Polyrotaxane coated modified hollow glass bead and composite material thereof

Abstract

The invention belongs to the field of modification treatment of hollow glass beads, and particularly relates to a polyrotaxane coated modified hollow glass bead and a composite material thereof. The polyrotaxane coated modified hollow glass bead comprises a hollow glass bead core and a coating layer bonded on the hollow glass bead core, the coating layer is polyrotaxane formed by polyethylene glycol and amino cyclodextrin and is terminated by adamantyl groups. The hollow glass beads with rigidity and light weight are connected with the polyrotaxane which provides toughness and an interface enhancement effect in a chemical bonding manner to construct the hollow glass beads with core-shell structures, so that the synergistic effect of the light rigidity of the hollow glass beads and the obdurability of the polyrotaxane is realized; the microbeads can be effectively prevented from being broken in the material processing process, and meanwhile, the formed material has the characteristics of high toughness and impact resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of modification treatment of hollow glass microspheres, and particularly relates to a hollow glass microsphere coated with polyrotaxane and a composite material thereof. BACKGROUND

[0002] Hollow glass microspheres have low density, low thermal conductivity, high compressive strength, and good chemical stability, and are widely used as fillers in adhesives, thermal insulation coatings, plastics and rubbers. However, the surface properties of hollow glass microspheres determine that they have inert and brittle surfaces and poor impact resistance. When applied to composite materials, there may be problems such as poor interfacial bonding ability and reduced plasticity and toughness of the composite material.

[0003] A Chinese invention patent application with the application publication date of November 1, 2024 and the application publication number of CN 118878984 A discloses a low surface energy solid buoyancy material and a preparation method thereof. The low surface energy solid buoyancy material comprises the following raw materials in parts by mass: modified polypropylene resin 40-70 parts, modified hollow glass microspheres 30-60 parts, and polytetrafluoroethylene micro powder 3-8 parts. The modified polypropylene resin is modified with APAO (a copolymer of propylene and ethylene). The modified hollow glass microspheres are modified with a coupling agent (KH550, KH560, KH570).

[0004] The use of a coupling agent to modify the hollow glass microspheres in the above-mentioned prior art can improve the wettability and interfacial bonding ability of the hollow glass microspheres, but cannot effectively change the inherent defects of the hollow glass microspheres, such as brittleness and poor impact resistance. This leads to a sharp decrease in the toughness and impact resistance of the corresponding composite material, thereby limiting the application of hollow glass microspheres in composite materials with high toughness requirements. SUMMARY

[0005] The purpose of the present application is to provide a hollow glass microsphere coated with polyrotaxane, which solves the problem that the use of hollow glass microspheres as fillers in composite materials has a great adverse effect on the toughness of the composite material.

[0006] The second purpose of the present application is to provide a high-toughness hollow glass microsphere composite material to solve the problem of poor toughness of existing composite materials containing hollow glass microspheres.

[0007] In order to achieve the above-mentioned purposes, the technical scheme of the polyrotaxane-coated hollow glass microsphere of the present application is as follows: A polyrotaxane-coated hollow glass microsphere, comprising a hollow glass microsphere core and a coating layer bonded to the hollow glass microsphere core; the coating layer is a polyrotaxane formed by polyethylene glycol and aminocyclo dextrin, and is terminated with adamantane groups.

[0008] The present application is an opening application, which connects the hollow glass microspheres with rigidity and light weight and the polyrotaxane providing toughness and interface enhancement together by chemical bonding to build the core-shell structure hollow glass microspheres, realizes the synergistic effect of the light weight and rigidity of the hollow glass microspheres and the toughness of the polyrotaxane, can effectively avoid the breakage of the microspheres in the material processing process, and simultaneously makes the formed material have the characteristics of high toughness and impact resistance.

[0009] Preferably, the bonding is formed by the coupling reaction of the carboxyl on the surface carboxyl-modified hollow glass microspheres and the amino on the polyrotaxane.

