A Highly Photosensitive and Excellent Polarization Property TAPMP Photopolymer Holographic Storage Material and Its Preparation Method

Abstract

The present invention discloses a highly photosensitive and excellent polarization property TAPMP photopolymer holographic storage material. The raw materials of each component, by mass fraction, are as follows: methyl methacrylate: 100 wt%, azobisisobutyronitrile: 1 wt%, phenanthrenequinone: 1.3 wt%, triethanolamine: 0.5 wt%, monomer acrylamide: 1 wt%, methylene bisacrylamide: 0.4 wt%; wherein MBA reacts with the PMMA long chain during the thermal polymerization stage to form a more stable three-dimensional network structure. The monomer AA, as a comonomer, directly reacts with the photosensitizer PQ under the assistance of the co-photoinitiator TEA during the photoreaction stage to generate photoproducts, improving the photosensitivity of the PQ / PMMA material, reducing the shrinkage of the photopolymer, and enhancing the polarization performance of the material, realizing the excellent medium of the photopolymer material for highly photosensitive polarization holographic storage.

Description

Technical Field

[0001] The present invention belongs to the technical field of holographic storage materials, and particularly relates to a TAPMP (triethanolamine / acrylamide / phenanthrenequinone / N,N'-methylenebisacrylamide-polymethyl methacrylate) photopolymer holographic storage material with high photosensitivity and excellent polarization characteristics and a preparation method thereof. Background Art

[0002] The advent of the big data era has been accompanied by a huge increase in data, and there is an urgent need for a more effective and reliable storage method for data storage. Volume holographic storage technology uses multiple laser beams to record 2D information pages into 3D photopolymers. Due to its high storage density, fast writing / reading speed, and low cost, it is considered a promising optical data storage technology. In addition, in traditional holography, since the recorded is the amplitude and phase distributions of two interfering waves, only the same components of the polarization states of the two interfering waves are considered, and the actual polarization states of the two interfering waves are ignored. On the contrary, in polarization holography, the amplitudes and phases of the two waves and the polarization states of the two waves are both recorded. Therefore, combining volume holographic storage technology is expected to have richer reconstruction features and a wide range of applications. Polarization-sensitive recording materials are the key to polarization holography. Phenanthrenequinone-doped polymethyl methacrylate (PQ / PMMA) photopolymers are considered a promising polarization holographic recording medium due to their long-term stability, negligible volume shrinkage, and polarization sensitivity. However, their poor polarization holographic characteristics hinder their application in fast polarization holographic storage. Summary of the Invention

[0003] The present invention provides a TAPMP (triethanolamine / acrylamide / phenanthrenequinone / N,N'-methylenebisacrylamide-polymethyl methacrylate) photopolymer holographic storage material with high photosensitivity and excellent polarization characteristics and a preparation method thereof. Based on the PQ / PMMA photopolymer, the material adds a co-initiator triethanolamine (TEA), a monomer acrylamide (AA), and a cross-linking agent methylenebisacrylamide (MBA). Among them, the cross-linking agent MBA reacts with the PMMA long chain during the thermal polymerization stage of material preparation to generate a more stable three-dimensional network structure. The monomer AA, as a comonomer, directly reacts with the photosensitizer PQ under the assistance of the co-initiator TEA during the photoreaction stage to generate photoproducts. Therefore, the photosensitivity of the PQ / PMMA material is greatly improved, the shrinkage of the photopolymer is reduced, and the polarization performance of the material is enhanced, realizing the excellent medium of the photopolymer material as a high photosensitivity polarization holographic storage. The preparation process of this material is simple, low-cost, the thickness value can reach the millimeter level and is accurately controllable, and the photoinduced shrinkage is negligible, greatly improving the sensitivity and polarization characteristics of the PQ / PMMA material, making this new type of photopolymer material the core recording material required in the application of polarization holography and data storage fields.

