Crystalline orientation in syndiotactic polystyrene cast films
Crystalline orientation in syndiotactic polystyrene cast films
复制标题
间规聚苯乙烯流延薄膜中的晶体取向
DOI：
10.1021/ma011853u
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发表时间：
2002
期刊：
影响因子：
5.5
通讯作者：
G. Guerra
中科院分区：
文献类型：
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作者：
Paola Rizzo;Marina Lamberti;A. Albunia;O. R. Ballesteros;G. Guerra
分析了溶液铸造法制备的笼形物s-PS薄膜和经适当处理法制备的半晶薄膜的晶相取向的种类和程度。包合物和纳米孔膜可以呈现高度的单平面取向，对应于ac晶体平面平行于膜平面的趋势。这种取向的驱动力是具有最小链间和最大面间距离的平行s(2/1)2螺旋排列趋向于平行于薄膜平面。退火后还保持了高度的单平面取向，从而形成γ型，即呈现相同螺旋构象的另一种晶体形式。基于正交单元格的γ型反射的试探性索引，再次表明ac平面相对于薄膜表面的平行性存在。一个实质性的平面方向，对应于平面…
The kind and degree of crystalline phase orientation for clathrate s-PS films, obtained by solution-casting procedures, and for semicrystalline films, obtained by suitable treatments on these cast films, are analyzed. Clathrate as well as nanoporous form films can present high degrees of uniplanar orientation, corresponding to the tendency of the ac crystallographic planes, to be parallel to the film plane. The driving force for this kind of orientation is the tendency of rows of parallel s(2/1)2 helices with minimum interchain and maximum interplanar distances to be parallel to the film plane. A high degree of uniplanar orientation is also maintained after annealing procedures leading to γ form, that is the other crystalline form which presents the same helical conformation. A tentative indexing of the γ form reflections, based on an orthorhombic unit cell, again indicates the presence of parallelism of ac planes with respect to the film surface. A substantial planar orientation, corresponding to the pla...