A photocurable flammable polymer and its application

Abstract

The present invention discloses a photocurable flammable polymer and its application. The polymer comprises an energetic prepolymer, a diluent and a photoinitiator; the energetic prepolymer is a mixture of one or two of terminal acrylate-based poly-3-nitrate methyl-3-methyloxetane and terminal acrylate-based polyglycidyl ether nitrate; the polymer component of the present invention has an energetic group nitrate group, the flammable polymer can self-sustain combustion in an oxygen-free environment, and the polymer can be used to prepare flammable components such as flammable ordnance components.

Description

Technical Field

[0001] The present invention relates to the field of processing and manufacturing of combustible components, and in particular to a combustible polymer based on DLP and SLA light-curing 3D printing and its application. Background Art

[0002] Conventional preparation methods for combustible components include filtration molding, rolling, and pressing. The existing preparation methods for combustible components have the problems of long manufacturing process cycle, poor precision (±0.5mm), and difficulty in demolding complex structures. As a new type of military product, combustible components such as combustible ordnance components have played an extremely important role in the development history of world weapons, equipment and ammunition. With the advantages of light weight and disappearance after burning, they have become an important part of military weapons and equipment, and their influence on improving the comprehensive performance of weapons and equipment is constantly increasing.

[0003] 3D printing (additive manufacturing) is an advanced technology that constructs objects by printing layer by layer based on digital model files. Among the 3D printing methods, DLP (Digital Light Procession) and SLA (Stereolithography Appearance) photocuring 3D printing are a type of 3D printing process technology based on ultraviolet light curing. They use ultraviolet lasers of specific wavelengths and intensities to cure photosensitive resins layer by layer to build three-dimensional entities. Compared with other 3D printing methods, they have the advantages of high molding accuracy and good surface quality. Compared with the traditional molding methods of the above-mentioned flammable components, the use of this type of 3D printing technology to prepare flammable components has the advantages of high accuracy and the ability to prepare complex structures. Flammable components need to be containers in a closed or limited space and can self-sustainingly burn and disappear in an oxygen-free environment. However, the polymers currently available for DLP and SLA printing are inert polymers, and there is a lack of flammable polymers that can self-sustainingly burn in an oxygen-free environment. Summary of the invention

[0004] In view of the defects or shortcomings of the prior art, the present invention provides a photocurable flammable polymer.

[0005] To this end, the polymer provided by the present invention comprises an energetic prepolymer, a diluent and a photoinitiator;

[0006] The energetic prepolymer is a mixture of one or both of acrylate-terminated poly-3-nitrate methyl-3-methyloxetane (APNIMMO) and acrylate-terminated polyglycidyl ether nitrate;

[0007] The diluent is one or a mixture of two or more of isobornyl acrylate, isobornyl methacrylate, ethoxylated oxyphenyl acrylate, ethoxyethoxyethyl acrylate, dipropylene glycol acrylate, tripropylene glycol diacrylate, hexylene glycol diacrylate, propoxylated glycerol triacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, alkoxylated pentaerythritol tetraacrylate and dimethylolpropane tetraacrylate;

[0008] The photoinitiator is one or a mixture of two or more of 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0009] Optionally, the energetic prepolymer content is 30% to 80%, the diluent content is 20% to 70%, and the sum of the mass percentages of the energetic prepolymer and the diluent is 100%. The amount of the photoinitiator added accounts for 0.3% to 5% of the mass of the energetic prepolymer and the diluent.

[0010] The polymer component of the present invention has an energetic group nitrate ester group, and the combustible polymer can self-sustain combustion in an oxygen-free environment. The polymer can be used as a raw material for DLP and SLA light-curing 3D printing to prepare combustible components such as combustible components, such as combustible ignition cartridges, combustible cartridges / tubes, and combustible fire transmission tubes. Therefore, the manufacture of combustible components no longer requires the production of molds and large, complex molding equipment.

[0011] The present invention also provides a method for preparing a flammable component. The provided preparation method uses the above-mentioned light-curable flammable polymer as a raw material and adopts a DLP light-curing 3D printing method or a SLA light-curing 3D printing method to prepare the flammable component. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The three-dimensional model and the finished product of the combustible ignition cartridge prepared in Example 3 are schematic diagrams, (a) is a three-dimensional model of the printed combustible component, (b) is the prepared combustible component;

[0013] Figure 2 Schematic diagram of the three-dimensional model of the combustible cartridge prepared in Example 4 and the finished product, (a) is a three-dimensional model of the printed combustible components, (b) is the prepared combustible components;

[0014] Figure 3 This is the structural identification diagram of the acrylate-terminated polyglycidyl ether nitrate used in the examples. DETAILED DESCRIPTION

[0015] Unless otherwise specified, the scientific and technical terms in this article are understood according to the common understanding of ordinary technicians in the relevant fields. It should also be understood that the temperatures and concentrations involved in this article are approximate values ​​for illustrative purposes. Although methods and materials similar or equivalent to the methods and materials described herein can be used for the implementation of the present disclosure, some suitable methods and materials are described below. The equipment, materials, methods, solution concentrations and embodiments described herein are merely exemplary and are not intended to be limiting. In a specific scheme, a skilled technician can use a conventional experimental period to optimize the material ratio, concentration, and operating parameter values ​​involved in the method according to the disclosure of the present invention to achieve the purpose of the present invention.

