降凝剂是一种少量加入即可显著改善柴油低温流动性的添加剂，因操作简单、加剂量少、成本低等优势备受关注，而当前降凝剂市场普遍存在降滤效果低、普适性差、机理不明确等问题，严重制约其发展。申请人前期研究发现，聚甲基丙烯酸酯类（PMA）降凝剂具有丰富的结构多样性和良好的普遍适用性，研究潜力巨大。.本项目以甲基丙烯酸酯为核心单体，设计、优选不同协同单体，利用不同功能基团侧链修饰，构筑不同极性和结构特征的新型PMA类降凝剂；研究并揭示不同降凝剂分子结构与其性能的构效关系，总结不同剂、油之间溶解性、分散度和感受性差异；基于不同目标柴油开展降凝剂的广谱性研究，辅以剂型复配等手段协同增效，开发高效广谱性柴油降凝剂；进一步从分子水平探寻不同降凝剂对柴油组分低温结晶行为的调控作用，建立降凝机理模型。本项目的实施将有助于指导新型降凝剂分子设计与优化，丰富柴油降凝剂多样性，扩大我国超低温柴油产量，助力民生国防新发展。

Pour point depressants (PPDs) are the additives that can significantly improve the cold flow properties of diesel fuels at low temperature by adding a small dosage. It has attracted much attention due to its advantages such as simple operation, lower dosage and cost-effective. Nevertheless, many problems such as poor cold filter plugging point reduction, low universality, and unclear mechanism are still widespread in current PPDs field, and seriously restrict the development of novel PPDs. Through former researches of applicant, the polymethacrylate (PMA) PPDs have enormous potential due to its abundant structural diversity and better universal applicability..In this project, methacrylate is used as the core monomer, different co-monomers are designed and optimized, after side chain modification of different functional groups, the novel styles of PMA PPDs for diesel fuel with different polarity and structural characteristics are prepared. The structure-activity relationships of different PPDs molecules and their depressive performance are studied and revealed, as well as the solubility, dispersion and susceptibility between those PPDs and diesel fuel are summarized. Furthermore, the broad-spectrum study of various PPDs in different targeted diesel oils will be carried out. Then, the high-efficiency broad-spectrum PPDs are developed with the aid of multiple means such as compounding technology. At the same time, the regulatory mechanism of PPDs molecules on the crystallization behaviors of diesel oil at low temperature are explored on a molecular level. And the depressive mechanism models of those PPDs also will be established. Above all, the accomplishment of this project is expected to guide the design and optimization of novel PPDs, enrich the diversity of PPDs for diesel, expand the production of ultra-low temperature diesel in China, realize the improvement of cold performance enhancement technique of diesel, and promote the expand production and application of ultra-low temperature diesel in China. and facilitate the further developments of people's livelihood and national defense.