Hydroxyapatite-modified polyurethane elastomer having excellent mechanical strength and method for preparing the same

Abstract

The present application relates to a kind of hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and its preparation method, belong to polyurethane technical field.The polyurethane elastomer is cured by mixing component A and component B and is formed;With the total mass of raw material for preparing the A component 100%, each raw material component and its mass fraction are as follows: diisocyanate 44%~50%, polyglycol 50%~56%;With the total mass of raw material for preparing the B component 100%, each raw material component and its mass fraction are as follows: polyglycol 70%~76%, polyether 330N polyol 18%~21%, diol chain extender 5%~8%, A174 modified hydroxyapatite (HAP / A174) 0.2%~2%.The introduction of HAP / A174 in polyurethane elastomer can significantly improve its impact resistance and mechanical properties.In addition, the surface of HAP is modified by silane coupling agent A174, and A174 modification can provide the opportunity to increase the interface interaction of polyurethane and HAP / A174, so as to obtain polyurethane elastomer with high mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof, and belongs to the technical field of polyurethane. BACKGROUND

[0002] Polyurethane material is an elastomer formed by block of soft segment and hard segment. Since the polyurethane material has excellent mechanical properties, good processability and high dimensional stability, it has been widely used in different kinds of applications (waterproofing, coating, transportation, food processing and packaging, etc.). However, the polyurethane elastomer also has some shortcomings. For example, the polyurethane elastomer still has poor impact resistance under high-speed impact, and cracking occurs. At present, there are few studies on high-impact-resistant polyurethane elastomer materials, which also limits the application of polyurethane materials in the impact-resistant field.

[0003] In order to expand the application range of polyurethane materials and improve the mechanical and impact resistance properties of polyurethane, fillers are added to the polyurethane material. Through the full contact of the added fillers with the polyurethane segments, physical and chemical changes are produced, the interfacial strength is increased, and the mechanical properties and impact resistance effect of the polyurethane material are improved, so as to effectively avoid the damage caused by impact.

[0004] Hydroxyapatite (HAP) is a natural bioceramic material, and its molecular formula is Ca 10 (PO4)6(OH)2, and its main components are calcium hydroxide and calcium phosphate, which have excellent strength and hardness. It is widely used for preparing bone repair composite scaffolds, and the scaffold doped with HAP has higher mechanical properties. The unique structure and hardness of hydroxyapatite make it a popular research object of high-performance impact-resistant materials in recent years. It is known that there are adhesion and dispersion problems between polymer and ceramic composite materials, which cause the interfacial failure between polyurethane and ceramic materials and hinder the application. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows.

[0007] A hydroxyapatite modified polyurethane elastomer with excellent mechanical strength, wherein the polyurethane elastomer is formed by mixing and curing the A component and the B component;

[0008] Taking the total mass of the raw materials for preparing the A component as 100%, the components and their mass fractions are as follows: diisocyanate 44% to 50%, polyglycol 50% to 56%;

[0009] The raw material components and their mass fractions, based on the total mass of the raw materials for preparing the B component being 100%, are as follows: polyhydric alcohol 70% to 76%, polyether 330N polyol 18% to 21%, diol chain extender 5% to 8%, and A174 modified hydroxyapatite (HAP / A174) 0.2% to 2%;

[0010] The molar ratio of the active -H contained in the B component to the -NCO groups contained in the A component is 1:1.04 to 1:1.06.

[0011] Preferably, the mass fraction of the A174 modified hydroxyapatite in the B component is 0.2% to 1%.

[0012] Preferably, the polyhydric alcohol is one or more of polytetrahydrofuran ether diol (PTMG), polyethylene glycol (PEG), and polytetramethylene glycol (PTD).

[0013] Preferably, the molecular weight of the polyhydric alcohol is 1860 to 2100.

[0014] Preferably, the diisocyanate is one or more of p-phenylene diisocyanate (PPDI), diphenyl methane diisocyanate (MDI), and toluene diisocyanate (TDI).

[0015] Preferably, the diol chain extender is one or more of 1,4-butanediol (BDO), 1,4-cyclohexanediol (PCHC), and 1,5-pentanediol (PTDO).

[0016] Preferably, the molecular weight of the polyether 330N polyol is 4750 to 5000.

