Pq / pmma photopolymer holographic storage material doped with petmp and preparation method thereof

Abstract

The application belongs to the technical field of holographic polymer materials, and particularly relates to a PETMP doped PQ / PMMA photopolymer holographic storage material and a preparation method thereof. The preparation method adds PETMP, MMA, PQ and AIBN, and sequentially carries out mixing, prepolymerization and thermal polymerization to obtain the PETMP doped PQ / PMMA photopolymer holographic storage material. Compared with the traditional PQ / PMMA material, the recording grating diffraction efficiency of the PETMP doped PQ / PMMA photopolymer holographic storage material is improved to more than 80%, the refractive index modulation is higher, and the storage capacity of the material can be effectively improved. At the same time, the diffraction efficiency is greatly improved by doping PETMP, the light response speed is accelerated, better optical properties are exhibited, and the PETMP doped PQ / PMMA photopolymer holographic storage material has a wide application prospect in the field of holographic storage.

Description

Technical Field

[0001] This invention belongs to the field of holographic polymer materials technology, specifically relating to PETMP-doped PQ / PMMA photopolymer holographic storage materials and their preparation methods. Background Technology

[0002] Currently, with the rapid development of information technology, the amount of data is also experiencing explosive growth. Therefore, the long-term storage of massive amounts of data has become a technological challenge in the era of big data. Holographic storage technology stores data in the three-dimensional volume of a polarizing material using a two-dimensional data page access method, achieving ultra-high theoretical storage density and ultra-fast data conversion rate.

[0003] Among polarizing materials, traditional phenanthrenequinone (PQ)-doped polymethyl methacrylate (PMMA) materials are a good choice for holographic storage materials due to their negligible photo-shrunk properties, centimeter-scale sample thickness, and simple preparation. For example, the PQ / PMMA photopolymer material disclosed in Chinese invention patent CN112812210A uses MMA (methyl methacrylate), AIBN (azobisisobutyronitrile), and PQ to prepare a photopolymer with stable performance, allowing for multiple reads from a single recording, and very low photo-shrunk. However, the PQ- / PMMA material has a low phenanthrenequinone (PQ) content, only 0.7 wt%, resulting in lower diffraction efficiency and photoresponse speed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a PETMP (pentaerythritol tetra-3-mercaptopropionate) doped PQ / PMMA photopolymer holographic storage material with high diffraction efficiency and photoresponse speed, and a method for preparing the same.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a PETMP-doped PQ / PMMA photopolymer holographic storage material, the raw materials of which include PETMP, MMA, PQ and AIBN.

[0006] Another technical solution adopted in this invention is: a method for preparing a PETMP-doped PQ / PMMA photopolymer holographic storage material, comprising the following steps: adding PETMP, MMA, PQ and AIBN, and sequentially mixing, prepolymerizing and thermally polymerizing to obtain the PETMP-doped PQ / PMMA photopolymer holographic storage material.

[0007] The beneficial effects of this invention are as follows: the photopolymer holographic storage material of this invention, through PETMP doping, can improve the performance of PQ / PMMA photopolymer holographic storage materials. Compared with traditional PQ / PMMA materials, the PETMP-doped PQ / PMMA photopolymer holographic storage material achieves a recording grating diffraction efficiency of over 80%, exhibits a higher refractive index modulation, and can effectively increase the material's storage capacity. Simultaneously, PETMP doping also significantly improves diffraction efficiency and accelerates photoresponse speed, demonstrating better optical properties. PETMP-doped PQ / PMMA photopolymer holographic storage materials have broad application prospects in the field of holographic storage. Attached Figure Description

[0008] Figure 1 The figures shown are diffraction efficiency test diagrams for Embodiment 2 and Comparative Example 1 of the present invention.

[0009] Figure 2 The figures shown are test diagrams of refractive index modulation in Embodiment 2 and Comparative Example 1 of the present invention. Detailed Implementation

[0010] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0011] A PETMP-doped PQ / PMMA photopolymer holographic storage material, the raw materials of which include PETMP, MMA, PQ and AIBN.

[0012] As described above, the beneficial effects of this invention are as follows: By doping with PETMP, this invention can improve the performance of PQ / PMMA photopolymer holographic storage materials. Compared with traditional PQ / PMMA materials, the PETMP-doped PQ / PMMA photopolymer holographic storage material achieves a recording grating diffraction efficiency of over 80%, exhibits higher refractive index modulation, and can effectively increase the material's storage capacity. Simultaneously, PETMP doping also significantly improves diffraction efficiency and accelerates photoresponse speed, demonstrating better optical properties. PETMP-doped PQ / PMMA photopolymer holographic storage materials have broad application prospects in the field of holographic storage.