[0004] To achieve the above object, the present invention is implemented by the following technical solutions:

[0005] A highly photosensitive and excellent polarization characteristic TAPMP photopolymer holographic storage material, and its component raw materials, by mass fraction, are: methyl methacrylate (MMA): 100 wt%, azobisisobutyronitrile (AIBN): 1 wt%, phenanthrenequinone (PQ): 1 - 1.3 wt%, triethanolamine (TEA): 0.5 wt% - 2.0 wt%, monomer acrylamide (AA): 0.5 wt% - 2.0 wt%, crosslinking agent methylene bisacrylamide (MBA): 0.4 wt%.

[0006] The preparation method of the above highly photosensitive and excellent polarization characteristic TAPMP photopolymer holographic storage material includes the following steps:

[0007] (1) Add the co - photoinitiator triethanolamine TEA, monomer acrylamide AA, crosslinking agent N,N'-methylenebisacrylamide MBA into the solution of monomer methyl methacrylate MMA in a certain proportion, then add the thermal initiator azobisisobutyronitrile AIBN and photosensitizer phenanthrenequinone PQ into this solution, and mix and disperse them evenly by ultrasonic waves to obtain a solution containing photosensitizer;

[0008] (2) Put the solution containing photosensitizer into a constant - temperature magnetic stirrer and stir it in a water bath to obtain a colloidal substance with viscosity;

[0009] (3) Inject the colloidal substance with viscosity into a glass sealing mold with polytetrafluoroethylene, take it out after baking reaction, and cool it to stop polymerization and demold to obtain a sheet material.

[0010] Further, weigh TEA, AA, MBA, AIBN and PQ and add them to MMA to form a mixed solution, and the ultrasonic dispersion time is 25 - 30 min.

[0011] Further, put the solution containing photosensitizer into a constant - temperature magnetic stirrer, and the temperature of the water bath is 65°C.

[0012] Further, put the solution containing photosensitizer into a constant - temperature magnetic stirrer, and the stirring speed of the water bath and stirring is 720 - 900 r / min.

[0013] Further, put the solution containing photosensitizer into a constant - temperature magnetic stirrer, and the time of the water bath and stirring is 75 - 85 min.

[0014] Further, inject the colloidal solution into a glass sealing mold with polytetrafluoroethylene, and the baking polymerization temperature is 45°C - 65°C.

[0015] Further, the colloidal solution is injected into a glass sealed mold with polytetrafluoroethylene, and the baking polymerization time is 21 - 22 hours.

[0016] Advantages of the present invention:

[0017] (1) The preparation method of the high photosensitivity and excellent polarization characteristic TAPMP photopolymer holographic storage material of the present invention makes the prepared TAPMP photopolymer an excellent medium for holographic storage. It has a low cost, the thickness value is accurately controllable and the photoinduced shrinkage is negligible. It has high sensitivity and good polarization characteristics, and is suitable as a new type of photopolymer material with high sensitivity and excellent polarization characteristics. Compared with the traditional phenanthraquinone-doped polymethyl methacrylate (PQ / PMMA) material, it has higher sensitivity, polarization diffraction efficiency and refractive index modulation characteristics. Specifically, after doping with the co-initiator TEA, the comonomer AA, and the crosslinking agent MBA, the sensitivity of the PQ / PMMA photopolymer is increased from 0.3 cm / J to 3.0 cm / J, the orthogonal polarization diffraction efficiency is increased from 5% to 20%, and the refractive index modulation is increased from 2x10 -5 to 7x10 -5 , greatly improving the holographic characteristics of the material and effectively increasing the storage capacity of the material.

