PMMA/glass fiber composite material and preparation method and application thereof
Technical Field
The invention relates to the field of materials, in particular to a PMMA/glass fiber composite material and a preparation method and application thereof.
Background
Compared with traditional decorative materials (such as glass, stone and the like), the light-transmitting composite material has the advantages of low density, good toughness, easy shaping and the like, and is widely applied to suspended ceilings, light-transmitting background walls, special-shaped lamp decorations, ground light-transmitting upright posts, various tables and ornaments with unique shapes and the like. The glass fiber reinforced composite material is also widely applied to the fields of aerospace, sports goods, wind power blades and the like, but the glass fiber reinforced composite material is low in light transmittance (less than or equal to 35%) and is not suitable for application of a front plate and a back plate of a solar cell. In the photovoltaic field, a part of high-light-transmission polymer materials (PC/PMMA) also begin to replace the traditional glass front plate and are applied to some solar cells, but because the problems of low shrinkage matching, low structural strength, low impact strength and the like of the front plate and the back plate exist, the high-light-transmission polymer materials are widely applied, and particularly the popularization of the high-light-transmission polymer materials on flexible thin-film solar cells is restricted.
Disclosure of Invention
In order to solve the technical problems, the invention provides a PMMA/glass fiber composite material and a preparation method and application thereof.
In a first aspect, the present invention provides a method for preparing a PMMA/glass fiber composite material, the method comprising:
mixing methyl methacrylate, a cross-linking agent and a ketone peroxide initiator to obtain a resin mixture, wherein the mass ratio of the methyl methacrylate to the cross-linking agent is (1-5) to 1, and the ratio of the total mass of the methyl methacrylate and the cross-linking agent to the mass of the ketone peroxide initiator is 200 (1-3);
mixing the resin mixture with alkali-free glass fibers, and curing and molding to obtain the PMMA/glass fiber composite material, wherein the mass ratio of the resin mixture to the alkali-free glass fibers is (60-85): (15-40).
In a second aspect, the present invention provides a PMMA/glass fiber composite material prepared by the above method of the present invention.
In a third aspect, the invention provides an application of the PMMA/glass fiber composite material in the preparation of solar cells.
The invention researches and develops a PMMA/glass fiber composite material by adjusting the formula of the resin mixture (comprising the specific mass ratio of methyl methacrylate to a cross-linking agent, the specific type and the amount of an initiator), taking the resin mixture as an alkali-free glass fiber impregnating compound and adjusting the proportion of the resin mixture to the alkali-free glass fiber, wherein the PMMA/glass fiber composite material has good visible light transmittance, shrinkage matching property, structural strength and impact strength.
According to a preferred embodiment, the mass ratio of the cross-linking agent to the styrene is selected to be styrene, the mass ratio of the methyl methacrylate to the styrene is controlled to be (2-5):1, the ratio of the total mass of the methyl methacrylate and the styrene to the mass of the ketone peroxide initiator is controlled to be 200: (1-3), and the mass ratio of the resin mixture to the alkali-free glass fiber is controlled to be (60-85): (15-40), the PMMA composite material reinforced by the high-light-transmission glass fiber is prepared, can meet the requirements of solar cells on shrinkage matching of a front plate and a back plate and high light transmittance of the front plate, and has excellent structural strength and impact resistance. Specifically, the PMMA/glass fiber composite material prepared by the method has high light transmittance (the visible light transmittance is more than or equal to 70 percent, such as 70-82 percent) and high mechanical property (the tensile strength is more than or equal to 290MPa, such as 290MPa-350MPa, and the impact strength is more than or equal to 14KJ/m2E.g. 14KJ/m2-40KJ/m2) The shrinkage is less than or equal to 0.2 percent (such as 0.1 to 0.2 percent), the shrinkage of the non-fiber reinforced PMMA material is about 0.6 percent), and the preparation method also has the advantages of low cost, quick preparation and continuous production. The PMMA composite material reinforced by the high-light-transmission glass fiber can be used as a front plate or back plate material of a solar cell in a photovoltaic building integration (BIPV, such as a solar power generation tile, a power generation wall, a power generation window and the like), and can also be used as a front plate or back plate material of a solar cell in a solar power generation block or a power generation road.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.
