Shock absorber buffer block containing high-strength polyurethane composite material and preparation method

Abstract

The invention relates to the technical field of high polymer materials, and discloses a shock absorber buffer block containing a high-strength polyurethane composite material and a preparation method. The shock absorber buffer block is prepared from the following raw materials in parts by weight: 100 parts of polyether polyol, 5-10 parts of DOPO-based magnolol, 2-4 parts of silicone oil, 3-5 parts of a catalyst, 1-2 parts of deionized water, 10-20 parts of a solvent, 100-120 parts of an isocyanate curing agent and 2-5 parts of isocyanate modified attapulgite, and the raw materials are uniformly mixed to obtain the shock absorber buffer block. According to the preparation method, DOPO-based magnolol is prepared, more hydroxyl groups in the DOPO-based magnolol can generate higher cross-linking density during curing, the mechanical property of the buffer block is improved, a DOPO flame-retardant structure in the DOPO-based magnolol and attapulgite form an organic-inorganic synergistic flame-retardant structure, the flame-retardant property of the buffer block is improved, and the impact resistance of the buffer block is improved. And the flame retardant property of the buffer block is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high polymer materials, in particular to a shock absorber bumper block containing high-strength polyurethane composite material and a preparation method. BACKGROUND

[0002] The shock absorber bumper block is mainly applied in the automobile industry, and its main function is to serve as a buffer when the shock absorber stroke reaches the limit (for example, when the vehicle passes through a large pit, experiences severe bumps or causes the vehicle body to greatly pitch due to emergency braking), and it is severely compressed to serve as a "last line of defense" to prevent rigid collision of metal parts (piston rod and bottom of the oil cylinder) and thus protect the shock absorber assembly and the vehicle body structure. If the strength is insufficient, the bumper block will be crushed or permanently deformed, losing the buffering function. Modern high-performance bumper blocks usually use polyurethane material, which has excellent mechanical strength and wear resistance, but poor flame retardant performance, which can endanger people's lives and property safety.

[0003] Patent CN 119219885 A discloses a high-strength polyurethane foaming material and a preparation method thereof, which solves the problems of poor strength and wear resistance of the polyurethane foaming material, but does not improve the flame retardant performance. SUMMARY

[0004] (I) Technical problems solved

[0005] In view of the deficiencies of the prior art, the application provides a shock absorber bumper block containing high-strength polyurethane composite material and a preparation method, and the prepared shock absorber bumper block has excellent strength and flame retardant performance.

[0006] (II) Technical solutions

[0007] A shock absorber bumper block containing high-strength polyurethane composite material, which is composed of the following raw materials in parts by weight: 100 parts by weight of polyether polyol, 5-10 parts by weight of DOPO-based magnolia officinalis phenol, 2-4 parts by weight of silicone oil, 3-5 parts by weight of catalyst, 1-2 parts by weight of deionized water, 10-20 parts by weight of solvent, 100-120 parts by weight of isocyanate curing agent, and 2-5 parts by weight of isocyanate modified attapulgite.

[0008] The preparation method of the shock absorber bumper block comprises the following preparation steps:

[0009] Polyether polyol, DOPO-based magnolol, silicone oil, catalyst, deionized water and solvent are stirred and mixed uniformly to obtain A component; isocyanate curing agent, isocyanate modified attapulgite are stirred uniformly to obtain B component; A component and B component are stirred and mixed uniformly, placed in a mold to foam, after the foam is formed, first placed in an oven at 80℃ for 4h, then heated to 120℃ for 2-4h, cut into shape using a foam cutting machine to obtain a shock absorber buffer block containing high-strength polyurethane composite material.

[0010] Preferably, the polyether polyol is one of polyether polyol 4110, polyether polyol TSU-450L, polyether polyol YD-303 and polyether polyol N-403.

[0011] Preferably, the catalyst is N,N-dimethylcyclohexylamine; the isocyanate curing agent is polymethylene polyphenyl polyisocyanate; and the solvent is n-pentane.