[0013] PETMP, as a high-refractive-index monomer, offers the following advantages when added to PQ / PMMA materials:

[0014] 1. PETMP plays a role in the photoreaction process of PQ / PMMA materials, improving diffraction efficiency.

[0015] 2. Adding PETMP will inhibit the generation of PMMA during the thermal polymerization process, resulting in more MMA remaining in the photoreaction process. The carbon-carbon double bonds in the remaining MMA will accelerate the photoreaction rate, improve photosensitivity, and shorten the response time.

[0016] 3. The thiol functional groups unique to PETMP are more polar than those of olefins (MMA), so adding PETMP can improve the solubility of PQ and thus enhance the uniformity of the material.

[0017] Furthermore, the mass ratio of PETMP, MMA, AIBN, and PQ is 0.05–0.2: 99–101: 1–2: 1;

[0018] As described above, the diffraction efficiency increases with the increase of PETMP content, until the optimal doping ratio of PETMP, 0.05-0.2%, is reached. The PQ ratio affects the diffraction efficiency and photosensitivity. The higher the PQ content, the faster the material's response speed. However, PQ has a maximum solubility value, and excessive PQ will result in PQ residue that cannot be dissolved. The AIBN ratio affects the stirring time in the water bath. Excessive AIBN will lead to violent polymerization and is prone to explosive polymerization.

[0019] Another technical solution adopted in this invention is: a method for preparing a PETMP-doped PQ / PMMA photopolymer holographic storage material, comprising the following steps: adding PETMP, MMA, PQ and AIBN, and sequentially mixing, prepolymerizing and thermally polymerizing to obtain the PETMP-doped PQ / PMMA photopolymer holographic storage material.

[0020] As can be seen from the above description, the preparation method of the present invention can improve the performance of PQ / PMMA photopolymer holographic storage materials by doping with PETMP.

[0021] Further, the specific steps for mixing are as follows: sonicate in a water bath at 58–62°C for 15–20 minutes.

[0022] As can be seen from the above description, ultrasonic mixing can effectively improve solubility. Ultrasound can affect the chain length of polymers. If the ultrasonic time is too short, PQ will not be completely dissolved. If the ultrasonic time is too long, the internal monomers will begin to polymerize.

[0023] Furthermore, the specific steps of prepolymerization are as follows: stirring at 58–62°C for 70–80 min.

[0024] As described above, a prepolymerization temperature that is too low will result in an excessively long reaction time or even prevent the thermal polymerization reaction from occurring; a prepolymerization temperature that is too high will make the reaction rate difficult to control and may easily lead to explosive polymerization. A stirring time that is too short will result in insufficient monomer viscosity, affecting material forming; a stirring time that is too long will result in excessive monomer viscosity, affecting subsequent operations.

[0025] Furthermore, the specific steps of thermal polymerization are as follows: place at 50-60℃ for 8-24 hours.

[0026] As can be seen from the above description, both 50℃ and 60℃ can shape the material, but the baking time is relatively longer at lower temperatures and shorter at higher temperatures.

[0027] Embodiment 1 of the present invention is: a PETMP-doped PQ / PMMA photopolymer holographic storage material, which is composed of PETMP, MMA, PQ and AIBN in a mass ratio of 0.1:99.9:1:1.

[0028] Embodiment 2 of the present invention is as follows:

[0029] A method for preparing PETMP-doped PQ / PMMA photopolymer holographic storage materials includes the following steps:

[0030] S1: Add PETMP and MMA monomers to a 30mL transparent vial, then add PQ photosensitizer and AIBN thermal initiator. The mass ratio of PETMP, MMA, AIBN and PQ is 0.1:99.9:1:1. Sonicate the vial in a 60℃ water bath for 17min to ensure that the components in the vial are fully mixed.

[0031] S2: Stir the well-mixed transparent mixture in a magnetic stirrer at 60°C for 75 minutes until the mixture changes from a solution to a viscous state.

[0032] S3: The viscous mixture is injected into a mold to a height of 2 mm. Then, it is placed horizontally in an oven at 55°C for 12 hours to allow for sufficient thermal polymerization. After cooling, the PETMP-doped PQ / PMMA photopolymer holographic storage material is obtained.

[0033] Embodiment 3 of the present invention is as follows:

[0034] A method for preparing PETMP-doped PQ / PMMA photopolymer holographic storage materials includes the following steps:

[0035] S1: Add PETMP and MMA monomers to a 30mL transparent vial, then add PQ photosensitizer and AIBN thermal initiator. The mass ratio of PETMP, MMA, AIBN and PQ is 0.05:99:1:1. Sonicate the vial in a 58℃ water bath for 20 minutes to ensure that the components in the vial are fully mixed.

[0036] S2: Stir the well-mixed transparent mixture in a magnetic stirrer at 58°C for 80 minutes until the mixture changes from a solution to a viscous state.

