CN110482531B

CN110482531B - Preparation method and product of polybenzoxazine resin-based graphene

Info

Publication number: CN110482531B
Application number: CN201910759381.4A
Authority: CN
Inventors: 曹丽军; 刘小青; 江艳华
Original assignee: Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: Ningbo Institute of Material Technology and Engineering of CAS
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2022-08-30
Anticipated expiration: 2039-08-16
Also published as: CN110482531A

Abstract

The invention discloses a preparation method of polybenzoxazine resin-based graphene, which is characterized in that a benzoxazine monomer or oligomer is synthesized by taking a phenol source, an amine source and paraformaldehyde or formaldehyde as raw materials, polybenzoxazine is obtained through thermosetting and crosslinking, and high-quality polybenzoxazine-based graphene is further obtained through laser induction. The prepared polybenzoxazinyl graphene is good in conductivity, high in monolayer proportion, high in specific surface area and excellent in electrochemical performance, has important significance in promoting development of carbon sources for preparing graphene, and has great application value in various photoelectric devices, electrochemical devices, sensors and the like.

Description

Preparation method and product of polybenzoxazine resin-based graphene

Technical Field

The invention belongs to the field of graphene preparation and application, and particularly relates to a preparation method and a product of polybenzoxazine based graphene by using polybenzoxazine resin as a carbon source and by using laser induction.

Background

Due to the unique 2-dimensional sp of graphene ² The topological carbon structure endows graphene with incomparable physical and chemical properties, and further, in recent decades, the research on the application potential of graphene is focused everywhere from coatings, biotechnology, engineering materials, energy storage materials, environmental technology, biomedicine and biosensors.

However, to date, graphene still faces a great challenge to prepare high-performance graphene and graphene nanomaterials by a simple process at low cost. Generally, the current methods for preparing graphene nano materials are classified into a layer by layer method and a composite method. The Layer by Layer method generally uses a traditional Chemical Vapor Deposition (CVD) process to prepare graphene materials, the process is complex and harsh, precious metal catalysis is required, the temperature is higher than 1000 ℃, high vacuum is used for assisting in injecting carbon sources, and then a complex substrate transfer technology is required, so that a bottleneck of large-scale preparation is faced. The composite method is to improve the compatibility of graphene and a matrix by a complicated method, and then to complete the preparation of the material by means of coating, printing, curing molding or extrusion molding. In order to maximize the performance of the graphene, high-temperature annealing (250-400 ℃) is carried out in the processes, but most of matrix polymers are unstable, so that the overall performance of the obtained graphene nano material is defective.

A simple technique for ideally preparing graphene, which can replace the above method, has recently been developed: high-molecular graphene (Laser-I) induced by Lasernd detected Graphene, LIG). LIG mechanism directly utilizes laser energy to convert sp on a high polymer material substrate ³ Conversion of hybridized carbon atoms to sp ² And hybridizing carbon atoms to obtain the graphene. LIG is a general technique for preparing graphene by laser doping metal or specific polymers, and there are limited synthetic polymers, Polyimide (PI), Polysulfone (PSU), Polyetherimide (PEI) and polytetrafluoroethylene (Teflon), which can be used to prepare graphene at present, and natural polymers, such as cellulose, starch, coconut shell, potato and wood.

The applications of LIG have found numerous applications in a wide range of fields, supercapacitors, antibacterial treatments, transparent electric heaters, pressure sensors, electrolytic waters and desalination. Chemical stability and mechanical stability of a matrix, namely a polymer part, loaded by graphene in the structure of the graphene nano material become the primary conditions for exerting and maintaining the performance of the graphene, and particularly in the actual severe environment, few attention is paid to literature reports so far. Obviously, the above mentioned various macromolecules also have various defects, such as the defects that PI can not resist alkali, PEI can not resist water, Teflon is expensive in price, poor in processability and the like; natural polymers are subject to different sources, which results in unstable quality of graphene. Therefore, it is important to find a novel polymer which is suitable for LIG and has high stability.

