An isotropic glass fiber-reinforced photocurable material and a method for producing the same

Abstract

The application discloses an isotropic glass fiber reinforced photocuring material and a preparation method thereof, and specifically comprises the following steps: firstly, alkylated modified glass fibers are prepared by treating glass fibers through a chemical grafting modification method; then, bisphenol A epoxy acrylate, monofunctionality acrylate monomer and a photoinitiator are mixed, and the alkylated modified glass fibers are added as a reinforcing phase, so that an isotropic photocuring material is obtained through a photocuring 3D printing technology. The alkylated modified glass fibers are used as the reinforcing phase, the chemical bonding between the fibers and the matrix is enhanced, the tensile strength of a printed product is significantly improved, and anisotropy is reduced. The innovation realizes the mechanical properties of the reinforcing material while maintaining isotropy by optimizing the combination mechanism of the modified glass fibers and the resin matrix, and indicates that the application prospect of the photocuring 3D printing product in the industrial field will be widened.

Description

Technical Field

[0001] This invention relates to an isotropic glass fiber reinforced photocurable material and its preparation method, specifically to enhancing the isotropic mechanical properties of a photosensitive acrylate resin system by alkylating modified glass fibers, belonging to the field of chemical and polymer materials technology. Background Technology

[0002] Photopolymer 3D printing is an advanced technology that uses computer-controlled visible or ultraviolet light to initiate the polymerization of liquid photosensitive resin layer by layer on a printing platform to build three-dimensional structures. This technology can be categorized into stereolithography (SLA), digital light processing (DLP), liquid crystal display (LCD), continuous liquid interface manufacturing (CLIP), and high-area rapid printing (HARP), among others. These technologies are characterized by high efficiency, high resolution, and easy separation of printed structures, while also supporting the recycling of uncured resin, demonstrating significant advantages for industrial applications.

[0003] However, the mechanical properties of currently widely used photopolymer 3D printing acrylic resins are not ideal, limiting their widespread application in medical devices, electronic components, automotive parts, and aerospace. This stems from two factors: the inherent structural characteristics of acrylic materials and the relatively weak interlayer bonding caused by the layer-by-layer deposition modeling technique of photopolymer 3D printing. Consequently, the mechanical properties of the samples exhibit significant anisotropy, especially in the vertical printing direction where performance is significantly lower than in the horizontal direction.

[0004] Therefore, improving the mechanical properties of photopolymer 3D printing resins to meet a wider range of application needs has become a current research hotspot in the scientific research field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an isotropic glass fiber reinforced photocurable material and its preparation method. By using alkylated modified glass fiber as the reinforcing phase, the chemical bonding between the fiber and the matrix is ​​enhanced, significantly improving the tensile strength of the printed product and reducing anisotropy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The first objective of this invention is to provide an isotropic glass fiber reinforced photocurable material, wherein the isotropic glass fiber reinforced photocurable material is a photosensitive resin in which alkylated modified glass fibers are distributed, the content of the alkylated modified glass fibers is 10-30 wt.% of the photosensitive resin, wherein the tensile strength anisotropy of the isotropic glass fiber reinforced photocurable material is not higher than 9.3%, and the elongation at break anisotropy is lower than or higher than 9.0%.

[0008] A second objective of this invention is to provide the use of alkylated modified glass fibers in the preparation of isotropic glass fiber reinforced photocurable materials, wherein the isotropic glass fiber reinforced photocurable material is as described above, and the alkylated modified glass fibers are obtained by grafting glass fibers with a silane coupling agent.

[0009] A third objective of this invention is to provide a method for preparing an isotropic glass fiber reinforced photocurable material, the method comprising the following steps:

[0010] Bisphenol A epoxy acrylate, monofunctional acrylate monomer and photoinitiator are mixed to obtain photosensitive resin;

[0011] Alkylated modified glass fibers are added to the photosensitive resin, with the content of the alkylated modified glass fibers being 10-30 wt.% of the photosensitive resin. After dispersion and mixing, an alkylated modified glass fiber reinforced photosensitive resin solution is obtained. This solution is then subjected to 3D printing and post-curing to prepare a composite material, which is an isotropic glass fiber reinforced photocurable material. The alkylated modified glass fibers are obtained by grafting glass fibers with a silane coupling agent.

