Study of surface properties of blend films using stereocomplexation between enantiomeric polylactide chains

This study investigated the stereocomplex-induced surface structure of enantiomeric poly(lactide) (PLA) blend films by differential scanning calorimeter, electron spectrometer for chemical analysis, and contact angle measurements. The design of the blend systems is based on principles of surface segregation of a modified component with a low surface energy, fluorocarbons (F), as an end group. The two blend systems, uncomplexed (F-l-PLA/l-PLA) and complexed (F-l-PLA/d-PLA), showed quite different surface structures: the surface segregation of fluorocarbon groups in the (F-l-PLA/l-PLA) blend film was observed while the surface structure of the (F-l-PLA/d-PLA) blend film was similar to its bulk one. This indicates that the interchain interaction to form stereocomplexes between l- and d-PLA is strong enough to overcome the driving force of fluorocarbon groups toward the surface.