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CN-121991544-A - Hyperbranched polymer grafted silicon carbide composite filler and preparation method and application thereof

CN121991544ACN 121991544 ACN121991544 ACN 121991544ACN-121991544-A

Abstract

The application discloses hyperbranched polymer grafted silicon carbide composite filler, a preparation method and application thereof, which belong to the technical field of high polymer composite materials, wherein the composite filler comprises SiC, HBP and nano functional particles; the preparation method comprises the steps of grafting an HBP intermediate layer on the surface of hydroxylated SiC to obtain SiC-g-HBP, loading nano functional particles on the surface of the HBP layer by utilizing rich amino functional groups on the surface of the HBP to form composite filler, dispersing the composite filler in a resin matrix, and curing and forming to obtain the composite material.

Inventors

  • BI XIUMEI
  • WU XINTAO

Assignees

  • 威海市兰海融智新材料有限公司

Dates

Publication Date
20260508
Application Date
20260325

Claims (10)

  1. 1. The hyperbranched polymer grafted silicon carbide composite filler is characterized by comprising a silicon carbide core, an amino-terminated hyperbranched polymer intermediate layer grafted on the surface of the silicon carbide core, and a functional nanoparticle layer loaded on the hyperbranched polymer intermediate layer.
  2. 2. The hyperbranched polymer grafted silicon carbide composite filler according to claim 1, wherein the amino group content of the amino-terminated hyperbranched polymer is 2.5-4.5 mmol/g, the molecular weight is 2000-4000, and the functional nanoparticle is one of nano silicon dioxide, nano aluminum oxide or nano zirconium oxide.
  3. 3. The preparation method of the hyperbranched polymer grafted silicon carbide composite filler is characterized by comprising the following steps of: Firstly, silicon carbide surface treatment, namely adding silicon carbide powder into alkali solution for treatment to obtain hydroxylated silicon carbide; secondly, constructing an interface phase, namely placing the hydroxylated silicon carbide in a mixed solvent for ultrasonic stirring to prepare dispersion liquid, and dripping the amino-terminated hyperbranched polymer into the dispersion liquid for reaction after dissolving to prepare SiC-g-HBP slurry; Thirdly, constructing a functional nanoparticle layer, namely preparing suspension after ultrasonic dispersion of the functional nanoparticles, dripping the suspension into the SiC-g-HBP slurry, reacting the active amino with hydroxyl, and performing post-treatment after the reaction is finished to obtain the functional composite filler.
  4. 4. The method for preparing a hyperbranched polymer grafted silicon carbide composite filler according to claim 3, wherein the surface treatment in the step (one) is carried out at a temperature of 70-90 ℃ for a time of 4h, the particle size of the silicon carbide powder is 3-5 μm, the concentration of the alkali solution is 10 wt%, and the mass ratio of the silicon carbide powder to the alkali solution is 1:3-5.
  5. 5. The method for preparing hyperbranched polymer grafted silicon carbide composite filler according to claim 3, wherein the mixed solvent in the step (two) consists of water and absolute ethyl alcohol, and the volume ratio of the water to the absolute ethyl alcohol is 1:1-4.
  6. 6. The preparation method of the hyperbranched polymer grafted silicon carbide composite filler according to claim 3, wherein the mass ratio of the hydroxylated silicon carbide to the mixed solvent in the step (II) is 1:9-11, the addition amount of the amino-terminated hyperbranched polymer is 5-15% of the mass of the hydroxylated silicon carbide, the pH of a reaction system is 5.0-6.0, the reaction temperature is 65-85 ℃ and the reaction time is 6 h.
  7. 7. The method for preparing hyperbranched polymer grafted silicon carbide composite filler according to claim 3, wherein the mass ratio of the functional nanoparticles to the hydroxylated silicon carbide in the step (III) is 0.15-0.25:1, the reaction temperature is 65-85 ℃ and the reaction time is 4 h.
  8. 8. The method for preparing the hyperbranched polymer grafted silicon carbide composite filler according to claim 3, wherein the specific step of the post-treatment in the step (three) is that after the reaction is finished, the precipitate is alternately washed 3 times by deionized water and ethanol, dried at 60 ℃ for 24 h, and ground and crushed.
  9. 9. The application of hyperbranched polymer grafted silicon carbide composite filler is characterized in that the composite filler is used for preparing an epoxy resin composite material, and the composite material comprises epoxy resin, composite filler and a curing agent, wherein in the composite filler, an amino-terminated hyperbranched polymer intermediate layer is subjected to chemical crosslinking reaction with the epoxy resin through active amino groups.
  10. 10. The use of the hyperbranched polymer grafted silicon carbide composite filler according to claim 9, wherein the hyperbranched polymer grafted silicon carbide composite filler comprises, by weight, 100 parts of epoxy resin, 20-40 parts of composite filler and 60-70 parts of curing agent.