[0012] Preferably, the preparation method of the DOPO-based magnolol comprises the following steps:

[0013] (1) Magnolol, enamine and formaldehyde are added to a dioxane solvent, stirred and dissolved, the temperature is controlled at 80-90℃, and the reaction is carried out for 20-24h. After the reaction is completed, the temperature is cooled to room temperature, and vacuum distillation is carried out. Deionized water and sodium hydroxide solution are used for washing in sequence, and drying is carried out to obtain tetraenyl magnolol. The molar ratio of magnolol, enamine and formaldehyde is 1:2-2.2:4-4.2, and the reaction synthesis route is as follows:

[0014] , wherein n=1-3;

[0015] (2) Under an ice water bath, tetraenyl magnolol is added to be dispersed in a dioxane solvent, m-chloroperbenzoic acid (m-CPBA) is added and stirred and mixed uniformly, the temperature is slowly increased to 35-40℃, and the reaction is carried out for 35-40h. After the reaction is completed, filtration is carried out, the filtrate is collected, sodium carbonate solution is extracted, deionized water is used for washing, drying is carried out, and rotary evaporation is carried out to obtain tetraoxymagnolol. The molar ratio of tetraenyl magnolol and m-CPBA is 1:6-8, and the reaction synthesis route is as follows:

[0016] ;

[0017] (3) Tetraoxymagnolol and DOPO are dispersed in toluene solvent, stirred and dispersed, triphenylphosphine is added, reflux reaction is carried out for 20-24h under nitrogen protection, after the reaction is completed, rotary evaporation is carried out, deionized water is used for washing, and drying is carried out to obtain DOPO-based magnolol. The molar ratio of tetraoxymagnolol, DOPO and triphenylphosphine is 1:4-4.2:0.015-0.02, and the reaction synthesis route is as follows:

[0018] .

[0019] Preferably, in the (1), the enamine is one of 3-buten-1-amine, 4-penten-1-amine, 5-hexen-1-amine.

[0020] (Three) beneficial technical effects

[0021] The application uses magnolol, m-chloroperbenzoic acid, DOPO and the like as raw materials, and obtains a DOPO-based magnolol through Mannich reaction, epoxidation reaction and ring-opening reaction, wherein the DOPO-based magnolol not only contains a flame-retardant DOPO structure, but also has a tetrahydroxy structure, which can improve the density of the composite material when curing with an isocyanate group, and in turn improve the strength of the buffer block. In addition, the application uses isocyanate-modified attapulgite, which is uniformly dispersed in the composite material matrix. Since the isocyanate-modified attapulgite contains an isocyanate group, it can be cured on the surface of the attapulgite to form a crosslinked network structure, and the attapulgite is uniformly dispersed in the matrix, which can well play a supporting and reinforcing role, and can effectively improve the strength of the buffer block. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in combination with examples and comparative examples.

[0023] The preparation method of the isocyanate-modified attapulgite is as follows: 5g of activated attapulgite is dispersed in a toluene solution containing 1g of toluene diisocyanate, high-speed dispersion is performed for 20min under a nitrogen atmosphere, heating is performed to 80℃, and reaction is performed for 2h. After the reaction is completed, cooling is performed to room temperature, filtration, washing and drying are performed, and the isocyanate-modified attapulgite is obtained.

[0024] Example 1

[0025] (1) 0.1mol of magnolol, 0.2mol of 3-buten-1-amine and 0.4mol of formaldehyde are added to a dioxane solvent, stirring and dissolution are performed, the temperature is controlled to 90℃, reaction is performed for 24h, after the reaction is completed, cooling is performed to room temperature, vacuum distillation is performed, and deionized water and sodium hydroxide solution are sequentially used for washing and drying, and the tetraenyl magnolol is obtained.

