Study On Monomers Synthesis Of Bio-based Materials From Biomass Furan Platform Molecules

The synthesis of bio-based materials and their monomers from biomass resources is considered to be a very promising research direction.This is considered to be one of the important ways to achieve carbon peaking and carbon neutrality.Furfural and 5-Hydroxymethylfurfural,as furan-based platform molecules,have a wide range of sources and are renewable.Through their catalytic transformation,a variety of bio-based material monomers can be synthesized.Although there are many schemes for synthesizing bio-based material monomers based on furfural and 5-hydroxymethylfurfural as raw materials,there are still many challenges,such as the high cost of catalysts,the large energy consumption of the reaction process,the use of toxic and harmful substances,and the waste discharge,etc.Therefore,it is still of great significance to further develop a green and efficient catalytic system,improve the atomic economy of the reaction,and improve the controllability of the reaction.Secondly,for the current material monomers,we need to develop more synthetic routes based on target products,so that the synthesis routes of target compounds can be more diversified and the reaction process and reaction process can be simplified.In addition,we also need to design and synthesize new bio-based material monomers based on the current substrate structure,enrich bio-based material monomers,and broaden the application of bio-based material monomers.In this context,the new paths,new methods,and new structures for the synthesis of bio-based material monomers using furan-based platform molecules as raw materials are respectively studied and elaborated.The aim is to further broaden the application scope of furan-based platform molecules by developing a new route for the synthesis of bio-based material monomers.Secondly,we should develop new methods for the synthesis of bio-based materials monomers,and propose more green,efficient,and stable reaction strategies.We should also design and synthesize new bio-based material monomers to further enrich the types of bio-based material monomers and broaden the application scope of bio-based material monomers.In the first chapter,we introduce the research background of biomass resources and bio-based materials.The types and synthesis methods of bio-based material monomers synthesized by furan-based platform molecules are reviewed in detail.In the second chapter,the photocatalytic oxidation of furfural derivatives to synthesize y-butyrolactone and succinic anhydride was reported for the first time.The catalyst used is non-metallic carbon nitride.The reaction conditions are mild and no additives are used.By optimizing the reaction conditions,the yield of butyrolactone can reach 85%,and the yield of succinic acid can reach 60%.Through a series of control experiments,catalyst characterization,DFT theoretical calculation,etc.,the structure-activity relationship between the catalyst and the substrate molecule was discussed,and the possible reaction mechanism was proposed.And through the study of the reaction mechanism,the application scope of the catalytic system is further expanded.The photocatalytic oxidative cleavage of α-amino acid,diol,and lignin model molecules is realized,and the corresponding amide and carboxylic acid compounds are synthesized.In the third chapter,a new method for synthesizing 2,5-furandicarbaldehyde from 5-hydroxymethylfurfural is developed.5-Hydroxymethylfurfural can be converted into 2,5-furandicarbaldehyde by photocatalytic dehydrogenation with a yield of 82%.The catalyst used is a non-precious metal modified carbon nitride photocatalyst.The reaction conditions are mild,and the reaction process is free of oxidants and additives.The structure-activity relationship of the catalysts was described in detail employing TEM,EDX-Mapping,XPS,XRD,UV-Vis,and other characterization methods.The effects of photogenerated holes and electrons on the reaction were investigated,and the possible reaction mechanism was proposed.Additionally,it was found that alkaline conditions are more favorable for the photocatalytic dehydrogenation of 5-hydroxymethylfurfural.Based on this,the reaction conditions were optimized and the Cannizzaro mechanism was used to realize the one-step synthesis of 2,5-furandicarboxylic acid by photocatalytic dehydrogenation of 5-hydroxymethylfurfural with a yield of about 37%.When 5-hydroxymethylfuroic acid was used as the raw material,the yield of 2,5-furandicarboxylic acid was about 77%.The reaction system was further expanded,and 4-hydroxymethylfurfural was used as the raw material to synthesize 2,4-furandicarbaldehyde and 2,4-furandicarboxylic acid respectively.In the fourth chapter,new bio-based material monomers are designed and synthesized.We used 4-hydroxymethylfurfural and 5-hydroxymethylfurfural as raw materials to synthesize 4-OBMF and 5-OBMF,respectively.The catalyst used is a sulfonated magnetic solid acid catalyst.The magnetic solid acid catalyst is an N-doped carbon nanotube structure modified with-SO3H groups,and its magnetic cores are Fe,Co,or Ni nanoparticles respectively.It should be emphasized that the magnetic core is formed in situ during the calcination of the catalyst.The magnetic core not only has a size effect on the catalyst but also endows the catalyst with excellent magnetic separation performance,which makes the separation of the catalyst and the reaction solution easier.By optimizing the reaction conditions,the yield of 5-OBMF can reach 92%.The mechanism of the action of the catalyst on the substrate molecules was investigated by kinetic experiments and control experiments.And the possible reaction mechanism was proposed.It should be emphasized that 4-OBMF compounds with novel structures were also synthesized for the first time in this chapter.In the fifth chapter,the full text is summarized and prospected.In summary,this work is focused on the catalytic transformation of furan-based platform molecules.Bio-based material monomers were synthesized using green and efficient catalytic strategy.We use non-precious metal heterogeneous catalysts to catalyze the corresponding reactions,mainly due to the high efficiency,cheapness,stability,easy separation and recovery,and good recyclability of non-precious metal heterogeneous catalysts.The reaction conditions are as mild as possible,solvent-free,additive-free,etc.,to reduce energy consumption and the use of harmful substances,and improve the atom economy of the reaction.Based on this,in this paper,material monomers such as lactones,acid anhydrides,diacids,dialdehydes,and diols were synthesized using biomass furan platform molecules.