阅读说明：本技术 一种光/热驱动自修复防腐涂层材料及其制备方法和应用 (Light/heat driven self-repairing anticorrosive coating material and preparation method and application thereof ) 是由 李伟华 杨皓程 申婷 陈楚楚 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种光/热驱动自修复防腐涂层材料及其制备方法和应用。所述光/热驱动自修复防腐涂层材料,包含石蜡、非极性热塑性聚合物和光热填料；所述非极性热塑性聚合物为石蜡与非极性热塑性聚合物质量含量的10％～50％；所述光热填料为非极性热塑性聚合物与石蜡质量含量的0.5％～5％。本发明通过将非极性热塑性聚合物在加热搅拌条件下溶于石蜡,得到无色透明铸膜溶液；再向溶液中加入光热填料,混匀,使光热填料充分分散,得到光/热驱动自修复防腐涂层材料；本发明涂层材料是基于融化、流动再融合的物理型本征自修复物质,在水中具有优异的自修复性能和防腐性能,具有较大的应用前景。(The invention discloses a light/heat driven self-repairing anticorrosive coating material and a preparation method and application thereof. The light/heat driven self-repairing anticorrosive coating material comprises paraffin, a non-polar thermoplastic polymer and a photo-thermal filler; the mass content of the non-polar thermoplastic polymer is 10-50% of that of the paraffin and the non-polar thermoplastic polymer; the photo-thermal filler is 0.5-5% of the mass content of the non-polar thermoplastic polymer and the paraffin. The preparation method comprises the steps of dissolving a nonpolar thermoplastic polymer in paraffin under the conditions of heating and stirring to obtain a colorless transparent casting solution; adding photo-thermal filler into the solution, and uniformly mixing to fully disperse the photo-thermal filler to obtain a photo/thermal driving self-repairing anticorrosive coating material; the coating material is a physical intrinsic self-repairing substance based on melting and flowing re-fusion, has excellent self-repairing performance and corrosion resistance in water, and has a wide application prospect.)

1. The light/heat driven self-repairing anticorrosive coating material is characterized by comprising paraffin, a non-polar thermoplastic polymer and a photo-thermal filler; the mass content of the non-polar thermoplastic polymer is 10-50% of that of the paraffin and the non-polar thermoplastic polymer; the photo-thermal filler is 0.5-5% of the mass content of the non-polar thermoplastic polymer and the paraffin.

2. The light/heat driven self-repairing anticorrosive coating material of claim 1, wherein the non-polar thermoplastic polymer accounts for 20-40% of the mass content of the paraffin and the non-polar thermoplastic polymer; the photo-thermal filler is 1-4% of the mass content of the non-polar thermoplastic polymer and the paraffin.

3. The light/heat driven self-healing corrosion protective coating material of claim 1 or 2, wherein the non-polar thermoplastic polymer is one or more of isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra-high molecular weight polyethylene, polystyrene, styrene-butadiene-styrene block copolymer, or styrene-isoprene-styrene block copolymer.

4. The light/heat driven self-healing corrosion protective coating material of claim 1 or 2, wherein the paraffin wax is one or more of a fully refined paraffin wax, a semi-refined paraffin wax, or a crude paraffin wax.

5. The light/heat driven self-healing anticorrosive coating material according to claim 1 or 2, wherein the photo-thermal filler is one or more of graphite, carbon particles, carbon nanotubes, amorphous carbon, graphene or derived materials thereof, or an allotrope of carbon material.

6. The preparation method of the light/heat driven self-repairing anticorrosive coating material as claimed in any one of claims 1 to 5, characterized by comprising the following steps:

s1, dissolving a nonpolar thermoplastic polymer in paraffin under the heating and stirring conditions to obtain a colorless and transparent casting film solution;

s2, adding the photo-thermal filler into the solution obtained in the step S1, and uniformly mixing to fully disperse the photo-thermal filler to obtain the photo/thermal driving self-repairing anticorrosive coating material.

7. The preparation method according to claim 6, wherein the heating is performed at 90-250 ℃ and the stirring time is 1-3 h.

