989