CN111607217B

CN111607217B - 3D printing continuous fiber amido urea polymer composite material and preparation method

Info

Publication number: CN111607217B
Application number: CN202010643838.8A
Authority: CN
Inventors: 夏和生; 王硕; 程煜; 马珍万; 王占华
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2021-06-25
Anticipated expiration: 2040-07-07
Also published as: CN111607217A

Abstract

The invention provides a 3D printing continuous fiber amido urea polymer composite material and a preparation method, which are obtained by mixing a dynamic amido urea bond polymer, continuous fibers and a curing agent, and then dipping and curing. The invention discloses a 3D printing continuous fiber amido urea polymer composite material, and relates to a preparation method. The dry fiber strands are fully impregnated with a polymer containing dynamic amido urea bonds by a pre-impregnation method, and then extruded by a screw. The prepreg filaments are obtained from the machine. FDM-printed fiber-reinforced composites have excellent interlaminar properties, high tensile strength, and excellent dimensional stability. Due to the existence of dynamic bonds, the resin matrix can be destroyed to recover the fibers under specific conditions; and the FDM-printed continuous fiber-reinforced composite material can achieve repair of interlayer properties after failure.

Description

3D printing continuous fiber amidourea polymer composite material and preparation method thereof

Technical Field

The invention relates to the field of polymer composite materials and preparation thereof, and relates to a 3D printing continuous fiber amidourea polymer composite material and a preparation method thereof.

Background

The problem faced by 3D printing of continuous fiber reinforced composite at present is that, one of the types of resin substrates applied to FDM printing is relatively few, and PLA, ABS, PEEK, PEI and the like are mainly applied in industry, and development of novel composite substrate resins, such as a novel reversible crosslinked dynamic resin substrate developed in the present invention, is urgently needed. And secondly, the viscosity of the melt or solution of the conventional polymers applied to the field of 3D printing continuous fiber reinforced composite materials is a key factor for restricting FDM printing, and for a reversible cross-linked dynamic resin matrix, when the temperature reaches above the dynamic temperature, the viscosity of the dynamic polymer is sharply reduced due to reversible breakage of chemical bonds, so that the reversible cross-linked dynamic resin matrix is more suitable for FDM printing. The third most important point is that the fiber composite material produced by FDM printing has poor interlayer fusion of resin matrix due to the introduction of fibers, so that the interlayer shear strength of the composite material is low.

Disclosure of Invention

The invention provides a novel dynamic amido urea polymer as a matrix resin of a continuous fiber reinforced composite material, which can enrich resin types, and simultaneously, due to the existence of dynamic bonds, the viscosity of the polymer is more sensitive to temperature, thereby being more beneficial to FDM printing. And the dynamic covalent bond is strongly bonded, so that the bonding strength between fiber composite material layers is improved to a great extent, and the defects can be reduced.

The invention adopts the technical scheme that the composite material for 3D printing continuous fiber amidourea polymer is prepared from the following raw materials in parts by weight: 10-50 parts of dynamic amido urea bond polymer, 0.1-50 parts of curing agent and 10-80 parts of continuous fiber (comprising carbon fiber and glass fiber).

The dynamic amido urea bond polymer is a dynamic amido urea bond high-performance reversible dynamic cross-linked polymer, the network of the dynamic cross-linked polymer contains dynamic amido urea bonds, and the structural formula of the dynamic cross-linked polymer is as follows:

the molecular chain structure of the polymer is disclosed in patent CN 109265636.

The continuous fibers include continuous carbon fibers and continuous glass fibers. The continuous carbon fiber and the continuous glass fiber used may also be modified products of the continuous carbon fiber and the continuous glass fiber, for example, by using a surface oxidation method, a surface coating method, a surface deposition method, a surface polymer grafting method, and the like. The continuous fibers may be a mixture of continuous carbon fibers and continuous glass fibers or a modified product thereof at an arbitrary ratio.