In a first aspect, the present invention provides a method for preparing a PMMA/glass fiber composite material, the method comprising:
mixing methyl methacrylate, a cross-linking agent and a ketone peroxide initiator to obtain a resin mixture, wherein the mass ratio of the methyl methacrylate to the cross-linking agent is (1-5) to 1, and the ratio of the total mass of the methyl methacrylate and the cross-linking agent to the mass of the ketone peroxide initiator is 200 (1-3);
mixing the resin mixture with alkali-free glass fibers, and curing and molding to obtain the PMMA/glass fiber composite material, wherein the mass ratio of the resin mixture to the alkali-free glass fibers is (60-85): (15-40).
It will be appreciated by those skilled in the art that methyl methacrylate inevitably introduces some impurities during the manufacturing process, and in the present invention, according to an alternative embodiment, the purity of methyl methacrylate is above 95%.
In the present invention, according to an alternative embodiment, the mass ratio of the methyl methacrylate to the crosslinking agent is (2-5): 1. Within the above ratio range, the visible light transmittance of the PMMA/glass fiber composite material can be further improved (can be improved to 70% or more) and the shrinkage of the PMMA/glass fiber composite material can be reduced (can be reduced to 0.2% or less).
In the present invention, according to an alternative embodiment, the cross-linking agent is at least one of styrene, phenyl propene and butadiene.
The inventor of the invention finds in research that the cross-linking agent can be used as a cross-linking agent in a curing and forming process and also can be used as a solvent, so that the alkali-free glass fiber can be better infiltrated, and the refractive index of a resin mixture can be improved to be closer to that of the alkali-free glass fiber, so that the visible light transmittance of a composite material system is improved. Wherein, when the cross-linking agent is styrene, the prepared PMMA/glass fiber composite material has obviously better effect: has obviously better visible light transmittance, shrinkage matching, structural strength and impact strength.
In the present invention, according to an alternative embodiment, said ketone peroxide initiator comprises methyl ethyl ketone peroxide and/or cyclohexanone peroxide.
In the resin mixture, the mass ratio of the methyl methacrylate to the cross-linking agent is (2-5):1, and the ratio of the total mass of the methyl methacrylate and the cross-linking agent to the mass of the ketone peroxide initiator is (1-3), so that the refractive index of the resin mixture is close to 1.50, for example, 1.49-1.53, and the refractive index of the resin mixture is close to that of the alkali-free glass fiber, thereby being beneficial to the infiltration of the resin mixture to the alkali-free glass fiber. At normal temperature, the resin mixture is in a liquid state.
It will be appreciated by those skilled in the art that each type of commercially available ketone peroxide initiator is essentially a 30 wt% to 60 wt% (e.g., 40 wt% to 60 wt%) liquid mixture. Therefore, in the present invention, the ratio of the total mass of the methyl methacrylate and the crosslinking agent to the mass of the ketone peroxide initiator is 200 (1-3), wherein the mass of the ketone peroxide initiator in the ratio is: the ketone peroxide initiator is present as a liquid mixture of the mass of solute (e.g., methyl ethyl ketone peroxide or cyclohexanone peroxide, the solvent may be dimethyl phthalate).
In the present invention, according to an optional embodiment, the content of the alkali-free glass fiber is 25 wt% to 35 wt% based on the weight of the mixture of the resin composition and the alkali-free glass fiber. When the content of the alkali-free glass fiber is within the range (25 wt% -35 wt%), the glass fiber has good visible light transmittance, shrinkage matching property, structural strength and impact strength.