Based on benzoxazine chemistry, benzoxazine monomers are first synthesized by mannich condensation of phenols, amines and formaldehyde without the addition of initiators or catalysts; subsequently, polybenzoxazines are formed by thermal curing polymerization of the monomers. The diversity of phenolic, amine and aldehydes gives benzoxazine significant flexibility in molecular design. Thus, a variety of multifunctional, high performance polymers can be prepared. In view of the advanced properties possessed by polybenzoxazines: the graphene nano material has excellent chemical stability, no release of small molecules during curing, high carbon residue rate, low volume shrinkage rate, and superior thermal stability and mechanical stability, and the preparation and the application of the graphene nano material based on the polymer laser induction are researched.

Disclosure of Invention

The invention provides a preparation method of polybenzoxazine resin-based graphene, which is simple to prepare, simple and convenient to operate, excellent and stable in performance and easy for large-scale production.

The invention adopts the following technical scheme:

a preparation method of polybenzoxazine-based graphene comprises the steps of synthesizing benzoxazine monomers and/or oligomers by taking a phenol source, an amine source and paraformaldehyde or formaldehyde as raw materials, heating, curing and crosslinking to obtain polybenzoxazine resin (PBZ), and finally obtaining the polybenzoxazine-based graphene (LIG-PBZ) through laser induction.

The specific preparation route is as follows:

the structural formula of the phenol source is shown as the formula (I):

wherein R is ₁ ，R ₂ And R ₃ Each independently is H, C ₁ ～C ₁₅ Alkyl, benzene ring, naphthalene ring, hydroxyphenyl substituted C ₁ ～C ₅ An alkyl group.

Further preferably, the phenol source is at least one of bisphenol A and bisphenol F, because bisphenol A and bisphenol F can contribute to higher carbon residue rate.

The amine source is monoprimary amine and/or diprimary amine.

Further preferably, the amine source is at least one of methylamine, ethylamine, butylamine, ethylenediamine, butanediamine, propylenediamine, polyetheramine, cyclobutyl amine, aniline, 4-diaminodiphenylmethane, 3' -methylene diphenylamine and diaminodiphenylsulfone, wherein the amine source containing a single benzene ring and a double benzene ring can provide higher carbon residue rate.

Preferably, the molar ratio of the phenol source to the amine source to the paraformaldehyde or the formaldehyde functional group is 1:1: 2-2.2, and feeding is carried out.

Preferably, the benzoxazine monomer and/or oligomer is heated to the curing temperature of 100 ℃ to 300 ℃ for a curing time of 0.5-8 h.

The induced laser is of the type comprising CO ₂ Laser, ultraviolet laser, or infrared laser; the diameter of the laser used is 30-200 μm; the resolution of the laser used is 100-1000 p.p.i.; laser energy density of 0.05-40J/mm ² (ii) a The energy density is power density and scanning time

The invention also provides polybenzoxazine resin-based graphene prepared by the method, and in an optimized scheme, the specific surface area of the polybenzoxazine resin-based graphene can be larger than 800m ² The surface resistance can be lower than 35 ohm/square.

The invention provides a preparation method of polybenzoxazine resin-based graphene, which comprises the steps of synthesizing benzoxazine monomers or oligomers by adopting a phenol source, an amine source and paraformaldehyde or formaldehyde, obtaining polybenzoxazine resin (PBZ) through thermosetting crosslinking, and further obtaining polybenzoxazine-based graphene (LIG-PBZ) through laser induction. Because PBZ has high carbon residue rate, excellent chemical stability and good mechanical property, the three-dimensional porous LIG-PBZ can be obtained through laser induction, the intrinsic processability and the low cost benefit are shown when a large-scale graphene nano material device is prepared, and a reliable source is provided for preparing a high-performance graphene nano material.

The LIG-PBZ has the advantages of simple preparation, simple and convenient operation, excellent and stable performance and easy large-scale production. The prepared LIG-PBZ has good conductivity, high single-layer proportion, high specific surface area and excellent electrochemical performance, the surface resistance of the LIG-PBZ can reach 31-35 ohm/square, and the specific surface area can reach 814-884 m ² (ii) in terms of/g. The LIG-PBZ can expand the application range of graphene, has important significance for promoting development and preparation of carbon sources of graphene, and has very important application value in various photoelectric devices, electrochemical devices, sensors and the like.