The carbon continuous fibers are at least one of T300 carbon fibers, T400 carbon fibers, T700 carbon fibers, T800 carbon fibers, T1000 carbon fibers, M35 carbon fibers, M40 carbon fibers, M46 carbon fibers, M50 carbon fibers, M55 carbon fibers, and M60 carbon fibers.

The glass continuous fiber is at least one of A-grade glass fiber, AR-grade glass fiber, C-grade glass fiber, D-grade glass fiber, E-CR-grade glass fiber and S-grade glass fiber.

The curing agent is a polyiso-nitrile acid ester curing agent or a polyamino curing agent, and is one or more of the following structural formulas:

the invention also provides a method for preparing the 3D printing continuous fiber amidourea polymer composite material, which is characterized in that the 3D printing continuous fiber amidourea polymer composite material is prepared by two-step 3D printing (FDM):

the first step is to produce 3D printed continuous fiber dynamic amido urea bonded polymer prepreg strands using a prepreg process. In the process, the temperature is heated to be higher than the dynamic temperature of the dynamic polymer, and the dynamic polymer in the dynamic state is fully impregnated into the dry continuous fiber by utilizing the high pressure of the screw extruder.

And secondly, feeding the prepreg strands into a nozzle of a 3D printer, and reactivating the reversible dynamic property of the dynamic polymer in the printer and simultaneously printing out the dynamic polymer and the continuous fiber tows to obtain the reinforced composite material.

The dynamic polymer is used as matrix resin, strong chemical bonding can be formed between layers, and the interaction between the layers can be greatly improved. Meanwhile, the triangular defects formed in the strand silk fusion process can be effectively reduced.

The invention has the following beneficial effects:

the invention discloses a 3D printing continuous fiber amidourea polymer composite material and relates to a preparation method. The fiber reinforced composite material obtained by FDM printing has excellent interlayer performance, higher tensile strength and excellent size stability. The existence of dynamic bonds can destroy the resin matrix and recycle the fiber under specific conditions; and the interlaminar performance of the FDM printed continuous fiber reinforced composite can be repaired after the FDM printed continuous fiber reinforced composite fails.

Drawings

The present invention will be further explained in detail with reference to the drawings and examples.

FIG. 1 is a graph showing the results of a short beam shearing experiment in example 1 of the present invention;

FIG. 2 is a graph showing the results of a short beam shearing experiment in example 2 of the present invention;

FIG. 3 is a graph showing the repairing effect in example 2 of the present invention;

FIG. 4 is a graph showing the results of a tensile test of the recovered material of example 2 of the present invention.

Detailed Description

Example 1

70g T300 carbon fibers were fed into a miniature screw extruder simultaneously with 30g of a polyamideurea Polymer (PASC) and the temperature was heated to 140 ℃ to extrude prepreg strands under the high pressure of the screw extruder. And printing by a 3D printer to obtain the fiber reinforced composite material CFRC-1.

Example 2

60g T300 carbon fibers were fed into a miniature screw extruder simultaneously with 40g of a polyamidourea Polymer (PASC) and heated to 140 ℃ to extrude prepreg strands under the high pressure of the screw extruder. And printing by a 3D printer to obtain the fiber reinforced composite material CFRC-2.

Example 3

Grade 70g E glass fibers were fed into a miniature screw extruder along with 30 grams of a polyamideurea Polymer (PASC) and heated to 140 ℃ to extrude prepreg strands under the high pressure of the screw extruder. And printing by a 3D printer to obtain the fiber reinforced composite material GFRC-1.

Example 4

Grade 60g E glass fiber was fed into a miniature screw extruder along with 40g of a polyamideurea Polymer (PASC) and heated to 140 ℃ to extrude prepreg strands under high pressure from the screw extruder. And printing by a 3D printer to obtain the fiber reinforced composite material GFRC-2.