In the present invention, the manner of mixing the resin mixture with the alkali-free glass fiber may include: the alkali-free glass fiber is firstly placed in a mould, then the resin mixture is poured into the mould, the resin mixture in a liquid state can be soaked into the alkali-free glass fiber, the amount of the resin mixture and the alkali-free glass fiber is controlled (the resin mixture and the alkali-free glass fiber are mixed or soaked uniformly), the resin mixture is cured and formed, and the alkali-free glass fiber is embedded into the cured and formed resin mixture (namely, the PMMA resin matrix).
In the present invention, the alkali-free glass fiber is not particularly limited, and may be various commercially available alkali-free glass fibers, for example, an alkali-free glass fiber cloth or a long continuous fiber.
In the present invention, according to an alternative embodiment, the conditions for curing and forming include: the temperature is 20-40 ℃. Or naturally curing and molding at normal temperature. When the surface hardness of the material is more than or equal to 2HB, the material is cured and molded, the demolding can be carried out within 2 hours generally, and the complete curing time can be 24-48 hours. The equipment and method for curing and forming are well known to those skilled in the art and will not be described in detail herein.
In a second aspect, the present invention provides a PMMA/glass fiber composite material prepared by the above method of the present invention.
It will be understood by those skilled in the art that the PMMA/glass fiber composite prepared by the present invention comprises: the PMMA resin comprises a PMMA resin matrix and alkali-free glass fibers embedded in the PMMA resin matrix, wherein the mass ratio of the PMMA resin matrix to the alkali-free glass fibers is (60-85): (15-40). Namely: the PMMA/glass fiber composite material comprises a PMMA resin matrix and alkali-free glass fibers embedded in the PMMA resin matrix in a specific proportion, wherein the alkali-free glass fibers and the PMMA resin matrix are integrally formed, and the composite material is an alkali-free glass fiber reinforced PMMA material.
In the present invention, according to an alternative embodiment, the alkali-free glass fibers are present in an amount of 25 wt% to 35 wt%, based on the weight of the PMMA/glass fiber composite. When the content of the alkali-free glass fiber is within the range (25 wt% -35 wt%), the glass fiber has good visible light transmittance, shrinkage matching property, structural strength and impact strength.
In the present invention, according to an alternative embodiment, the visible light transmittance of the PMMA/glass fiber composite material of the present invention is not less than 70%, for example, 70% to 82%.
In the present invention, according to an alternative embodiment, the PMMA/glass fiber composite of the present invention has a tensile strength of not less than 290MPa, for example, 290MPa to 350 MPa.
In the present invention, according to an alternative embodiment, the impact strength of the PMMA/glass fiber composite material of the present invention is not less than 14KJ/m2For example, 14KJ/m2-40KJ/m2。
In the present invention, according to an alternative embodiment, the shrinkage of the PMMA/glass fiber composite of the present invention is not more than 0.2%, for example, 0.1% to 0.2%.
In the present invention, according to an alternative embodiment, the PMMA/glass fiber composite material of the present invention is formed into a plate having a thickness of 2.5mm to 3.5 mm.
In a third aspect, the invention provides an application of the PMMA/glass fiber composite material in the preparation of solar cells. In particular, the PMMA/glass fiber composite can be used as a material for preparing a front plate or a rear plate of a solar cell, particularly a thin film solar cell.
Examples
The present invention will be described in detail below by way of examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, each material used was commercially available, and each method used was a method conventional in the art.
The refractive index of the resin blend was measured using a Mettler-Torrilti refractive index Meter (R4).
Methyl methacrylate was purchased from Beijing Hua instrumental Intelligent science, Inc. with a purity of 98%.
Alkali-free glass fiber cloth was purchased from Clalas corporation and had a refractive index of 1.545.
Initiator MEKP-9 was obtained from Soujin U.S.A. methyl ethyl ketone peroxide in dimethyl phthalate, the mass concentration of methyl ethyl ketone peroxide being 50%.
Example 1
This example illustrates the PMMA/glass fiber composite of the present invention and its method of preparation.
