Phase segregation of poly(3-dodecylthiophene)-block-poly(methyl methacrylate) copolymers

Abstract

We investigated, via small angle X-ray scattering (SAXS), the ordered-to-disordered transition temperature (T-ODT) of symmetric poly(3-dodecylthiophene)-block-poly(methyl methacrylate) copolymers (P3DDT-b-PMMA) with different molecular weights synthesized by anionic coupling reaction. When the molecular weight of P3DDT-b-PMMA was properly chosen, the T-ODT was observed within experimentally accessible temperature range (higher than the glass transition and melting temperature for PMMA and P3DDT, respectively, but lower than the thermal degradation temperature). We also measured the temperature dependence of Flory-Huggins interaction parameter (chi) between P3DDT and PMMA as chi = 0.1109 + 76.63/T, in which T is the absolute temperature. (C) 2013 Elsevier Ltd. All rights reserved.