[0010] Preferably, the polyrotaxane-coated modified hollow glass microspheres are prepared by a method comprising the following steps: (1) mixing and reacting polyethylene glycol and aminocyclo-dextrin to prepare aminated quasi-polyrotaxane; (2) using adamantane to end-cap the aminated quasi-polyrotaxane to prepare aminated adamantane end-capped polyrotaxane; (3) coupling the aminated adamantane end-capped polyrotaxane with the surface carboxyl-modified hollow glass microspheres.

[0011] Further preferably, in step (1), the mass of the polyethylene glycol corresponding to 15-20 g of the aminocyclo-dextrin is 0.7-1.2 g; and the mixing and reacting is first reacted at 80-85 ℃ for 1-3 h, and then stirred and reacted at room temperature for 6-12 h.

[0012] Further preferably, in step (3), the amount of the surface carboxyl-modified hollow glass microspheres corresponding to 1 g of the aminated adamantane end-capped polyrotaxane is 20-25 g.

[0013] Further preferably, the surface carboxyl-modified hollow glass microspheres are prepared by a method comprising the following steps: S1. activating the hollow glass microspheres in lye to obtain activated hollow glass microspheres; S2. surface-modifying the activated hollow glass microspheres using an amino-silane coupling agent to obtain surface-amino-modified hollow glass microspheres; S3. reacting the surface-amino-modified hollow glass microspheres with an acid anhydride to obtain the surface-carboxyl-modified hollow glass microspheres.

[0014] Preferably, in step S2, the amino-silane coupling agent, water and ethanol are mixed according to the mass ratio of 1: (0.2-0.3): (4-5) to obtain a silane coupling agent solution; and the silane coupling agent solution and the activated hollow glass microspheres are mixed according to the mass ratio of (0.5-1): 10 and reacted at 60-80 ℃ for 1-2 h.

[0015] Preferably, in step S3, the reaction uses succinic anhydride, and the amount of succinic anhydride used is 10-12 g per 25 g of surface-aminated modified hollow glass microspheres.

[0016] The technical scheme of the high-toughness hollow glass microsphere composite material of the present application is: A high-toughness hollow glass microsphere composite material comprises a resin matrix and the above-mentioned polyrotaxane-coated modified hollow glass microspheres dispersed in the resin matrix.

[0017] The high-toughness hollow glass microsphere composite material provided by the present application has significantly improved compatibility with the matrix material and significantly improved toughening effect on the matrix material compared with unmodified hollow glass microspheres. Experimental results show that the tensile strength, tensile modulus, bending strength, bending modulus, IZOD notched impact strength and other indicators of strength and toughness of the composite material using the polyrotaxane-coated modified hollow glass microspheres are significantly improved.

[0018] Preferably, the resin matrix is selected from one of polyethylene, polypropylene and epoxy resin. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 SEM image of unmodified hollow glass microspheres HL50; Fig. 2 SEM image of hollow glass microspheres HL50 modified using KH550; Fig. 3 SEM image of polyrotaxane-coated modified hollow glass microspheres obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0020] (I) Preferred embodiment description of the polyrotaxane-coated modified hollow glass microspheres of the present application Polyrotaxane is a mechanically interlocked supramolecular system in which a linear polymer chain passes through a ring molecule and the two ends are capped with bulky groups, having a slip ring effect. Polyrotaxane is often used in hydrogels or elastomers, and can impart certain self-repairing and stimulus-responsive properties to the corresponding materials.

[0021] The technical concept of the present application is to coat a polyrotaxane structure on the surface of inorganic microspheres by chemical fixation. This new core-shell structure combines the low density and rigidity of hollow glass microspheres with the super-toughness and intelligent response of polyrotaxane, achieving a synergistic effect of the two, thereby completely changing the current situation that the use of hollow glass microspheres significantly degrades the strength and toughness of the material, and greatly expanding the application scenarios of hollow glass microspheres in lightweight and high-toughness applications.

[0022] The technical scheme of the polyrotaxane coated modified hollow glass microsphere is that a polyrotaxane coating layer is connected to the surface of the hollow glass microsphere through chemical bonding. The polyrotaxane is formed by using a polyethylene glycol chain to pass through an amino cyclodextrin and using an adamantane group to terminate.

