The Film Preparation Of Polymers Confined On The Surface Layer And Its Relaxation Behavior

Because of the different geometrics and environments, polymers have many differentconfined states. Recently, more and more attentions have been paid to the nanoconfinementpolymer. In the process of confined polymer materials applied, the properties of the surface aretaking a very important role. As a kind of nonequilibrium3D confined structure, micelle has veryspecial property.In this thesis, Contact angle, AFM and SFG are employed to study the segments relaxationbehaviors of the surface micelle core and the surface structure of the polystyrene film. Somemain conclusions shown in below:（1） For PS-PAA micellar system, the relaxation behavior of the PS segments confined inthe surface micelle core is different from the PS film and bulk （T_g^Film＜T^onset＜T_g^Bulk）. The PSsegments will be more difficult to relax if the tightness degree of the molecular chains is greater.When the molecular weight of PS segments is beyond the critical entanglement molecular weight(just like PS₂₇₈-PAA₄₇micelles and PS₄₀₄-PAA₆₃micelles), the slight increase of the tightnessdegree will greatly suppress the relaxation of PS segments confined in micellar core. When themolecular weight of PS segments is under the critical entanglement molecular weight (just likePS₁₅₄-PAA₄₉micelles), the suppression effect is not so obvious. The possible reason is that themolecular chains arrangement in PS₂₇₈-PAA₄₇micelles and PS₄₀₄-PAA₆₃micelles is affected bypacking effect and entanglement effect, which is only packing effect in PS₁₅₄-PAA₄₉micelles.（2） For PMMA-PAA micellar system, the relaxation behavior of the PMMA segmentsconfined in the surface micelle core is different from the PMMA film and bulk （T^onset＜T_g^Film≈T_g^Bulk）. The confined PMMA segments will be easier to relax when the PAA segmentlength increased. The possible reason is that increasing the PAA segment length will decrease themicellar size. The PMMA segments relaxation will be affected by the size effect.（3） The surface structure of PS cast film was studied. The benzene ring will occupy thesurface when the film-forming solution concentration is low. The backbone and end group willoccupy the surface when the film-forming solution concentration is high. The possible reason ofthis distinguish is that different film-forming solution concentrations lead to differententanglement degree.（4） The surface structure of PS spin-coated film was studied. The benzene ring occupiedthe surface was appeared in every PS spin-coated film. This is could be due to the β relaxation ofthe benzene ring. The solution concentration, molecular weight and spin speed do not affect the surface structure of the spin-coated film.