固体核磁共振定量分析聚丙烯催化剂中的有机组分

Quantitative analysis of organic components in polypropylene catalyst by using solid-state NMR

利用固体核磁共振的^(13)C交叉极化魔角旋转(CP/MAS)和定量交叉极化魔角旋转(QCP/MAS)实验技术对聚丙烯DQ催化剂的组成进行定性及定量分析。建立了DQ催化剂中不同有机组分的QCP/MAS表征方法,考察了接触时间和转速对信号增强的影响,在选定接触时间为200μs,转动频率为8 kHz的实验条件下,测定了DQ催化剂中不同含碳官能团的增强因子及有机组分的物质的量比例。结合气相色谱–质谱联用实验结果证明,在制备过程中,未经陈化处理的DQ催化剂原料间发生化学反应,产生了邻苯二甲酸酐、邻苯二甲酸二乙酯等活性组分。超高效液相色谱实验数据显示,是否进行陈化这一步骤,所得聚丙烯催化剂产品中引入的邻苯二甲酸二乙酯含量差异明显。

Solid-state nuclear magnetic resonance(NMR) methods including ^13C cross polarization/magic angle spinning nuclear magnetic resonance(CP/MAS NMR),^13C quantitative cross polarization/magic angle spinning(QCP/MAS) NMR experiments were performed to analyze the organic components in polypropylene DQ-catalyst.The QCP NMR method was been applied to quantitatively characterize CP enhancement factors for carbon and mole fractions of organic components in catalyst,and the influence of CP contact time and MAS rate on the quantitative results were studied.The results combining GC-MS data showed that the chemical reaction existed during aging process in preparation of DQ-catalyst,and produced phthalic anhydride and diethyl phthalate.Data from UPLC analysis showed that whether or not to undergo aging process the content of diethyl phthalate in the product of polypropylene catalyst was significantly different.