Precise Acid Copolymer Exhibits a Face-Centered Cubic Structure.
Precise Acid Copolymer Exhibits a Face-Centered Cubic Structure.
复制标题
精密酸共聚物呈现面心立方结构。
作者：
C. F. Buitrago;Kathleen L. Opper;K. Wagener;K. Winey
在每21个碳原子上有双磷酸垂坠的线性聚乙烯精确功能化，显示出酸聚集体的面心立方（FCC）包装。来自各向同性薄膜的x射线散射产生高阶散射峰，用于确定室温（aFCC = 4.19 nm）和聚乙烯基体熔融温度（aFCC = 4.06 nm）下的晶格参数。在拉伸精确的酸性共聚物时，具有两个共存晶体取向的各向异性散射模式产生，两者都具有FCC晶格沿拉伸方向的⟨110⟩方向。这是酸性共聚物中聚集体的立方有序的第一个报告，它是聚合物分子精度的直接结果。
A linear polyethylene precisely functionalized with geminal phosphonic acid pendants on every 21st carbon atom exhibits face-centered cubic (FCC) packing of acid aggregates. X-ray scattering from isotropic films result in higher-order scattering peaks used to determine the lattice parameter at room temperature (aFCC = 4.19 nm) and above the melting temperature of the polyethylene matrix (aFCC = 4.06 nm). Upon stretching the precise acid copolymer, an anisotropic scattering pattern featuring two coexisting crystalline orientations results, both having the ⟨110⟩ direction of the FCC lattice along the stretching direction. This is the first report of cubic ordering of aggregates in an acid copolymer and it is the direct consequence of the molecular precision of the polymer.