[0012] A fourth objective of this invention is to provide applications of isotropic glass fiber reinforced photocurable materials prepared as described above, or as any of the methods described above, in the fields of medical devices, electronic components, automotive parts, or aerospace.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0014] 1. Glass fiber (GF) is a high-performance inorganic non-metallic material. When added as a reinforcing phase to a photosensitive resin matrix, it significantly improves mechanical properties. Building upon this, this invention utilizes a silane coupling agent to undergo a grafting reaction with GF, yielding alkylated modified glass fiber. Using this alkylated modified glass fiber as a reinforcing phase further enhances the chemical bond between the fiber and the matrix, significantly improving the tensile strength of the printed product and reducing anisotropy. This innovation, by optimizing the bonding mechanism between the modified glass fiber and the resin matrix, achieves enhanced mechanical properties while maintaining isotropy, indicating a promising future for the industrial application of photopolymer 3D printed products.

[0015] 2. This invention provides a novel glass fiber reinforced photosensitive acrylate resin system specifically designed for photopolymer DLP 3D printing. This system utilizes the bridging effect of GF between layers to effectively compensate for insufficient interfacial bonding during layer-by-layer deposition. This method is simple to operate and significantly improves the anisotropy of photosensitive acrylate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the reasons for the anisotropy of mechanical properties in photopolymer 3D printed parts.

[0017] Figure 2 This is a schematic diagram illustrating the principle of the present invention.

[0018] Figure 3 These are viscosity curves of printing solutions with different GF addition amounts provided in Experimental Example 1 of this invention.

[0019] Figure 4 These are UV-cured photo-DSC curves of printing solutions with different GF addition amounts provided in Experimental Example 1 of this invention.

[0020] Figure 5 This is the relationship between curing depth and ultraviolet exposure energy provided in Experimental Example 1 of this invention.

[0021] Figure 6 This is a 3D printing process diagram of the modified GF-enhanced sample provided in Embodiment 1 of the present invention.

[0022] Figure 7 These are the infrared spectra of GF before and after modification provided in Embodiment 1 of the present invention.

[0023] Figure 8 These are the thermogravimetric analysis curves of GF before and after modification provided in Embodiment 1 of the present invention.

[0024] Figure 9 The tensile properties of the modified GF composite material provided in Example 1 of this invention are anisotropic.

[0025] Figure 10 This is the tensile fracture section of the modified GF-reinforced sample printed in the horizontal direction according to Embodiment 1 of the present invention.

[0026] Figure 11 This is the tensile fracture section of the modified GF-reinforced sample printed in the vertical direction according to Embodiment 1 of the present invention.

[0027] Figure 12 This is a 3D printed nut and bolt model provided in Embodiment 1 of the present invention.

[0028] Figure 13 This is the 3D printed hollow structure model provided in Embodiment 1 of the present invention. Detailed Implementation

[0029] In the DLP 3D printing process, because each layer of photosensitive resin is cured and then the next layer is added, the bonding strength between layers is limited. This insufficient interlayer bonding strength causes the printed parts to exhibit extremely obvious anisotropy in terms of mechanical properties, such as... Figure 1As shown, this anisotropy can exacerbate stress concentration when the part is subjected to complex stresses, thus adversely affecting the overall performance of the part.

[0030] Currently, the main solutions to the anisotropy of mechanical properties in photopolymer 3D printed products include core-shell particle toughening, constructing a dual-curing network, and introducing dynamic covalent bonds. These strategies aim to enhance interlayer bonding, but core-shell particle toughening cannot eliminate the anisotropy of elongation at break; dual-curing systems require additional heat treatment; and the introduction of dynamic disulfide bonds requires the design and synthesis of specific structures, and its tensile strength is relatively low.

[0031] Based on this situation, the present invention provides a novel alkylated modified glass fiber reinforced photosensitive acrylate resin system specifically designed for photopolymer DLP 3D printing, such as... Figure 2 As shown, this system utilizes the bridging effect of alkylated modified GF between layers to effectively compensate for the insufficient interfacial bonding force during the layer-by-layer deposition process.

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. However, this should not be construed as limiting the scope of the present invention to the following examples. Various substitutions or modifications made based on ordinary technical knowledge and conventional methods in the art without departing from the above-described methodological concept of the present invention should be included within the scope of the present invention.