[0017] Preferably, the hydroxyapatite has a spherical structure and a particle size of 100 nm to 200 nm.

[0018] Preferably, the A174 modified hydroxyapatite is prepared by the following method: HAP is added to a mixed solution of ethanol and water and stirred for 10 to 20 minutes, hydrochloric acid solution is used to adjust the pH to 3.5 to 4 and mixed for more than 1 hour; silane coupling agent A174 is added under an inert gas atmosphere and mixed for more than 1 hour, and then dried at 70°C to obtain A174 modified hydroxyapatite (HAP / A174); the addition amount of the silane coupling agent A174 is 2 wt% to 3 wt% of the HAP. The A174 modified hydroxyapatite is dried and stored.

[0019] A hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof, the method steps comprising:

[0020] (1) under vacuum gas protection, mixing raw materials of diisocyanate and polyglycol of A component, heating to 78-85℃, stirring for 4-5h, cooling to obtain viscous polyurethane prepolymer, i.e. A component;

[0021] (2) mixing A component and B component uniformly, pouring into mold, curing for 2-3h at 70-80℃ to obtain hydroxyapatite modified polyurethane elastomer with excellent mechanical strength;

[0022] Preferably, polyglycol, polyether 330N polyol and diol chain extender in B component all need to be dehydrated at 105-110℃ under vacuum condition.

[0023] Preferably, in step (2), mixing preheated A component polyurethane prepolymer and B component raw materials, stirring at a speed of 1000-3000r / min for 10-20s, and then pouring into polytetrafluoroethylene mold.

[0024] Beneficial effects

[0025] The application provides a hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof. The introduction of HAP / A174 into the polyurethane elastomer can obviously improve the impact resistance and mechanical properties. In addition, the surface of HAP is modified by silane coupling agent A174, and the A174 modification can provide the opportunity to increase the interfacial interaction between the polyurethane and HAP / A174, so as to obtain the polyurethane elastomer with high mechanical properties. The physical crosslinking network is generated between HAP / A174 and the polyurethane matrix, the interfacial strength is enhanced, and thus the mechanical strength and impact resistance of the polyurethane elastomer are effectively improved. The introduction of HAP / A174 increases the Si-O-P bond of the nanocomposite, can effectively contact and bond the composite, increase the friction and thus hinder the molecular chain segment from dissipating more heat, and improve the macroscopic properties of the material.

[0026] The application provides a hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof. The polyurethane elastomer is obtained by mixing and curing A and B components. The mass fraction of each raw material in A and B components needs to be set to ensure that the content of -NCO groups in the polyurethane is slightly more than that of -OH groups, so that the mechanical properties and deformation capacity of the polyurethane are guaranteed. Too much isocyanate content will lead to difficulty in forming the polyurethane structure, accelerate the polymerization and curing in the mixing process, and the polyurethane elastomer cannot be obtained; too much hydroxyl in the main raw materials will lead to increased viscosity in the material mixing process, and the mechanical properties of the prepared polyurethane are reduced.

[0027] The present application provides a hydroxyapatite modified polyurethane elastomer with excellent mechanical strength and a preparation method thereof. The polyurethane elastomer with HAP / A174 added when mixing components A and B is a key step for improving the mechanical properties of the polyurethane elastomer. Experiments show that the mechanical properties of the polyurethane composite prepared by adding HAP / A174 when mixing components A and B are significantly better than those of the polyurethane elastomer prepared by using the semi-prepolymer method to obtain component A. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The infrared spectra of HAP and HAP / A174.

[0029] Figure 2 The mechanical property test results of the polyurethane elastomers described in the examples and comparative examples.

[0030] Figure 3 The Hopkinson bar test results of the polyurethane elastomers described in the examples and comparative examples.

[0031] Figure 4 The damping performance test results of the polyurethane elastomers described in the examples and comparative examples. DETAILED DESCRIPTION

[0032] The present application will be further described in detail below with specific examples.

[0033] Example 1

[0034] In this embodiment, the molecular weight of polytetrahydrofuran ether diol is 1960, and the molecular weight of polyether 330N polyol is 4800.

