Synthesis Of Polymer Supported Catalysts Based On Activated Ester Functionalization

In recent years,homogeneous catalysts have been extensively studied and applied because of their high catalytic activity.However,homogeneous catalysts are expensive and usually require the use of heavy metal ions,which not only pollutes the product but also increases the difficulty of post-treatment,and makes the catalysts difficult to separate from the reaction system.At the same time,the application of the homogeneous catalyst in organic synthesis and industry is greatly limited.Therefore,in the field of organic catalysis,the preparation of catalysts which can be recycled,high catalytic activity,simple operation and easy recovery has attracted wide attention.Polymer supported catalysts have the advantages of high catalytic activity,good stereoselectivity,good stability and reusability.They can overcome the shortcomings of homogeneous catalytic reactions and develop rapidly.In addition,the post-treatment of these catalysts is simple,which can be reused by separating them from other components in the reaction system by solid-liquid separation method,and can significantly reduce production costs and environmental pollution.In this paper,organic macromolecule materials are used as metal catalyst carriers to modify the polymer carriers by activating ester functionalization reaction,and then coordinate with metal ions to synthesize a new type of polymer supported catalyst,and to study its catalytic performance.The main research contents and results are as follows:?1?Thermosensitive polymer P(MASI-co-DEGMMA-co-OEGMMA₃₀₀)was prepared by solution free radical polymerization,and then functional polymer P(MAAm-pybox-co-DEGMMA-co-OEGMMA₃₀₀)was synthesized by introducing organic ligand pybox through activation ester functionalization reaction,and further coordinate with ZnCl₂ to afford a polymer supported zinc???catalyst.The UV-Vis was used to test the transition temperatures of the thermosensitive polymer carrier,functional polymer and its supported zinc???catalyst.It was found that the transition temperature of P(MASI-co-DEGMMA-co-OEGMMA₃₀₀)was 41.8?,the P(MAAm-pybox-co-DEGMMA-co-OEGMMA₃₀₀)was 40.0?,and its supported zinc???catalyst was 42.9?.The prepared polymer supported zinc???catalyst was applied to the Knoevenagel condensation reaction in a pure water system at room temperature,and the catalyst showed good catalytic effect.After the end of the reaction,the catalyst was recovered by heating and centrifugation,and still had high catalytic activity after repeated use for 5 times.?2?Thermosensitive polymer P?NHSA-co-NIPAAm?was prepared by solution free radical polymerization,and then the functional ligand P?AAm-tpy-co-NIPAAm?was obtained by introduce the organic ligand tpy through activation ester functionalization reaction,and further coordinate with CuCl₂·2H₂O to obtain a polymer supported copper???catalyst.The optimum decolorization conditions for the catalytic degradation of reactive brilliant blue KN-R by tripyridyl copper???complex were obtained:at room temperature,pH=9,dye concentration 150 mg/L,tripyridyl copper???complex 15 mg/100 mL,hydrogen peroxide concentration 3%,decolorization 55 min,decolorization rate of dye solution can reach more than 95%,and in circulation and the decolorization effect remained good after 5 times of use.Under the optimum conditions,the application of polymer supported copper???catalyst to catalytic degradation of reactive brilliant blue KN-R also has excellent decolorization performance.After 8 cycles of recycling,the decolorization rate does not decrease significantly,and the catalyst can be recovered by centrifugation after the end of the reaction.In summary,from the perspective of improving the activity and separation effect of the catalyst,the polymer was modified by activating ester functionalization strategy,and a new type of polymer supported catalyst was successfully prepared,and the activity,stability and reusability of the prepared catalyst were studied.The results show that the polymer supported catalyst not only has high catalytic activity and stability,but can be reused by simple centrifugation after the reaction is completed,and the catalytic activity is not significantly decreased after repeated use for several times.