[0033] Example

[0034] The first aspect of the present invention is to provide an isotropic glass fiber reinforced photocurable material, wherein the isotropic glass fiber reinforced photocurable material is a photosensitive resin in which alkylated modified glass fibers are distributed, the content of the alkylated modified glass fibers is 10-30 wt.% of the photosensitive resin, wherein the tensile strength anisotropy of the isotropic glass fiber reinforced photocurable material is not higher than 9.3%, and the elongation at break anisotropy is not higher than 9.0%.

[0035] Preferably, the alkylated modified glass fiber content is 20-30 wt.% of the photosensitive resin. More preferably, the alkylated modified glass fiber content is 30 wt.% of the photosensitive resin.

[0036] Optionally, in one embodiment of the present invention, the tensile strength anisotropy of the isotropic glass fiber reinforced photocurable material is not higher than 7.5%, and the elongation at break anisotropy is not higher than 7.0%.

[0037] Preferably, the tensile strength anisotropy of the isotropic glass fiber reinforced photocurable material is not higher than 5.0%, and the elongation at break anisotropy is not higher than 3.5%.

[0038] Optionally, in one embodiment of the present invention, the tensile strength of the isotropic glass fiber reinforced photocurable material is higher than 70 MPa.

[0039] Optionally, in one embodiment of the present invention, the elongation at break of the isotropic glass fiber reinforced photocurable material is higher than 6%.

[0040] Optionally, in one embodiment of the present invention, the isotropic glass fiber reinforced photocurable material is at 2985 cm⁻¹. -1 and 2902cm -1 The peaks at 1054 cm⁻¹ exhibit both asymmetric and symmetric CH₂ vibrations, respectively. -1 It exhibits a Si-O-Si stretching vibration peak at 1411 cm⁻¹. -1 It has a CH bending vibration peak of -CH3.

[0041] A second aspect of the present invention is to provide the use of alkylated modified glass fibers in the preparation of isotropic glass fiber reinforced photocurable materials, wherein the isotropic glass fiber reinforced photocurable material is as described above, and the alkylated modified glass fibers are obtained by grafting glass fibers with a silane coupling agent.

[0042] Optionally, in one embodiment of the present invention, the grafting reaction of the glass fiber with the silane coupling agent specifically includes the following steps:

[0043] (a) Treat the glass fiber with acetone at room temperature for 12-48 hours to remove surface contaminants, then wash with water and dry to obtain pretreated glass fiber.

[0044] (b) The pH of a 95% ethanol aqueous solution was adjusted to 3 ± 0.5 with an acidic solution, and a silane coupling agent and the pretreated glass fiber were added to carry out a grafting reaction to obtain the grafted product.

[0045] (c) After the reaction is complete, the grafted product is washed and dried to obtain alkylated modified glass fiber.

[0046] Optionally, in one embodiment of the present invention, the amount of the 95% ethanol aqueous solution added is 50-100 ml, based on 5 g equivalent of glass fiber.

[0047] Optionally, in one embodiment of the present invention, the acidic solution is one or more of hydrochloric acid, sulfuric acid, or nitric acid solutions.

[0048] Optionally, in one embodiment of the present invention, the content of the alkylated modified glass fiber is 10-30 wt.% of the photosensitive resin.

[0049] Preferably, the alkylated modified glass fiber content is 20-30 wt.% of the photosensitive resin. More preferably, the alkylated modified glass fiber content is 30 wt.% of the photosensitive resin.

[0050] Optionally, in one embodiment of the present invention, the grafting reaction temperature is 0–50°C and the reaction time is 5–12 h.

[0051] Optionally, in one embodiment of the present invention, the silane coupling agent includes at least one of KH570, KH540 and KH590.

[0052] Optionally, in one embodiment of the present invention, the mass ratio of the silane coupling agent to the glass fiber is 0.1 to 0.3:1.

[0053] A third aspect of the present invention is to provide a method for preparing an isotropic glass fiber reinforced photocurable material, the method comprising the following steps:

[0054] Bisphenol A epoxy acrylate, monofunctional acrylate monomer and photoinitiator are mixed to obtain photosensitive resin;

[0055] Alkylated modified glass fibers are added to the photosensitive resin, dispersed, and mixed to obtain an alkylated modified glass fiber reinforced photosensitive resin solution. 3D printing and post-curing are then performed to prepare a composite material, which is an isotropic glass fiber reinforced photocurable material. The alkylated modified glass fibers are obtained by grafting glass fibers with a silane coupling agent.

