Graphene modified polyurethane bonding material and preparation method thereof

Abstract

The invention belongs to the technical field of polyurethane bonding materials, and discloses a graphene modified polyurethane bonding material which comprises the following components: 65-70 parts of polyether polyol, 45-50 parts of polyisocyanate, 5-7 parts of modified graphene, 1-1.5 parts of a catalyst, 5-8 parts of a foaming agent, 3-4 parts of a coupling agent, 15-25 parts of modified inorganic fibers and 20-30 parts of a diluent. According to the graphene modified polyurethane composite material provided by the invention, the inorganic fibers are subjected to surface modification and activation treatment, so that reactive groups on the surfaces of the inorganic fibers are improved, reaction sites of the inorganic fibers and the coupling agent are increased, and the compatibility of the inorganic fibers and polyurethane is obviously improved; the method is simple to operate and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyurethane adhesive materials, and particularly relates to a graphene-modified polyurethane adhesive material and a preparation method thereof. Background Art

[0002] Polyurethane is a block copolymer with both plasticity and elasticity. The molecular chain contains groups such as ester groups, ether groups, urethane groups, and urea groups, and has high mechanical strength, elasticity, and good low-temperature flexibility. It is widely used in many fields such as manufacturing microcellular foams, sealing gaskets, insulating boards, tires, hard plastic parts, synthetic leather, etc. Since polyurethane is a polymer composed of alternating sequences of hard and soft segments, its applications are restricted due to insufficient performance in aspects such as conductivity and heat conduction. Therefore, it is necessary to modify polyurethane materials.

[0003] With the development of nanomaterials, the preparation of polymer composites using nanomaterials has become a current research hotspot. Since its discovery, graphene has excellent mechanical, thermal, and electrical conductivity properties, etc., and can be used as a filler to be compounded with polymers. With the addition of a very small amount, the performance of the polymer can be significantly improved. Graphene is a layered compound composed of carbon element six-membered rings, with surface inertness and stability. The thickness of a single-layer graphene is less than 1 nm, and the area size is between a few and dozens of μm. The π-π stacking group action and strong van der Waals force action between graphene sheets cause the graphene sheets to stack together, making it difficult to be uniformly dispersed in aqueous solutions, common solvents, or other polymer matrices. Especially in aqueous solutions, due to the surface chemical inertness and hydrophobicity of graphene and its large specific surface area, graphene is extremely prone to agglomeration and difficult to be uniformly dispersed, greatly limiting its applications. Moreover, graphene has a large van der Waals force on its surface, resulting in agglomeration phenomena, poor compatibility with polymers, and difficult to be dispersed evenly. Therefore, it is necessary to perform functional modification on the surface of graphene to improve its dispersibility in polymers and the interfacial compatibility between the two.

[0004] A large number of studies have shown that the compounding of graphene and polyurethane can improve the mechanical properties, antistatic properties, etc. of polyurethane materials. How to improve the dispersibility of graphene in polyurethane composites and its compatibility with the materials, so as to improve the comprehensive performance of polyurethane composites, has become a research hotspot in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide a graphene-modified polyurethane adhesive material and a preparation method thereof to solve the technical problems raised in the background art.

[0006] To achieve the above object, the specific technical solution of the present invention is as follows: A graphene-modified polyurethane adhesive material, comprising the following components: 65-70 parts of polyether polyol, 45-50 parts of polyisocyanate, 5-7 parts of modified graphene, 1-1.5 parts of catalyst, 5-8 parts of foaming agent, 3-4 parts of coupling agent, 15-25 parts of modified inorganic fiber, and 20-30 parts of diluent;

[0007] The preparation method of the modified graphene comprises the following steps:

[0008] (1) Add graphene into N, N-dimethylformamide, and then add PVP, and carry out ultrasonic dispersion for 50-60 min to obtain a graphene dispersion;

[0009] (2) Then add isophorone diisocyanate into the graphene dispersion, and react at 90-100 °C for 5-6 h;

[0010] (3) Continuously add dimethylolpropionic acid, carry out stirring reaction, after the reaction is completed, carry out filtration and washing, and dry the filter cake to obtain the modified graphene;

[0011] The preparation method of the modified inorganic fiber comprises the following steps:

[0012] (a) Immerse the mixture of titanium dioxide fiber, glass fiber, and carbon fiber evenly in dilute sulfuric acid for 3-5 h, filter and dry, add it into distilled water, then add cellulose and mix evenly, and then carry out hydrothermal reaction at 95-100 °C for 3-5 h. After the reaction is completed, the product is centrifuged, washed, and dried to obtain cellulose-modified inorganic fiber;

[0013] (b) After the cellulose-modified inorganic fiber obtained in step (a) is activated by high-speed stirring, add it into the coupling agent, mix evenly, and dry to obtain the modified inorganic fiber.