[0023] The chemical bonding method is used to ensure the reliability of the combination of the coating layer and the hollow glass microsphere, thereby protecting the hollow glass microsphere and avoiding the coating layer from slipping off during the processing of the composite material.

[0024] The polyrotaxane coated modified hollow glass microsphere is prepared according to the following steps: (1) mixing and reacting polyethylene glycol and amino cyclodextrin to obtain amino- modified quasi-polyrotaxane.

[0025] In this step, the polyethylene glycol and the amino cyclodextrin are reacted in water, the polyethylene glycol molecular chain passes through the amino cyclodextrin, and white solid powder, i.e. amino-modified quasi-polyrotaxane, is obtained. The polyethylene glycol is carboxyl-terminated polyethylene glycol.

[0026] The average molecular weight of the polyethylene glycol is 20,000-35,000, for example, PEG-20,000, PEG-35,000, etc. can be selected. 15-20 g of amino cyclodextrin corresponds to 0.7-1.2 g of polyethylene glycol, and the amount of water used is 400 mL.

[0027] The reaction is first reacted at 80-85℃ for 1-3 h, then stirred at room temperature for 6-12 h, and then the white powder is cooled and precipitated. After vacuum drying and other post-treatment, the amino-modified quasi-polyrotaxane is obtained.

[0028] (2) using adamantane to terminate the amino-modified quasi-polyrotaxane to obtain amino-modified adamantane-terminated polyrotaxane.

[0029] In this step, the adamantane amine hydrochloride is used to perform the termination reaction in a solvent in the presence of benzotriazol-1-yl-oxytris(dimethylamino) phosphonium hexafluorophosphate (BOP) and N-ethyldiisopropylamine (DIPEA). The adamantane group is used to physically block the amino cyclodextrin from slipping off because the size of the adamantane group is larger than the cavity of the amino cyclodextrin.

[0030] 10 g of amino-modified quasi-polyrotaxane corresponds to 0.3-0.5 g of adamantane amine hydrochloride, and the amount of organic solvent used is 50-60 mL. The organic solvent can be N,N-dimethylformamide.

[0031] 10 g of amino-modified quasi-polyrotaxane corresponds to 0.1-0.2 g of BOP, and the amount of DIPEA used is 0.8-1.2 g.

[0032] The end-capping reaction is stirred at 40-60℃ for 3-12h, then kept at 4-5℃ for 12h or more, and then methanol is added until white solid powder precipitates.

[0033] (3) The amino-substituted adamantane-terminated polyrotaxan is coupled with the surface carboxyl-modified hollow glass microspheres.

[0034] In this step, the amino group on the amino-substituted adamantane-terminated polyrotaxan is coupled with the carboxyl group on the surface carboxyl-modified hollow glass microspheres to form an amide bond, thereby realizing the chemical bonding and fixation of the polyrotaxan coating layer.

[0035] The above reaction is carried out in the presence of a condensing agent. The pH of the reaction is controlled at 6-7, and the reaction temperature is 25-40℃. The reaction time is 2-12h, preferably 6-12h. The amount of surface carboxyl-modified hollow glass microspheres corresponding to 1g of amino-substituted adamantane-terminated polyrotaxan is 20-25g. The above coupling reaction is carried out in water, and the amount of water corresponding to 1g of amino-substituted adamantane-terminated polyrotaxan is 100-120g.

[0036] The condensing agent can be selected from DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride), EDC / NHS, etc. Taking DMTMM as an example, the amount of DMTMM corresponding to 1g of amino-substituted adamantane-terminated polyrotaxan is 0.1-0.2g.

[0037] The above surface carboxyl-modified hollow glass microspheres are prepared by the following steps: S1. Activating the hollow glass microspheres in a lye to obtain activated hollow glass microspheres.

[0038] The hollow glass microspheres are placed in a 0.1-0.5mol / L sodium hydroxide solution and kept at 20-90℃ for 0.5-6h, then filtered or centrifuged, washed with deionized water until neutral, and dried to complete the activation of the hollow glass microspheres.

