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CN-121991498-A - Thermoplastic composite material prepared based on waste composite material pyrolysis product and preparation method thereof

CN121991498ACN 121991498 ACN121991498 ACN 121991498ACN-121991498-A

Abstract

The application discloses a thermoplastic composite material prepared based on a waste composite material pyrolysis product and a preparation method thereof, and particularly relates to the technical field of fiber reinforced composite material recycling. The preparation method of the thermoplastic composite material comprises the steps of crushing a waste carbon fiber composite material, controlling the pyrolysis temperature to be within 450-600 ℃ and the pyrolysis time to be 30-60 minutes to obtain a pyrolysis solid product, separating the obtained pyrolysis solid product to obtain a fraction A and a fraction B respectively, premixing the fraction A and the pyrolysis carbon micro powder according to the mass ratio of 2:1-5:1 to obtain a mixed reinforcement, and carrying out melt blending and extrusion molding on the mixed reinforcement and a thermoplastic resin matrix to obtain the thermoplastic composite material. The thermoplastic composite material prepared by the scheme aims at synchronously strengthening the interface and the matrix by constructing a multi-stage reinforced structure and realizing the high-value utilization of the full components of the pyrolysis product of the waste carbon fiber composite material.

Inventors

  • LIU XIAOLING
  • ZHANG YANG
  • LIU ZIQIAN
  • LU MINGYAN
  • YI XIAOSU

Assignees

  • 宁波诺丁汉大学
  • 江苏集萃碳纤维及复合材料应用技术研究院有限公司
  • 长三角碳纤维及复合材料技术创新中心

Dates

Publication Date
20260508
Application Date
20260224

Claims (9)

  1. 1. A thermoplastic composite material comprising a matrix phase, a primary reinforcing phase and a secondary reinforcing phase, the primary reinforcing phase and the secondary reinforcing phase being dispersed throughout the matrix phase; wherein, the first-stage reinforcing phase and the matrix phase form a mechanical interlocking structure, and the second-stage reinforcing phase is filled between the adjacent first-stage reinforcing phases.
  2. 2. A thermoplastic composite according to claim 1, wherein the primary reinforcing phase is regenerated carbon fibers and the secondary reinforcing phase is a cracked carbon powder, the cracked carbon powder filling the resin rich regions between adjacent regenerated carbon fibers.
  3. 3. A method for preparing a thermoplastic composite based on a waste composite pyrolysis product, comprising the steps of: s1, crushing a waste carbon fiber composite material, and placing the crushed waste carbon fiber composite material in a closed pyrolysis furnace, wherein the pyrolysis temperature is controlled to be within 450-600 ℃ under the protection of inert gas, and the pyrolysis time is 30-60 minutes, so as to obtain a pyrolysis solid product; s2, separating the obtained pyrolysis solid product to obtain a fraction A and a fraction B respectively, wherein the fraction A is regenerated carbon fiber, the fraction B is pyrolysis carbon residue, and the pyrolysis carbon residue is ball-milled to obtain pyrolysis carbon micro powder; s3, premixing the fraction A and the cracking carbon micro powder according to the mass ratio of 2:1-10:1 to obtain a mixed reinforcement; and S4, carrying out melt blending on the mixed reinforcement and the thermoplastic resin matrix, and then carrying out extrusion molding to obtain the thermoplastic composite material.
  4. 4. The method for producing a thermoplastic composite material based on a pyrolysis product of a waste composite material according to claim 1, wherein the pyrolysis temperature in step S1 is 450 ℃.
  5. 5. The method for producing a thermoplastic composite material based on a pyrolysis product of a waste composite material according to claim 1, wherein the pyrolysis time in step S1 is 30 minutes.
  6. 6. The method for producing a thermoplastic composite material based on a pyrolysis product of a waste composite material according to claim 1, wherein in the step S2, the particle size of the cracked carbon fine powder is 1 μm to 20 μm.
  7. 7. The method for preparing a thermoplastic composite material based on a waste composite material pyrolysis product according to claim 1, wherein any one of a silane coupling agent and a titanate coupling agent is added during the mixing process of step S3.
  8. 8. The method for preparing thermoplastic composite materials based on waste composite pyrolysis products according to claim 1, wherein in step S3, the mass ratio of fraction a to the cracked carbon micropowder is 8:1.
  9. 9. The method for producing a thermoplastic composite material based on a pyrolysis product of a waste composite material according to claim 1, wherein in the step S4, the thermoplastic resin matrix includes any one of PP, PA6, PC and ABS.

