Synthesis And Applications Of Novel Bio-based Furan Polymers

From the perspective of reducing environmental load and improving sustainability,the preparation of chemicals and polymer materials based on renewable resources has important scientific significance and research value.Among them,the synthesis of biobased furan polymers has attracted much attention and various types of furan polymers have been developed.In this dissertation,a series of monomers with unique structure were designed from a wide range of bio-based small molecules of furan.Polymers containing furan rings were prepared by metathesis polymerization and ring-opening polymerization,and the relationship between structural differences and polymer properties was systematically studied.Because the polymer has good hydrophobicity,the hydrophobic modification of waste textiles has been successfully realized.Specific studies are as follows:1.Two α,ω-diene monomers which are isomers of each other and have furan rings were designed and synthesized,and the saturated furan long chain polyesters were successfully synthesized based on acyclic diene metathesis and hydrogenation reduction reaction.The effects of the chain structure of polyesters on their thermal properties,crystallization capacity and hydrophobicity were systematically studied.Two α,ω-diene monomers were prepared by the esterification reaction between the bio-based furan derivatives(2,5-furan dicarboxylic acid and 2,5-furan dimethyl alcohol)and the downstream products of undecylenic acid(10-undecylenol and 10-undecylenyl chloride),and six unsaturated long-chain polyesters were prepared by their own homopolymerization or copolymerization of the two monomers.Further hydrogenation and reduction to obtain a high molecular weight saturated furanyl polyester.The results show that the structural difference of raw materials has little effect on the properties of polymers,and all polyesters have great thermal stability and semi-crystalline property.The homopolymer and copolymer have different crystallization behavior due to the difference in the regularity in the chain.Small molecule precursors were obtained by alcoholysis because of the existence of breakable ester bond sites.The prepared polyester has the properties of polyethylene-like material,and the functional hydrophobic coating was successfully constructed by nano precipitation method.2.Cyclic monomers with different methylene numbers were designed and synthesized,and a series of semi-aromatic polyesters were obtained by entropy-driven ring-opening polymerization.The effects of methylene chain length of repeating units on the properties of polyesters(thermal properties,crystallization capacity and hydrophobicity)were studied in detail.A series of macrocyclic monomers were prepared based on the esterification of 2,5-furanediol with different chain lengths at low concentration,and the white furanyl polyester was obtained by further ring opening polymerization,which successfully avoided the problem of product coloring which was difficult to overcome by traditional condensation polymerization process.The results show that the polymer has excellent thermal stability,but the length of the fat chain of the repeating unit affects the properties of the polymer.The crystallization capacity and melting point of long-chain polyesters with odd-numbered methylene chains are not as good as those of even-numbered polyesters.By wrapping and modifying polymer nanoparticles with sodium dodecyl sulfate,tannic acid and octadecylamine,a functional superhydrophobic coating was successfully constructed on the surface of PET fabric.3.The whole biological monomer with furan ring in main chain and long alkyl chain in side chain was designed and synthesized.The preparation process was simple and the conversion rate was high.The comb-shaped furan polymers were prepared by ring-opening translocation polymerization,and the effects of catalyst/monomer feeding ratio on the properties of the polymers(thermal properties,crystallization capacity and hydrophobicity)were investigated.Based on the cycloaddition reaction of furfuryl alcohol and lamfuric anhydride,the intermediates of norbornene triepoxide derivatives were prepared successfully.After further esterification with 1-octadecyl alcohol,a new whole-biological monomer was obtained.A series of combs containing furan rings were synthesized by ring-opening translocation polymerization by adjusting the amount of catalyst.The molecular weight of the polymer is high,the dispersion is very narrow,and the molecular weight increases with the increase of monomer/catalyst ratio.Due to the limited methylene chain length of the side chain,insufficient van der Waals forces lead to crystallization.In addition,the polymer has excellent thermal stability and good hydrophobicity,which can be used to construct a functional hydrophobic coating on the fabric surface after simple drip coating.