成核剂在聚丙烯的结晶过程中作为晶核，参与调节晶体的晶型、大小及其分布，促使形成不同性能的聚丙烯材料．成核剂促进聚合物结晶的机制是聚合物结晶领域的研究热点，但其结构对聚合物结晶的影响尚不清晰；而成核剂通常具有同分异构体，使其结构解析更加困难，但成核剂的结构解析是进一步研究其成核机理的基础．本文综合运用核磁共振（NMR）波谱、傅里叶变换-红外（FT-IR）光谱和扫描电镜能谱分析（SEM-EDS）表征了一种二元羧酸复合物类β晶型聚丙烯成核剂的结构和构型，结果表明该成核剂cis-△4-四氢邻苯二甲酸钙为消旋体，羧酸与钙以桥式螯合方式形成有机羧酸金属盐．
The nucleating agent acts as a crystal nucleus during polypropylene (PP) crystallization, affecting the structure and size distribution of the crystal, and in turn the properties of PP products. It is a hot research topic to study the mechanisms by which the nucleating agent promotes polymer crystallization. Currently it is still unclear how the structure of nucleating agent affects polymer crystallization. In addition, a nucleating agent may have different chemical structures due to isomerization, further complicating the nucleation mechanism study. Structural studies of nucleating agents are therefore the foundation of the nucleation mechanism studies. In this work, the structure and configuration of a β nucleating agent used in PP crystallization were studied by the combination of nuclear magnetic resonance (NMR) spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The FT-IR data suggested that the chelating way of calcium salt of cis-Δ4-tetrahydrophthalic acid in the nucleating agent belongs to the bridge type, while the cis-Δ4-tetrahydrophthalic acid is a mesomer.
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