[0026] (2) 80mmol of the tetraenyl magnolol is added to a dioxane solvent under an ice water bath, 480mmol of m-CPBA is added thereto, stirring and mixing are uniformly performed, slow heating is performed to 40℃, reaction is performed for 40h, after the reaction is completed, filtration is performed, the filtrate is collected, sodium carbonate solution extraction, deionized water washing, drying, and rotary evaporation are performed, and the tetraepoxy magnolol is obtained.

[0027] (3) 50 mmol of tetra-epoxy magnolol, 210 mmol of DOPO were dispersed in toluene, stirred and dispersed, 0.8 mmol of triphenylphosphine was added, refluxed for 24 h under nitrogen protection, after the reaction was completed, rotary evaporation, deionized water washing, drying, to obtain DOPO-based magnolol;

[0028] (4) 100 parts by weight of polyether polyol 4110, 5 parts by weight of DOPO-based magnolol, 2 parts by weight of silicone oil, 5 parts by weight of N,N-dimethylcyclohexylamine catalyst, 2 parts by weight of deionized water, and 15 parts by weight of n-pentane solvent were stirred and uniformly mixed to obtain component A; 100 parts by weight of polymethylene polyphenyl polyisocyanate (PM-200) and 2 parts by weight of isocyanate-modified attapulgite were stirred and uniformly mixed to obtain component B; components A and B were stirred and uniformly mixed, placed in a mold to foam, and after the foam was formed, it was first placed in an oven at 80°C for 4 h, then the temperature was increased to 120°C for 4 h of curing, and then cut into shape using a foam cutting machine to obtain a shock absorber buffer block containing a high-strength polyurethane composite material.

[0029] Example 2

[0030] (1) 0.1 mol of magnolol, 0.22 mol of 4-penten-1-amine, and 0.42 mol of formaldehyde were added to a dioxane solvent, stirred and dissolved, the temperature was controlled at 85°C, and reacted for 22 h. After the reaction was completed, it was cooled to room temperature, distilled under reduced pressure, washed with deionized water and sodium hydroxide solution in sequence, and dried to obtain tetra-alkenyl magnolol;

[0031] (2) 80 mmol of tetra-alkenyl magnolol was added to a dioxane solvent under ice water bath, 500 mmol of m-CPBA was added and stirred and uniformly mixed, slowly warmed to 35°C, reacted for 38 h, after the reaction was completed, filtration was performed, the filtrate was collected, extracted with sodium carbonate solution, washed with deionized water, dried, and rotary evaporated to obtain tetra-epoxy magnolol;

[0032] (3) 50 mmol of tetra-epoxy magnolol, 200 mmol of DOPO were dispersed in toluene, stirred and dispersed, 0.75 mmol of triphenylphosphine was added, refluxed for 24 h under nitrogen protection, after the reaction was completed, rotary evaporation, deionized water washing, drying, to obtain DOPO-based magnolol;

[0033] (4) According to parts by weight, 100 parts by weight of polyether polyol 4110, 8 parts by weight of DOPO-based magnolol, 4 parts by weight of silicone oil, 3 parts by weight of N,N-dimethylcyclohexylamine catalyst, 1 part by weight of deionized water and 10 parts by weight of n-pentane solvent are stirred and mixed uniformly to obtain component A; 110 parts by weight of polymethylene polyphenyl polyisocyanate (PM-200) and 4 parts by weight of isocyanate modified attapulgite are stirred uniformly to obtain component B; components A and B are stirred and mixed uniformly, foamed in a mold, and after the foam is formed, it is first placed in an oven at 80°C for 4h, then heated to 120°C for 3h, and then cut into shape using a foam cutting machine to obtain a shock absorber buffer block containing a high-strength polyurethane composite material.