[0016] The end group of the energetic prepolymer in the polymer of the present invention is an acrylate group, which can be quickly cured under ultraviolet light, and the side chain contains an -ONO2 energetic functional group, which can realize self-sustaining combustion of the polymer in an oxygen-free environment; thus, the polymer of the present invention is used as a raw material, and DLP photocuring or SLA photocuring printing technology is adopted to prepare a complex three-dimensional polymer combustible component that can self-sustain combustion in an oxygen-free environment.

[0017] The acrylate-terminated polyglycidyl ether nitrate of the present invention can be prepared by the following synthetic route:

[0018]

[0019] The corresponding preparation method comprises: adding an organic solvent solution of acryloyl chloride to an organic solvent solution of PGN at -5 to 5°C, and then reacting to prepare terminal acrylate polyglycidyl ether nitrate. Optionally, the organic solvent solution of PGN is prepared by dissolving PGN in a mixed solution of dichloromethane and triethylamine. Optionally, the organic solvent solution of acryloyl chloride is a dichloromethane solution of acryloyl chloride or a chloroform solution of acryloyl chloride. A specific example is: add 100g PGN to a reactor equipped with a mechanical stirring device, heat to 90°C, and remove water under reduced pressure for 1.5h; then cool to room temperature, add 500ml dichloromethane and (3.735g, 36.9mmol) triethylamine; then cool to 0°C with an ice-salt bath, and drop 80ml of dichloromethane solution containing (2.47g, 27.3mmol) acryloyl chloride for 6h; after the dropwise addition is completed, continue the reaction for 24h, wash the reaction solution with water until it is neutral, separate the liquids, and remove the solvent from the oil phase under reduced pressure to obtain the product. For the structural identification of the product prepared in this example, see Figure 3As shown, the NMR spectrum of the prepared product: δ=1.2, 3.5 and 3.7 ppm are attributed to the characteristic absorption peaks of PGN, δ=5.9, 6.1 and 6.4 ppm are attributed to the characteristic peaks of protons on the terminal double bonds (-CH=CH2) in APGN, which proves that the APGN photosensitive energetic resin is an acrylate-modified PGN resin. In the NMR carbon spectrum of the APGN photosensitive energetic resin, δ=164.9 ppm is attributed to the characteristic peaks of protons on the ester bonds (-C=O) in the terminal acrylate of APGN. δ=132.5 ppm and 127.3 ppm are attributed to the characteristic peaks of protons on the double bonds in the terminal acrylate of APGN. δ=14.8, 26.3 and 68-72 ppm are attributed to the characteristic peaks of protons of PGN.

[0020] Infrared spectrum: 1128cm -1 The infrared characteristic absorption peak of -CO- of PGN is 3440cm -1 The infrared absorption peak of the terminal hydroxyl group of PGN is 3440cm -1 The infrared absorption peaks of the terminal hydroxyl groups of PGN disappeared, and the peaks at 1734 and 1190 cm -1 There is an obvious infrared characteristic absorption peak belonging to the -C=O bond in acrylate, and its absorbance is relatively high. The identification data confirms that the obtained substance is indeed terminal acrylate polyglycidyl ether nitrate (APGN).

[0021] The present invention is further described below in conjunction with examples, but the scope of the present invention is not limited to the scope of the examples. The components used in the following examples are commercially available products or obtained by existing related methods or the preparation method provided by the present invention.

[0022] Embodiment 1:

[0023] In this embodiment, the following components in percentage by mass are mixed to obtain a photosensitive flammable polymer:

[0024] Acrylate-terminated poly (3-nitrate methyl-3-methyloxetane): 50%;

[0025] Isobornyl acrylate: 20%;

[0026] Trimethylolpropane triacrylate: 30%;

[0027] Ethyl 2,4,6-trimethylbenzoylphenylphosphonate: The added amount is 3% of the total mass of the above three components.

[0028] Embodiment 2:

[0029] In this embodiment, the following components in percentage by mass are mixed to obtain a photosensitive flammable polymer:

[0030] Acrylate-terminated polyglycidyl ether nitrate: 70%;

[0031] Ethoxyethoxyethyl acrylate: 10%;

[0032] Dipropylene glycol acrylate: 20%;

[0033] Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide: the addition amount is 4% of the total mass of the above three components.