[0039] Through the activation of the hollow glass microspheres, the content of hydroxyl groups on the surface of the hollow glass microspheres can be increased. Preferably, the activation temperature is 70-90℃, and the time is 2-6h.

[0040] S2. Surface-modifying the activated hollow glass microspheres using an amino-silane coupling agent to obtain surface-amino-modified hollow glass microspheres.

[0041] In this step, dry modification is used to realize the surface aminization of the activated hollow glass microspheres. Compared with the traditional wet modification process, the use of dry modification can improve the utilization rate of the coupling agent and avoid environmental pollution caused by wastewater discharge.

[0042] The amino silane coupling agent, water and ethanol can be mixed in a mass ratio of 1: (0.2-0.3): (4-5) to obtain a silane coupling agent solution. The silane coupling agent solution and the activated hollow glass microspheres are mixed in a mass ratio of (0.5-1): 10 and reacted at 60-80°C for 1-2h.

[0043] The amino silane coupling agent is a silane coupling agent with an amino group, for example, one or both of 3-aminopropyl triethoxysilane KH550 and 3-aminopropyl trimethoxysilane KH540 can be selected.

[0044] S3. The surface aminated modified hollow glass microspheres are reacted with an acid anhydride to obtain surface carboxylated modified hollow glass microspheres.

[0045] The acid anhydride used in this step can be succinic anhydride. The solvent can be selected from an ethanol-water mixed solvent. In this step, the carboxyl group on the succinic anhydride reacts with the amino group through an amidation reaction, leaving unreacted carboxyl groups on the surface of the hollow glass microspheres, thereby completing the carboxyl modification of the hollow glass microspheres.

[0046] In this step, the amount of succinic anhydride used per 25g of surface aminated modified hollow glass microspheres is 10-12g. The reaction temperature is 25-40°C, and the reaction time is 2-4h.

[0047] The above reaction is carried out in an organic solvent. The organic solvent can be selected from N, N-dimethylformamide. The amount of organic solvent used per 25g of surface aminated modified hollow glass microspheres is 80-100mL.

[0048] The above preferred embodiments will be illustrated by specific examples. In the following examples, the raw materials involved are all commercially available conventional raw materials, unless otherwise specified. In the following examples, "%" is the mass percentage, unless otherwise specified.

[0049] Example 1 The polyrotaxane-coated modified hollow glass microspheres of this example are composed of a hollow glass microsphere core and a polyrotaxane coating layer, and the polyrotaxane coating layer is bonded to the surface of the hollow glass microspheres through an amide bond.

[0050] The preparation process of the polyrotaxane-coated modified hollow glass microspheres of this example is as follows: 1. Activation of hollow glass microspheres: The hollow glass microspheres are placed in a 0.1M sodium hydroxide solution for activation treatment, the activation treatment temperature is 90°C, and the activation treatment time is 6h. After activation treatment, the hollow glass microspheres are separated by suction filtration, then washed with deionized water until near neutral, and dried for standby use; 2. Surface amination of hollow glass microspheres: 3-Aminopropyltriethoxysilane KH550, water, and ethanol were mixed in a mass ratio of 1:0.2:4 to prepare an amino silane coupling agent solution. The solution was atomized by a watering can or a spraying device and sprayed onto the surface of the activated hollow glass microspheres. The amount of the amino silane coupling agent solution used was 1 g per 10 g of the activated hollow glass microspheres. After the hollow glass microspheres were treated in a dry modification machine at 80 °C for 2 h, the surface of the hollow glass microspheres was modified with amino groups.

[0051] 3. Carboxylation of the surface of hollow glass microspheres A solution was prepared by dissolving 10 g of succinic anhydride in 100 mL of anhydrous DMF (N,N-dimethylformamide). 0.05 g of ethylamine was added as a catalyst, and 25 g of the hollow glass microspheres modified with amino groups were added. The mixture was stirred mechanically or ultrasonically in a thermostatic water bath at 25 °C for 4 h under nitrogen protection. The unreacted succinic anhydride was removed by washing the mixture twice with DMF, and the mixture was repeatedly washed with ultrapure water until the supernatant was neutral. The filter cake was dried in a vacuum drying oven at 40-50 °C for 6-12 h to obtain the carboxylated hollow glass microspheres.

