CN-122011494-A - Preparation method and application of self-adhesive porous polymer particles for electromagnetic wave absorption

Abstract

The invention discloses a preparation method of self-adhesive porous polymer particles for electromagnetic wave absorption, which comprises the steps of dispersing a reaction solution of the self-adhesive porous polymer particles in a continuous phase medium through a dispersing agent to form reaction micro-droplets, freezing and initiating polymerization of the reaction micro-droplets, and thawing after polymerization to obtain the self-adhesive porous polymer particles for electromagnetic wave absorption, wherein the reaction solution of the self-adhesive porous polymer particles comprises a monomer, a cross-linking agent, an initiator, a solvent, a dispersing agent, a wave absorbing filler and molecules containing self-adhesive functional groups, the self-adhesive functional groups are selected from one or more of hydrogen bonds, hydroxyl groups and amino groups, and the freezing point of the continuous phase medium is lower than that of the solvent. The self-adhesive porous polymer particles prepared by the invention can quickly form a large-area wave-absorbing coating on the surface of an object, have continuously adjustable aperture and porosity, can cope with electromagnetic waves with different frequencies, are convenient to repair, are green and environment-friendly, and provide a new idea for the field of electromagnetic wave absorption.

Inventors

• CHEN DI
• SHAO JIAHUI
• XU FENG
• QIN FAXIANG

Assignees

• 浙江大学

Dates

Publication Date

20260512

Application Date

20260312

Claims (10)

1. 1. The preparation method of the self-adhesive porous polymer particles facing electromagnetic wave absorption is characterized by comprising the following steps of: (1) Dispersing a reaction solution of self-adhesive porous polymer particles in a continuous phase medium through a dispersing agent to form reaction micro-droplets; (2) Freezing the reaction micro-droplets and initiating polymerization, and thawing after polymerization to obtain self-adhesive porous polymer particles facing electromagnetic wave absorption; the reaction solution of the self-adhesive porous polymer particles comprises a monomer, a cross-linking agent, an initiator, a solvent, a dispersing agent, a wave-absorbing filler and molecules containing self-adhesive functional groups, wherein the self-adhesive functional groups are selected from one or more of hydrogen bonds, hydroxyl groups and amino groups, and the solidifying point of the continuous phase medium is lower than that of the solvent.
2. 2. The method for preparing the self-adhesive porous polymer particles facing electromagnetic wave absorption according to claim 1, wherein the monomer is one or more selected from acrylic ester molecules with long alkyl chains in the skeleton, pentaerythritol tetra-3-mercaptopropionate, 1, 6-hexanedithiol or acrylamide; the cross-linking agent is selected from one or more of 1, 6-hexanediol diacrylate, polyethylene glycol diacrylate or methylene bisacrylamide; The initiator is a thermal initiation system selected from benzoyl peroxide, azodiisobutyronitrile or N, N-dimethylaniline, or a photoinitiation system selected from phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide; The solvent contained in the reaction liquid is selected from one of cyclohexane, n-hexadecane or stearic acid; the wave-absorbing filler is selected from one or more of poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid), graphene or nano ferroferric oxide particles.
3. 3. The method for producing self-adhesive porous polymer particles for electromagnetic wave absorption according to claim 1, wherein in the step (1), the self-adhesive functional group molecule is selected from one or more of dopamine, acrylate ureidopyrimidinone or N-acryl semicarbazide.
4. 4. The method for preparing self-adhesive porous polymer particles facing electromagnetic wave absorption according to claim 1, wherein in the step (1), the dispersant is one or more selected from polyvinylpyrrolidone, carboxymethyl cellulose or sodium polystyrene sulfonate.
5. 5. The method for producing self-adhesive porous polymer particles for electromagnetic wave absorption according to claim 1, wherein in step (1), the continuous phase medium is water.
6. 6. The method for producing self-adhesive porous polymer particles for electromagnetic wave absorption according to claim 1, wherein in the step (2), the freezing temperature is higher than the freezing point of the continuous phase medium and lower than the freezing point of the solvent in the reaction solution.
7. 7. The method of producing self-adhesive porous polymer particles for electromagnetic wave absorption according to claim 1, wherein in the step (2), the polymerization is performed under freezing conditions when thermally initiated and under freezing light conditions when photoinitiated, and the wavelength of the light source is in the range of 280 nm to 450 nm.
8. 8. A self-adhesive porous polymer particle obtained by the production method according to any one of claims 1 to 7.
9. 9. Use of self-adhesive porous polymeric particles according to claim 8 in a coating having electromagnetic wave absorption capacity, wherein the self-adhesive porous polymeric particles prepared are bonded by solvent-triggered particles to form a coating having electromagnetic wave absorption capacity.
10. 10. The use according to claim 9, wherein the solvent is selected from one of liquid paraffin, silicone oil.