[0056] Optionally, in one embodiment of the present invention, the monofunctional acrylate monomer includes one or more of isobornyl acrylate, dicyclopentadiene acrylate, hydroxyethyl acrylate, diethoxy acrylate, and tetrahydrofuran acrylate.

[0057] Optionally, in one embodiment of the present invention, the photoinitiator includes one or more of 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0058] Optionally, in one embodiment of the present invention, the mass ratio of the bisphenol A epoxy acrylate, the monofunctional acrylate monomer, and the photoinitiator is 24–36:4–16:0.4–0.8.

[0059] Optionally, in one embodiment of the present invention, the dispersion time is 1 to 5 minutes.

[0060] Optionally, in one embodiment of the present invention, the post-curing time is 10 to 50 seconds.

[0061] Optionally, in one embodiment of the present invention, the grafting reaction of the glass fiber with the silane coupling agent specifically includes the following steps:

[0062] (a) Treat the glass fiber with acetone at room temperature for 12-48 hours to remove surface contaminants, then wash with water and dry to obtain pretreated glass fiber.

[0063] (b) The pH of a 95% ethanol aqueous solution was adjusted to 3 ± 0.5 with an acidic solution, and a silane coupling agent and the pretreated glass fiber were added to carry out a grafting reaction to obtain the grafted product.

[0064] (c) After the reaction is complete, the grafted product is washed and dried to obtain alkylated modified glass fiber.

[0065] Optionally, in one embodiment of the present invention, the amount of the 95% ethanol aqueous solution added is 50-100 ml, based on 5 g equivalent of glass fiber.

[0066] Optionally, in one embodiment of the present invention, the acidic solution is one or more solutions such as hydrochloric acid, sulfuric acid, or nitric acid.

[0067] Optionally, in one embodiment of the present invention, the grafting reaction temperature is 0–50°C and the reaction time is 5–12 h.

[0068] Preferably, the grafting reaction is carried out at a temperature of 20–50°C for 6–12 hours.

[0069] Optionally, in one embodiment of the present invention, the silane coupling agent includes at least one of KH570, KH540 and KH590.

[0070] Optionally, in one embodiment of the present invention, the mass ratio of the silane coupling agent to the glass fiber is 0.1 to 0.3:1.

[0071] A fourth aspect of the invention is to provide the application of isotropic glass fiber reinforced photocurable materials prepared as described above, or as any of the methods described above, in the fields of medical devices, electronic components, automotive parts, or aerospace.

[0072] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the specific material ratios, process conditions, and results described in the embodiments are for illustrative purposes only and should not, and will not, limit the present invention as described in detail in the claims.

[0073] Example 1: Preparation of Unmodified GF-Reinforced Photocurable Composite Material

[0074] To explore the process conditions for the preparation of modified GF materials for photocurable composites, this invention first uses GF as a raw material and studies the effect of different GF addition amounts on the preparation of GF-reinforced photocurable composites. This aims to serve as a control for the preparation of modified GF-reinforced photocurable composites using modified GF materials, and also to provide some reference for the process conditions of using modified GF materials for the preparation of modified GF-reinforced photocurable composites.

[0075] The specific preparation method of the GF-reinforced photocurable composite material in this experimental example is as follows:

[0076] (a) Bisphenol A epoxy acrylate (24 g), dicyclopentadiene acrylate (16 g) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.8 g) were mixed to obtain a photosensitive resin;

[0077] (b) Then, 0, 4, 8, 12, 16, and 20 g of GF were added to the photosensitive resin respectively (corresponding to 0 wt.%, 10 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.%, respectively; in this invention, the amount of GF added refers to the mass ratio of GF to the photosensitive resin, and the amount of modified GF added subsequently refers to the mass ratio of modified GF to the photosensitive resin). The solution was dispersed in a high-speed disperser at 3000 r / min for 2 min to obtain a uniformly mixed GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare a GF-reinforced photocurable composite material.

[0078] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 20 seconds.

[0079] See appendix Figure 3 This is the viscosity curve of the printing solution with different GF addition amounts provided in Experimental Example 1 of this invention. As can be seen from the figure, when the GF addition amount is 50 wt.% and the shear rate is 1 s, the viscosity curve is significantly higher. -1 At that point, the viscosity of the resin system reached 9.8 Pa·s, making printing difficult. However, the viscosity of the printing solution with a concentration of 0-40 wt% was at most 6.8 Pa·s, both meeting the requirements for DLP 3D printing. Therefore, in other performance tests of GF-reinforced photopolymer composites, the GF addition amount was consistently 0-40 wt%.

