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CN-122011372-A - Crystalline bifuran polyamide with high barrier property and strong ultraviolet absorptivity, and preparation method and application thereof

CN122011372ACN 122011372 ACN122011372 ACN 122011372ACN-122011372-A

Abstract

The invention relates to a high-barrier high-ultraviolet-absorptivity crystalline furan polyamide and a preparation method and application thereof, and belongs to the technical field of bio-based high polymer materials. The invention obtains the crystalline furan polyamide through interfacial polymerization reaction of the furan acyl chloride monomer and the alicyclic diamine monomer. The crystalline furan-linked polyamide material provided by the invention realizes high crystallinity by eliminating intramolecular hydrogen bonds, thereby having excellent barrier property, strong ultraviolet absorption capacity and good mechanical property. The material has strong ultraviolet absorption capability, can completely absorb ultraviolet light below 400nm, has excellent gas barrier property, has oxygen transmission rate as low as 0.0139 barrer and water vapor transmission rate of 0.94 multiplied by 10 ‑4 g/cm < 2 >. S.Pa, is at a leading level in the field of polyamide barrier materials, and has wide application prospect in the fields of isolation packaging materials and ultraviolet shielding materials.

Inventors

  • XIONG BIJIN
  • Long Chijin
  • ZHU JINTAO
  • LIAO YONGGUI
  • YIN GUOCHUAN

Assignees

  • 华中科技大学

Dates

Publication Date
20260512
Application Date
20260316

Claims (10)

  1. 1. A process for the preparation of a crystalline furan polyamide comprising the steps of: (1) Carrying out reflux reaction on the difuran dicarboxylic acid and excessive thionyl chloride in the presence of a catalyst to obtain difuran acyl chloride monomers; (2) Dissolving the difuranyl chloride monomer obtained in the step (1) in an organic solvent to obtain an organic phase, adding an alkaline aqueous solution to form a phase interface, adding an alicyclic diamine monomer dissolved in the alkaline aqueous solution, and performing interfacial polymerization reaction to obtain the crystalline difuran polyamide.
  2. 2. The process for preparing a crystalline bisfuran polyamide as claimed in claim 1, characterized in that said cycloaliphatic diamine monomer is piperazine or 4,4' -bispiperidine.
  3. 3. The process for producing a crystalline bisfuran polyamide as claimed in claim 1 or 2, characterized in that in step (1), the catalyst is N, N-dimethylformamide, and the addition amount of N, N-dimethylformamide is 0.5% to 0.8% by mass of bisfuran dicarboxylic acid.
  4. 4. The process for the preparation of crystalline bifuran polyamide according to claim 1 or 2, characterized in that in step (1) the reflux reaction is carried out for a period of 3 to 8 hours.
  5. 5. The process for producing a crystalline bisfuran polyamide as claimed in claim 1 or 2, characterized in that in step (2), the ratio of the amounts of the substances of the alicyclic diamine monomer to the bisfuran acid chloride monomer is 1:1.
  6. 6. The method for producing a crystalline furan polyamide as claimed in claim 1 or 2, characterized in that in step (2), the alkaline aqueous solution is a KOH aqueous solution having a concentration of 0.5 to 2 mol/L.
  7. 7. The process for producing a crystalline bisfuran polyamide as claimed in claim 1 or 2, characterized in that in step (2), the precipitate obtained after the interfacial polymerization reaction is filtered, washed with water and an organic solvent in that order, and then dried to obtain the crystalline bisfuran polyamide.
  8. 8. Crystalline bifuran polyamide obtainable by the process according to any of claims 1 to 7.
  9. 9. Use of the crystalline bifuran polyamide according to claim 8 in a barrier packaging material.
  10. 10. Use of the crystalline bifuran polyamide according to claim 8 in an ultraviolet shielding material.