[0034] The following examples use a DLP light-curing 3D printing device of model HITech-DLP007B; and a SLA light-curing 3D printing device of model HITech-DLP002A to explain the specific application examples of the polymer of the present invention. It should be noted that the application scope of the polymer of the present invention is not limited to the above two specific devices and related processes, and commercially available DLP and SLA light-curing printing devices are applicable to the present invention.

[0035] Embodiment 3:

[0036] This example uses the polymer of Example 1 as a raw material and uses a DLP light-curing 3D printing device to perform 3D printing. Figure 1 The flammable ignition box (including the cover and the box body) of the three-dimensional model shown; in the specific process, the DLP optical machine has a band of 405nm, a resolution of 3840×2160 pixels, an exposure time of 1.5s, a layer height of 0.1mm, and the 3D printing platform descends to drive the resin to flow to form a new liquid layer, and then exposes the next layer of pattern again, and the printing platform continues to move downward to obtain a three-dimensional model print.

[0037] Embodiment 4:

[0038] This example uses the polymer of Example 2 as raw material and uses SLA equipment for 3D printing preparation Figure 2 The combustible cartridge is shown; in the specific process, the wavelength of the SLA laser is 405nm, the laser spot diameter is 85 microns, the scanning speed is 8m / s, the layer height is 0.05mm, and the 3D printing platform descends to drive the resin to flow to form a new liquid layer, and then scans the next layer of pattern again, and the platform continues to move downward to obtain a three-dimensional model print.

[0039] The flammable devices prepared in the above Examples 3 and 4 were subjected to a combustion test in a closed bomb filled with nitrogen at a certain pressure (for isolating oxygen), specifically according to the test method of "GJB770B 2005 Method 706.1 Burning Rate Target Line Method". It was measured that: under a nitrogen pressure of 4MPa, the burning speed of the flammable device prepared in Example 3 was 0.9mm / s, the burning speed under 11MPa was 3.8mm / s, and the burning speed under 16MPa was 5.2mm / s; under a nitrogen pressure of 4MPa, the burning speed of the flammable device prepared in Example 4 was 2.5mm / s, the burning speed under 11MPa was 7.3mm / s, and the burning speed under 16MPa was 10.1mm / s. This shows that the flammable device prepared by the polymer of the present invention can achieve self-sustaining combustion under oxygen-free conditions.

Claims

1. Application of a photocurable flammable polymer for preparing flammable components; the photocurable flammable polymer comprises an energetic prepolymer, a diluent and a photoinitiator; The energetic prepolymer is a mixture of one or both of acrylate-terminated poly-3-nitrate methyl-3-methyloxetane (APNIMMO) and acrylate-terminated polyglycidyl ether nitrate; The diluent is one or a mixture of two or more of isobornyl acrylate, isobornyl methacrylate, ethoxylated oxyphenyl acrylate, ethoxyethoxyethyl acrylate, dipropylene glycol acrylate, tripropylene glycol diacrylate, hexylene glycol diacrylate, propoxylated glycerol triacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, alkoxylated pentaerythritol tetraacrylate and dimethylolpropane tetraacrylate; The photoinitiator is one or a mixture of two or more of 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; The combustible components are combustible components that burn in an oxygen-free environment.

2. The use according to claim 1, characterized in that: In terms of mass fraction, the content of the energetic prepolymer is 30% to 80%, the content of the diluent is 20% to 70%, and the sum of the mass percentages of the energetic prepolymer and the diluent is 100%.

3. The use according to claim 1, characterized in that: The added amount of the photoinitiator accounts for 0.3% to 5% of the mass of the energetic prepolymer and the diluent.

4. A method for preparing a combustible component, characterized in that: Using a light-curable flammable polymer as a raw material, a DLP light-curable 3D printing method or a SLA light-curable 3D printing method is used to prepare a flammable component; the light-curable flammable polymer includes an energetic prepolymer, a diluent and a photoinitiator; The energetic prepolymer is a mixture of one or both of acrylate-terminated poly-3-nitrate methyl-3-methyloxetane (APNIMMO) and acrylate-terminated polyglycidyl ether nitrate; The diluent is one or a mixture of two or more of isobornyl acrylate, isobornyl methacrylate, ethoxylated oxyphenyl acrylate, ethoxyethoxyethyl acrylate, dipropylene glycol acrylate, tripropylene glycol diacrylate, hexylene glycol diacrylate, propoxylated glycerol triacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, alkoxylated pentaerythritol tetraacrylate and dimethylolpropane tetraacrylate; The photoinitiator is one or a mixture of two or more of 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; The combustible components are combustible components that burn in an oxygen-free environment.

5. The preparation method according to claim 4, characterized in that: The combustible component is a combustible ignition cartridge, a combustible cartridge, a combustible cartridge or a combustible fire transmission tube.

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