(1) Mixing methyl methacrylate, styrene and an initiator MEKP-9 to obtain a resin mixture, wherein the mass ratio of the methyl methacrylate to the styrene is 3:1, the ratio of the total mass of the methyl methacrylate and the styrene to the mass of the MEKP-9 is 100:2, and the refractive index of the resin mixture is 1.52;
(2) cutting the alkali-free glass fiber cloth, putting the cut alkali-free glass fiber cloth into a mold, pouring the resin mixture into the mold, soaking and mixing the resin mixture with the alkali-free glass fiber cloth, curing the mixture at 25 ℃ for 30 hours, and forming a plate with the thickness of 3mm to obtain the PMMA/glass fiber composite plate, wherein the mass ratio of the resin mixture to the alkali-free glass fiber cloth is 70: 30, the PMMA/glass fiber composite board comprises a PMMA resin matrix and alkali-free glass fibers embedded in the PMMA resin matrix.
Example 2
This example illustrates the PMMA/glass fiber composite of the present invention and its method of preparation.
(1) Mixing methyl methacrylate, styrene and an initiator MEKP-9 to obtain a resin mixture, wherein the mass ratio of the methyl methacrylate to the styrene is 2:1, the ratio of the total mass of the methyl methacrylate and the styrene to the mass of the initiator MEKP-9 is 100:1, and the refractive index of the resin mixture is 1.53;
(2) cutting the alkali-free glass fiber cloth, putting the cut alkali-free glass fiber cloth into a mold, pouring the resin mixture into the mold, soaking and mixing the resin mixture with the alkali-free glass fiber cloth, curing the mixture at 28 ℃ for 30 hours, and forming a plate with the thickness of 3.2mm to obtain the PMMA/glass fiber composite plate, wherein the mass ratio of the resin mixture to the alkali-free glass fiber cloth is 75: 25, the PMMA/glass fiber composite board comprises a PMMA resin matrix and alkali-free glass fibers embedded in the PMMA resin matrix.
Example 3
This example illustrates the PMMA/glass fiber composite of the present invention and its method of preparation.
(1) Mixing methyl methacrylate, styrene and an initiator MEKP-9 to obtain a resin mixture, wherein the mass ratio of the methyl methacrylate to the styrene is 5:1, the ratio of the total mass of the methyl methacrylate and the styrene to the mass of the MEKP-9 is 100:3, and the refractive index of the resin mixture is 1.50;
(2) cutting the alkali-free glass fiber cloth, putting the cut alkali-free glass fiber cloth into a mold, pouring the resin mixture into the mold, soaking and mixing the resin mixture with the alkali-free glass fiber cloth, curing the mixture at 25 ℃ for 30 hours, and forming a plate with the thickness of 2.8mm to obtain the PMMA/glass fiber composite plate, wherein the mass ratio of the resin mixture to the alkali-free glass fiber cloth is 65: 35, the PMMA/glass fiber composite board comprises a PMMA resin matrix and alkali-free glass fibers embedded in the PMMA resin matrix.
Example 4
The method of example 1 is followed except that, in the step (2), the mass ratio of the resin mixture to the alkali-free glass fiber cloth is 60: 40.
example 5
The method of example 1 is followed except that, in step (2), the mass ratio of the resin mixture to the alkali-free glass fiber cloth is 85: 15.
example 6
The procedure of example 1 was followed except that in step (1), styrene was replaced with phenylpropylene.
In this example, phenyl propylene is used as a cross-linking agent, and the network structure of the cross-linking reaction is different from that of example 1, and the resin casting body is in an unclarified state, so that the prepared PMMA/glass fiber composite material has a high haze appearance. The visible light transmittance was 51.2%.
Example 7
The procedure of example 1 was followed except that in step (1), butadiene was used in place of styrene.
In this example, butadiene was used as a cross-linking agent, and the network structure of the cross-linking reaction was different from that of example 1, and the resin casting was in an unclarified state, resulting in the production of a PMMA/glass fiber composite material having a high haze appearance. The visible light transmittance was 46.3%.
Example 8
The procedure of example 1 was followed except that in step (1), MEKP-9 was replaced with a dimethyl phthalate solution of cyclohexanone peroxide (cyclohexanone peroxide concentration of 50% by mass).