Drawings

FIG. 1 is a Raman spectrum of LIG-PBZ prepared in example 1 under laser-induced conditions: CO 2 ₂ LaserThe laser resolution is 100p.p.i., the scanning speed is fixed at 20mm/s, and the laser energy density is 0.02-50J/mm ² 。

FIG. 2 shows the LIG-PBZ surface resistance properties prepared in example 1, under the laser-induced conditions: CO 2 ₂ Laser, the laser resolution is 100p.p.i., the scanning speed is fixed at 20mm/s, and the laser energy density is 0.02-50J/mm ² 。

FIG. 3 is a microscopic electron micrograph of LIG-PBZ prepared in example 1, a: SEM, b: TEM, c: high resolution TEM, laser induced conditions: CO 2 ₂ Laser, laser energy density 1J/mm ² Laser resolution 100 p.p.i..

Fig. 4 shows the results of examples 2, 3 and 4 under laser-induced conditions: CO 2 ₂ Laser, laser energy density 1J/mm ² Raman spectra of three LIG-PBZ prepared with laser resolution 100p.p.i.

Detailed Description

The invention is further illustrated by the following examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

In the examples, scanning electron microscope (FESEM) photographs were taken by field emission scanning electron microscopy (Hitachi S4800); collecting a Transmission Electron Microscope (TEM) picture by a transmission electron microscope (USAFEI, Tecnai F20), scraping LIG-PBZ powder from a substrate at an accelerating voltage of 200kV, adding a proper amount of ethanol for ultrasonic dispersion, transferring the LIG-PBZ powder onto a special carbon net for TEM, and observing the TEM after the solvent is volatilized; raman spectra were collected by confocal raman spectroscopy (renishawinvivia refilex) using a 532nm light source; specific surface area was collected by a specific surface area and porosity analyzer (Micromeritics Instruments, ASAP 2020M); the sheet resistance was tested by Multi function Digital Four-Probe Tester (ST-2258C, Jingge Electronics, China).

Example 1

Phenol, 4, 4-diaminodiphenylmethane (DDM) and paraformaldehyde as raw materials

1. 31.33g (0.333mole) of phenol, 33.0g (0.166mole) of 4, 4-diaminodiphenylmethane (DDM), 19.99g (0.667mole) of paraformaldehyde and xylene (400mL) were added all at once to a 1000mL round bottom flask with a stirring, heating and condensing tube;

2. heating to 120 ℃, reacting for 6 hours, cooling to room temperature, and filtering to obtain a precipitate DDM benzoxazine after the solvent is completely volatilized;

3. 5g of DDM benzoxazine powder was spread evenly over 10cm ² Heating to 110 ℃ in a horizontal silica gel mold to melt the DDMBZ, degassing for 3 hours in vacuum, relieving pressure, keeping for 0.5 hour to level the DDMBZ, heating and curing in stages, heating to 180 ℃, 200 ℃ and 225 ℃ for 2 hours respectively, and then cooling to room temperature to obtain a transparent dark purple polybenzoxazine resin (PDDMBZ) plate;

4. laser induction was performed on PDDMBZ plates using a laser engraving system (DA-LMN100-171101, III Lasers technology, China): a 10.6 μm wavelength laser, pulse frequency 20kHz, beam diameter about 80 μm, pulse per inch pulse overlap ratio (p.p.i.) set at 100 p.p.i.; the PDDMBZ plate is placed under a laser lens and fixed, and the decoking distance from the laser lens to a sample is 10 mm. All laser-induced experiments were performed under air ambient conditions.

FIG. 1 shows that the laser energy density is 0.02-40J/mm ² Then, a standard graphene spectrogram of 1350cm appears ^-1 Peak D of (1580 cm) ^-1 G peak and 2700cm ^-1 The peak 2D of (2), the peak G and the peak 2D gradually increase with the increase of the laser energy, when the laser energy density reaches 50J/mm ² And meanwhile, the height of the G peak is reduced, and the 2D peak disappears, which indicates that the polybenzoxazine laser induces the graphene, and the used laser energy is too high, so that the high polymer is directly carbonized, and the graphene cannot be obtained.