[0080] See appendix Figure 4The figure shows the UV-cured photo-DSC curves of printing solutions with different GF addition amounts provided in Experimental Example 1 of this invention. As can be seen from the figure, the printing solution reacts rapidly under UV irradiation, reaching its peak value within approximately 10 seconds. Furthermore, as the GF addition amount in the printing solution increases, the peak value of the exothermic peak gradually decreases, and the time required to reach the peak value also gradually decreases, indicating that the curing speed decreases with increasing GF addition amount.

[0081] See appendix Figure 5 This is the relationship between curing depth and UV exposure energy provided in Experimental Example 1 of this invention. As shown in the figure, the transmission depth (Dp) and the critical UV exposure energy (Ec), i.e., the minimum energy required to begin curing, can be obtained by fitting the logarithm of the curing depth (Cd) of the printing solution to the UV exposure energy E according to the Jacob equation:

[0082]

[0083] The higher the GF content, the lower the curing depth Cd of the composite material.

[0084] See Table 1, which shows the transmission depth and critical ultraviolet exposure energy provided in Experimental Example 1 of this invention. As the content of GF-KH570-1 increases, the Dp and Ec values ​​show a decreasing trend, which means that the curing layer starts to form earlier.

[0085] Table 1. Transmission depth and critical ultraviolet exposure energy in Experiment Example 1

[0086]

[0087]

[0088] Referring to Table 2, which shows the tensile properties of the initial GF composite material provided in Experimental Example 1 of this invention, the resin material with 30 wt.% GF added exhibits the highest tensile strength (64.2 MPa). This represents a 43.9% increase compared to the sample prepared from pure resin (GF addition of 0 wt.%). Furthermore, the tensile strength does not increase with increasing GF content in the resin; it peaks at 30 wt% and then decreases with further increases in GF content. This invention aims to prepare an isotropic photocurable material with good mechanical properties. Since the composite material exhibits the highest tensile strength with 30 wt% GF added, subsequent examples control the GF addition amount within the range of 0-30 wt% during the preparation of modified GF-reinforced photocurable composite materials, exploring the influencing factors of anisotropy while ensuring good mechanical properties.

[0089] Table 2 Tensile properties of the initial GF composite material

[0090]

[0091] Example 1: Preparation of modified GF-reinforced photocurable composite material

[0092] In this embodiment of the invention, the process conditions of Experimental Example 1 above are used as a reference, and modified GF is used as a raw material to prepare modified GF reinforced photocurable composite material.

[0093] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0094] 1) Preparation of alkylated modified glass fiber GF-KH570-1

[0095] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0096] Add 50 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with hydrochloric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1 g of KH570 silane coupling agent, stir continuously at room temperature for 12 hours to obtain the grafted product.

[0097] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-1). GF-KH570-1 was used to prepare modified GF composite materials.

[0098] 2) Preparation of GF-KH570-1 reinforced photocurable composite material

[0099] Bisphenol A epoxy acrylate (24g), dicyclopentadiene acrylate (16g), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.8g) were mixed to obtain a photosensitive resin.

[0100] Then, 12g of GF-KH570-1 (corresponding to an addition amount of 30wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 2min using a high-speed disperser to obtain a uniformly mixed GF-KH570-1 reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-1 reinforced photocurable composite material.

[0101] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 20 seconds.

[0102] See appendix Figure 6This is a 3D printing process diagram of the modified GF reinforced sample provided in Example 1 of the present invention. The modified GF reinforced composite material was prepared by DLP 3D printing with KH-570 modified GF as the reinforcement and epoxy acrylate and dicyclopentadiene acrylate as the matrix.

[0103] See appendix Figure 7 It is the infrared spectrum of GF before and after modification when the addition amount is 30 wt.%, as provided in Example 1 of this invention, at 2985 cm⁻¹. -1 and 2902cm -1 CH2 asymmetric and symmetric vibration peaks appeared at 1054 cm⁻¹, respectively. -1 A stretching vibration peak of Si-O-Si appears at 1411 cm⁻¹. -1 The new peak appearing is the CH bending vibration peak of -CH3. This indicates that KH570 was successfully grafted onto the GF surface.