[0037] S3: Inject the viscous mixture into the injection mold to a height of 2 mm, then place it horizontally in an oven at 50°C for 24 hours to allow for sufficient thermal polymerization. After removing the mold and cooling, the PETMP-doped PQ / PMMA photopolymer holographic storage material is obtained.

[0038] Embodiment four of the present invention is as follows:

[0039] A method for preparing PETMP-doped PQ / PMMA photopolymer holographic storage materials includes the following steps:

[0040] S1: Add PETMP and MMA monomers to a 30mL transparent vial, then add PQ photosensitizer and AIBN thermal initiator. The mass ratio of PETMP, MMA, AIBN and PQ is 0.2:101:2:1. Sonicate the vial in a 62℃ water bath for 15min to ensure that the components in the vial are fully mixed.

[0041] S2: Stir the well-mixed transparent mixture in a magnetic stirrer at 62°C for 70 minutes until the mixture changes from a solution to a viscous state.

[0042] S3: Inject the viscous mixture into the injection mold to a height of 2 mm, then place it horizontally in an oven at 60°C for 8 hours to allow for sufficient thermal polymerization. After removing the mold and cooling, the PETMP-doped PQ / PMMA photopolymer holographic storage material is obtained.

[0043] Comparative Example 1 of the present invention is:

[0044] The only difference between Comparative Example 1 and Example 1 is that PETMP is not added. ， The mass ratio of MMA, AIBN, and PQ is 100:1:1.

[0045] The diffraction efficiencies of Example 2 (PETMP-PQ / PMMA) and Comparative Example 1 (PQ / PMMA) were tested, and the results are shown in [the table below]. Figure 1 ;Depend on Figure 1It can be seen that the PETMP-doped PQ / PMMA photopolymer holographic storage material in Example 1 achieved a diffraction efficiency of 80%, which accelerated the photoresponse speed and improved the uniformity of the material.

[0046] The refractive index modulation of Example 2 (PETMP-PQ / PMMA) and Comparative Example 1 (PQ / PMMA) was tested, and the test results are shown in [Figure number missing]. Figure 2 ;Depend on Figure 2 It can be seen that PETMP-PQ / PMMA has a higher refractive index modulation.

[0047] The above test methods are described in the reference: Po Hu, Jinhong Li, Junchao Jin, Xiao Lin, & Xiaodi Tan. Highly Sensitive Photopolymer for Holographic Data Storage Containing Methacryl Polyhedral Oligomeric Silsesquioxane[J]. ACS Appl. Mater. Interfaces 2022, 14, 18, 21544–21554.

[0048] In summary, the preparation method provided by this invention, which incorporates PETMP into PQ / PMMA materials, offers the following advantages: it plays a role in the photoreaction process of PQ / PMMA materials, improving diffraction efficiency; it suppresses the generation of PMMA during thermal polymerization, resulting in a greater amount of MMA remaining during the photoreaction process. The carbon-carbon double bonds in the remaining MMA accelerate the photoreaction rate, improve photosensitivity, and shorten the response time; the unique thiol functional groups in PETMP are more polar than those in olefinic MMA substances, thus increasing the solubility of PQ and improving the uniformity of the material. Therefore, compared with traditional PQ / PMMA materials, the PETMP-doped PQ / PMMA photopolymer holographic storage material achieves a recording grating diffraction efficiency of over 80%, exhibits higher refractive index modulation, and effectively improves the material's storage capacity. Simultaneously, PETMP doping significantly enhances diffraction efficiency and accelerates the photoresponse speed, demonstrating better optical properties. PETMP-doped PQ / PMMA photopolymer holographic storage materials have broad application prospects in the field of holographic storage.

[0049] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A PETMP-doped PQ / PMMA photopolymer holographic storage material, characterized in that, The raw materials include PETMP, MMA, PQ and AIBN; the mass ratio of PETMP, MMA, AIBN and PQ is 0.05~0.2:99~101:1~2:

1.

2. A method for preparing a PETMP-doped PQ / PMMA photopolymer holographic storage material, characterized in that, Includes the following steps: PETMP, MMA, PQ and AIBN were added, and the mixture, prepolymerization and thermal polymerization were carried out in sequence to obtain PETMP-doped PQ / PMMA photopolymer holographic storage material; The mass ratio of PETMP, MMA, AIBN and PQ is 0.05~0.2:99~101:1~2:

1.

3. The method for preparing the PETMP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific steps of the mixing are as follows: sonication in a water bath at 58~62℃ for 15~20 minutes.

4. The method for preparing the PETMP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific steps of the prepolymerization are as follows: stirring at 58~62℃ for 70~80 minutes.

5. The method for preparing the PETMP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific steps of the thermal polymerization are as follows: place at 50~60℃ for 8~24h.

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