[0052] 4. Synthesis and end-capping of polyrotaxanes 4.1 Amino cyclodextrin (20 g) was dissolved in 400 mL of deionized water by stirring, and 0.78 g of PEG-20000 (carboxyl-terminated) was added. The mixture was stirred at 80 °C for 1 h and then stirred at room temperature for 12 h. The white powder was separated by filtration after the white powder was precipitated by cooling to 10 °C. The powder was washed twice with deionized water and dried in a vacuum drying oven at 60 °C for 2 h to obtain the amino-terminated polyrotaxane in the form of white powder.

[0053] 4.2 Amino-terminated polyrotaxane (10 g), adamantylamine hydrochloride (0.5 g), BOP (0.1 g), and N-ethyldiisopropylamine (DIPEA) (1.2 g) were dissolved in 50 mL of N,N-dimethylformamide. The mixture was stirred at 60 °C for 12 h under nitrogen protection, and then the mixture was placed in a refrigerator at 4 °C for 12 h. Anhydrous methanol was added until the white solid powder was precipitated. The white solid powder was separated, washed, and dried to obtain the amino-terminated polyrotaxane capped with adamantylamine.

[0054] 5. Coupling reaction After 20 g of the hollow glass microspheres modified with carboxyl groups were stirred and mixed in 100 g of water, 1 g of the amino-terminated polyrotaxane capped with adamantylamine was added, and 0.1 g of DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride) was added. The mixture was reacted at 40 °C for 6 h. After the mixture was filtered, washed, and dried, the hollow glass microspheres coated with polyrotaxanes were obtained.

[0055] Example 2 The hollow glass microsphere coated by the polyrotaxane of the embodiment is composed of a hollow glass microsphere core and a polyrotaxane coating layer, and the polyrotaxane coating layer is bonded to the surface of the hollow glass microsphere through an amide bond.

[0056] The preparation process of the hollow glass microsphere coated by the polyrotaxane of the embodiment is as follows: 1. Activation of the hollow glass microsphere: The hollow glass microsphere is placed in a 0.5M sodium hydroxide solution for activation treatment, the activation treatment temperature is 70°C, and the time is 2h. After that, the hollow glass microsphere is separated by suction filtration, then washed with deionized water until near neutral, and dried for standby use. 2. Amino-functionalization of the surface of the hollow glass microsphere: 3-aminopropyltriethoxysilane KH550, water, and ethanol are mixed uniformly according to a mass ratio of 1:0.2:5 to prepare an amino-silane coupling agent solution. The solution is atomized by a sprinkler or a spraying device and sprayed onto the surface of the activated hollow glass microsphere. The amount of the amino-silane coupling agent solution used for every 10g of the activated hollow glass microsphere is 0.5g. After the reaction in a dry modification machine at 60°C for 1h, the surface of the hollow glass microsphere is amino-functionalized.

[0057] 3. Carboxyl-functionalization of the surface of the hollow glass microsphere 10g of succinic anhydride is dissolved in 80ml of anhydrous DMF (N,N-dimethylformamide) to prepare a solution. 0.05g of ethylamine is added as a catalyst, and 25g of the surface amino-functionalized hollow glass microsphere is added. The reaction is carried out under nitrogen protection in a 40°C constant temperature water bath with mechanical stirring or ultrasonic reaction for 2h. The unreacted succinic anhydride is removed by washing with DMF twice, and then the filter cake is washed repeatedly with ultrapure water until the supernatant is neutral. The filter cake is dried at 60°C under vacuum for 6-12 hours to obtain the carboxyl-functionalized hollow glass microsphere.