[0104] See appendix Figure 8 It is the thermogravimetric analysis curve of GF before and after modification when the addition amount is 30wt.% provided in Example 1 of the present invention. The mass loss of GF grafted with KH570 occurs at 250-500℃ and the mass loss reaches 1.6%.

[0105] See Table 3, which shows the tensile properties of the modified GF-KH570-1 composite material in different directions when the addition amount is 30 wt.% as provided in Example 1 of this invention. When 30 wt% GF-KH570 is added, the tensile strength of the printed sample reaches 74.5 MPa, which is 67.0% higher than that of the resin sample and 16.0% higher than that of the GF reinforced composite material.

[0106] Table 3 Tensile properties of the modified GF-KH570-1 composite material in different directions

[0107]

[0108] See appendix Figure 9 This is the anisotropy of tensile properties of the modified GF-KH570-1 composite material provided in Example 1 of this invention when the addition amount is 30 wt.%. The anisotropy of the printing material is calculated according to the following formula:

[0109]

[0110] Compared to the pure resin printed sample (39.2%), the tensile strength anisotropy of the printed sample containing 30 wt% GF prepared in Example 1 decreased significantly to 9.5%, while the elongation at break anisotropy decreased to 9.4%. When GF was modified in Example 1, the tensile strength anisotropy of the reinforced printed sample further decreased to 4.2%, while the elongation at break anisotropy decreased to 3.0%.

[0111] See appendix Figure 10 , 11 These are the tensile fracture sections of the modified GF-KH570-1 reinforced sample printed in the horizontal direction and the tensile fracture sections of the modified GF-KH570-1 reinforced sample printed in the vertical direction, respectively, provided in Embodiment 1 of the present invention. GF-KH570-1 is randomly distributed in the resin as a whole, and some fibers penetrate through different layers, which improves the interlayer adhesion and thus improves the mechanical strength in this direction.

[0112] See appendix Figure 12 It is a 3D printed nut and bolt model provided in Embodiment 1 of the present invention.

[0113] See appendix Figure 13 It is the 3D printed hollow structure model provided in Embodiment 1 of the present invention.

[0114] Example 2: Preparation of modified GF-reinforced photocurable composite material

[0115] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0116] 1) Preparation of alkylated modified glass fiber GF-KH570-2

[0117] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0118] Add 100 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with nitric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1.5 g of KH570 silane coupling agent, stir continuously at 30 °C for 8 hours to obtain the grafted product.

[0119] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-2). GF-KH570-2 was used to prepare modified GF composite materials.

[0120] 2) Preparation of GF-KH570-2 reinforced photocurable composite material

[0121] Bisphenol A epoxy acrylate (32g), dicyclopentadiene acrylate (8g) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.4g) were mixed to obtain a photosensitive resin;

[0122] Then, 12g of GF-KH570-2 (corresponding to an addition amount of 30wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 5min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-2 reinforced photocurable composite material.

[0123] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 30 seconds.

[0124] The tensile strength anisotropy of the GF-KH570-2 reinforced photocurable composite material sample prepared in this embodiment is 4.3%, and the elongation at break anisotropy is 2.8%.

[0125] Example 3: Preparation of modified GF-reinforced photocurable composite material

[0126] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0127] 1) Preparation of alkylated modified glass fiber GF-KH570-3

[0128] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0129] Add 70 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with hydrochloric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1.5 g of KH570 silane coupling agent, stir continuously at room temperature for 8 hours to obtain the grafted product.

[0130] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (GF-KH570-3). GF-KH570-3 was used to prepare modified GF composite materials.

[0131] 2) Preparation of GF-KH570-3 reinforced photocurable composite material

[0132] Bisphenol A epoxy acrylate (32g), dicyclopentadiene acrylate (8g) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.8g) were mixed to obtain a photosensitive resin;

[0133] Then, 8g of GF-KH570-3 (corresponding to an addition amount of 20wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 2min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-3-reinforced photocurable composite material.

[0134] After printing, use ethanol to clean the residual resin solution on the sample surface, and then use a full-band tracked light curing machine for post-curing, with a total curing time of about 30 seconds.

[0135] The tensile strength anisotropy of the GF-KH570-3 reinforced photocurable composite material sample prepared in this embodiment is 6.7%, and the elongation at break anisotropy is 6.4%.