Example 9
The procedure of example 1 was followed except that in step (1), the mass ratio of methyl methacrylate to styrene was 1: 1.
Comparative example 1
The procedure of example 1 was followed except that in step (1), the mass ratio of methyl methacrylate to styrene was 6: 1.
Comparative example 2
The method of example 1 was followed except that, in the step (2), the mass ratio of the resin composition to the alkali-free glass fiber cloth was 50: 50.
comparative example 3
The method of example 1 was followed except that, in the step (2), the mass ratio of the resin composition to the alkali-free glass fiber cloth was 90: 10.
comparative example 4
The process of example 1 was followed except that in step (1), the ratio of the total mass of methyl methacrylate and styrene to the mass of MEKP-9 was 100: 4.
In this comparative example, since the reaction was too rapid, local implosion occurred during the resin curing molding process, the wettability of the resin and the glass fiber was decreased in a microscopic state, and the prepared PMMA/glass fiber composite exhibited an overall whitish appearance (opaque).
Test examples
The PMMA/glass fiber composite plates prepared in the examples 1 to 9 and the comparative examples 1 to 4 are subjected to the following parameter tests, and the test data are shown in the table 1.
The method for testing the visible light transmittance comprises the following steps: GB/T2410 & lt 2008 & gt determination of light transmittance and haze of transparent plastic & lt.
Tensile strength test method: GB/T1040.2-2006 section 2 for determination of tensile Properties of plastics: test conditions for molded and extruded plastics, test speed: 50 mm/min.
Test method of impact strength: GB/T1043.1-2008' determination of impact property of plastic simply supported beam part 1: non-instrumented impact testing.
Shrinkage test method: ASTM D955 + 2008 Standard test method for measurement of shrinkage of model dimensions for thermoplastics.
TABLE 1
Comparing the data of example 1 and comparative example 1 in table 1, it can be seen that when the mass ratio of the methyl methacrylate to the cross-linking agent is (1-5):1, the PMMA/glass fiber composite material prepared has significantly better visible light transmittance, shrinkage matching property, structural strength and impact strength.
Comparing the data of example 1 and comparative examples 2 to 3 in table 1, it can be seen that the mass ratio of the resin mixture to the alkali-free glass fiber is controlled to (60-85): (15-40), the prepared PMMA/glass fiber composite material has obviously better visible light transmittance, shrinkage matching property, structural strength and impact strength.
Comparing the data of example 1 and comparative example 4 in table 1, it can be seen that, in the preparation process, when the ratio of the total mass of the methyl methacrylate and the crosslinking agent to the mass of the ketone peroxide initiator is controlled to be 200 (1-3), the prepared PMMA/glass fiber composite material has significantly better visible light transmittance, shrinkage matching property, structural strength and impact strength.
Comparing the data of example 1 and examples 4 to 5 in table 1, it can be seen that, in the preparation process, composite materials satisfying different conditions of visible light transmittance, shrinkage matching property, structural strength and impact strength can be prepared according to requirements, wherein when the content of the alkali-free glass fiber is 25 wt% to 35 wt% based on the weight of the mixture of the resin mixture and the alkali-free glass fiber, the prepared PMMA/glass fiber composite material has good visible light transmittance, shrinkage matching property, structural strength and impact strength.
Comparing the data of example 1 and examples 6-7 in table 1, it can be seen that when styrene is selected as the crosslinking agent, the PMMA/glass fiber composite material prepared has better visible light transmittance, and also has better visible light transmittance, shrinkage matching property, structural strength and impact strength.
Comparing the data of example 1 and example 9 in table 1, it is found that when the mass ratio of methyl methacrylate to the crosslinking agent is (2-5):1, the visible light transmittance of the PMMA/glass fiber composite material prepared can be further improved (can be improved to 70% or more) and the shrinkage of the PMMA/glass fiber composite material prepared can be reduced (can be reduced to 0.2% or less).
Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.