[0058] 4. Synthesis and end-capping of the polyrotaxane: 4.1 15g of aminocyclodextrin is added to 400mL of deionized water and stirred to dissolve. 1.2g of PEG-35000 (carboxyl-terminated) is added, and the mixture is stirred at 80°C for 3 hours. Then the mixture is stirred at room temperature for 6 hours, and white powder is precipitated after cooling to 10°C. The white powder is then filtered, washed with deionized water twice, and dried in a vacuum drying oven at 60°C for 5 hours to obtain the aminofunctionalized polyrotaxane in the form of white powder.

[0059] 4.2 10 g of the amino-terminated polyrotaxane, 0.3 g of adamantylamine hydrochloride, 0.1 g of BOP and 0.8 g of N-ethyldiisopropylamine (DIPEA) were dissolved in 50 mL of N,N-dimethylformamide, stirred at 40°C for 3 hours under nitrogen protection, and then placed in a refrigerator at 4°C for 12 hours. Anhydrous methanol was added until white solid powder was precipitated. The white solid powder was separated, washed and dried to obtain the amino-terminated adamantane-terminated polyrotaxane.

[0060] 5. Coupling reaction After 20 g of the hollow glass microspheres with surface carboxyl groups were stirred and mixed in 100 g of water, 1 g of the amino-terminated adamantane-terminated polyrotaxane was added, and 0.1 g of DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride) was added. The reaction was carried out at 25°C for 12 hours. After filtration, washing and drying, the hollow glass microspheres coated with polyrotaxane were obtained.

[0061] (B) Preferred embodiment of the high-toughness hollow glass microsphere composite material On the basis of the hollow glass microspheres coated with polyrotaxane described above, the hollow glass microspheres coated with polyrotaxane can be added as fillers to the matrix material in a conventional manner to form a composite material.

[0062] The matrix material herein can be rubber, plastic, etc., such as polyethylene, polypropylene, epoxy resin, etc.

[0063] The composite material added with the hollow glass microspheres coated with polyrotaxane described above can organically combine the sliding ring effect of polyrotaxane and the light weight and rigidity characteristics of hollow glass microspheres, avoid the breakage of hollow glass microspheres during material processing, and make the formed material have high toughness.

[0064] The following will be illustrated by specific examples.

[0065] Example 3 The high-toughness hollow glass microsphere composite material of this example is a polypropylene composite material, which is composed of a polypropylene matrix (Ningbo Fude T30S) and hollow glass microspheres coated with polyrotaxane dispersed in the polypropylene matrix. The specific manufacturing process is described as follows: The polypropylene and 10% of the polyrotaxane-coated hollow glass microspheres of Example 1 by mass of the polypropylene were mixed, extruded by a double screw extruder, and then injection molded to obtain the polypropylene composite material.

[0066] (III) Experimental examples The hollow glass microspheres treated in different ways were made into standard samples according to the method of Example 2, and then the tensile strength, tensile modulus, bending strength, bending modulus and IZOD notched impact strength were tested. The test results are shown in Table 1 below.

[0067] In Table 1, #1 microbeads are the original HL50 sample; #2 microbeads are KH550 coupling agent microbeads (the same product obtained in step 2 of Example 1); #3 is the polyrotaxane-coated hollow glass microbeads HL50 from Example 1. HL50 is a commercially available product manufactured by Zhengzhou Shenglet Hollow Microbead New Material Co., Ltd.

[0068] SEM images of microbeads #1, #2, and #3 are shown below. Figs. 1-3 As shown. By Figs. 1-3 It can be seen that the surface of the original microspheres (microsphere #1) is relatively smooth. After modification with KH550, the surface roughness of microsphere #2 increased significantly. After polyrotaxane coating modification, the surface of microsphere #3 changed significantly compared with microspheres #1 and #2. The entire polyrotaxane coating layer is uniformly and densely distributed, creating favorable conditions for composite with the matrix material.

