Investigation of the Structures and Dynamics of Fluoropolymers Using Novel Methods of Solid-state ^<19>F NMR Spectroscopy.

采用^<19>F魔角旋转（MAS）和^1H【双箭头】^<19>F交叉极化(CP)/MAS核磁共振（NMR）光谱技术，探索了固态功能含氟聚合物结构和分子迁移率分析的新方法。新颖的^<19>F核磁共振方法，如选择性观察迁移率与非晶迁移率差别不大的聚合物的结晶域，非晶聚合物中特征局部迁移率的估计，估计原子间H-F距离的评估方法等，除了分析由高丰核组成的多自旋系统中的CP动力学和各种测量磁弛豫时间的方法之外，还开发了新的方法。这种^1H【双箭头】^<19>F CP/MAS技术应用于(1)具有明显多态性的聚偏氟乙烯（PVDF）和(2)相结构尚未进一步阐明的聚偏氟乙烯（PVF）。I)根据每个信号的强度估计结晶度和结构异构程度，II)主链的构象由^<19>F的化学位移（共振位置）确定，III)多晶之间和结晶/非晶态域之间的分子迁移率差异，并通过磁松弛测量和^1H【双箭头】^<19>F CP动力学分析研究了F- h原子间距离。IV)通过变温（VT）测量澄清了在高温下晶体结构的逐渐变化。随后，衍生核磁共振技术被应用于(3)Cytop是一种无定形全氟聚合物，(4)乙烯/四氟乙烯共聚物（ETFE），(5)偏氟乙烯/三氟乙烯共聚物（P(VDFITrFE)），具有非常高的铁电性，(6)PVDF/PMMA的混相共混物，(7)耐候性高的聚氯三氟乙烯（PCTFE）， (8) PCTFE/PVDF的非混相共混物，(9)适用于光波导电路的含氟芳族聚酰亚胺。这一系列的研究表明，^<19> fmas和^1H【双箭头】^<19> fcp /MAS NMR方法对于分析功能含氟聚合物的结构和运动是非常有用和有前景的。少

Various spectroscopic techniques using ^<19>F magic angle spinning (MAS) and ^1H【double arrow】^<19>F cross polarization (CP)/MAS nuclear magnetic resonance (NMR) spectroscopy were developed to explore new methodology for the analysis of structure and molecular mobility of functional fluoropolymers in the solid state. Novel ^<19>F NMR methods, such as a selective observation of the crystalline domain of polymers whose mobility does not much differ from the amorphous domain, an estimation of the characteristic local mobility in the amorphous polymers, an appraisal method for estimating interatomic H-F distances, etc. were developed in addition to the analysis of CP dynamics in a multi-spin system consisting of highly abundant nuclei and various methods for measuring magnetic relaxation times. Such ^1H【double arrow】^<19>F CP/MAS techniques were applied for (1)polyvinylidene fluoride (PVDF) exhibiting distinct polymorphism and (2)polyvinylfluoride (PVF) whose phase structure has not been c … More larified yet. I)The degrees of crystallinity and structural isomerism were estimated from the intensity of each signal, II)the conformations of the main chain were determined from ^<19>F chemical shifts (resonant positions), III) the difference in molecular mobility among polymorphs and between crystalline/amorphous domains, and the F-H interatomic distances were investigated from the magnetic relaxation measurements and the analysis of ^1H【double arrow】^<19>F CP dynamics, and IV)the gradual changes in conformation of the crystalline domains at elevated temperatures were clarified by the variable temperature (VT) measurements. Subsequently, derivative NMR techniques were applied for (3)Cytop that is an amorphous perfluoropolymer, a crystalline (4)ethylene/tetrafluoro-ethylene copolymer (ETFE), (5)vinylidene fluoride/trifluoroethylene copolymer (P(VDFITrFE)) that exhibits very high ferroelectricity, (6)miscible blends of PVDF/PMMA, (7)polychlorotrifluoroethylene (PCTFE) having high weatherability, (8)immiscible blends of PCTFE/PVDF, and (9)fluorine-containing aromatic polyimides applicable for optical waveguide circuits. This series of research has shown that ^<19>F MAS and the ^1H【double arrow】^<19>F CP/MAS NMR methods are very useful and promising for the analysis of structures and motility of functional fluoropolymers. Less