Thermodynamics of Symmetric Diblock Copolymers Containing Poly(styrene-ran-styrenesulfonic acid)
Is Version Of
We examine the thermodynamic behavior of diblock copolymers representing the binary pairs of the ternary system: poly(dimethylsiloxane)/poly(ethylene-stat-propylene)/poly(styrene-ran-styrenesulfonic acid), D/EP/SS. We employ small-angle X-ray scattering, electron microscopy, and rheology to characterize the order-to-disorder transition temperature TODTand lamellar period d of 28 materials with varying molecular weights and sulfonation extents. These data are then interpreted in the context of self-consistent mean-field theory employing the continuous Gaussian chain model to deduce the interaction parameters as a function of temperature and sulfonation extent. We find that while EPD and SSEP are amenable to such treatment, the SS/D interaction forces SSD chains to stretch beyond the realm of applicability of the Gaussian chain model.
Reprinted with permission from Macromolecules 46 (2013): 179–187, doi:10.1021/ma301228v. Copyright 2012 American Chemical Society.