Compatibility of poly(α-methyl styrene-co-acrylonitrile) with PMMA: A neutron and cloud point study

Abstract 

Cloud point (CP) experiments were perform-ed using blends of deuterated polymethylmethacrylate (PMMA(D)) and a statistical copolymer P(αMS – co- AN) which consists of α-methylstyrene (αMS) and acrylonitrile (AN). A lower critical solution temperature (LCST) behavior is found. The corresponding interaction parameter χ is calculated accounting for temperature and concentration dependence. In order to improve the accuracy, temperature dependent small-angle neutron scattering experiments are performed for a 50/50 blend which reveal spinodal and binodal temperatures. Additionally, bilayers of P(αMS – co- AN) and PMMA(D) are prepared and annealed. The compositions of coexisting phases and the interface widths are determined by neutron reflectometry (NR). Interaction parameters calculated from the compositions of coexisting phases are in agreement with SANS and CP results. Effects of molar mass distribution are discussed.