[0035] (1) HAP was mixed with an ethanol solution (Vethanol:Vwater=9:1) at room temperature for 15 minutes. The PH was adjusted to 3.5-4 with a hydrochloric acid solution of PH=1, and stirred at room temperature for 1 h. Under inert conditions, 0.45 ml of silane A174 was added to the beaker and mixed for 1 h. Then, the mixture was poured into a polytetrafluoroethylene mold and dried at 70℃ to obtain A174 modified hydroxyapatite (HAP / A174).

[0036] (2) 54.05 g of polytetrahydrofuran ether diol and 45.12 g of diphenyl methane diisocyanate were added to a 250 mL three-necked flask and heated to 82℃. The raw materials were stirred at a speed of 200 r / min to mix uniformly, and the reaction was carried out for 4 h to obtain a polyurethane prepolymer.

[0037] Take 0.3143g of the prepolymer solution in 25mL of isopropanol solution, heated in a water bath for 15min in the environment of 48℃ to make it fully reacted, drop 5 drops of bromocresol blue indicator, then add 25mL of di-n-butylamine in toluene solution to completely dissolve the indicator; using 0.1022mol / L of dilute hydrochloric acid titration to obtain the isocyanate content of 12.51% in the prepolymer;

[0038] The ratio of the mass of the acidic non-water-soluble bromocresol blue in the bromocresol blue indicator (g) to the volume of the solvent sodium hydroxide (mL) is 1:1000, and the concentration of the sodium hydroxide is 0.1mol / L.

[0039] (3) At room temperature, 36.04g of polytetrahydrofuran ether glycol, 10.02g of polyether 330N polyol, 3.77g of 1,4-butanediol and 0.3g of HAP / A174 were sequentially added to the container, then 44.28g of the prepolymer in step (2) was added, and stirred at a stirring rate of 2000r / min for 18s; poured into a container of polytetrafluoroethylene, and placed in an oven at 70℃ for curing for 3h to obtain a polyurethane elastomer with a mass fraction of HAP / A174 of 0.3% (denoted as 0.3% HAP / A174).

[0040] Example 2

[0041] In this embodiment, the molecular weight of the polytetrahydrofuran ether glycol is 1960, and the molecular weight of the polyether 330N polyol is 4800.

[0042] (1) HAP was mixed with ethanol solution (Vethanol:Vwater=9:1) at room temperature for 15 minutes. The PH was adjusted to 3.5-4 with a hydrochloric acid solution of PH=1, and stirred at room temperature for 1h. Under inert conditions, 0.45ml of silane A174 was added to the beaker and mixed for 1h. Then, the mixture was poured into a polytetrafluoroethylene mold and dried at 70℃ to obtain A174 modified hydroxyapatite (HAP / A174).

[0043] (2) 54.05g of polytetrahydrofuran ether glycol and 45.12g of diphenyl methane diisocyanate were added to a 250mL three-necked flask, and the raw materials were stirred at a rate of 200r / min to make them uniformly mixed, and the polyurethane prepolymer was obtained after reacting for 4h;

[0044] Take 0.3143g of the prepolymer solution in 25mL of isopropanol solution, heated in a water bath for 15min in the environment of 48℃ to make it fully reacted, drop 5 drops of bromocresol blue indicator, then add 25mL of di-n-butylamine in toluene solution to completely dissolve the indicator; using 0.1022mol / L of dilute hydrochloric acid titration to obtain the isocyanate content of 12.51% in the prepolymer;

[0045] The ratio of the mass (g) of acidic non-water-soluble bromocresol blue in the bromocresol blue indicator and the volume (mL) of the solvent sodium hydroxide is 1:1000, and the concentration of the sodium hydroxide is 0.1 mol / L.

[0046] (3) At room temperature, 36.12 g of polytetrahydrofuran ether glycol, 10.03 g of polyether 330N polyol, 3.75 g of 1,4-butanediol, and 0.475 g of HAP / A174 were sequentially added to the container, followed by the addition of 44.13 g of the prepolymer in step (2), and stirring at a stirring rate of 2000 r / min for 18 s; pouring into a container of polytetrafluoroethylene, and placing in an oven at 70°C for 3 h of curing to obtain a polyurethane elastomer with a mass fraction of HAP / A174 of 0.5% (denoted as 0.5% HAP / A174).