[0136] Example 4: Preparation of modified GF-reinforced photocurable composite material

[0137] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0138] 1) Preparation of alkylated modified glass fiber GF-KH570-4

[0139] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0140] Add 100 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with sulfuric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1 g of KH570 silane coupling agent, stir continuously at 50 °C for 8 hours to obtain the grafted product.

[0141] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (GF-KH570-4). GF-KH570-4 was used to prepare modified GF composite materials.

[0142] 2) Preparation of GF-KH570-4 reinforced photocurable composite material

[0143] Bisphenol A epoxy acrylate (24g), hydroxyethyl acrylate (16g), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.4g) were mixed to obtain a photosensitive resin.

[0144] Then, 8g of GF-KH570-4 (corresponding to an addition amount of 20wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 3min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-4-reinforced photocurable composite material.

[0145] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 40 seconds.

[0146] The tensile strength anisotropy of the GF-KH570-4 reinforced photocurable composite material sample prepared in this embodiment is 7.1%, and the elongation at break anisotropy is 6.9%.

[0147] Example 5: Preparation of modified GF-reinforced photocurable composite material

[0148] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0149] 1) Preparation of alkylated modified glass fiber GF-KH570-5

[0150] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0151] Add 100 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with nitric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1 g of KH570 silane coupling agent, stir continuously at 50 °C for 8 hours to obtain the grafted product.

[0152] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-5). GF-KH570-5 was used to prepare modified GF composite materials.

[0153] 2) Preparation of GF-KH570-5 reinforced photocurable composite material

[0154] Bisphenol A epoxy acrylate (24g), bisethoxy acrylate (16g), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.4g) were mixed to obtain a photosensitive resin.

[0155] Then, 12g of GF-KH570-5 (corresponding to an addition amount of 30wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 3min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-5 reinforced photocurable composite material.

[0156] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 40 seconds.

[0157] The tensile strength anisotropy of the GF-KH570-5 reinforced photocurable composite material sample prepared in this embodiment is 4.8%, and the elongation at break anisotropy is 3.3%.

[0158] Example 6: Preparation of modified GF-reinforced photocurable composite material

[0159] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0160] 1) Preparation of alkylated modified glass fiber GF-KH570-6

[0161] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0162] Add 80 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with sulfuric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1.5 g of KH570 silane coupling agent, stir continuously at room temperature for 6 hours to obtain the grafted product.

[0163] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-6). GF-KH570-6 was used to prepare modified GF composite materials.

[0164] 2) Preparation of GF-KH570-6 reinforced photocurable composite material

[0165] Bisphenol A epoxy acrylate (28g), hydroxyethyl acrylate (12g), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.4g) were mixed to obtain a photosensitive resin.

[0166] Then, 4g of GF-KH570-6 was added to the photosensitive resin (correspondingly, the amount of GF-KH570-6 added was 10wt.%), and dispersed at 3000r / min for 2min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-6 reinforced photocurable composite material.

[0167] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 20 seconds.

[0168] The tensile strength anisotropy of the GF-KH570-6 reinforced photocurable composite material sample prepared in this embodiment is 9.3%, and the elongation at break anisotropy is 8.9%.

[0169] Example 7: Preparation of modified GF-reinforced photocurable composite material

[0170] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0171] 1) Preparation of alkylated modified glass fiber GF-KH570-7

[0172] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0173] Add 50 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with sulfuric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 1 g of KH570 silane coupling agent, stir continuously at room temperature for 10 hours to obtain the grafted product.

[0174] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-7). GF-KH570-7 was used to prepare modified GF composite materials.

[0175] 2) Preparation of GF-KH570-7 reinforced photocurable composite material

[0176] Bisphenol A epoxy acrylate (36g), bisethoxy acrylate (4g) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.8g) were mixed to obtain a photosensitive resin;

[0177] Then, 8g of GF-KH570-7 (corresponding to an addition amount of 20wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 2min using a high-speed disperser to obtain a uniformly mixed GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-7 reinforced photocurable composite material.

[0178] After printing, use ethanol to clean the residual resin solution on the sample surface, and then use a full-band tracked light curing machine for post-curing, with a total curing time of about 30 seconds.

[0179] The tensile strength anisotropy of the GF-KH570-7 reinforced photocurable composite material sample prepared in this embodiment is 7.3%, and the elongation at break anisotropy is 6.6%.

