Morphology Control And Amplification Synthesis Of Hypercrosslinked Microporous Polymers

Hypercrosslinked porous polymers(HCPs)synthesized by Friedel-Crafts reaction is a class of microporous organic polymers with good physical and chemical stability.They show the advantages of low density,large specific surface area,adjustable pore size,and easy functionalization.So they are widely used in the fields such as gas capture and storage,pollutant treatment,catalysis and sensing.With the development of the external crosslinking method,the researches on the types and morphologies of hypercrosslinked porous polymers have been greatly developed.However,HCPs with special morphology are usually prepared based on the template method which is need to form a template-polystyrene precursor first.It limits the types of substrates that can be used for morphology research.So it is necessary to develop a universal method for preparing template-HCPs composite materials.A new method for the preparation of HCPs composites with designed morphology is studied in this paper.Using a phenyl-containing silane coupling agent instead of KH-570 for functionalization we can obtain a phenyl-modified template.So a template-HCPs composite can be directly obtained by crosslinking aromatic monomers with phenyl groups on the surface by Friedel-Crafts reaction without emulsion polymerization.The thickness of the HCPs layer in the product can be directly adjusted by adjusting the amount of monomers.A complete hollow spherical structure can be obtained after etching.By controlling the temperature,composite materials with good dispersibility can be obtained.This is a new method provided for further studying the influence of micromorphology on the properties of HCPs and the preparation of HCPs composites.And compared with other microporous organic polymers,HCPs have advantages of mild reaction condition and low price of reaction materials.So they show the possibility of industrialization.By gradually expanding the scale of the reaction,we discovered and solved a series of problems exposed by the expansion of the reaction system.Due to the change of the purity of the raw materials and heat affection,the properties of the products will decrease greatly.Secondly,because of the solidification of products,it is difficult to realize continuous production.So it is necessary to find a balance between high specific surface area and maintaining the fluid state of the reaction system.In this paper,the experimental scale was gradually enlarged by empirical amplification method.The reaction process was studied at 2 L,20 L and 1000 L with benzene as monomer.The products before and after enlargement were characterized by FTIR,¹³C NMR,FSEM,FTEM,TGA and pore analysis.We gradually add catalyst to alleviate the thermal effect of the reaction.By increasing the ratio of raw materials to promote the solid content of the reaction system.By increasing the amount of cross-linking agent to maintain a higher specific surface area of the product.We reduce the amount of catalyst to avoid product solidification.304 stainless steel reactor is used to avoid the corrosion of the equipment by the reaction system.The stirring blade is modified to improve the uniformity of the reaction system.While we used industrial raw materials,the BET specific surface area of the 1000 L pilot-produced HCPs is 624-740 m²/g,and the hydrogen storage capacity at 77 K/1 bar is 1.17 wt%.In this work,a treatment plan for the wastes in the production process was proposed,and the production cost was estimated based on the actual amount of trial production,which was about 79.5yuan/kg.Repeated trial production experiments three times showed that the production process was highly reliable.