[0047] Example 3

[0048] In this embodiment, the molecular weight of the polytetrahydrofuran ether glycol is 1960, and the molecular weight of the polyether 330N polyol is 4800.

[0049] (1) HAP was mixed with an ethanol solution (Vethanol:Vwater = 9:1) at room temperature for 15 minutes at an ethanol:HAP ratio of 10 mL:5 g. The PH was adjusted to 3.5-4 with a hydrochloric acid solution of PH = 1, and stirred at room temperature for 1 h. Under inert conditions, 0.45 ml of silane A-174 was added to the beaker and mixed for 1 h. Then, the mixture was poured into a polytetrafluoroethylene mold and dried at 70°C to obtain A174-modified hydroxyapatite (HAP / A174).

[0050] (2) 54.05 g of polytetrahydrofuran ether glycol and 45.12 g of diphenyl methane diisocyanate were added to a 250 mL three-necked flask, and the raw materials were stirred at a rate of 200 r / min to mix them uniformly, and the reaction was carried out for 4 h to obtain a polyurethane prepolymer;

[0051] 0.3143 g of the prepolymer was dissolved in 25 mL of isopropyl alcohol solution, and heated in a water bath at 48°C for 15 min to fully react. After adding 5 drops of bromocresol blue indicator, 25 mL of di-n-butylamine in toluene was added to completely dissolve the indicator; using 0.1022 mol / L of dilute hydrochloric acid for titration, it was found that the isocyanate content in the prepolymer was 12.51%;

[0052] The ratio of the mass (g) of acidic non-water-soluble bromocresol blue in the bromocresol blue indicator and the volume (mL) of the solvent sodium hydroxide is 1:1000, and the concentration of the sodium hydroxide is 0.1 mol / L.

[0053] (3) At room temperature, 36.06 g of polytetramethylene ether glycol, 10.12 g of polyether 330N polyol, 3.79 g of 1,4-butanediol, and 0.95 g of HAP / A174 were sequentially added to a container, followed by the addition of 44.32 g of the prepolymer in step (2), which was stirred at a stirring rate of 2000 r / min for 18 s; poured into a container of polytetrafluoroethylene, and placed in an oven at 70°C for curing for 3 h to obtain a polyurethane elastomer with a mass fraction of 1% of HAP / A174 (denoted as 1% HAP / A174).

[0054] Comparative Example 1

[0055] In the present comparative example, the molecular weight of the polytetramethylene ether glycol was 1960, and the molecular weight of the polyether 330N polyol was 4800.

[0056] (1) 54.03 g of polytetramethylene ether glycol and 45.02 g of diphenylmethane diisocyanate were added to a 250 mL three-necked flask, and the raw materials were uniformly mixed by stirring at a rate of 200 r / min while being heated to 82°C, and a polyurethane prepolymer was obtained after 4 h of reaction;

[0057] 0.3115 g of the prepolymer was dissolved in 25 mL of an isopropanol solution, and heated in a water bath at 48°C for 15 min to fully react. After 5 drops of bromocresol blue indicator were added, 25 mL of a toluene solution of di-n-butylamine was added to completely dissolve the indicator. Titration with 0.1022 mol / L dilute hydrochloric acid showed that the isocyanate content in the prepolymer was 12.33%;

[0058] The ratio of the mass (g) of acidic water-insoluble bromocresol blue in the bromocresol blue indicator to the volume (mL) of the solvent sodium hydroxide was 1:1000, and the concentration of the sodium hydroxide was 0.1 mol / L.

[0059] (2) At room temperature, 36.12 g of polytetramethylene ether glycol, 10.05 g of polyether 330N polyol, and 3.74 g of 1,4-butanediol were sequentially added to a container, followed by the addition of 44.37 g of the prepolymer in step (1), which was stirred at a stirring rate of 2000 r / min for 18 s; poured into a container of polytetrafluoroethylene, and placed in an oven at 70°C for curing for 3 h to obtain a polyurethane elastomer blank (denoted as PU).

[0060] Comparative Example 2

[0061] In the present comparative example, the molecular weight of the polytetramethylene ether glycol was 1960, and the molecular weight of the polyether 330N polyol was 4800.

