Surface dilational moduli of poly (ethylene oxide), poly (methyl methacrylate), and their blend films

► Surface dilational moduli were measured for compatible blend films of PEO and PMMA. ► The surface dilational moduli of the blend films were less than those of PMMA and larger than those of PEO. ► Lissajous orbits of the blend films changed from positive hysteresis loops to negative loops.