Thermal stability and interfacial segregation for polymer thin films blended with a homologue having different tacticity

Thermal stability and interfacial segregation were examined for binary blend thin films of poly(methyl methacrylate)s (PMMA's) with different tacticities after thermal annealing. The de-wetting of isotactic PMMA thin film on hydrophobic surface of a silicon substrate was remarkably suppressed by blending a homologue with different tacticity: either atactic or syndiotactic, even when its molecular weight is lower than that of the isotactic. Moreover, it was revealed by neutron reflectometry that either atactic or syndiotactic deuterated PMMA preferentially segregates at the air surface of a binary blend thin film with the isotactic after thermal annealing when the molecular weights of both the blend components are almost the same. (author)