Scattering studies of self-assembling processes of polymer blends in spinodal decomposition. II. Temperature dependence

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Abstract
Our previous work on time evolution of the interfacial structure for a near critical mixture of polybutadiene and polyisoprene undergoing the spinodal decomposition (SD) [T. Hashimoto, M. Takenaka, and H. Jinnai, J. Appl. Crystallogr. 2 4, 457 (1991)] was extended to explore the behavior as a function of temperature T, again using the time‐resolved light scattering method. The study involved the investigation of the time evolutions of various characteristic parameters such as the wave number q m (t;T ) of the dominant mode of the concentration fluctuations, the maximum scattered intensity I m (t;T ), the scaled structure factor F(x;T ), the interfacial area density Σ(t;T ), and the characteristic interfacial thickness t I (t;T ) from the early‐to‐late stage SD, where t refers to time after the onset of SD and x refers to the reduced scattering vector defined by x=q/q m (t;T ); q is the magnitude of the scattering vector. The results confirm the model previously proposed at a given T over a wider temperature range corresponding to the quench depth ΔT=T−T s =5.5–34.5 K, or ε T =(χ−χ s )/χ s =4.50×10− 2 to 2.79×10− 1, where T s is the spinodal temperature, and χ and χ s are the Flory interaction parameters at T and T s , respectively. This blend is noted to have a phase diagram of the lower critical solution temperature type.