Preparation Of Porous Organic Polymer Based Solid Acids And Their Catalytic Activities

Nowadays scientists pay more attention to the solid acids,which are green catalysts with potential to replace the liquid acids.Some solid acids are successfully applied in the industry.Various solid acids such as metal oxides,heteropolyacids,carbon-based solid acids,macromolecular resins and natural clay are developed.The porous organic polymers are based on organic skeleton and have good compatibility to organic reactants.Especially,the hypercrosslinked porous polymers linked by covalent bonds have excellent stability.The abundant aromatic polycyclic structure of these materials also provides sufficient reaction sites for sulfonation.In this paper,porous organic polymers were prepared from naphthalene,phenanthrene and anthracene,respectively.By adjusting the reaction conditions,the surface area and pore structure of the polymer could be effectively controlled.A series of hypercrosslinked porous materials were obtained.On this basis,porous organic polymer based solid acid catalysts were prepared by sulfonation of the polymers to introduce sulfonic acid groups.The catalytic activities of these acid catalysts were investigated through specific reactions.The main research contents include:(1)Naphthalene was used as monomer and methanol formaldehyde(FDA)as external cross-linking agent.The reaction conditions were controlled to adjust the structures of the polymer.The polymers have the high surface area of 438 m~2/g.The solid acids give the high acidity of 3 mmol/g.The catalyst showed the high activity for the alkylation of resorcinol with the conversion of 98%and double substituted compounds selectivity of 72%when 0.01 mol resorcinol,5.5 mg catalyst and 0.02 mol tert-butanol were reacted at 120?for 5 h.The catalyst can be recycled and reused.The regeneration was also very simple by just acid pickling directly.(2)The polymer based on philippine was synthesized using melamine formaldehyde as external crosslinking agent.The structure of the polymer could be controlled by adjusting the reaction conditions.The high surface area could reach628.70 m~2/g and the acidity of the resulting solid acid was about 1 mmol/g.The optimal reaction condition:0.02 mol tartaric acid,0.08 mol butyl alcohol,catalyst 1%,120?and 4 h with the conversion of 98.2%.The catalyst could be recycled with the recycled activity over 85%after 4 times.(3)Four external crosslinking agents including formaldehyde,FDA,melamine formaldehyde and paraformaldehyde were applied with anthracene to form the special polymers respectively.The polymers showed different morphology and the surface area ranged from 498-619 m~2/g.20 catalysts were synthesized after sulfonated under the same reaction conditions.The catalytic activities were investigated via the synthesis of tetrahydrofuran.Among these catalysts,the highest catalytic activity was obtained from the solid acid using FDA as crosslinking agent with the conversion of 99.9%.However,the highest stability of the catalyst was the solid acid using formaldehyde as the crosslinking agent with the conversion of 50%after 4 times of reuse.