溶剂对SEBS/PMMA共混物薄膜形态的影响

Solvent Effect on the Surface Morphology of SEBS/PMMA Blend Films

采用原子力显微镜研究了聚(苯乙烯-嵌-乙烯/丁烯-嵌-苯乙烯)(SEBS)和聚甲基丙烯酸甲酯(PM-MA)共混物不同溶剂旋转涂膜的表面形态和相分离行为。结果表明,用共混物的氯仿溶液旋转涂膜,可见明显的共混物的宏观相分离和SEBS的微观相分离形态。改变选择性溶剂可使旋涂膜具有不同的均匀度和形态结构,其相区的尺寸和形状相差甚大,有海岛型、网状、双连续状结构。AFM显示用环己烷/丁酮混合溶剂旋转涂膜,共混物的相分离最为彻底;用选择性溶剂氯仿时次之,但有明显的相分离;对SEBS和PMMA均无选择性的单一溶剂或混合溶剂则无明显相分离。

The influences of solvents used for spin-coating on the surface morphology and phase seperation behavior of poly（styrene-block-ethylene/butylene-block-styrene） （SEBS）/poly （methyl methacrylate） （PMMA） blend films were investigated by AFM. An evident macro-phase separation between SEBS and PMMA blend and a micro-phase separation in SEBS copolymer were observed simultaneously in the blend film spin-coated from chloroform solvent. Different solvents can control the film morphologies with distinct domain shape and domain size. Island-sea morphology, mesh-like morphology and co-continuous morphology were obtained with solvents used. The extent of phase-separation for cyclohexane/ MEK spin-coated film was deeper than that for the other solvents. In the case of the chloroform spin-coated, the extending PMMA chains would be beneficial to the phase-separation, but the extent was confined by the coils of collapsed SEBS chains. In the case of those films spin-coated from 1,2-dichloroethane and n-heptane/acetone solvents, no notable phaseseparation was observed.