8. The application of the light/heat driven self-repairing anticorrosive coating material disclosed by any one of claims 1 to 5 in corrosion prevention is characterized in that the light/heat driven self-repairing anticorrosive coating material disclosed by any one of claims 1 to 5 is heated to a fluid state, then coated on a substrate, and naturally cooled to obtain a novel self-repairing anticorrosive coating.

9. Use according to claim 8, wherein the coating is brushing, dipping, knife coating or spraying.

Technical Field

The invention relates to the technical field of self-repairing anticorrosive coatings, in particular to an anticorrosive coating material capable of realizing self-repairing in air/water under the drive of light/heat, and a preparation method and application thereof.

Background

With the continuous promotion of the progress of the infrastructure of China, the field of the anticorrosive coating comes into a wider market. However, the coating also faces to the problems that cracks and scratches are generated along with the increase of service life and the impact of external factors, so that the mechanical performance of the coating is greatly influenced, the maintenance cost is increased, and even potential safety hazards are brought. Aiming at the problem, inspired by natural phenomena such as human skin self-healing and bark regeneration, related scholars put forward a self-healing concept, and expect that the coating can realize active healing after being damaged, namely the process of partially or completely recovering the original structure or function.

Self-repairing coating technology is developed to date, and can be classified into intrinsic type and external aid type according to the repairing mechanism. The difference between the two is that the micro-containers such as microcapsules, micro-vessels or nano-particles containing a repairing agent are required to be introduced into the micro-containers, and then the repairing agent release in the damaged area is triggered under external stimulation (force, pH value, temperature and the like), so that self-repairing is realized, while intrinsic self-repairing is realized by means of special chemical bonds (acylhydrazone bonds, disulfide bonds and Diels-Alder reaction) contained in the coating material or other physical and chemical properties such as hydrogen bonds, hydrophobicity, static electricity and metal ligand action and the like, wherein most of substances with intrinsic self-repairing performance need to be triggered by factors such as light, heat and the like to realize the repairing process. In addition, because light and heat have good environmental applicability and controllability, the light/heat triggering self-repairing technology is widely applied to the field of self-repairing.

The intrinsic self-repairing mode does not depend on a repairing agent, complex steps such as a repairing agent embedding technology in advance are omitted, the influence on the performance of the matrix is small, the molecular structure design of the coating matrix material is the biggest challenge faced by the method, and the development space of the method is limited. The external-aid self-repairing has the problems of slow repairing, limited repairing times, complex synthetic process, uneven dispersion of the microcapsules in resin, easy agglomeration and the like. In addition, as the service environment of most anticorrosive coatings is often higher in humidity or directly water environment, and the switching between the air environment and the water environment also means that the whole surface/interface state of the coating can be changed violently, which means that a substance capable of realizing self-repair in the air may not be suitable for use in the water environment. Therefore, the self-repairing performance of the self-repairing material in the water environment also becomes a common concern of researchers and a difficult problem to be solved urgently.

For the self-repairing process, the substances with intrinsic self-repairing property are directly applied, so that the complicated steps of synthesizing and embedding microcapsules or microvessels and the like can be omitted, but the chemical intrinsic self-repairing substances constructed based on dynamic covalent bonds also have the problems of complicated design and synthesis steps, complicated preparation process and the like. The design and synthesis steps related to the physical intrinsic self-repairing material based on melting and flowing re-fusion are far simpler than those of the chemical intrinsic self-repairing material constructed based on dynamic covalent bonds; therefore, in order to overcome the difficulties that the preparation process of the traditional self-repairing coating technology such as microcapsules, microvessels, dynamic reversible covalent bonds construction and the like is complicated, the preparation cost is high, large-scale production is difficult to realize and the like, the physical intrinsic self-repairing substance for realizing self-repairing based on melting and flow re-fusion is selected as a coating component to be regarded as a self-repairing strategy with a high expectable value, but related reports of the physical intrinsic self-repairing coating material for realizing self-repairing based on melting and flow re-fusion are not found at present. Therefore, on the basis of the principle of a physical intrinsic self-repairing coating which realizes self-repairing by melting and flowing re-fusion, how to prepare a coating which presents solid properties in a service state and can present liquid-like properties when damaged and how to realize self-repairing in a water environment is a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings in the prior art and provide a light/heat driven self-repairing anticorrosive coating material.