[0062] (1) 54.03 g of polytetrahydrofuran ether glycol and 45.08 g of diphenyl methane diisocyanate were added into a 250 mL three-necked flask, and the raw materials were stirred at a speed of 200 r / min to mix them uniformly, and the polyurethane prepolymer was obtained after 4 h of reaction at a temperature of 82°C;

[0063] 0.3205 g of the prepolymer was dissolved in 25 mL of isopropyl alcohol solution, and heated in a water bath at 48°C for 15 min to fully react. After 5 drops of bromocresol blue indicator were added, 25 mL of di-n-butylamine toluene solution was added to completely dissolve the indicator. Titration was performed using 0.1022 mol / L dilute hydrochloric acid, and the isocyanate content in the prepolymer was determined to be 12.64%.

[0064] The ratio of the mass (g) of acidic water-insoluble bromocresol blue in the bromocresol blue indicator to the volume (mL) of solvent sodium hydroxide was 1:1000, and the concentration of the sodium hydroxide was 0.1 mol / L.

[0065] (2) At room temperature, 36.14 g of polytetrahydrofuran ether glycol, 10.03 g of polyether 330N polyol, 3.76 g of 1,4-butanediol, and 0.475 g of HAP were sequentially added into a container, and 44.17 g of the prepolymer in step (1) was added. The mixture was stirred at a speed of 2000 r / min for 18 s. The mixture was poured into a container of polytetrafluoroethylene, and placed in an oven at 70°C for 3 h to solidify, thereby obtaining a polyurethane elastomer comparative sample (denoted as 0.5% HAP) with a mass fraction of HAP of 0.5%.

[0066] Comparative Example 3

[0067] In this comparative example, the molecular weight of the polytetrahydrofuran ether glycol was 1960, and the molecular weight of the polyether 330N polyol was 4800.

[0068] (1) 54.01 g of polytetrahydrofuran ether glycol, 45.13 g of diphenyl methane diisocyanate, and 2.332 g of HAP / A174 were added into a 250 mL three-necked flask, and the raw materials were stirred at a speed of 200 r / min to mix them uniformly, and the polyurethane prepolymer was obtained after 4 h of reaction at a temperature of 82°C;

[0069] 0.3102 g of the prepolymer was dissolved in 25 mL of isopropyl alcohol solution, and heated in a water bath at 48°C for 15 min to fully react. After 5 drops of bromocresol blue indicator were added, 25 mL of di-n-butylamine toluene solution was added to completely dissolve the indicator. Titration was performed using 0.1012 mol / L dilute hydrochloric acid, and the isocyanate content in the prepolymer was determined to be 12.34%.

[0070] The ratio of the mass (g) of acidic non-water-soluble bromocresol blue in the bromocresol blue indicator and the volume (mL) of the solvent sodium hydroxide is 1:1000, and the concentration of the sodium hydroxide is 0.1 mol / L.

[0071] (2) At room temperature, 36.14 g of polytetrahydrofuran ether glycol, 10.03 g of polyether 330N polyol, and 3.76 g of 1,4-butanediol were sequentially added to the container, followed by 44.34 g of the prepolymer in step (1), and stirred at a stirring rate of 2000 r / min for 18 s; poured into a container of polytetrafluoroethylene, and placed in an oven at 70°C for 3 h to solidify, to obtain a polyurethane elastomer of HAP / A174 mass fraction 0.5% prepared by the semi-prepolymer method (denoted as Y-HAP / A174).

[0072] Comparative Example 4

[0073] In the present comparative example, the molecular weight of the polytetrahydrofuran ether glycol is 1960, and the molecular weight of the polyether 330N polyol is 4800.

[0074] (1) HAP was stirred with an ethanol solution (Vethanol:Vwater = 9:1) at room temperature for 15 minutes at a ratio of 2:1 of ethanol (10 mL):HAP (5 g). The PH was adjusted to 3.5-4 with a hydrochloric acid solution of PH = 1, and stirred at room temperature for 1 h. Under inert conditions, 0.45 ml of silane KH550 was added to the beaker and mixed for 1 h. Then, the mixture was poured into a polytetrafluoroethylene mold and dried at 70°C to obtain KH550 modified hydroxyapatite (HAP / KH550).

