Synthesis Of Polyether-Ester Based On 2,5-Furan Dicarboxylic Acid And Its Copolymerization With Polylactic Acid

Global plastic pollution is getting worse,from a sustainability point of view,bio based 2,5-furan dicarboxylic acid（FDCA）is very likely to replace petroleum based terephthalic acid（TPA）.At present,many studies in the field of polymer materials have focused on the polyester synthesized by FDCA and various diols.However,their weak crystallization and low elongation at break limit their application.There is still room for progress in the performance of materials based on FDCA to meet the needs of industrial applications.The thermoplastic elastomer behavior of polyether ester materials fills the weakness of high rigidity of aromatic polyester materials.In this paper,the biological aromatic dibasic acid FDCA was selected to synthesize polyether ester by melt polycondensation with 1,3-propylene glycol with different substituents,and the best binary composite catalyst was selected for polymerization.A polymer with a number average molecular weight of 10000-40000 g/mol can be obtained in 2-7 h.The successful synthesis of polyether ester material was proved by NMR test.The properties of polyether ester were characterized by mechanical property test,DSC,TGA and hydrophilicity test,and the properties of polyether ester were regulated by controlling the feeding amount of diol.With the change of the number of substituents（methyl）on propylene glycol,the tensile strength of polyether ester material can be increased from 5 MPa to 55 MPa,and the elongation at break can be increased from 10%to 1000%.By adjusting the proportion of polyether segments in polyether ester materials,excellent mechanical properties materials with tensile strength greater than 10 MPa and elongation at break greater than 200%can be obtained.Through the thermal performance test,polyether ester shows excellent thermal stability,T_5%value is greater than 350℃,T_dmax value is greater than400℃.However,the hydrophilicity of polyether ester materials follows the trend of weakening with the increase of the number of substituent methyl groups on propylene glycol.Polylactic acid has the disadvantage of high brittleness,which limits its application range.Polyether ester materials have polyether segments,so they are flexible.This paper adopts the chemical copolymerization of polylactic acid with all biological polyether ester to improve its properties.High molecular weight copolymer was obtained by ternary composite catalyst.The chemical structure of the copolymer was determined by NMR.When the lactic acid fragment in the copolymer is increased from 23%to 77%,the tensile strength of the copolymer can be increased from 10 MPa to 47 MPa,and the elongation at break can be increased from 11%to 562%.DSC and TGA shows that the copolymer is endowed with high thermal resistance,with T_5%value between320-350℃and T_dmax value between 405-410℃.It fills the deficiency of weak elasticity and easy decomposition of polylactic acid.The mechanical and thermophysical properties of the copolymer can be effectively controlled by adjusting the content of lactic acid fragment in the copolymer.It will contribute to the field of polymer material synthesis and copolymerization modified polylactic acid.