[0069] Table 1 Performance test results of PP composite materials based on hollow glass microspheres with different treatments

[0070] As shown in Table 1, the composite materials of polyrotaxane-coated hollow glass microspheres based on the examples exhibit similar lightweighting effects at the same dosage, but tensile strength, tensile modulus, flexural strength, flexural modulus, and IZOD notched impact strength are all significantly improved. Notably, the IZOD notched impact strength of the product with added conventional hollow glass microspheres drops sharply, indicating a significant decrease in the impact resistance of the composite material. Modification of the microspheres with the conventional coupling agent KH550 has virtually no effect on improvement, while the polyrotaxane-coated hollow glass microspheres of Example 1 effectively improve impact resistance, achieving an impact resistance level comparable to that of the original PP.

[0071] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polyrotaxane-coated modified hollow glass microsphere, characterized by, The hollow glass microsphere comprises a hollow glass microsphere core and a coating layer bonded to the hollow glass microsphere core; the coating layer is a polyrotaxane formed by polyethylene glycol and aminocyclo-dextrin and terminated by adamantane groups.

2. The polyrotaxane-coated modified hollow glass microsphere according to claim 1, wherein The bonding is formed by coupling reaction of carboxyl groups on the surface carboxyl-modified hollow glass microspheres and amino groups on the polyrotaxane.

3. The polyhedral oligomeric silsesquixane-coated modified hollow glass microsphere of claim 1, wherein the hollow glass microsphere has a diameter of 1 to 100 micrometers. The polyrotaxane-coated modified hollow glass microspheres are prepared by a method comprising the following steps: (1) mixing polyethylene glycol and aminocyclo-dextrin to prepare an aminated quasi-polyrotaxane; (2) using adamantane to terminate the aminated quasi-polyrotaxane to prepare an aminated adamantane-terminated polyrotaxane; (3) coupling reaction of the aminated adamantane-terminated polyrotaxane and the surface carboxyl-modified hollow glass microspheres.

4. The polyrotaxane-coated modified hollow glass microspheres as described in claim 3, characterized in that, In step (1), 15-20 g of aminocyclo-dextrin corresponds to 0.7-1.2 g of polyethylene glycol; the mixing reaction is first reacted at 80-85°C for 1-3 h, and then stirred at room temperature for 6-12 h.

5. The polyhedral oligomeric silsesquixane-coated modified hollow glass microsphere of claim 3, wherein the hollow glass microsphere has a diameter of 1 to 100 micrometers. In step (3), 20-25 g of the surface carboxyl-modified hollow glass microspheres corresponds to 1 g of the aminated adamantane-terminated polyrotaxane.

6. The polyhedral oligomeric silsesquixane-coated hollow glass microspheres of claim 2 or 3, wherein the hollow glass microspheres have a diameter of 1 to 100 microns. The surface carboxyl-modified hollow glass microspheres are prepared by a method comprising the following steps: S1. activating hollow glass microspheres in a lye to obtain activated hollow glass microspheres; S2. surface modification of the activated hollow glass microspheres using an aminosilane coupling agent to obtain surface aminated-modified hollow glass microspheres; S3. reaction of the surface aminated-modified hollow glass microspheres and an acid anhydride to obtain surface carboxyl-modified hollow glass microspheres.

7. The polyhedral oligomeric silsesquixane-coated modified hollow glass microsphere of claim 6, wherein the hollow glass microsphere has a diameter of 1 to 100 microns. In step S2, the aminosilane coupling agent, water and ethanol are mixed in a mass ratio of 1: (0.2-0.3): (4-5) to obtain a silane coupling agent solution; the silane coupling agent solution and the activated hollow glass microspheres are mixed in a mass ratio of (0.5-1):10 and reacted at 60-80°C for 1-2 h.

8. The polyhedral oligomeric silsesquixane-coated modified hollow glass microsphere of claim 6, wherein the hollow glass microsphere has a diameter of 1 to 100 microns. In step S3, the reaction uses succinic anhydride, and 10-12 g of succinic anhydride corresponds to 25 g of the surface aminated-modified hollow glass microspheres.

9. A high-toughness hollow glass microsphere composite material, characterized by, The resin matrix is selected from one of polyethylene, polypropylene and epoxy resin.

10. The high-toughness hollow glass microsphere composite material according to claim 9, wherein, The resin matrix is selected from one of polyethylene, polypropylene and epoxy resin.

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