Self-repairing acrylate photosensitive resin for 3D printing and manufacturing method thereof

Abstract

The invention discloses a self-repairing acrylate photosensitive resin for 3D printing and a manufacturing method thereof, the self-repairing acrylate photosensitive resin comprises filler nanocellulose and polymer matrix acrylate, the nanocellulose has rich surface hydroxyl and a nano-sized structure, and the polymer matrix acrylate is a polymer matrix acrylate. The self-repairing performance of the self-repairing acrylate photosensitive resin is endowed on the basis of an interface hydrogen bond network between a hydroxyl group on the surface of the nanocellulose and a hydroxyl group at the end of an acrylate molecular chain. The self-repairing acrylate photosensitive resin can be printed and formed by using DLP-3D printing equipment. The problems of microcracks, scratches, cracks and the like inevitably generated in the use process of the 3D printing elastomer due to external force are solved, and the 3D printing elastomer has the characteristics that the raw materials are derived from biomass, the 3D printing elastomer is green and environment-friendly, the preparation process is simple, and the 3D printing elastomer has self-repairing capability and relatively good mechanical property and self-repairing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of acrylate preparation, and in particular to a 3D printing self-repairing acrylate photosensitive resin material and a preparation method thereof. Background Art

[0002] DLP light-curing 3D printing technology is widely used in the field of consumer products due to its advantages such as high molding accuracy, lightweight printing and batch manufacturing. As 3D printed products enter the consumer goods market, higher requirements are placed on the strength, toughness, wear resistance and comfort of the products. In the daily use process, consumer products will inevitably produce microcracks and fractures, which greatly affect their service life and service cycle. Therefore, photosensitive resin materials with self-healing properties have gradually become a research focus.

[0003] Self-healing refers to the material that can achieve self-repair of part or all of its properties under certain conditions after it is subjected to the influence of external forces and produces microcracks, cuts, and damage at the physical level. Self-healing elastomers are divided into external-aided and intrinsic self-healing according to the repair mechanism. Compared with external-aided repair, intrinsic self-healing can be repaired by dynamic non-covalent bonds, such as van der Waals forces, π-π stacking, hydrogen bonds, metal-ligand interactions, etc. It has the advantages of high repair efficiency, spontaneous repair and multiple repairs, and can effectively improve the service life of the material. The self-healing efficiency of the material can effectively improve its service life, but there is a contradiction between mechanical strength and self-healing efficiency in self-healing materials. Polymer-based composite materials have the advantages of high mechanical strength, fatigue resistance and good friction performance. The addition of fillers can improve the strength of the material by utilizing the volume reinforcement effect, and at the same time, construct reversible dynamic bonds at the interface between the filler and the polymer molecular chain to give the material self-healing properties, which can effectively improve the mechanical, thermal and tribological properties of polymer materials, and thus become a hope for solving the above problems.

[0004] Nanocellulose is renewable, safe, green, environmentally friendly, and non-toxic, and is widely used in the preparation of self-healing materials. A self-healing photosensitive resin with dynamic non-covalent action is constructed between the interface of the acrylic polymer molecular chain and nanocellulose. The reversible dynamic bond can be repaired to give the material repair properties. The volume reinforcement effect of nanocellulose and the non-covalent action of the interface can effectively improve the mechanical properties of the material, thereby effectively improving the various properties of the material.

[0005] Therefore, there is a need in the market for a self-healing acrylic photosensitive resin for 3D printing, which has raw materials derived from biomass, is green and environmentally friendly, has a simple preparation process, has self-repairing ability, and has good mechanical properties and self-repairing properties, and a manufacturing method thereof. Summary of the invention

[0006] The present invention aims to provide a self-repairing acrylic photosensitive resin for 3D printing, which has raw materials derived from biomass, is green and environmentally friendly, has a simple preparation process, has self-repairing ability, and has good mechanical properties and self-repairing properties, and a method for manufacturing the same.