The invention also aims to provide a preparation method of the light/heat driven self-repairing anticorrosive coating material.

Still another object of the invention is to provide application of the light/heat driven self-repairing anticorrosive coating material.

The above object of the present invention is achieved by the following technical solutions:

a light/heat driven self-repairing anticorrosive coating material comprises paraffin, a non-polar thermoplastic polymer and a photo-thermal filler; the mass content of the non-polar thermoplastic polymer is 10-50% of that of the paraffin and the non-polar thermoplastic polymer; the photo-thermal filler is 0.5-5% of the mass content of the non-polar thermoplastic polymer and the paraffin.

It is well known that substances with flow properties have the disadvantages of being easily lost and difficult to stabilize on the substrate surface, and it is common to know such substances (thermoplastic polymers or substances with lower melting points) that they require heat (or other forms of conversion heat) to achieve solid-liquid transition. Therefore, a substance capable of realizing solid-liquid conversion under a relatively mild heating condition is found, a proper photo-thermal filler is introduced to endow the coating with a light/heat response function, and material loss after solid-liquid conversion is avoided by means of some principles and technologies, so that the coating which is in a solid property in a service state and is in a liquid-like property caused by light/heat when damaged is prepared, and self-repairing in a water environment can be realized.

In the coating material of the present invention, a nonpolar thermoplastic polymer is used as a film-forming substance, paraffin is used as one of coating composition components and is simultaneously a solid solvent for the nonpolar thermoplastic polymer, and a carbon material is introduced as a photothermal filler. Paraffin is a known material capable of undergoing solid-liquid conversion under relatively mild heating conditions and within a wide temperature range, and has great potential for realizing solid-liquid conversion self-repair. However, the brittleness of paraffin and the loss of paraffin after melting under heat pose a challenge for the construction of paraffin-based coatings. Based on the advantages and disadvantages of paraffin, the inventor prevents the loss of liquid paraffin by adding a proper polymer system into a paraffin system as a film forming substance and using the polymer system as a paraffin excipient with a liquid supporting framework. The polymer is preferably a nonpolar thermoplastic polymer which can be mutually dissolved at high temperature and phase-separated at low temperature with paraffin, and the solidifying point of the polymer is higher than that of the paraffin, so that the construction of a supporting framework network can be realized in the phase-separating process (when the paraffin is still in a liquid phase). Meanwhile, a substance (such as a carbon material) with a photo-thermal effect is introduced, so that the coating is endowed with a fixed-point self-repairing function based on the photo-thermal effect. The invention utilizes paraffin as solid solvent, and the solid-liquid phase change under relatively mild heating condition is the fundamental guarantee for realizing self-repair. The light/heat driven self-repairing anticorrosive coating material disclosed by the invention has a solid property in a service state and a liquid-like property caused by light/heat when damaged, and can realize self-repairing in a water environment. At present, in the field of self-repair, self-repair is mostly realized by constructing reversible dynamic covalent bonds or other intermolecular interactions, the cost of related raw materials is high, the synthesis steps are complex, and the research of self-repair realized by utilizing the physical phase change of materials rarely appears.

Preferably, the non-polar thermoplastic polymer is 20% to 40% (e.g., 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%) of the mass content of the paraffin wax and the non-polar thermoplastic polymer; the photo-thermal filler is 1-4% (for example, 1-2%, 2-3%, 3-4%) of the mass content of the nonpolar thermoplastic polymer and the paraffin.

Preferably, the non-polar thermoplastic polymer is one or more of isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra-high molecular weight polyethylene, polystyrene, styrene-butadiene-styrene block copolymer or styrene-isoprene-styrene block copolymer.