[0075] (2) 54.05 g of polytetrahydrofuran ether glycol and 45.12 g of diphenyl methane diisocyanate were added to a 250 mL three-necked flask, and the raw materials were stirred at a rate of 200 r / min to mix uniformly, and the reaction was carried out for 4 h to obtain a polyurethane prepolymer;

[0076] 0.3143 g of the prepolymer was dissolved in 25 mL of isopropyl alcohol solution, heated in a water bath at 48°C for 15 min to fully react, 5 drops of bromocresol blue indicator were added, and then 25 mL of di-n-butylamine toluene solution was added to completely dissolve the indicator; using 0.1022 mol / L of dilute hydrochloric acid for titration, it was found that the isocyanate content in the prepolymer was 12.51%;

[0077] The ratio of the mass (g) of acidic non-water-soluble bromocresol blue in the bromocresol blue indicator and the volume (mL) of the solvent sodium hydroxide is 1:1000, and the concentration of the sodium hydroxide is 0.1 mol / L.

[0078] (3) At room temperature, 36.12 g of polytetrahydrofuran ether glycol, 10.03 g of polyether 330N polyol, 3.75 g of 1,4-butanediol and 0.475 g of HAP / KH550 were sequentially added into the container, and then 44.13 g of the prepolymer in step (2) was added, and stirred at a stirring rate of 2000 r / min for 18 s; poured into a container of polytetrafluoroethylene, and placed in an oven at 70°C for 3 h to solidify, to obtain a polyurethane elastomer with a mass fraction of 0.5% of HAP / KH550 (denoted as 0.5% HAP / KH550).

[0079] The final products prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to tensile testing, under the premise of using a 500N mechanical sensor, the size of the test sample was selected to be a small test sample of 5mm x 100mm, and the test was carried out at a tensile rate of 500mm / min, and the results are shown in Table 1. Figure 2 The tensile strength of the polyurethane elastomer blank sample in Comparative Example 1 was 14.45 MPa, and the elongation at break was 523.67%. The mechanical properties of the polyurethane elastomer comparative sample with a mass fraction of 0.5% of HAP in Comparative Example 2 were about 22 MPa; the mechanical properties of the polyurethane elastomer comparative sample with a mass fraction of 0.5% of HAP / A174 prepared by prepolymer method in Comparative Example 3 were about 25 MPa, and the mechanical properties of the polyurethane elastomer comparative sample with a mass fraction of 0.5% of HAP / KH550 in Comparative Example 4 were about 29 MPa; while the mechanical properties of the polyurethane elastomers obtained in Examples 1-3 were significantly increased, the average stress of Example 2 was about 38 MPa, and the elongation at break was 1589.34%, which was significantly increased compared with the tensile strength of the polyurethane elastomer blank sample, and the elongation at break was increased by about 2.4 times; it shows that the modified HAP of A174 added into the polyurethane improves the compatibility, the interfacial interaction is enhanced, more physical crosslinking and chemical bonds are produced, and the mechanical properties are significantly improved.

[0080] The final products prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to impact testing using a Hopkinson bar, and it was found that the polyurethane elastomers showed different impact results when the prepared elastomers were impacted at a strain rate of 11000 / S, as shown in Table 2. Figure 3As shown, the average stress of the blank polyurethane elastomer sample was around 10 MPa; the average stress of the polyurethane elastomer with added HAP under impact was around 14 MPa; the average stress of the polyurethane elastomer with added HAP / A174 prepared by the prepolymer method was slightly increased due to the increase of Si-OP bonds, reaching around 18 MPa; the average stress of the polyurethane with HAP modified by KH550 was 15 MPa, but the sample showed a fragmented appearance; while the polyurethane with added HAP / A174 by the mixing method remained unchanged under impact, and the average stress was significantly increased to around 30 MPa. This shows that the addition of HAP / A174 filler and polyurethane matrix generated strong bond energy, thus significantly improving the impact resistance of polyurethane elastomer.

