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

利用魔角旋转(MAS)和~1H[双箭头]~(19)&gt；F交叉极化(CP)/MAS核磁共振(核磁共振)光谱技术，开发了多种光谱技术，以探索分析固态功能氟聚合物结构和分子迁移率的新方法。除了分析由高丰度核组成的多自旋体系的CP动力学和测量磁弛豫时间的各种方法外，还发展了新的核磁共振方法，如选择性地观察迁移率与无定形结构域没有太大差别的聚合物的晶区，估计非晶态聚合物中的特征局域迁移率，估计原子间H-F距离的估计方法等。这种技术被应用于(1)表现出明显多态的聚偏氟乙烯(PVDF)和(2)相结构不是c…的聚偏氟乙烯(PVF)更离谱的是。I)根据每个信号的强度估计结晶度和结构异构性，ii)根据主链的化学位移(共振位置)确定主链的构象，iii)晶型之间和晶态/非晶区之间分子迁移率的差异，并通过磁弛豫测量和^1H[双箭头]^19&gt；19&gt；F CP动力学的分析研究了F-H原子间距，以及IV)通过变温(VT)测量阐明了晶区构象在高温下的逐渐变化。随后，导数核磁共振技术被应用于(3)无定形全氟聚合物Cytop，(4)结晶(4)乙烯/四氟乙烯共聚物(ETFE)，(5)表现出很高铁电性的偏氟乙烯/三氟乙烯共聚物(P(VDFITrFE))，(6)PVDF/PMMA的可混合共混物，(7)具有高耐候性的聚氯三氟乙烯(PCTFE)，(8)PCTFE/PVDF的不相容共混物，以及(9)适用于光波导电路的含氟芳香族聚酰亚胺。这一系列的研究表明，^&lt；19&gt；F MAS和^1H[双箭头]^19&gt；F CP/MAS核磁共振方法在分析功能氟聚合物的结构和运动性方面是非常有用和有前途的。较少

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