通过宽线固体核磁共振氢谱研究半晶高分子的相结构

宽线固体核磁共振氢谱(~1H NMR)是一种研究半晶高分子相结构的经典方法.本文以半晶聚乙烯的宽线固体~1H NMR谱为例,探讨了通过Gaussian/Sinc、Gaussian和Lorentzian函数组合对宽线固体~1H NMR谱图进行拟合的方案,并根据半晶聚乙烯的相结构成分对拟合得到的各信号成分进行归属.并在此基础上探讨了各个相结构中分子链运动与信号线型的相关性,以及利用宽线固体~1H NMR谱测量半晶高分子结晶度存在的困难.

A Wide-Line Solid-State 1H NMR Study of Phase Structures of Semi-Crystalline Polymers

Wide-line solid-state proton nuclear magnetic resonance (¹H NMR) spectrometry is a classical technique to study the phase structures of semi-crystalline polymers. In this paper, the wide-line solid-state ¹H NMR spectrum of semi-crystalline polyethylene was acquired, and fitted with the combination of Gaussian/Sinc, Gaussian and Lorentzian functions. The four signal components decomposed from the wide-line solid-state ¹H NMR spectra were assigned to the crystallization phase, crystalline interface phase, amorphous interface phase and amorphous phase, respectively. The chain dynamics in different phase was also studied with the temperature-dependent wide-line solid-state ¹H NMR method. The difficulties in determining the crystallinity of semi-crystalline polymers with wide-line solid-state ¹H NMR were discussed.