[0014] Preferably, the components are as follows: 65 parts of polyether polyol, 45 parts of polyisocyanate, 5 parts of modified graphene, 1 part of catalyst, 5 parts of foaming agent, 3 parts of coupling agent, 15 parts of modified inorganic fiber, and 20 parts of diluent.

[0015] Preferably, the optimal components are as follows: 67.5 parts of polyether polyol, 47.5 parts of polyisocyanate, 6 parts of modified graphene, 1.25 parts of catalyst, 6.5 parts of foaming agent, 3.5 parts of coupling agent, 20 parts of modified inorganic fiber, and 25 parts of diluent.

[0016] Preferably, the components are as follows: 70 parts of polyether polyol, 50 parts of polyisocyanate, 7 parts of modified graphene, 1.5 parts of catalyst, 8 parts of foaming agent, 4 parts of coupling agent, 25 parts of modified inorganic fiber, and 30 parts of diluent.

[0017] Preferably, a method for preparing the graphene-modified polyurethane adhesive material according to any one of claims 1-4 comprises the following steps:

[0018] S1: Stir and react polyether polyol, polyisocyanate, modified graphene, catalyst, foaming agent, coupling agent and diluent to obtain mixture A;

[0019] S2: Mix and react the mixture A obtained in S1 with modified inorganic fibers to obtain mixture B;

[0020] S3: The temperature of the mixing reaction in S2 is 50-60°C, the stirring speed is 400-500 r / min, and the stirring time is 50-60 min.

[0021] The present invention has the following advantages:

[0022] 1. For the graphene-modified polyurethane adhesive material and its preparation method, through the graphene-modified polyurethane composite material provided by the present invention, the inorganic fibers are surface-modified and activated, which increases the reactive groups on their surface, resulting in more reaction sites with the coupling agent and significantly improved compatibility with polyurethane. At the same time, the added coupling agent makes the modification.

[0023] 2. For the graphene-modified polyurethane adhesive material and its preparation method, through the graphene-modified polyurethane composite material, the used modified graphene and modified inorganic fibers as co-modifying agents make the performance of the polyurethane composite material more excellent. Specific embodiments

[0024] Example 1

[0025] A method for preparing the graphene-modified polyurethane adhesive material of the present invention comprises the following steps:

[0026] S1: Stir and react 65 parts of polyether polyol, 45 parts of polyisocyanate, 5 parts of modified graphene, 1 part of catalyst, 5 parts of foaming agent, 3 parts of coupling agent and 20 parts of diluent to obtain mixture A;

[0027] S2: Mix and react the mixture A obtained in S1 with 15 parts of modified inorganic fibers to obtain mixture B;

[0028] S3: The temperature of the mixing reaction in S2 is 50°C, the stirring speed is 400 r / min, and the stirring time is 50 min. Pour it into a mold and let it cool naturally to obtain the product.

[0029] Example 2

[0030] A method for preparing the graphene-modified polyurethane adhesive material of the present invention comprises the following steps:

[0031] S1: Stir and react 67.5 parts of polyether polyol, 47.5 parts of polyisocyanate, 6 parts of modified graphene, 1.25 parts of catalyst, 6.5 parts of foaming agent, 3.5 parts of coupling agent and 25 parts of diluent to obtain mixture A;

[0032] S2: Mix and react the mixture A obtained in S1 with 20 parts of modified inorganic fiber to obtain mixture B;

[0033] S3: The temperature of the mixing reaction in S2 is 55 °C, the stirring speed is 450 r / min, the stirring time is 55 min, and it is poured into a mold and cooled naturally to obtain the product.

[0034] Example 2

[0035] A preparation method of a graphene-modified polyurethane adhesive material of the present invention comprises the following steps:

[0036] S1: Stir and react 70 parts of polyether polyol, 50 parts of polyisocyanate, 7 parts of modified graphene, 1.5 parts of catalyst, 8 parts of foaming agent, 4 parts of coupling agent and 30 parts of diluent to obtain mixture A;

[0037] S2: Mix and react the mixture A obtained in S1 with 25 parts of modified inorganic fiber to obtain mixture B;

[0038] S3: The temperature of the mixing reaction in S2 is 60 °C, the stirring speed is 500 r / min, the stirring time is 60 min, and it is poured into a mold and cooled naturally to obtain the product.

[0039] Table 1: Performance test results

[0040] Density 60% Compression Tensile Fracture Glass Transition (Temperature) Example 1 249 16.5 30 410 165 Example 2 260 17 32 480 170 Example 3 250 16 29 380 160

[0041] As can be seen from the above table, the present invention uses graphene to reinforce the polyurethane composite material. By surface-modifying graphene, the dispersibility and compatibility of graphene in the composite material are improved, so that the prepared composite material has high fracture toughness and the strength of the polyurethane composite material is improved; at the same time, by adding modified inorganic fiber, the heat resistance of the composite material is synergistically improved together with graphene, and the comprehensive performance of the composite material is improved.

[0042] It will be understood that the present invention is described by way of some embodiments, and those skilled in the art will be aware that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Additionally, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope protected by the present invention.

Claims

1. A graphene-modified polyurethane adhesive material, characterized in that: It includes the following components: 65-70 parts of polyether polyol, 45-50 parts of polyisocyanate, 5-7 parts of modified graphene, 1-1.5 parts of catalyst, 5-8 parts of foaming agent, 3-4 parts of coupling agent, 15-25 parts of modified inorganic fiber, and 20-30 parts of diluent; The preparation method of modified graphene includes the following steps: (1) Add graphene into N,N-dimethylformamide, and then add PVP, and carry out ultrasonic dispersion for 50-60 min to obtain a graphene dispersion; (2) Then add isophorone diisocyanate into the graphene dispersion and react at 90-100 °C for 5-6 h; (3) Continuously add dimethylolpropionic acid and carry out stirring reaction. After the reaction is completed, filter and wash, and dry the filter cake to obtain modified graphene; The preparation method of modified inorganic fiber includes the following steps: (a) Immerse the mixture of titanium dioxide fiber, glass fiber, and carbon fiber evenly in dilute sulfuric acid for 3-5 h, filter and dry, add it into distilled water, then add cellulose and mix evenly, and then carry out hydrothermal reaction at 95-100 °C for 3-5 h. After the reaction is completed, centrifuge, wash, and dry the product to obtain cellulose-modified inorganic fiber; (b) After high-speed stirring and activating the cellulose-modified inorganic fiber obtained in step (a), add it into the coupling agent, mix evenly, and dry to obtain the modified inorganic fiber.

2. The graphene-modified polyurethane adhesive material according to claim 1, characterized in that: The components are as follows: 65 parts of polyether polyol, 45 parts of polyisocyanate, 5 parts of modified graphene, 1 part of catalyst, 5 parts of foaming agent, 3 parts of coupling agent, 15 parts of modified inorganic fiber, and 20 parts of diluent.

3. The graphene-modified polyurethane adhesive material according to claim 1, characterized in that: The optimal components are as follows: 67.5 parts of polyether polyol, 47.5 parts of polyisocyanate, 6 parts of modified graphene, 1.25 parts of catalyst, 6.5 parts of foaming agent, 3.5 parts of coupling agent, 20 parts of modified inorganic fiber, and 25 parts of diluent.

4. A graphene-modified polyurethane adhesive material according to claim 1, wherein: The components are as follows: 70 parts of polyether polyol, 50 parts of polyisocyanate, 7 parts of modified graphene, 1.5 parts of catalyst, 8 parts of foaming agent, 4 parts of coupling agent, 25 parts of modified inorganic fiber, and 30 parts of diluent.

5. The preparation method of the graphene-modified polyurethane adhesive material according to any one of claims 1-4, comprising the following steps: S1: Stir and react polyether polyol, polyisocyanate, modified graphene, catalyst, foaming agent, coupling agent, and diluent to obtain mixture A; S2: Mix and react the mixture A obtained in S1 with modified inorganic fiber to obtain mixture B; S3: The temperature of the mixing reaction in S2 is 50-60 °C, the stirring speed is 400-500 r / min, and the stirring time is 50-60 min.