Micellisation of diblock copoly(oxyethylene/oxybutylene) in aqueous solution

Abstract

Six diblock copoly(oxybutylene/oxyethylene)s (E₉₂B₇, E₅₀B₁₃, E₄₉B₈, E₅₀B₄, E₂₄B₁₀ and E₂₇B₅, where E represents oxyethylene and B represents oxybutylene) have been prepared by sequential anionic copolymerisation and their micellisation in aqueous solution investigated. Surface tension, static and dynamic light scattering and gel permeation chromatography techniques were used to study solutions at temperatures in the range 20 to 50 °C over a wide concentration range from dilute to 100 g dm^–3. The micellar properties reported are critical micelle concentrations, micellar molar masses and radii. The thermodynamics of micellisation of E_mB_n diblock copolymers is discussed in relation to that of related triblock copolymers (E_mB_nE_m and E_mP_nE_m, where P represents oxypropylene).