Description

Hyperbranched polymer grafted silicon carbide composite filler and preparation method and application thereof Technical Field The application belongs to the technical field of high polymer composite materials, and particularly relates to hyperbranched polymer grafted silicon carbide composite filler, and a preparation method and application thereof. Background Silicon carbide (SiC) is used as an important inorganic functional filler, is widely used for preparing high-temperature-resistant and abrasion-resistant polymer-based composite materials due to excellent heat stability, high hardness and good chemical inertness, but natural incompatibility exists between the SiC filler and epoxy resin, the SiC surface is hydrophilic, the epoxy resin is hydrophobic, so that the filler is easy to agglomerate in a matrix, interface bonding is weak, even microscopic defects are formed, the silicon carbide becomes a channel for corrosive medium permeation, the overall performance of the composite material is reduced, therefore, how to improve the interface compatibility of the SiC filler and the polymer matrix becomes the key for improving the performance of the composite material, in order to solve the problems, researchers try various SiC surface modification methods mainly comprising silane coupling agent treatment, surface grafting polymers and the like, wherein hyperbranched polymers (Hyperbranched Polymers, HBP) are grafted and modified SiC in recent years, the hyperbranched polymers have the unique advantages of three-dimensional spherical structure, abundant terminal functional groups, low viscosity, high reactivity and the like, and a layer of compact organic interface phase can be constructed on the SiC surface, and various SiC-HBP composite filler preparation methods and application thereof are disclosed in the prior art. The patent CN104829944A grafts hyperbranched polyaramide onto the surface of nano SiC whisker by a three-step method, namely, firstly, hydroxylating SiC to obtain SiC-OH, then, silanizing to introduce a reaction base point (SiC-APS), and finally, grafting hyperbranched polymer by solution polymerization to prepare SiC-HBP composite filler, and using the SiC-HBP composite filler in a modified polypropylene composite material, thereby effectively improving the dispersibility and interface bonding strength of the filler; Enhancing Interfacial Properties of Epoxy Coatings via Hyperbranched Modification of SiC Fillers: Experimental and Simulation Insights（Chemical Engineering Journal,Volume 511,1 May 2025,161841） The application of hyperbranched modified SiC filler in epoxy coating is disclosed, wherein hyperbranched polymer containing hydroxyl and carboxyl is synthesized by one-step method, and grafted to SiC surface through dehydration condensation reaction to obtain HBP-SiC composite filler, the result shows that the carboxyl and ether bond on HBP-SiC surface form covalent bond and hydrogen bond with epoxy resin, the compatibility of filler and resin is remarkably improved, the hydrophilicity is greatly improved, when the addition amount is 30%, the abrasion mass loss of the coating is reduced to 0.0124 g, and high impedance modulus is still maintained after high-temperature high-pressure corrosion test, excellent wear resistance and corrosion resistance are shown, and molecular dynamics simulation further proves that the introduction of HBP-SiC reduces the free volume fraction of the coating and the diffusion coefficient of corrosion medium, and a denser interface structure is formed. However, existing SiC-HBP technology still suffers from the following disadvantages: The existing SiC-HBP mainly solves the problems of filler dispersibility and interface compatibility, the modification effect is concentrated on improving mechanical properties and basic corrosion resistance, and multiple functions such as abrasion resistance, flame retardance and high temperature resistance are difficult to endow a composite material at the same time, however, in practical application, the composite material always needs to meet multiple requirements at the same time, the prior art usually adopts a mode of blending various functional fillers, but the compatibility among different fillers is poor, interface defects are easy to occur, for example, the mechanical properties can be deteriorated by adding a flame retardant, the corrosion resistance can be reduced by adding a hard wear-resistant filler, and therefore, how to further construct the composite material with multiple functions on the basis of the SiC-HBP, and the synergistic enhancement rather than mutual restriction among the functions is ensured, so that the technical problem to be solved in the field is urgent. According to the application, after the hyperbranched polymer is grafted to the SiC surface, the rich terminal functional groups (such as amino, carboxyl and hydroxyl) of the hyperbranched polymer can be crosslinked with a resin matrix, and can be