Structure and Physical Properties of Polymers at Nanoscale Interface with Liquids

讨论了聚甲基丙烯酸甲酯(PMMA)在不同界面、气体和液体中的热分子运动。即使在空气界面上也能清楚地观察到αα-和β-松弛过程。空气界面的松弛温度均低于块体中相应的松弛温度。此外，表面弛豫过程的峰值温度降至体相温度以下的程度强烈依赖于薄膜的立体规整性。在此基础上，研究了PMMA与水、正己烷、甲醇等液体界面的力学性能。在薄膜最外层附近，弹性模数减小。界面区弹性模数的降低程度与膜中液体的吸入量一致。因此，可以说，聚合物的界面分子运动可以根据聚集态进行调节。

Thermal molecular motion of poly(methyl methacrylate)(PMMA) at various interfaces, gases and liquids, was discussed. Theαa-andβ-relaxation processes were clearly observed even at the air interface. Both relaxation temperatures at the air interface were lower than the corresponding ones in the bulk. In addition, the extent to which the peak temperature for the surface relaxation processes fell below that of the bulk strongly depended on the stereoregularity of the films. Then, mechanical properties of PMMA were also studied at interfaces with liquids such as water, hexane and methanol. The modulus decreased closer to the outermost region of the film. The extent to which the modulus decreased in the interfacial region was consistent with the amount of liquid sorbed into the film. Therefore, it can be claimed that interfacial molecular motion of polymers can be regulated on the basis of the aggregation states.