RELATIONSHIPS BETWEEN LATERAL FORCE AND VISCOELASTIC PROPERTIES FOR AMORPHOUS POLYMER-FILMS BASED ON LATERAL FORCE MICROSCOPY

The relationships between lateral force and viscoelastic properties of amorphous polymer surfaces with Tg's lower and higher than room tempe rature (295 K, RT) and their blend systems have been studied on the ba sis of lateral force microscopic (LFM) measurement. Under the conditio ns of scanning rate of 10(2) - 10(5) nm sec(-1), normal load of 5 nN a nd RT, the lateral forces of poly(methyl methacrylate) (PMMA) and poly isoprene (PI) homopolymers with Tg's fairly higher and lower than RT, respectively, did not depend on the scanning rate. Whereas, the latera l force of poly(methyl acrylate) (PMA) with Tg less than or equal to R T decreased with an increase in the scanning rate. Also, poly(vinyl ac etate) (PVAc) with Tg greater than or equal to RT showed slight depend ence on the scanning rate. The scanning rate dependence of lateral for ce was similar to the frequency dependence of mechanical loss modulus. The results indicate that the magnitude of lateral force strongly dep ends on the state of thermal molecular motion. The lateral force-visco elastic properties of miscible polymer blends was also investigated by LFM.