[0034] Example 3

[0035] (1) 0.1 mol of magnolol, 0.2 mol of 5-hexene-1-amine and 0.41 mol of formaldehyde were added to a dioxane solvent, stirred and dissolved, the temperature was controlled at 80°C, and the reaction was carried out for 24h. After the reaction was completed, it was cooled to room temperature, distilled under reduced pressure, and then washed with deionized water and sodium hydroxide solution in sequence, and dried to obtain tetraenyl magnolol;

[0036] (2) Under ice water bath, 80mmol of tetraenyl magnolol was added to be dispersed in a dioxane solvent, 600mmol of m-CPBA was added and stirred and mixed uniformly, slowly heated to 40°C, and reacted for 35h. After the reaction was completed, it was filtered, the filtrate was collected, extracted with sodium carbonate solution, washed with deionized water, dried, and rotary evaporated to obtain tetraoxymagnolol;

[0037] (3) 50mmol of tetraoxymagnolol and 210mmol of DOPO were dispersed in a toluene solvent, stirred and dispersed, 1mmol of triphenylphosphine was added, and refluxed under nitrogen protection for 22h. After the reaction was completed, it was rotary evaporated, washed with deionized water, and dried to obtain DOPO-based magnolol;

[0038] (4) According to parts by weight, 100 parts by weight of polyether polyol 4110, 10 parts by weight of DOPO-based magnolol, 3 parts by weight of silicone oil, 4 parts by weight of N,N-dimethylcyclohexylamine catalyst, 2 parts by weight of deionized water and 20 parts by weight of n-pentane solvent are stirred and mixed uniformly to obtain component A; 120 parts by weight of polymethylene polyphenyl polyisocyanate (PM-200) and 5 parts by weight of isocyanate modified attapulgite are stirred uniformly to obtain component B; components A and B are stirred and mixed uniformly, foamed in a mold, and after the foam is formed, it is first placed in an oven at 80°C for 4h, then heated to 120°C for 2h, and then cut into shape using a foam cutting machine to obtain a shock absorber buffer block containing a high-strength polyurethane composite material.

[0039] Comparative Example 1

[0040] The difference between the present comparative example and Example 1 is that in step (4), attapulgite is used instead of isocyanate modified attapulgite, and the remaining steps are substantially the same as those of Example 1.

[0041] Comparative Example 2

[0042] The difference between the present comparative example and Example 1 is that in step (4), tetra-epoxy magnolol is used instead of DOPO-based magnolol, and the remaining steps are substantially the same as those of Example 1.

[0043] Comparative Example 3

[0044] (1) 80 mmol of magnolol was added to a dispersion in dioxane solvent, 240 mmol of m-CPBA was added thereto, the mixture was stirred and mixed uniformly, slowly warmed to 40°C, and reacted for 40 h. After the reaction was completed, the filtrate was collected by suction filtration, extracted with a sodium carbonate solution, washed with deionized water, dried, and rotary evaporated to obtain di-epoxy magnolol. The reaction synthesis route is as follows:

[0045] ;

[0046] (2) 50 mmol of di-epoxy magnolol and 105 mmol of DOPO were dispersed in toluene solvent, stirred and dispersed, and then 0.4 mmol of triphenylphosphine was added thereto. Under nitrogen protection, the mixture was refluxed and reacted for 24 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain DOPO-based magnolol. The reaction synthesis route is as follows:

[0047] ;

[0048] (3) 100 parts by weight of polyether polyol 4110, 5 parts by weight of DOPO-based magnolol, 2 parts by weight of silicone oil, 5 parts by weight of N,N-dimethylcyclohexylamine catalyst, 2 parts by weight of deionized water, and 15 parts by weight of n-pentane solvent were stirred and mixed uniformly to obtain component A; 100 parts by weight of polymethylene polyphenyl polyisocyanate (trade name PM-200) and 2 parts by weight of isocyanate modified attapulgite were stirred and mixed uniformly to obtain component B; components A and B were stirred and mixed uniformly, placed in a mold to foam, and after the foam was formed, it was first placed in an oven at 80°C for 4 h, then warmed to 120°C for 4 h of curing, and then cut into shape using a foam cutting machine to obtain a shock absorber buffer block containing a high-strength polyurethane composite material.

