Small-Angle X-ray Scattering Analysis on the Estimation of Interaction Parameter of Poly(<i>n</i>-butyl acrylate)-<i>b</i>-poly(methyl methacrylate)

Abstract

The temperature dependence of the Flory–Huggins interaction parameter χ for poly(n-butyl acrylate)-b-poly(methyl methacrylate) (PBA-b-PMMA) was quantified from small-angle X-ray scattering (SAXS) analysis using random phase approximation (RPA) theory. It was found from the χ estimation (χ=0.0103+14.76/T) that the enthalpic contribution, χH, a measure for temperature susceptibility of χ, is 1.7–4.5 folds smaller for PBA-b-PMMA than for the conventional styrene-diene-based block copolymers, which have been widely used for thermoplastic elastomers. This finding suggests that these fully acrylic components can be a desirable chemical pair for constituting terpolymers applied for thermally stable and mechanically resilient elastomers.

Keywords

• acrylic block copolymer
• Flory–Huggins interaction parameter
• thermoplastic elastomer
• small-angle X-ray scattering