[0180] Example 8: Preparation of modified GF-reinforced photocurable composite material

[0181] The specific preparation method of the modified GF-reinforced photocurable composite material in this embodiment is as follows:

[0182] 1) Preparation of alkylated modified glass fiber GF-KH570-8

[0183] 6g of initial GF was first treated with acetone at room temperature for 24h to remove surface contaminants. The treated product was then washed with deionized water and dried in an oven at 60℃ for 12h to obtain pretreated glass fiber.

[0184] Add 50 mL of 95% ethanol aqueous solution to a beaker, adjust the pH to about 3 with hydrochloric acid solution, transfer the mixed solution to a single-necked flask, add 5 g of pretreated glass fiber and 0.5 g of KH570 silane coupling agent, stir continuously at room temperature for 12 hours to obtain the grafted product.

[0185] After the reaction was completed, the grafted product was washed with ethanol and then dried in an oven at 60°C for 12 hours to obtain KH570 modified glass fiber (denoted as GF-KH570-8). GF-KH570-8 was used to prepare modified GF composite material.

[0186] 2) Preparation of GF-KH570-8 reinforced photocurable composite material

[0187] Bisphenol A epoxy acrylate (32g), tetrahydrofuran acrylate (8g) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (0.8g) were mixed to obtain a photosensitive resin;

[0188] Then, 4g of GF-KH570-8 (corresponding to an addition amount of 10wt.%) was added to the photosensitive resin and dispersed at 3000r / min for 2min using a high-speed disperser to obtain a uniformly mixed modified GF-reinforced photosensitive resin solution. After removing air bubbles, the solution was poured into a commercial 405nm DLP 3D printer to prepare GF-KH570-8 reinforced photocurable composite material.

[0189] After printing, the residual resin solution on the sample surface was cleaned off with ethanol, and then post-cured using a full-band tracked light curing machine for a total curing time of 40 seconds.

[0190] The tensile strength anisotropy of the GF-KH570-8 reinforced photocurable composite material sample prepared in this embodiment is 9.1%, and the elongation at break anisotropy is 9.0%.

[0191] 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. An isotropic glass fiber reinforced photocurable material, characterized in that, The isotropic glass fiber reinforced photocurable material is a photosensitive resin in which modified glass fibers are distributed, and the content of the modified glass fibers is 30 wt.% of the photosensitive resin. The preparation method of the isotropic glass fiber reinforced photocurable material includes the following steps: Bisphenol A epoxy acrylate, monofunctional acrylate monomer and photoinitiator are mixed to obtain photosensitive resin; 30 wt.% modified glass fiber was added to the photosensitive resin, dispersed, and mixed to obtain a modified glass fiber reinforced photosensitive resin solution. 3D printing and post-curing were then performed to prepare the composite material, which is an isotropic glass fiber reinforced photocurable material. The modified glass fiber is obtained by grafting glass fiber with a silane coupling agent, specifically including the following steps: (a) Treat the glass fiber with acetone at room temperature for 12-48 h to remove surface contaminants, then wash with water and dry to obtain pretreated glass fiber; (b) The pH of the 95% ethanol aqueous solution was adjusted to 3±0.5 with an acidic solution, and silane coupling agent KH570 and the pretreated glass fiber were added to carry out the grafting reaction to obtain the grafted product. (c) After the reaction is complete, the grafted product is washed and dried to obtain modified glass fiber; The mass ratio of the silane coupling agent to the glass fiber is 0.1 to 0.3:

1.

2. The isotropic glass fiber reinforced photocurable material according to claim 1, characterized in that, The monofunctional acrylate monomers include one or more of isobornyl acrylate, dicyclopentadiene acrylate, hydroxyethyl acrylate, diethoxy acrylate, and tetrahydrofuran acrylate.

3. The isotropic glass fiber reinforced photocurable material according to claim 1, characterized in that, The photoinitiator includes one or more of 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

4. The isotropic glass fiber reinforced photocurable material according to claim 1, characterized in that, The dispersion time is 1 to 5 minutes.

5. The isotropic glass fiber reinforced photocurable material according to claim 1, characterized in that, The post-curing time is 10–50 s.

6. The application of the isotropic glass fiber reinforced photocurable material as described in any one of claims 1-5 in the fields of medical devices, electronic components, automotive parts or aerospace.

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