[0049] The limiting oxygen index of the sample was tested using an oxygen index analyzer;

[0050] The UL-94 of the sample was tested using a vertical burning tester;

[0051] The heat resistance of the sample is tested by using a thermal gravimetric analyzer, the temperature rising rate is 10℃ / min, and the temperature rising range is 50-800℃.

[0052] Table 1:

[0053] Limiting oxygen index (%) UL-94 (rating) 700℃ char yield (%) Example 1 28.7 V-0 11.4 Example 2 31.2 V-0 12.3 Example 3 33.4 V-0 12.8 Comparative Example 1 24.2 V-1 9.6 Comparative Example 2 19.8 - - Comparative Example 3 27.3 V-0 6.7

[0054] As shown in Table 1, the buffer block prepared by the application has good flame retardant performance and heat resistance. In Comparative Example 1, attapulgite is used instead of isocyanate modified attapulgite, and the unmodified attapulgite has poor dispersion performance in the organic matrix, which seriously affects the flame retardant performance and heat resistance of the buffer block. In Comparative Example 2, tetra-epoxy magnolol is used instead of DOPO-based magnolol, which does not contain a flame-retardant DOPO structure and cannot form an organic-inorganic synergistic flame-retardant system with modified attapulgite, so its flame retardant performance is the worst. In addition, it does not contain a benzoxazine structure and a rigid benzene ring structure with good heat resistance, so its heat resistance is also poor. In Comparative Example 3, it contains a flame-retardant DOPO structure, but it does not contain a benzoxazine structure compared with DOPO-based magnolol. The benzoxazine structure can absorb heat and cross-link at high temperatures to further improve the compactness of the buffer block. As the temperature rises, the benzoxazine structure can form a dense carbon layer on the surface of the matrix, which can hinder the transfer of heat and matter, helping to improve the flame retardant performance and heat resistance. However, Comparative Example 3 does not contain such a structure, so its heat resistance and flame retardant performance are not as good as those of the application.

[0055] The apparent density of the sample is evaluated according to ASTM D1622 by using an electronic balance, and the sample size is 50x50x25mm. 3 .

[0056] The compressive strength is tested by using a mechanical testing machine, and the sample size is 50x50x25mm. 3 , and the compression rate is 2.5mm / min.

[0057] Table 2:

[0058] Density (kg / m 3 ) Compressive strength (MPa) Example 1 72.0 0.35 Example 2 74.3 0.37 Example 3 75.1 0.38 Comparative Example 1 62.3 0.30 Comparative Example 2 57.9 0.28 Comparative Example 3 68.4 0.32

[0059] It can be seen from the table that the buffer block prepared by the application has high strength, the attapulgite is used instead of isocyanate modified attapulgite in Comparative Example 1, the unmodified attapulgite has poor dispersing performance in the organic matrix, thus affecting the strength and density of the buffer block, the uniformly dispersed organic modified attapulgite is used in the application, which can not only play a supporting and reinforcing role, but also form a large crosslinking density through the curing of the isocyanate groups on the surface, thus effectively improving the strength and density of the buffer block, the tetraoxirane thick oaks phenol is used instead of the DOPO-based thick oaks phenol in Comparative Example 2, which does not contain reactive hydroxyl groups, thus cannot form a dense crosslinking network structure, and the higher the crosslinking density, the better the mechanical properties, thus the mechanical properties of Comparative Example 2 are poor, Comparative Example 3 contains hydroxyl groups, but the mechanical properties are still poorer than those of the application, and the reason is speculated as follows: the Mannich reaction using enamine in the application can effectively increase the carbon chain, the longer the carbon chain, the greater the physical crosslinking density, and the better the mechanical properties.

[0060] In conclusion, the shock absorber buffer block containing the high-strength polyurethane composite material prepared by the application has good flame retardant performance, high-temperature resistance, large density and compressive strength.