Description

Crystalline bifuran polyamide with high barrier property and strong ultraviolet absorptivity, and preparation method and application thereof Technical Field The invention belongs to the technical field of bio-based high polymer materials, and particularly relates to a crystalline furan-linked polyamide with high barrier property and strong ultraviolet absorptivity, and a preparation method and application thereof. Background In the context of sustainable development strategies, the synthesis of bio-based polyamides using renewable biomass resources to replace petroleum-based products has become a research hotspot. 2, 5-furandicarboxylic acid (FDCA) is an ideal substitute monomer for terephthalic acid because of its renewable, readily available and environmentally friendly source of raw materials. Research has shown that FDCA-based polymers can achieve and even exceed conventional petroleum-based aromatic polymers in terms of thermal, mechanical and barrier properties. 2,2 '-Bisfuran-5, 5' -dicarboxylic acid (BFDCA) is an important derivative of FDCA, and is formed by connecting two coplanar furan rings at a dihedral angle of 180 degrees, so as to form an extended pi-pi conjugated structure. Compared with mono furan and biphenyl, the di furan has stronger molecular rigidity due to higher rotation energy barrier between heterocycles, and is beneficial to improving the planeness, rigidity, mechanical property, light absorption capability, heat resistance and gas barrier property of the furan-based polymer. It has been shown that BFDCA-based polyesters have higher glass transition temperatures than PET and PEF and higher modulus retention at high temperatures, and their highly conjugated molecular structure also imparts excellent UV absorption capability to the materials. However, the crystallization properties of the existing furan polyamides are generally weaker. Research shows that the introduction of furan ring reduces the hydrogen bond action among polyamide molecular chains, and promotes the formation of intramolecular hydrogen bonds, thereby preventing the regular accumulation of molecular chains and reducing the crystallization capability. Since gas molecules are difficult to penetrate or diffuse through the crystalline regions of the polymer, the degree of crystallization has a decisive influence on the gas barrier properties of the material. Therefore, how to eliminate intramolecular hydrogen bonds and improve the crystallinity of furan polyamide through molecular design, so as to cooperatively improve the thermal property, mechanical property, ultraviolet absorption property and barrier property of furan polyamide is a technical problem to be solved currently. Disclosure of Invention The invention overcomes the defects of low crystallinity, insufficient barrier property and insufficient ultraviolet absorption property of the prior furan polyamide, and obtains the crystalline furan polyamide through the interfacial polymerization reaction of the furan acyl chloride monomer and the alicyclic diamine monomer. The crystalline furan-linked polyamide material provided by the invention realizes high crystallinity by eliminating intramolecular hydrogen bonds, thereby having excellent barrier property, strong ultraviolet absorption capacity and good mechanical property. According to a first aspect of the present invention, there is provided a process for the preparation of a crystalline bifuran polyamide comprising the steps of: (1) Carrying out reflux reaction on the difuran dicarboxylic acid and excessive thionyl chloride in the presence of a catalyst to obtain difuran acyl chloride monomers; (2) Dissolving the difuranyl chloride monomer obtained in the step (1) in an organic solvent to obtain an organic phase, adding an alkaline aqueous solution to form a phase interface, adding an alicyclic diamine monomer dissolved in the alkaline aqueous solution, and performing interfacial polymerization reaction to obtain the crystalline difuran polyamide. Preferably, the cycloaliphatic diamine monomer is piperazine or 4,4' -bipiperidine. Preferably, in the step (1), the catalyst is N, N-dimethylformamide, and the addition amount of the N, N-dimethylformamide is 0.5-0.8% of the mass of the difuran dicarboxylic acid. Preferably, in step (1), the reflux reaction is carried out for a period of 3 to 8 hours. Preferably, in step (2), the ratio of the amount of the alicyclic diamine monomer to the amount of the substance of the bisfuran acid chloride monomer is 1:1. Preferably, in the step (2), the alkaline aqueous solution is a KOH aqueous solution, and the concentration is 0.5-2 mol/L. Preferably, in the step (2), the precipitate obtained after the interfacial polymerization reaction is filtered, washed with water and an organic solvent in sequence, and then dried to obtain the crystalline bisfuran polyamide. According to another aspect of the present invention, there is provided the crystalline bisfuran polyamide produce