Synthesis And Application Of Furandicarboxylic Acid-based Biomass Polyamides

With the increasing demand for petrochemical resources,we must face such problems as increasing solid waste,shortage of oil resources and global climate change,and find suitable solutions.Therefore,renewable biomass resources have become an ideal substitute for traditional petrochemical resources.Catalytic conversion of biomass resources to produce chemicals and polymer materials is an important way to solve the problem of oil shortage.Dimethyl 2,5-furandicarboxylate prepared from polysaccharide biomass resources has a structure similar to terephthalic acid,so DMFDCA can replace petroleum-based monomer PTA and be used in the preparation of new furan-based polyamide materials.In this paper,polyamide based on 2,5-furanedicarboxylic acid diamine was studied in the following aspects:Firstly,PA6F and PA10 F were synthesized by melt polycondensation of dmfdca with hexanediamine and decanediamine.A series of furan-based polyamide materials were prepared by changing the starting feed ratio of the two monomers.The structure of PA was characterized by FTIR and NMR;the crystallinity and thermal properties of PA were analyzed by X-ray diffraction,differential scanning calorimetry and thermal weight loss analysis;the polymer was also analyzed Solubility and UV light test to explore its solubility and UV resistance.The results showed that the furanyl polyamides PA6 F and PA10 F were successfully prepared.The prepared polymers were semi crystalline polymers with high molecular weight,excellent thermal stability and UV resistance.Secondly,the problem of water resources is one of the important problems that need to be solved in today's society.Compared with other water treatment technologies,membrane separation has significant advantages of high efficiency,environmental protection and energy saving,and has become the main treatment means in the field of water treatment.Using PA10F(Mw=33000)as raw material,N,N-dimethylformamide(DMF)as solvent and water as coagulation bath,PA10 F nanofiltration membranes with different concentration of casting solution were prepared by non solvent induced phase separation(NIPS),which can be used for wastewater treatment.The performance of PA10 F membrane was analyzed by testing the morphology,roughness,surface charge,retention and antibacterial properties of the membrane.The results show that the surface of PA10 F is negatively charged,and the rejection rate of metal ions is low,but the rejection rate of MB(Mr=799.80),CR(Mr=696.68)and AF(Mr=585.54)with different molecular sizes is the highest,which can reach 100%,99.06% and 98.01% respectively,and has good cycle stability;PA10F membrane also has excellent anti fouling performance,and the flux recovery rate can reach 94.01%.At the same time,the performance differences of PA10 F membrane prepared by different concentrations of casting solution were studied.Finally,the PA10 F membrane with 25 wt% casting solution had better comprehensive performance.