[0061] The specific embodiments are only an explanation of the application, and are not a limitation of the application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the specification, as long as the modifications are within the scope of the claims of the application, and are protected by the patent law.

Claims

1. A shock absorber bumper block comprising a high-strength polyurethane composite, characterized in that, The shock absorber buffer block is composed of the following raw materials by weight: 100 parts by weight of polyether polyol, 5-10 parts by weight of DOPO-based magnolol, 2-4 parts by weight of silicone oil, 3-5 parts by weight of catalyst, 1-2 parts by weight of deionized water, 10-20 parts by weight of solvent, 100-120 parts by weight of isocyanate curing agent, and 2-5 parts by weight of isocyanate modified attapulgite. The preparation method of the shock absorber buffer block comprises the following preparation steps: The polyether polyol, the DOPO-based magnolol, the silicone oil, the catalyst, the deionized water, and the solvent are stirred and uniformly mixed to obtain component A; the isocyanate curing agent and the isocyanate modified attapulgite are stirred and uniformly mixed to obtain component B; components A and B are stirred and uniformly mixed, foamed in a mold, and then placed in an oven at 80°C for 4h for curing, and then heated to 120°C for 2-4h for curing, and then cut into a shape using a foam cutting machine to obtain a shock absorber buffer block containing a high-strength polyurethane composite material.

2. The high-strength polyurethane composite containing shock absorber bumpers according to claim 1, characterized by, The polyether polyol is one of polyether polyol 4110, polyether polyol TSU-450L, polyether polyol YD-303, and polyether polyol N-403.

3. The high-strength polyurethane composite containing shock absorber bumpers according to claim 1, characterized by, The catalyst is N,N-dimethylcyclohexylamine; the isocyanate curing agent is polymethylene polyphenyl polyisocyanate; and the solvent is n-pentane.

4. The high-strength polyurethane composite containing shock absorber bumpers according to claim 1, characterized by, The preparation method of the DOPO-based magnolol comprises the following steps: (1) Magnolol, enamine, and formaldehyde are added to a dioxane solvent, stirred and dissolved, the temperature is controlled at 80-90°C, and reaction is performed for 20-24h; after the reaction is completed, the temperature is cooled to room temperature, and vacuum distillation is performed, followed by washing with deionized water and sodium hydroxide solution in sequence, and drying to obtain tetraenyl magnolol; (2) Under an ice water bath, tetraenyl magnolol is added to a dispersion in a dioxane solvent, m-CPBA is added thereto, stirred and uniformly mixed, slowly heated to 35-40°C, and reaction is performed for 35-40h; after the reaction is completed, filtration is performed, the filtrate is collected, extracted with sodium carbonate solution, washed with deionized water, dried, and rotary evaporated to obtain tetraoxymagnol; (3) dispersing and stirring the tetra-epoxy magnolol and DOPO in toluene, adding triphenylphosphine thereto, refluxing and reacting for 20-24 hours under nitrogen protection, after the reaction is completed, spinning evaporation, deionized water washing, drying, and obtaining DOPO-based magnolol, the structural formula of which is: wherein n = 1-3.

5. The high-strength polyurethane composite-containing shock absorber bumper block according to claim 4, characterized by, In the (1), the molar ratio of magnolol, enamine, and formaldehyde is 1:2-2.2:4-4.

2.

6. The high-strength polyurethane composite containing shock absorber bumpers according to claim 4, characterized by, In the (1), the enamine is one of 3-buten-1-amine, 4-penten-1-amine, and 5-hexen-1-amine.

7. The high-strength polyurethane composite containing shock absorber bumpers according to claim 4, characterized by, In the (2), the molar ratio of tetraenyl magnolol and m-CPBA is 1:6-8.

8. The high-strength polyurethane composite containing shock absorber bumpers according to claim 4, characterized by, In the (3), the molar ratio of tetraoxymagnolol, DOPO, and triphenylphosphine is 1:4-4.2:0.015-0.02.

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