Characterization of elastomer sliding behavior across silica and polydimethylsiloxane grafted surfaces

A novel combination of experimental techniques including a lateral force ap paratus was developed for the purpose of characterizing the slip of polymer materials over hard surfaces. Quantitative shear stress data were obtained by sliding a crosslinked polydimethylsiloxane elastomer across smooth fat- tipped styli (mesas). A first set of mesas had a native silica (SiO) surfac e; a second set was functionalized with linear hydroxyl-terminated polydime thylsiloxane (PDMS-OH) polymers. The shear stress associated with sliding a cross the SiO mesas was as much as a factor of 10 greater than that for sli ding across the PDMS-OR functionalized mesas. Possible mechanisms underlyin g this difference in behavior an discussed. (C) 2000 The Society of Rheolog y. [S0148-6055(00)01405-X].