Preferably, the paraffin wax is full refined paraffin wax, semi-refined paraffin wax, crude paraffin wax, No. 52, No. 54, No. 56, No. 58 and other paraffin waxes with different brands or a mixture of the paraffin waxes

The self-repairing response of the coating is quick and controllable, and can be triggered by various modes including but not limited to heat, photo-heat, electric heat, electromagnetic heat and the like, so that the remote in-situ repair can be realized. Preferably, the photo-thermal filler is graphite, carbon particles, carbon nanotubes, amorphous carbon, graphene or a derivative thereof ((graphene oxide and reduced graphene oxide)), an allotrope of a carbon material, or a mixture thereof.

The invention also claims a preparation method of any one of the light/heat driven self-repairing anticorrosive coating materials, which is characterized by comprising the following steps:

s1, dissolving a nonpolar thermoplastic polymer in paraffin under the heating and stirring conditions to obtain a colorless and transparent casting film solution;

s2, adding the photo-thermal filler into the solution obtained in the step S1, and uniformly mixing to fully disperse the photo-thermal filler to obtain the photo/thermal driving self-repairing anticorrosive coating material.

Preferably, the heating is between 90 and 250 ℃, and the stirring time is 1 to 3 hours.

The invention also provides an application of any one of the light/heat driven self-repairing anticorrosive coating materials in corrosion prevention, wherein the light/heat driven self-repairing anticorrosive coating material is heated to a fluid state and then coated on a substrate, or the just prepared self-repairing anticorrosive coating material is directly coated on the substrate while the coating material is hot and waits for natural cooling, so that a novel self-repairing anticorrosive coating can be obtained.

Preferably, the heating is performed at 160-230 ℃.

Preferably, the coating is brushing, dipping, knife coating or spraying.

Compared with the prior art, the invention has the following beneficial effects:

(1) the light/heat driven self-repairing anticorrosive coating material is a physical intrinsic self-repairing substance based on melting and flowing re-fusion, and compared with the traditional material for realizing self-repairing by constructing reversible dynamic covalent bonds or other intermolecular interactions, the light/heat driven self-repairing anticorrosive coating material has the advantages of simple design and synthesis steps.

(2) The light/heat driven self-repairing anticorrosive coating material disclosed by the invention utilizes the nonpolar thermoplastic polymer which is mutually soluble with paraffin as a framework to coat and shape the liquid paraffin after phase change, so that the problem of loss of the liquid paraffin is effectively avoided. Compared with the traditional coating which is prepared by constructing a porous substrate firstly, pouring molten paraffin on the surface of the porous substrate, taking the paraffin as a component and realizing reparation through solid-liquid phase change, the polymer and the paraffin in the coating material are mutually dissolved at high temperature, and after phase separation at low temperature, a mutually penetrated bicontinuous structure can be directly formed, so that the coating material has better limiting and shaping effects on liquid paraffin.

(3) The paraffin in the coating material is a solid solvent, does not relate to a common organic solvent, does not generate volatile organic compounds, is green and environment-friendly, and has excellent water resistance so that the coating has a good isolation effect on corrosive media in the environment; the coating material of the invention has simple preparation method and required equipment, cheap and easily obtained raw materials, various coating modes and wide application range, and is suitable for various substrates, such as: metal, glass, plastic, etc., and is suitable for large-scale production.

Drawings

FIG. 1 is a process for preparing the self-repairing anticorrosive coating of the present invention.

FIG. 2 is an SEM image of a self-healing corrosion protective coating of example 3 of the present invention.

Fig. 3 is a graph comparing the stability test of the medium paraffin-photothermal filler coating and the polymer/paraffin-photothermal filler coating in hot water of 99 c according to example 3 of the present invention.

FIG. 4 shows the self-repairing effect of the self-repairing anticorrosive coating in hot water according to example 3 of the present invention; a. before repairing; b. and (5) after repairing.

FIG. 5 is a corrosion resistance test of the self-repairing anticorrosive coating in example 3 of the present invention: a. stainless steel impedance spectrogram; b. polypropylene/paraffin coating impedance spectrum.

Detailed Description

The invention is further described with reference to the drawings and the following detailed description, which are not intended to limit the invention in any way. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Unless otherwise indicated, reagents and materials used in the following examples are commercially available.

The preparation process of the self-repairing anticorrosive coating according to the following specific embodiment of the invention is shown in fig. 1: