PMMA (polymethyl methacrylate) resin-based solid buoyancy material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of synthesis of polymer resin and composite materials thereof, and discloses a PMMA (polymethyl methacrylate) resin-based solid buoyancy material as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, mixing PMMA with a solvent to obtain a PMMA solution; then dispersing the light filler into the PMMA solution to obtain a mixed solution; the solvent in the mixed solution is removed through heating and drying, and a porous prefabricated part is obtained; and injecting a resin stock solution containing MMA into the porous prefabricated member, and then carrying out a curing reaction to obtain the PMMA resin-based solid buoyancy material. According to the method, the problem of uneven distribution caused by floating of the light filler in the resin due to light density is effectively avoided, and the light filler and the resin pouring stock solution do not need to be stirred and mixed, so that bubbles which are difficult to remove are not generated, and the defect of air holes remaining in the buoyancy material after curing can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular resin and its composite material synthesis, and particularly relates to a PMMA resin-based solid buoyancy material and a preparation method and application thereof. BACKGROUND

[0002] The solid buoyancy material is a kind of foam material formed by filling light hollow fillers into a polymer matrix material, which has the characteristics of low density and high strength, and is widely used in the field of deep sea exploration. The commonly used high molecular matrix material of the composite foam material is a thermosetting resin such as epoxy resin, unsaturated resin and phenolic resin, and the commonly used light hollow filler is a hollow glass microsphere (HGM). When the matrix material is a thermosetting resin, the cross-linking and curing of the resin result in the composite foam material being non-recyclable, which produces solid waste and causes environmental pollution. Therefore, the recyclable thermoplastic resin material is expected to be widely applied.

[0003] Polymethyl methacrylate (PMMA) is an important transparent engineering plastic, also known as acrylic or organic glass. The density of PMMA is about 1.14~1.20g / cm 3 , which has good light transmittance, electrical insulation, chemical stability and mechanical strength. The thermal conductivity of PMMA is about 0.15~0.19W / (m K), and it can be dissolved in organic solvents such as carbon tetrachloride, benzene, toluene, dichloroethane, trichloromethane and acetone, so it also has the advantages of recyclability and reuse. Therefore, PMMA can be considered as a matrix resin for application in places with lower density requirements such as ship buoyancy material.

[0004] A patent with the application number 2024106156074 discloses a PMMA thermoplastic lightweight material and a preparation method thereof. The patent discloses a method for compounding glass microspheres and PMMA, which adopts a normal temperature direct mixing method to stir and mix liquid PMMA resin stock solution, glass microspheres, initiator and other components in proportion, and then heat and cure to obtain the PMMA thermoplastic lightweight material. The method is simple and convenient to operate, but the glass microspheres are inorganic materials and their surfaces are not organically modified, so the interface bonding is poor when they are compounded with PMMA organic polymers. When the liquid PMMA resin stock solution is mixed with hollow glass microspheres, the system viscosity increases, resulting in a large number of bubbles, which are difficult to remove and seriously affect the overall performance of the composite material. Therefore, it is necessary to develop a solid buoyancy material with good interface bonding between light fillers and PMMA resin matrix material and without bubbles in the prepared composite material. SUMMARY

[0005] The purpose of this invention is to provide a PMMA resin-based solid buoyancy material, its preparation method, and its application, thereby solving the problem of poor interfacial bonding between existing lightweight fillers and PMMA resin matrix materials.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing a PMMA resin-based solid buoyancy material, comprising the following steps: First, PMMA is mixed with a solvent to obtain a PMMA solution; then, a light filler is dispersed into the PMMA solution to obtain a mixed solution. The solvent in the mixed solution is removed by heating and drying to obtain a porous preform; The resin stock containing MMA is injected into a porous preform and then cured to obtain a PMMA resin-based solid buoyancy material.

[0007] Preferably, the ratio of PMMA, lightweight filler and solvent is 1~20g:30~70g:100mL.

[0008] Preferably, the relative molecular mass of the PMMA is 40,000 to 1,000,000; the solvent is acetone, methyl methacrylate, dimethyl sulfoxide, dichloromethane, or chloroform; the lightweight filler includes one or a combination of hollow glass microspheres, ceramic hollow microspheres, fly ash hollow glass microspheres, phenolic resin hollow microspheres, and polystyrene hollow microspheres.

[0009] Preferably, the method for dispersing the lightweight filler into the PMMA solution is one or more of mechanical stirring, shaking, and ultrasonic treatment.

[0010] Preferably, the heating and drying temperature is 30~100℃; the heating and drying time is 0.5~10h.

[0011] Preferably, the method for injecting the MMA-containing resin stock solution into the porous preform is casting, high-pressure injection, or vacuum injection; the parameters of the curing reaction are: first curing at 20~80℃ for 0.1~48h, and then post-curing at 20~120℃ for 1~48h.

[0012] Preferably, the mass ratio of the MMA-containing resin stock solution to the lightweight filler is 100:5~80.

[0013] Preferably, the MMA-containing resin stock solution comprises MMA monomer, PMMA and an initiator; the mass ratio of the MMA monomer, PMMA and initiator is 100:0~50:0.5~5.

[0014] The present invention also provides a PMMA resin-based solid buoyancy material prepared by the above preparation method.

[0015] The present invention also provides the application of a PMMA resin-based solid buoyancy material or a PMMA resin-based solid buoyancy material prepared by the above preparation method in ship hulls, diving equipment or buoys.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a solution impregnation method to coat the surface of a lightweight filler with a solution containing PMMA macromolecules. Then, the small molecule solvent is quickly removed by heating and drying. The PMMA macromolecules are difficult to volatilize due to their high boiling point and remain on the surface of the lightweight filler. This allows the lightweight fillers to stack up and be stably bonded together by the PMMA macromolecules. The volatilized small molecule solvents form new pores between the stacked lightweight fillers. These pores are beneficial for the injection of resin materials.

[0017] (2) In this invention, a small molecule solvent is used as a medium to coat PMMA macromolecules onto the surface of lightweight fillers, and lightweight fillers can be bonded and fixed with PMMA resin at a low temperature. This method ensures that the lightweight fillers maintain the hollow sphere shell unchanged.

[0018] (3) In this invention, a porous preform is prepared by pre-bonding lightweight fillers with PMMA resin, and then resin is injected into the porous preform to obtain a solid buoyancy material. Compared with the method of directly mixing the two, the method of this invention effectively avoids the problem of uneven distribution of lightweight fillers in the resin due to their low density. At the same time, in the method of this invention, the lightweight fillers and the resin injection solution do not need to be stirred and mixed again, so no air bubbles that are difficult to remove are generated, and the residual pore defects inside the buoyancy material after curing can be avoided.

[0019] (4) In this invention, the surface of the lightweight filler is coated with PMMA macromolecules, which enables the lightweight filler to be well integrated with the resin stock solution injected later, effectively improving the interfacial bonding force between the lightweight filler and the PMMA resin matrix material. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0021] Figure 1 This is a flowchart illustrating the preparation process of the PMMA resin-based solid buoyancy material of the present invention. Detailed Implementation

[0022] This invention provides a method for preparing a PMMA resin-based solid buoyancy material, the preparation flow chart of which is shown below. Figure 1As shown, it includes the following steps: First, PMMA is mixed with a solvent to obtain a PMMA solution; then, a light filler is dispersed into the PMMA solution to obtain a mixed solution. The solvent in the mixed solution is removed by heating and drying to obtain a porous preform; The resin stock containing MMA is injected into a porous preform and then cured to obtain a PMMA resin-based solid buoyancy material.

[0023] In this invention, the preferred ratio of PMMA, lightweight filler and solvent is 1~20g:30~70g:100mL, more preferably 10~20g:40~60g:100mL, and even more preferably 20g:50g:100mL.

[0024] In this invention, the relative molecular mass of the PMMA is preferably 40,000 to 1,000,000, more preferably 50,000 to 500,000, and even more preferably 60,000; the solvent is preferably acetone, methyl methacrylate, dimethyl sulfoxide, dichloromethane, or chloroform, and even more preferably acetone; the lightweight filler preferably includes one or a combination of hollow glass microspheres, ceramic hollow microspheres, fly ash hollow glass microspheres, phenolic resin hollow microspheres, and polystyrene hollow microspheres, and even more preferably hollow glass microspheres, ceramic hollow microspheres, or phenolic resin hollow microspheres, and even more preferably hollow glass microspheres.

[0025] In this invention, the lightweight filler is further modified with a silane coupling agent before being dispersed into the PMMA solution; the silane coupling agent is preferably KH-570; the mass of the silane coupling agent is preferably 1 to 10% of the mass of the lightweight filler, more preferably 2 to 7%, and more preferably 5%.

[0026] In this invention, the method of dispersing the lightweight filler into the PMMA solution is preferably one or more of mechanical stirring, shaking, and ultrasonic treatment, more preferably ultrasonic treatment, and even more preferably ultrasonic treatment for 30 minutes.

[0027] In this invention, the heating and drying temperature is preferably 30~100℃, more preferably 55~70℃, and even more preferably 60℃; the heating and drying time is preferably 0.5~10h, more preferably 2~5h, and even more preferably 3h.

[0028] In this invention, the method of injecting the MMA-containing resin stock solution into the porous preform is preferably casting, high-pressure injection, or vacuum injection; the parameters of the curing reaction are preferably: first curing at 20~80℃ for 0.1~48h, and then post-curing at 20~120℃ for 1~48h; more preferably, first curing at 30~60℃ for 10~36h, and then post-curing at 80~100℃ for 2~12h; more preferably, first curing at 35℃ for 12h, and then post-curing at 80℃ for 3h.

[0029] In this invention, the mass ratio of the MMA-containing resin stock solution to the lightweight filler is preferably 100:5~80, more preferably 100:10~60, and even more preferably 100:50.

[0030] In this invention, the MMA-containing resin stock solution preferably comprises MMA monomer, PMMA, and an initiator; the mass ratio of the MMA monomer, PMMA, and initiator is preferably 100:0~50:0.5~5, more preferably 100:10~40:1~4, and even more preferably 100:20:2; the relative molecular mass of the PMMA is preferably 40,000~1,000,000, more preferably 40,000~400,000, and even more preferably 50,000; the initiator is preferably one of an azo compound initiator, an oxidizing initiator, and a redox initiator, and even more preferably a redox initiator.

[0031] In this invention, the azo compound initiator is preferably azobisisobutyronitrile (AIBN) or azobisisoheptanenitrile (ABVN), more preferably AIBN; the oxidizing initiator is preferably benzoyl peroxide (BPO) or dodecyl peroxide (LPO), more preferably BPO; the redox initiator preferably includes an oxidizing agent and a reducing agent; the oxidizing agent is preferably benzoyl peroxide (BPO) or dodecyl peroxide (LPO), more preferably BPO; the reducing agent is preferably N,N-dimethyl-p-toluidine (DMT) or N,N-dimethylaniline (DMA), more preferably DMA.

[0032] The present invention also provides a PMMA resin-based solid buoyancy material prepared by the above preparation method.

[0033] The present invention also provides the application of a PMMA resin-based solid buoyancy material or a PMMA resin-based solid buoyancy material prepared by the above preparation method in ship hulls, diving equipment or buoys.

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a method for preparing a PMMA resin-based solid buoyancy material, including the following steps: Step 1: Weigh 20g of PMMA macromolecular powder with a relative molecular mass of 60,000, pour it into 100mL of acetone solution and stir to fully dissolve the PMMA to prepare an acetone solution containing dissolved PMMA molecules. Then weigh 50g of hollow glass microspheres with a particle size of 30μm, disperse them in the acetone solution containing dissolved PMMA molecules, and use sonication to treat them for 30min to ensure that the acetone solution completely wets the surface of the hollow glass microspheres. Step 2: Place the thoroughly mixed material from Step 1 into a vacuum drying oven and dry at 60°C for 3 hours to remove acetone and obtain a porous preform. The volatilized acetone is recovered by a cooling device. Step 3: Seal the porous preform obtained in Step 2 in a vacuum bag membrane, and evacuate the bag membrane to remove gas. Then, while evacuating, pour in the resin stock solution until the porous preform is filled with resin. Stop pouring and stop evacuating. Then, place the vacuum bag membrane in an oven and heat to cure. The curing reaction conditions are: first react at 35℃ for 12 hours, and then cure at 80℃ for 3 hours to obtain PMMA resin-based solid buoyancy material. The resin stock solution consists of MMA monomer and initiator. The initiator is a redox initiator (oxidant is BPO, and reducing agent is DMA). The mass ratio of MMA monomer to initiator is 100:1, and the mass ratio of resin stock solution to hollow glass microspheres is 100:30.

[0037] The density of the PMMA resin-based solid buoyancy material prepared in this embodiment is 0.68 g / cm³. 3 It has a compressive strength of 95 MPa and a water absorption rate of less than 1%.

[0038] Example 2

[0039] This embodiment provides a method for preparing a PMMA resin-based solid buoyancy material, including the following steps: Step 1: Weigh 5g of PMMA macromolecular powder with a relative molecular mass of 200,000, pour it into 100mL of MMA monomer solution and stir to fully dissolve the PMMA to prepare an MMA solution containing dissolved PMMA molecules. Then weigh 40g of hollow glass microspheres with a particle size of 80μm, disperse them in the MMA solution containing dissolved PMMA molecules, and shake them evenly on a shaker to ensure that the MMA solution completely wets the surface of the hollow glass microspheres. Step 2: Place the thoroughly mixed material from Step 1 into a vacuum drying oven and dry at 60°C for 3 hours to remove MMA and obtain porous preforms. The volatilized MMA is recovered by a cooling device. Step 3: Seal the porous preform obtained in Step 2 in a vacuum bag membrane, and evacuate the bag membrane to remove gas. Then, inject the resin stock solution into the porous preform by pressure injection, stop the injection and stop evacuation. Then, place the vacuum bag membrane in an oven for heating and curing. The curing reaction conditions are: first react at 60℃ for 4 hours, and then cure at 80℃ for 3 hours to obtain PMMA resin-based solid buoyancy material. The resin stock solution consists of MMA monomer, PMMA macromolecules and an initiator. The initiator is the oxidant BPO. The mass ratio of MMA monomer, PMMA macromolecules and initiator is 100:30:2. The relative molecular mass of PMMA macromolecules is 50,000. The mass ratio of resin stock solution to hollow glass microspheres is 100:10.

[0040] The density of the PMMA resin-based solid buoyancy material prepared in this embodiment is 0.95 g / cm³. 3 It has a compressive strength of 98 MPa and a water absorption rate of less than 1%.

[0041] Example 3

[0042] This embodiment provides a method for preparing a PMMA resin-based solid buoyancy material, including the following steps: Step 1: Weigh 20g of PMMA macromolecular powder with a relative molecular mass of 40,000, pour it into 100mL of acetone solution and stir to fully dissolve the PMMA to prepare an acetone solution containing dissolved PMMA molecules. Then weigh 30g of hollow glass microspheres with a particle size of 120μm, disperse them into the acetone solution containing dissolved PMMA molecules, and stir and mix them using mechanical stirring to ensure that the acetone solution completely wets the surface of the hollow glass microspheres. Step 2: Place the thoroughly mixed material from Step 1 into a vacuum drying oven and dry at 60°C for 3 hours to remove acetone and obtain a porous preform. The volatilized acetone is recovered by a cooling device. Step 3: Seal the porous preform obtained in Step 2 in a vacuum bag membrane, and evacuate the bag membrane to remove gas. Then, while evacuating, inject resin stock solution until the porous preform is filled with resin. Stop injecting the solution and stop evacuating. Then, place the vacuum bag membrane in an oven and heat to cure. The curing reaction conditions are: first react at 50℃ for 12 hours, and then cure at 110℃ for 2 hours to obtain PMMA resin-based solid buoyancy material. The resin stock solution consists of MMA monomer, PMMA macromolecules and an initiator, with AIBN as the initiator. The mass ratio of MMA monomer, PMMA macromolecules and initiator is 100:20:2.5. The relative molecular mass of PMMA macromolecules is 100,000. The mass ratio of resin stock solution to hollow glass microspheres is 100:75.

[0043] The density of the PMMA resin-based solid buoyancy material prepared in this embodiment is 0.35 g / cm³. 3 It has a compressive strength of 18 MPa and a water absorption rate of less than 1%.

[0044] Example 4

[0045] This embodiment provides a method for preparing a PMMA resin-based solid buoyancy material, including the following steps: Step 1: Weigh 20g of PMMA macromolecular powder with a relative molecular mass of 40,000, pour it into 100mL of acetone solution and stir to fully dissolve the PMMA, thus preparing an acetone solution containing dissolved PMMA molecules. Then, weigh 30g of modified hollow glass microspheres with a particle size of 120μm, disperse them in the acetone solution containing dissolved PMMA molecules, and stir and mix them mechanically to ensure that the acetone solution completely wets the surface of the modified hollow glass microspheres. The modified hollow glass microspheres are KH-570 modified hollow glass microspheres (KH-570 mass is 1% of the mass of the hollow glass microspheres), and the modification method is based on patent CN200810201267.1. Step 2: Place the thoroughly mixed material from Step 1 into a vacuum drying oven and dry at 60°C for 3 hours to remove acetone and obtain a porous preform. The volatilized acetone is recovered by a cooling device. Step 3: Seal the porous preform obtained in Step 2 in a vacuum bag membrane, and evacuate the bag membrane to remove gas. Then, while evacuating, inject resin stock solution until the porous preform is filled with resin. Stop injecting the solution and stop evacuating. Then, place the vacuum bag membrane in an oven and heat it for curing. The curing reaction conditions are: first react at 50℃ for 12 hours, and then post-cur at 110℃ for 2 hours to obtain PMMA resin-based solid buoyancy material. The resin stock solution consists of MMA monomer and initiator. The initiator is AIBN. The mass ratio of MMA monomer to initiator is 100:2.5, and the mass ratio of resin stock solution to hollow glass microspheres is 100:60.

[0046] The density of the PMMA resin-based solid buoyancy material prepared in this embodiment is 0.39 g / cm³. 3 It has a compressive strength of 20 MPa and a water absorption rate of less than 1%.

[0047] In this embodiment, the surface of the hollow glass microspheres is grafted with γ-(methacryloyloxy)propyltrimethoxysilane KH-570. On the one hand, the γ-(methacryloyloxy) group on KH-570 is similar to the ester structure of PMMA, and has excellent compatibility, which increases the adsorption of PMMA on the surface of the hollow glass microspheres. At the same time, when the MMA resin stock of the porous preform is cured, the unsaturated olefin on KH-570 can copolymerize with MMA to form chemical bonds, which greatly enhances the interfacial bonding strength between the hollow glass microspheres and PMMA.

[0048] Example 5

[0049] Unlike Example 1, this example uses lightweight filler material: hollow ceramic microspheres, wherein the density of the hollow ceramic microspheres is 0.30 g / cm³. 3 Under the same conditions, the density of the PMMA resin-based solid buoyancy material prepared in this embodiment is 0.56 g / cm³. 3 It has a compressive strength of 75 MPa and a water absorption rate of less than 1%.

[0050] Example 6

[0051] Unlike Example 1, this example uses phenolic resin hollow microspheres as the lightweight filler, wherein the density of the phenolic resin hollow microspheres is 0.20 g / cm³. 3 Under the same conditions, the PMMA resin-based solid buoyancy material prepared in this embodiment has a density of 0.42 g / cm³. 3 It has a compressive strength of 38 MPa and a water absorption rate of less than 1%.

[0052] Comparative Example 1

[0053] This comparative example provides a method for preparing a PMMA resin-based solid buoyancy material, including the following steps: Step 1: Weigh the resin stock solution, hollow glass microspheres, and initiator at a mass ratio of 100:60:4; Step 2: Take the weighed resin stock solution, initiator, and hollow glass microspheres, mix them evenly, react at 35℃ for 18 hours, and then cure at 100℃ for 2 hours to obtain PMMA resin-based solid buoyancy material.

[0054] The resin stock solution consists of MMA monomers and PMMA macromolecules, with a mass ratio of 100:20. The relative molecular mass of the PMMA macromolecules is 60,000. The particle size of the hollow glass microspheres is 30 μm. The initiator is a redox initiator (the oxidant is BPO and the reducing agent is DMT).

[0055] The density of the PMMA resin-based solid buoyancy material prepared in this comparative example is 0.59 g / cm³. 3 It has a compressive strength of 65 MPa and a water absorption rate of less than 1%.

[0056] By comparing the performance data with that of Example 1, it can be seen that the PMMA resin-based solid buoyancy material prepared by the method of the present invention has further improved performance compared with the PMMA resin-based solid buoyancy material obtained by directly mixing all hollow glass microspheres into MMA monomer and then curing.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a PMMA resin-based solid buoyancy material, characterized in that, Includes the following steps: First, PMMA is mixed with a solvent to obtain a PMMA solution; then, a light filler is dispersed into the PMMA solution to obtain a mixed solution. The solvent in the mixed solution is removed by heating and drying to obtain a porous preform; The resin stock containing MMA is injected into a porous preform and then cured to obtain a PMMA resin-based solid buoyancy material.

2. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The ratio of PMMA, lightweight filler and solvent is 1~20g:30~70g:100mL.

3. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The relative molecular mass of the PMMA is 40,000 to 1,000,000; the solvent is acetone, methyl methacrylate, dimethyl sulfoxide, dichloromethane, or chloroform; the lightweight filler includes one or a combination of hollow glass microspheres, ceramic hollow microspheres, fly ash hollow glass microspheres, phenolic resin hollow microspheres, and polystyrene hollow microspheres.

4. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The method for dispersing the lightweight filler into the PMMA solution is one or more of mechanical stirring, shaking, and ultrasonic treatment.

5. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The heating and drying temperature is 30~100℃; the heating and drying time is 0.5~10h.

6. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The method for injecting the MMA-containing resin stock solution into the porous preform is by casting, high-pressure injection, or vacuum injection; the parameters of the curing reaction are: first curing at 20~80℃ for 0.1~48h, and then post-curing at 20~120℃ for 1~48h.

7. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The mass ratio of the MMA-containing resin stock solution to the lightweight filler is 100:5~80.

8. The method for preparing a PMMA resin-based solid buoyancy material according to claim 1, characterized in that, The MMA-containing resin stock solution includes MMA monomer, PMMA and initiator; the mass ratio of MMA monomer, PMMA and initiator is 100:0~50:0.5~5.

9. A PMMA resin-based solid buoyancy material prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the PMMA resin-based solid buoyancy material according to claim 9 or the PMMA resin-based solid buoyancy material prepared by any one of claims 1 to 8 in ship hulls, diving equipment or buoys.

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