Description

Thermoplastic composite material prepared based on waste composite material pyrolysis product and preparation method thereof Technical Field The application relates to the technical field of fiber reinforced composite material recycling, in particular to a thermoplastic composite material prepared based on waste composite material pyrolysis products and a preparation method thereof. Background With the wide application of carbon fiber reinforced Composite (CFRP) in the fields of aerospace, new energy automobiles, wind power generation and the like, the number of produced waste materials and scrapped composite products is increased sharply. Since CFRP is generally formed by compounding carbon fibers with a thermosetting resin (such as an epoxy resin), its crosslinked network structure makes it difficult to degrade in natural environments. Therefore, how to efficiently and highly valued recycle the waste CFRP has become a global technical problem in the field of composite materials. For this purpose, china patent application No. 2024102948712 discloses a method for recycling carbon fiber reinforced resin matrix composite materials. According to the method, the CFRP waste materials are pyrolyzed, and after the carbon fibers are released, the purity of the carbon fibers is recovered through ultrasonic cleaning. However, the prior art described above, which aims at removing carbon deposits and obtaining clean fibers, has significant drawbacks in practical applications. When the regenerated chopped carbon fiber with clean surface is used as the reinforcing filler to prepare the thermoplastic composite material, the surface activity of the fiber after carbon deposit removal is lower due to the lack of the synergistic filling effect of micro-nano scale particles, so that the modulus of the final material is limited in lifting range, and the interface bonding performance between the fiber and matrix resin is also not ideal. At present, carbon deposition is removed by high-temperature oxidation treatment or a stay time prolonging mode in the prior art, but the severe process conditions are difficult to accurately control, excessive oxidation of a carbon fiber body is extremely easy to occur, etching pits are generated on the surface of the fiber, even the diameter is reduced, so that the tensile strength of monofilaments of the regenerated carbon fiber is seriously damaged, and the monofilaments are often difficult to retain to 80% of the original strength. In addition, the treatment mode takes the carbon-rich residues generated by pyrolysis of the waste resin as impurities and removes the impurities through combustion, so that not only is the waste of precious carbon resources caused, but also the recovery of the 'full component' of the waste composite material is not realized, and the additional oxidation carbon removal process obviously increases the energy consumption and the equipment operation cost in the recovery process. Therefore, how to realize the full component recovery of the carbon fiber reinforced composite material is urgent to be solved by the person skilled in the art. Disclosure of Invention The invention provides a thermoplastic composite material prepared based on a waste composite material pyrolysis product and a preparation method thereof. The thermoplastic composite material prepared by the scheme aims at synchronously strengthening the interface and the matrix by constructing a multi-stage reinforced structure and realizing the high-value utilization of the full components of the pyrolysis product of the waste carbon fiber composite material. The aim of the invention is realized by the following technical scheme: A thermoplastic composite material comprises a matrix phase, a primary reinforcing phase and a secondary reinforcing phase, wherein the primary reinforcing phase and the secondary reinforcing phase are dispersed in the matrix phase, the primary reinforcing phase and the matrix phase form a mechanical interlocking structure, and the secondary reinforcing phase is filled between adjacent primary reinforcing phases. Preferably, the primary reinforcing phase is regenerated carbon fibers, the secondary reinforcing phase is cracked carbon micropowder, and the cracked carbon micropowder is filled in resin-rich regions between adjacent regenerated carbon fibers. The invention also provides a method for preparing the thermoplastic composite material based on the pyrolysis product of the waste composite material, which comprises the following steps: s1, crushing the waste carbon fiber composite material, placing the crushed waste carbon fiber composite material in a closed pyrolysis furnace, controlling the pyrolysis temperature to be within 450-600 ℃ under the protection of inert gas, and obtaining a pyrolysis solid product after pyrolysis for 30-60 minutes, wherein in the process, a resin matrix in the waste composite material is cracked and converted into oil gas volatile matters and solid