Description

The aqueous solutions of two triblock copolymers of poly(oxybutylene/oxyethylene /oxybutylene) were studied by surface tensiometry, viscometry and dynamic laser light scattering techniques at various temperatures (293, 303, 313 and 323K).Effect of block architecture and temperature on surface and miceller properties was also studied. Critical micelle concentration (CMC) and thermodynamics of micellization were determined by surface tensiometry. Surface activity of these triblock copolymers was studied by measuring surface parameter i.e surface pressure (π), surface excess concentration ( Г ), area per molecule (oA), of polymer and standard Gibb's free energy of adsorption (ΔGads) at different temperature. Miceller parameter like CMC, surface tension at CMC (γCMC) were determined. Thermodynamic parameters, standard free energy of micellization (ΔGmic), standard entropy of micellization (ΔSmic) and enthalpy (ΔHmic) was calculated from CMC value at different temperature.Viscometry was used to determine intrinsic viscosity (η) and intermicellar interactions (KH) using Huggins's equation. Dynamic light scattering was used for determination of hydrodynamic radius (Rh).