Thermal composition fluctuations in binary homopolymer mixtures as a function of pressure and temperature

Abstract Thermal composition fluctuations were studied by SANS in two d-PB/PS binary polymer mixtures as a function of temperature and pressure. The difference between both blends is related to the microstructure. The structure factor at scattering vector Q = 0 was analyzed by a crossover function from which the critical temperature, the Ginzburg number and the entropic term of the Flory-Huggins interaction parameter were obtained. Our experiments show that Gi is influenced by the microstructure and is connected to the packing of the polymers.