The Study On Palladium-Catalyzed Biomass-Derived Furfural Derivatives To Bifuranedioic Acid And Bifurandialdehyde

With the increasing depletion of fossil resources,the world is facing environmental problems and energy crises.Versatile polymer materials occupy a very important position in the modern chemical industry.Exploring new technologies for synthesizing polymer monomers from biomass has become an urgent need for polymer production.Although C6 chemicals prepared from cellulose have been extensively researched and many results have been achieved in the application as polymer monomers,the industrial route for large-scale production from cellulose to glucose has not yet been achieved in the industry.The industry has already realized the production of furfural from hemicellulose derived from agricultural and forestry by-products.However,since furfural is a monofunctional molecule,the market capacity is very limited,which severely limits the use of furfural as a platform for agricultural and forestry by-products.This thesis has developed palladium-catalyzed furfural derivatives to synthesize polymer monomers,and it has also been applied to polymer synthesis research,opening up a polymer industrial application with great market potential for the comprehensive utilization of biomass furfural.In the second chapter of the thesis,we developed a one-step reductive coupling of 5-bromo-furoic acid to 2,2-bifuryl-5,5-dicarboxylic acid(BFDCA)using water as the solvent and CO as the reducing agent.Remarkably,separations of the catalyst and product from the reaction medium are simple including catalyst filtration,medium acidification followed by simple filtration of the BFDCA product.The selectivity of the target product is >99%.After simple drying,the catalyst can be directly recycled for more than 10 times without obvious catalyst deactivation,and the BFDCA synthesis of 50 g scale has been realized,which makes this method have the potential for large-scale BFDCA synthesis.In addition,BFDCA can synthesize stable liquid crystal polymers with ethylene glycol,1,4-butanediol,and 1,6-hexanediol.The similar physical properties and lower liquid crystal behavior make it have the potential to replace petroleum derivative 4,4'-biphthalic acid(BDA)monomers in polymers.The third chapter of the thesis is a continuation of the previous chapter.In view of the efficient catalytic performance of Pd/C catalysts,we have developed a method for directly synthesizing 2,2'-bifuryl-5,5'-dicarbaldehyde with 5-bromofurfural using acetonitrile as the solvent and CO as the reducing agent.The selectivity of the target product is still >99%.This lays a good foundation for the further large-scale synthesis of 2,2'-bifuryl-5,5'-dicarbaldehyde and replaces the petroleum derivative 4,4'-biphenyldialdehyde as a polymer monomer.It also opens up broad prospects for the application of hemicellulose derived from agricultural and forestry by-products in the polymer industry.