用于有机烃高效吸附分离的金刚烷结构多孔氰酸酯树脂合成研究

The present project aims at the demands for adsorption/separation of some important organic alkanes/olefins (aromatic hydyocarbons) in petrochemical industry. At first, several adamantane-based cyanate monomers with different geometrical configurations are designed and synthesized. Then, by means of solution polycondensation reactions, a series of hyper-cross-linked porous cyanate resins with the varied content of cycloaliphatic or aromatic ring in the porous cyanate networks are obtained. The influences of chemical structures of cyanante monomers on the porosity parameters such as specific surface area, pore size and distribution of polyimides are studied. The adsorption properties of alkane and its corresponding olefin with the same number of carbon atom, linear alkanes and their branched isomers, linear olefins and their branched isomers, linear and branched alkanes and olefins with different numbers of carbon atoms, olefins with different numbers of C=C double bond and the aromatic/aliphatic hydrocarbons with the similar molecular size are measured and systematically studied. The van der Waals and pi-pi interactions between olefins (aromatic hydrocarbons) and the aromatic components, between porous polymer skeleton and the adsorptions of alkanes/olefins (aromatic hydrocarbons) as well as the relationships between the adsorption/separation of organic hydrocarbons and chemical and porous structures of microporous polymers are also investigated to reveal the effects of micro-environment of porous channels on the adsorption/separations of alkanes/olefins (aromatic hydrocarbons). A new class of porous polymer materials with highly efficient adsorption/separation properties will be achieved.

本课题针对石化工业重要烷烃/烯烃(芳烃)及其异构体分离纯化的技术需求，首先合成基于金刚烷结构的具有不同几何构型氰酸酯树脂单体，经溶液缩聚反应制备脂环和苯环含量系列变化的大比表面积高度交联多孔金刚烷氰酸酯树脂网络。研究金刚烷几何构型对多孔氰酸酯树脂比表面积、孔径尺寸及分布孔等形貌参数的影响；系统研究直链烷烃和相同碳数烯烃、直链烷烃和其支链同分异构体、直链烯烃和其支链同分异构体、具有不同C=C双键数目的烯烃以及分子尺寸类似的芳烃/脂环烷烃的吸附性能；研究碳原子数变化对直链烷烃和烯烃的吸附性能；研究多孔聚合物骨架与烯烃、芳烃和烷烃分子间范德华相互作用或pi-pi相互作用的差异对烷烃/烯烃(芳烃)吸附分离性能的影响；揭示多孔聚合物孔道微化学环境和孔形貌参数与有机烃选择吸附能力之间的内在变化规律，得到具有高效吸附和分离有机烃性能的新型多孔高分子材料。

本项目圆满完成预定目标。已在ACS Appl. Mater. Interfaces, J. Mater. Chem. A, Chem. Commun. Polym. Chem. 等本领域高水平国际学术期刊上发表SCI论文12篇，超出项目申请书中发表学术论文5-8篇的预期目标，申请中国发明专利1项。后续还有多篇论文将随后整理发表。.主要创新性结果如下：.（1）成功合成了1,3,5,7-四(4-氰酰基苯基)金刚烷、三(4-氰酰基苯基)胺、9-(4’-氰酰基苯基)-3,6-双氰酰基咔唑及3,6-氰酰基咔唑四种新型氰酸酯单体，经三聚成环反应得到PCN-AD、PCN-TA、PCN-DC和PCN-TC微孔聚合物。通过FTIR、固体13C CP/MAS NMR、WAXD、FE-SEM、TGA和元素分析等手段对结构进行了表征。.(2) 所制备四种微孔氰酸酯的BET比表面积高达843 m2/g。由于PCN-AD同时具有大量的苯环芳香结构和金刚烷脂肪环状烷烃结构，所以对苯和环己烷均有着较高的吸附量，其吸附量分别为98.0和57.4 wt%，PCN-TA由于咔唑和苯环较高的电子密度和电子离域效应，使得苯蒸汽吸附量高达100.9 wt%。.（3）所制备四种微孔氰酸酯对C2-C3有机烃如乙烷、乙烯、丙烷和丙烯表现出较高的吸附容量和对甲烷气体的分离能力。例如，基于三官能团咔唑的微孔氰酸酯树脂PCN-TC在273 K和298 K下丙烯/甲烷的分离系数高达868和471，是目前文献报道的多孔聚合物的最高值。而且，咔唑和苯环较高的电子密度和电子离域效应使得PCN-TC对C4有机烃丁二烯的吸附量和对1-丁烯的分离系数分别高达49.1 wt%和3.85，显示出优异的吸附分离性能。.（4）成功合成了2,6,14-三氰酰基三蝶烯和2,6,14-三(4-氰酰基苯基)三蝶烯新型氰酸酯树脂单体，经三聚成环聚合得到两种微孔氰酸酯树脂PCN-TPC和PCN-TPPC。通过FTIR、固体13C CP/MAS NMR、WAXD、FE-SEM、TGA、元素分析、气体吸附和计算机模拟等手段对单体和聚合物的结构和孔形貌进行了表征。.（5）聚合物的BET比表面积高达686 m2/g，由于PCN-TPPC聚合物网络中苯环结构含量较多，导致其苯吸附量为77.8 wt%，苯/环己烷分离比达到7.2，为PCN-TPC的3倍。