Example 5

Short beam shear test (SBS) was performed on fiber reinforced composites CFRC-1 and CFRC-2 to study interlaminar properties. The composite printed in examples 1 and 2 was cut into a rectangular shape having dimensions of 35mm (length) x 7mm (width) x 1mm (thickness), and a test span length of 25 mm. And then the interlaminar performance of the composite material is tested and characterized by using a three-point bending mode of a universal stretching machine (Instron 5567), and the testing speed is 1 mm/min. According to ASTM Standards 2344, the interlaminar shear strength of CFRC-1 and CFRC-2 can be calculated to be 31.32MPa and 37.75MPa, respectively. The test results are shown in fig. 1 and 2.

Example 6

Research on repairable performance of the fiber composite material CFRC-2. CFRC-2 after failure of the short beam shear test, the specimens were placed under gentle pressure (about 3-4MPa) and repaired at 140 ℃ for 1 h. The repaired CFRC-2 sample strip is subjected to a short beam shearing test (SBS). The healing effect is shown in figure 3.

Example 7

Cutting CFRC-2 into appropriate size, placing in 500ml beaker with 100ml DMF, placing the beaker in 110 ℃ oil bath pan, after 4 hours, taking out the carbon fiber, washing three times with DMF and three times with ethanol. And placing the dried polymer fragments in a hot press, hot-pressing for 1h at 140 ℃ under the pressure of 15MPa, and then carrying out mechanical test on the polymer PASC. The test results are shown in fig. 4.

While the present invention has been described in detail, it is to be understood that the invention is not limited to the embodiments described above, and that various changes and modifications may be made by those skilled in the art without departing from the spirit of the present invention.

Claims

1. The 3D printing continuous fiber amidourea polymer composite material is characterized by being prepared from the following raw materials in parts by weight:

10-50 parts of dynamic amido urea bond polymer;

0.1-50 parts of curing agent;

10-80 parts of continuous fibers.

2. The 3D printing continuous fiber amidourea polymer composite of claim 1, wherein the dynamic amidourea bond polymer has a network structure comprising dynamic amidourea bonds having a structural formula:

3. the 3D printed continuous fiber amidourea polymer composite of claim 1, wherein: the continuous fiber is at least one of carbon continuous fiber and glass continuous fiber.

4. The 3D printed continuous fiber amidourea polymer composite of claim 1, wherein: the continuous fiber is at least one of modified carbon continuous fiber and glass continuous fiber.

5. The 3D printed continuous fiber amidourea polymer composite of claim 3 or 4, wherein: the carbon continuous fiber is at least one of T300 carbon fiber, T400 carbon fiber, T700 carbon fiber, T800 carbon fiber, T1000 carbon fiber, M35 carbon fiber, M40 carbon fiber, M46 carbon fiber, M50 carbon fiber, M55 carbon fiber and M60 carbon fiber.

6. The 3D printed continuous fiber amidourea polymer composite of claim 3 or 4, wherein: the glass continuous fiber is at least one of A-grade glass fiber, AR-grade glass fiber, C-grade glass fiber, D-grade glass fiber, E-CR-grade glass fiber and S-grade glass fiber.

7. The 3D printed continuous fiber amidourea polymer composite of claim 1, wherein: the curing agent is at least one of polyisocyanate curing agent or polyamino curing agent.

8. The 3D printed continuous fiber amidourea polymer composite of claim 1, wherein: the curing agent is specifically one or more of the following structural formulas:

9. the method of making a 3D printing continuous fiber amidourea polymer composite of any of claims 1-8, wherein:

firstly, a preimpregnation method is utilized to generate continuous fiber dynamic amido urea bond polymer preimpregnated filaments; during which the temperature is heated above the dynamic temperature of the dynamic amidourea linkage polymer; fully impregnating continuous fibers by utilizing a high-pressure dynamic amide urea bond polymer of a screw extruder;

and (3) feeding the prepreg strands into a nozzle of a 3D printer, reactivating the reversible dynamic property of the dynamic polymer in the printer, and simultaneously printing out the dynamic polymer and the continuous fiber tows to obtain the reinforced composite material.