FIG. 2 shows that the laser energy density is 0.02-40J/mm ² Within the range, the surface resistance decreases with increasing laser energy; but when the laser energy density reaches 50J/mm ² And in the process, the surface resistance is increased by 8 orders of magnitude, which shows that the benzoxazine resin is directly carbonized due to overhigh laser energy, and graphene cannot be obtained.

Fig. 3, a shows that under the laser-induced condition, three-dimensional porous graphene is obtained; b shows that there is graphene lamellar structure formation; and c is a high-resolution transmission electron microscope, which shows that graphene crystal lattices are formed.

Example 2

Phenol, 4, 4-diaminodiphenylmethane (DDS) and paraformaldehyde as raw materials

Steps

1, 2, 3 were prepared as required in example 1;

the laser induction conditions were as described in step 4 of example 1, with a laser fluence of 1J/mm ² The obtained polybenzoxazine resin-based graphene is tested, and has the surface resistance of 36 ohm/square and the specific surface area of 854m ² /g。

Example 3

Bisphenol A, aniline and paraformaldehyde as raw materials

The preparation of the

components

1, 2 and 3 is carried out according to the requirements of the embodiment 1, the feeding mole numbers are bisphenol A0.166mol, aniline 0.333mol and paraformaldehyde 0.667mol, the reaction temperature is 110 ℃, and the reaction time is 6 hours;

the laser induction conditions were as described in step 4 of example 1, with a laser fluence of 1J/mm ² The obtained polybenzoxazine resin-based graphene is tested, and has the surface resistance of 31 ohm/square and the specific surface area of 884m ² /g。

Example 4

Bisphenol F, aniline and paraformaldehyde as raw materials

The preparation steps 1, 2 and 3 are as required in the embodiment 1, the feeding mole number is bisphenol F0.166mol, aniline 0.333mol, paraformaldehyde 0.667mol, the reaction temperature is 110 ℃, and the reaction time is 6 hours;

the laser induction conditions were as described in step 4 of example 1, with a laser fluence of 1J/mm ² The obtained polybenzoxazine resin-based graphene is tested, and has the surface resistance of 39 ohm/square and the specific surface area of 814m ² /g。

Fig. 4, examples 2, 3, and 4 were performed under the laser-induced conditions: CO 2 ₂ Laser, laser energy density 1J/mm ² And comparing the Raman diagrams of the graphene prepared by the laser resolution of 100p.p.i. to show that the graphene obtained by the polybenzoxazine laser induction has universality.

Claims

1. A preparation method of polybenzoxazine based graphene comprises the steps of synthesizing benzoxazine monomers and/or oligomers by taking a phenol source, an amine source and paraformaldehyde or formaldehyde as raw materials, heating, curing and crosslinking to obtain polybenzoxazine resin, and finally obtaining the polybenzoxazine based graphene through laser induction;

the molar ratio of the phenol source to the amine source to the paraformaldehyde or formaldehyde functional group is 1:1: 2-2.2;

the laser is induced, and the type of laser used comprises CO ₂ Laser, ultraviolet laser, or infrared laser;

the laser induction is carried out by using laser energy density of 0.05-40J/mm ² 。

2. The method of claim 1, wherein the phenolic source has a formula as shown in formula (I):

wherein R is ₁ ，R ₂ And R ₃ Each independently is H, C ₁ ～C ₁₅ Alkyl, benzene ring, naphthalene ring, hydroxyphenyl-substituted C ₁ ～C ₅ An alkyl group.

3. The method of claim 2, wherein the phenol source is at least one of bisphenol A and bisphenol F.

4. The method of claim 1, wherein the amine source is a monoprimary amine and/or a diprimary amine.

5. The method of claim 4, wherein the amine source is at least one of methylamine, ethylamine, propylamine, butylamine, ethylenediamine, propylenediamine, butylenediamine, polyetheramine, cyclobutylamine, aniline, 4 '-diaminodiphenylmethane, 3' -methylenedianiline, and diaminodiphenylsulfone.

6. The method for preparing polybenzoxazine-based graphene according to claim 1, wherein the temperature for heating, curing and crosslinking the benzoxazine monomer and/or oligomer is 100-300 ℃ for 0.5-8 h.

7. A polybenzoxazinyl graphene prepared according to the method for preparing a polybenzoxazinyl graphene as claimed in any one of claims 1 to 6.