[0018] (2) In the TAPMP material, the co-initiator TEA mainly provides electrons for the photosensitizer PQ, thus accelerating the ability of PQ to obtain electrons and making the photoreaction occur faster. At the same time, the comonomer AA provides more vinyl groups during the photoreaction stage to react with PQ to produce photoproducts, further accelerating the photoreaction process, and thus improving the photosensitivity and polarization characteristics of the material. At the same time, the introduction of the crosslinking agent MBA reacts with the substrate PMMA during the thermal polymerization stage to produce a more stable three-dimensional structure, reducing the photoinduced wrinkling of the material during holographic recording and improving the mechanical properties of the material. The high photosensitivity and excellent polarization holographic characteristics of this new type of photopolymer material make it have broad application prospects in holographic information storage. Description of the Drawings

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention;

[0020] Figure 1 It is a comparative diagram of the diffraction efficiency curves measured by recording with two orthogonally polarized linearly polarized light beams for the TAPMP and the original PQ / PMMA photopolymer holographic storage materials of the present invention;

[0021] Figure 2The figure shows the comparison of the orthogonal polarization refractive index modulation curves before and after exposure of the TAPMP of the present invention and the original PQ / PMMA photopolymer holographic storage material;

[0022] Figure 3 The figure shows the angular multiplexing grating measured by recording with two orthogonally polarized linearly polarized light beams for the TAPMP photopolymer holographic storage material of the present invention;

[0023] Figure 4 The figure shows the schematic diagram of the chemical reaction molecular formula structure occurring in the TAPMP material during the thermal polymerization stage and the photopolymerization stage. Detailed implementation manners

[0024] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] The following will, with reference to the drawings, detail the technical solutions provided by each embodiment of the present invention.

[0026] Embodiment 1

[0027] The TAPMP photopolymer holographic storage material of this embodiment has excellent polarization sensitivity and can be applied to the field of polarization holographic storage. The weight ratio of each component raw material can be: MMA (methyl methacrylate) 100wt%, AIBN (azobisisobutyronitrile) 1wt%, PQ (phenanthraquinone) 1.3wt%, TEA (triethanolamine) 0.5wt%, AA (acrylamide) 1.0wt%, MBA (methylenebisacrylamide) 0.4wt%.

[0028] It should be noted that the weight ratio of each component raw material of the above TAPMP photopolymer is based on the weight of MMA being 1 (100wt%), and the weight percentage of other raw material components relative to MMA. That is, MMA: 100wt%, AIBN: 1wt%, PQ: 1.3wt%, TEA: 0.5wt%, AA: 1.0wt%, MBA: 0.4wt%. For example, the weight ratio of each component raw material of the material MMA: AIBN: PQ: TEA: AA: MBA is 100: 1: 1.3: 0.5: 1: 0.4.

[0029] The preparation method of the TAPMP photopolymer holographic storage material of this embodiment includes the following steps:

[0030] (1) Add the co - photo - initiator triethanolamine (TEA), monomer acrylamide (AA), cross - linker N,N'-methylenebisacrylamide (MBA) into the solution of monomer methyl methacrylate (MMA) in a certain proportion. Then add the thermal initiator azobisisobutyronitrile (AIBN) and photosensitizer phenanthraquinone (PQ) into this solution, and mix them evenly by ultrasonic dispersion to obtain a solution containing photosensitizer.

[0031] (2) Put the solution containing photosensitizer into a constant - temperature magnetic stirrer and stir it in a water bath to obtain a viscous colloidal substance.

[0032] (3) Inject the viscous colloidal substance into a glass - sealed mold with polytetrafluoroethylene, take it out after baking and polymerization reaction, and cool it to stop polymerization and demold to obtain a sheet material; the thickness of the obtained sheet material is uniform, and its thickness is 1.5 mm.

[0033] In this example, the time of ultrasonic mixing and dispersion in step (1) is 30 min.

[0034] In this example, the temperature of the water bath in step (2) is 65 °C.

[0035] In this example, the rotation speed of stirring in step (2) is 720 r / min; the stirring time is 85 min.

[0036] In this example, the temperature of baking and polymerization reaction of stirring in step (2) is 45 °C - 65 °C. The time of baking and polymerization reaction is 22 h.