Description

Preparation method and application of self-adhesive porous polymer particles for electromagnetic wave absorption Technical Field The invention relates to the field of manufacturing of porous polymer particles, in particular to a preparation method and application of self-adhesive porous polymer particles for electromagnetic wave absorption. Background Since the 21 st century, various information technologies are continuously developed after the informatization revolution, and civil miniaturized or wearable electronic communication products are continuously emerging, so that the requirements of intelligent information interaction and fast-paced life of people are met, and the life of people is facilitated. However, at the side of people, the densely existing electronic products can emit electromagnetic waves when in use, so that a complex electromagnetic environment is formed. This phenomenon is considered to be a new type of environmental pollution. Excessive electromagnetic waves can affect the normal operation of precision electronic equipment and also can pose a threat to human health. In order to solve this problem, researchers have explored and developed wave absorbing materials in an attempt to protect by absorbing external electromagnetic waves. The wave absorbing materials commonly used today dissipate electromagnetic waves mainly by dielectric and magnetic losses. Common materials that achieve wave absorbing properties through dielectric loss include carbon materials such as carbon black, graphite, graphene, carbon nanotubes, and other conductive materials such as silver, MXene, polyaniline, poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid. The material for obtaining the wave absorbing performance through magnetic loss mainly comprises magnetic iron, cobalt, nickel and compounds thereof. In order to obtain good wave absorbing performance, the existing wave absorbing coating or structural member depends on high-content wave absorbing materials, so that the density of the materials is high, the thickness is high, and the quality is high. And when the material is damaged after long-time use, the performance is reduced, and the repair difficulty is higher. In order to solve the above-mentioned problems of the conventional wave-absorbing material having a large thickness and mass, a porous material may be used. The construction of porous structures within materials is a common method of enhancing the wave absorbing properties of materials while also reducing the mass. The porous material can continuously reflect electromagnetic waves after entering the pore canal, prolong the process of the electromagnetic waves for loss, thereby consuming more energy of the electromagnetic waves, enhance the interface polarization by utilizing the characteristic of large specific surface area of the porous material, and reduce the quality of the wave-absorbing material and enhance the impedance matching characteristic by virtue of the air in the pores of the material. Ice templates are a special template pore-forming method that uses crystallization of a solvent as a pore-forming agent. The pore-forming method can regulate and control the shape of the pores, and the process is simple and environment-friendly. Meanwhile, the method has wide selectivity on a pore-forming system, can prepare a porous material based on aqueous reaction solution below a freezing point, can be also adapted to a system based on an organic solvent, and can realize freezing pore-forming by reducing the temperature below the freezing point of the corresponding solvent. However, there are also problems in preparing a large-area, small-thickness porous material coating and fixing it to the surface of the device to be protected. Conventional porous wave absorbing materials, such as composite aramid paper, do not have good adhesion per se and require the use of an adhesive for fixation. Thus, in addition to breakage of the coating surface by interaction with the external environment, adhesive failure can also lead to coating release. Therefore, how to provide a solution to the problems of coating preparation and repair at the same time is a technical problem that needs to be solved in the art. Disclosure of Invention The invention provides a preparation method of self-adhesive porous polymer particles for electromagnetic wave absorption, the prepared porous polymer particles can react with a solvent on the surface of an object to form a wave-absorbing coating rapidly and automatically, the electromagnetic wave absorption performance is realized, the object is protected, the pore diameter and the porosity of the porous polymer particles are continuously adjustable, electromagnetic waves in different frequency bands can be absorbed, and the repair is convenient. The preparation method of the self-adhesive porous polymer particles facing electromagnetic wave absorption comprises the following steps: (1) Dispersing a reaction solution of se