Z型全氟聚醚的结构表征

Structural characterization of Z-type perfluoropolyether

具有功能性端基的全氟聚醚具有优异的化学稳定性及较强的加工可塑性,被广泛用于航天航空、电子、化工等领域。在其制备及应用过程中,基于核磁共振技术的结构表征和解析至关重要。然而由于全氟聚醚及其活性化合物的结构复杂、分子量大且分布较宽,因此在核磁测试中存在制样难、主链骨架结构和端基难以分辨和归属等问题,进而影响对全氟聚醚的定性定量分析。针对Z型惰性及活性全氟聚醚的结构解析,系统考察了不同种类氘代试剂和含氟助溶剂的复配、样品浓度、测试条件等因素的影响,探索得到较优的核磁样品制备条件;进一步分析了Z型全氟聚醚混合物的氟谱,确定了全氟聚醚的主链结构和端基的归属;利用端基分析法计算得到分子量及聚合度、两组分全氟聚醚混合物组成。

Perfluoropolyether(PFPE)with functional end groups possesses excellent chemical stability and strong processing plasticity,thus being widely applied in high-end fields such as aerospace,electronics,chemical engineering.During production and application,it’s significant to characterize and analyze PFPE structure based on nuclear magnetic resonance technology(NMR).However,due to structure complexity,high molecular weight and wide distribution of PFPE,there have been difficulties in preparing samples for NMR test,distinguishing and attributing the main chain structure and end groups in NMR spectra,which further affects qualitative and quantitative analysis of PFPE.In view of the structural analysis of Z-type PFPE,this study investigated combination of kinds of deuterated solvents and fluorinated cosolvent,sample concentration and test conditions,obtaining a better method of NMR sample preparation.The attribution of main chain structure and end groups of PFPE were determined.Also,the molecular weight,the degree of polymerization,and the composition of twocomponent PFPE mixture were calculated by analyzing the end groups of PFPE.