[0037] The preparation method of the TAPMP photopolymer holographic storage material in this example uses a two - step polymerization method. Using methyl methacrylate (MMA) and acrylamide (AA) as monomers, azobisisobutyronitrile (AIBN) as the thermal initiator, cross - linker N,N'-methylenebisacrylamide (MBA) as the cross - linker, phenanthraquinone (PQ) as the photosensitizer, and triethanolamine (TEA) as the co - photo - initiator, a co - photo - initiator TEA, comonomer AA, cross - linker MBA - doped TAPMP photopolymer holographic storage material based on methyl methacrylate is prepared. After selecting the optimal mixing ratio of raw materials, the raw materials are mixed evenly by ultrasonic oscillation, and the material is pre - polymerized and stirred using a constant - temperature water bath. When the mucus reaches the preset viscosity, the material can be put into a mold and cured in a constant - temperature oven; the obtained sample of the TAPMP photopolymer holographic storage material is uniformly transparent, thickness - controllable, has high photosensitivity and excellent polarization holographic characteristics, and can meet the practical requirements of holographic storage.

[0038] Figure 1Line graph of the diffraction efficiency comparison measured for the TAPMP and PQ / PMMA photopolymer holographic storage materials of Example 1 by recording with two orthogonally polarized linearly polarized light beams (recording signal light s, recording reference light p, and reproducing reference light p). It can be seen from the curve that as the exposure time increases, the diffraction efficiency of the material gradually increases. Compared with the PQ / PMMA material, the maximum diffraction efficiency of the TAPMP material can exceed 20%.

[0039] Figure 2 Curve comparison diagram of the refractive index modulation of the TAPMP and PQ / PMMA photopolymer holographic storage materials of Example 1 before and after exposure. It can be seen from the figure that as the exposure time increases, the refractive index of the material has changed significantly. Compared with the PQ / PMMA material, the maximum refractive index modulation of the TAPMP material can reach 7×10 -5 。

[0040] Figure 3 66 grating number images were recorded by angular multiplexing at the same point for the TAPMP photopolymer holographic storage material of Example 1 under the interference of two orthogonally polarized linearly polarized light beams.

[0041] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A highly photosensitive and excellent polarization characteristic TAPMP photopolymer holographic storage material, characterized in that: The raw materials of each component, by mass fraction, are as follows: methyl methacrylate: 100 wt%, azobisisobutyronitrile: 1 wt%, phenanthraquinone: 1.3 wt%, triethanolamine: 0.5 wt%, monomer acrylamide: 1 wt%, methylenebisacrylamide: 0.4 wt%.

2. A preparation method of a highly photosensitive and excellent polarization characteristic TAPMP photopolymer holographic storage material as described in claim 1, characterized in that: It includes the following steps: (1) Add triethanolamine, monomer acrylamide, and methylenebisacrylamide into methyl methacrylate, then add azobisisobutyronitrile and phenanthraquinone, and mix and disperse them evenly by ultrasonic treatment to obtain a solution containing a photosensitizer; (2) Stir the solution containing the photosensitizer obtained in step (1) in a water bath to obtain a colloidal substance with viscosity; (3) Inject the colloidal substance with viscosity obtained in step (2) into a mold, take it out after baking and polymerization reaction, and then cool and demold to obtain a highly photosensitive and excellent polarization characteristic TAPMP photopolymer holographic storage material.

3. The preparation method according to claim 2, characterized in that: In step (1), the time for ultrasonic mixing and dispersion is 25 - 30 min.

4. The preparation method according to claim 2, characterized in that: In step (2), the temperature of the water bath is 65 °C.

5. The preparation method according to claim 2, characterized in that: In step (2), the stirring speed is 720 - 900 r / min.

6. The preparation method according to claim 2, characterized in that: In step (2), the stirring time is 75 - 85 min.

7. The preparation method according to claim 2, characterized in that: In step (3), the temperature of the baking and polymerization reaction is 45 °C - 65 °C.

8. The preparation method according to claim 2, characterized in that: In step (3), the time for the baking and polymerization reaction is 21 - 22 h.

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