[0081] The damping behavior of composite materials is generally attributed to frictional motion at the filler-matrix interface, which significantly affects the energy dissipation of the composite material under external forces. DMA testing was performed on the final products prepared in Examples 1-3 and Comparative Examples 1-4 using compression testing. Figure 4 As shown, the damping coefficients of the composite materials with added fillers decreased to varying degrees, but the glass transition temperature (Tg) increased significantly. This indicates that adding fillers to the PU matrix increased the friction between the matrices, resulting in a more significant dissipation effect under stress. Increased interfacial bonding strength increased the rigidity of the composite material, increased the resistance to inter-segment sliding, leading to a decrease in tanδ and an increase in Tg. Among them, the damping temperature range of the polyurethane elastomer with 0.5% HAP / A174 increased from -59.935℃ to -39.335℃ to -43.389℃ to -27.026℃, showing the most significant rightward shift, and the glass transition temperature increased the most. This indicates that adding HAP / A174 to the polyurethane increased the friction between the matrices, resulting in a more significant dissipation effect under stress. The polyurethane elastomer with HAP / A174 has enhanced interfacial bonding strength, improved its resistance to intermolecular slippage, and has more steric hindrance, which is significantly enhanced compared to PU and HAP / PU. Specific results are shown in Tables 1-3.

[0082] Table 1. Mechanical property test results

[0083]

[0084] Table 2 Impact resistance test results

[0085]

[0086] Table 3 Damping performance test results

[0087]

[0088] In conclusion, the invention includes but is not limited to the embodiments described above, any equivalents thereto or modifications made thereon, which come within the scope of the invention as defined by the following claims.

Claims

1. A hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength, characterized in that: The polyurethane elastomer is formed by mixing and curing components A and B. Based on the total mass of the raw materials used to prepare component A as 100%, the components and their mass fractions are as follows: diisocyanate 44%~50%, polydiol 50%~56%; Based on the total mass of the raw materials used to prepare component B as 100%, the components and their mass fractions are as follows: polydiol 70%~76%, polyether 330N polyol 18%~21%, diol chain extender 5%~8%, A174 modified hydroxyapatite 0.2%~2%; The molar ratio of the active -OH group in component B to the -NCO group in component A is 1:1.04 to 1:1.

06. The polydiol is one or more of polytetrahydrofuran ether diol, polyethylene glycol, and polypentyl glycol; the molecular weight of the polydiol is 1860-2100. The diisocyanate is one or more of terephthalic diisocyanate, diphenylmethane diisocyanate and toluene diisocyanate; The diol chain extender is one or more of 1,4-butanediol, 1,4-cyclohexanediol, and 1,5-pentanediol; The molecular weight of the polyether 330N polyol is 4750~5000; The A174-modified hydroxyapatite was prepared by the following method: HAP was added to a mixed solution of ethanol and water and stirred for 10-20 minutes, the pH was adjusted to 3.5-4 with hydrochloric acid solution and mixed for more than 1 hour; silane coupling agent A174 was added under an inert gas atmosphere and mixed for more than 1 hour, and then dried at 70°C to obtain A174-modified hydroxyapatite; the amount of silane coupling agent A174 added was 2wt%-3wt% of HAP.

2. The hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength as described in claim 1, characterized in that: The mass fraction of A174 modified hydroxyapatite in component B is 0.2%~1%.

3. The hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength as described in claim 1, characterized in that: The hydroxyapatite has a spherical structure with a particle size of 100 nm to 200 nm.

4. A method for preparing a hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength as described in any one of claims 1 to 3, characterized in that: The method steps include: (1) Under vacuum gas protection, the raw materials diisocyanate and polydiol of component A are mixed, heated to 78~85℃, stirred and reacted for 4~5h, and cooled to obtain viscous polyurethane prepolymer, i.e. component A; (2) After mixing components A and B evenly, pour the mixture into a mold and cure it at 70~80℃ for 2~3h to obtain a hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength.

5. The method for preparing the hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength as described in claim 4, characterized in that: The polydiol, polyether 330N polyol, and diol chain extender in component B all need to be dehydrated under vacuum conditions at 105~110℃.

6. The method for preparing the hydroxyapatite-modified polyurethane elastomer with excellent mechanical strength as described in claim 4, characterized in that: In step (2), the preheated polyurethane prepolymer of component A and raw material of component B are mixed and stirred at a speed of 1000~3000r / min for 10~20s, and then poured into a polytetrafluoroethylene mold.

Images