[0007] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a self-repairing acrylate photosensitive resin for 3D printing, the self-repairing acrylate photosensitive resin comprises filler nanocellulose and polymer matrix acrylate, the nanocellulose is nanocellulose with surface hydroxyl groups and nano-sized structure, and a hydrogen bond network exists at the interface between the surface hydroxyl groups of the nanocellulose and the end hydroxyl groups of the acrylate molecular chain, and the preparation method of the self-repairing acrylate photosensitive resin comprises the following stages: S1: Nanocellulose Preparation ① Add natural cotton wool and saturated hydrochloric acid in a mass ratio of 1: (2.8-3.5) into a reaction vessel, heat to 50℃-60℃ and mechanically stir for 24h at a mechanical stirring rate of 500rpm-550rpm; ② After filtering the solid after acid hydrolysis from the hydrochloric acid using a suction filtration device, dilute and wash it with deionized water for 4-6 times, and then place the washed solid in a drying oven and dry it at 60°C-65°C for 18h-24h to obtain nanocellulose with a length and diameter of 20nm-200nm; S2: Preparation of self-healing acrylic photosensitive resin ① Filling nitrogen into a reaction container, and in a nitrogen atmosphere, uniformly mixing acrylate, photoinitiator, active diluent, and nanocellulose in a mass ratio of 100: (1-5): (15-30): (20-60) to obtain the desired self-healing acrylate photosensitive resin for 3D printing; wherein the active diluent is specifically an active diluent mixed with alcohol and ester.

[0008] In the above-mentioned self-healing acrylate photosensitive resin for 3D printing: the acrylate is hydroxyethyl acrylate.

[0009] In the above-mentioned method for preparing the self-healing acrylate photosensitive resin for 3D printing: the photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0010] In the above-mentioned method for preparing the self-healing acrylic photosensitive resin for 3D printing: the active diluent component is obtained by compounding ethylene glycol and dimethyl carbonate in a molar ratio of 1:1.

[0011] In the above-mentioned preparation method of the self-healing acrylic photosensitive resin for 3D printing, in stage S3, the specific parameters are: S2: Preparation of self-healing acrylic photosensitive resin ① Add hydroxyethyl acrylate monomer, inhibitor hydroquinone, and catalyst 4-dimethylaminopyridine into a reaction kettle, heat the solution to 100°C and stir for reaction for 12 hours to obtain an acrylate prepolymer; wherein the hydroquinone accounts for 0.28wt.%-0.35wt.% of the total amount of acrylate, and the amount of 4-dimethylaminopyridine is 0.8wt.%-1.5wt.% of the total amount of acrylate; under a nitrogen atmosphere, the acrylate prepolymer, photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, active diluent, and nanocellulose are mixed in a weight ratio of (50-60): (1-1.5): (15-20): (20-30), the stirring speed is 1200rpm, and the stirring time is 12 hours to obtain an acrylate photosensitive resin with self-healing properties.

[0012] Compared with the prior art, the present invention has the following advantages due to the adoption of the above technical solution: (1) The self-healing acrylic photosensitive resin synthesized in the present invention has high stability. The material after 3D printing has good mechanical properties, thermal properties, etc., and can be used as a raw material for 3D printing elastomers.

[0013] (2) The preparation method used in the present invention is to first prepare nanocellulose by using an acid hydrolysis method, and then use the hydroxyl groups at the end of the acrylate molecular chain to form interfacial hydrogen bonds with the hydroxyl groups on the surface of the nanocellulose. After adding a diluent and a photoinitiator, a self-healing acrylate photosensitive resin that can be used for 3D printing is obtained. The raw materials of this preparation method are derived from biomass, and it has the advantages of being green and environmentally friendly and having a simple preparation process.

[0014] (3) The self-healing acrylic photosensitive resin prepared by the present invention is poured into a DLP 3D printing device for printing. After printing, the product is cured at high temperature to obtain an elastic component with self-healing ability. The mechanical properties of the product are significantly better than those of commercially available products, as follows: viscosity 2300cp·s-3400cp·s, tensile strength 4.55MPa-11.4MPa, elongation at break 720%-1350%, self-healing efficiency 76%-91%, and bending resistance 27000-40000 times.

[0015] Therefore, the present invention has the characteristics that the raw materials are derived from biomass, are green and environmentally friendly, have a simple preparation process, have self-repairing ability, and have good mechanical properties and self-repairing properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a scanning electron microscope image of the tensile cross section of the material of the present invention with a scale of 100 μm; Figure 2 This is a scanning electron microscope image of the tensile section of the material of the present invention with a scale of 50 μm; Figure 3This is a scanning electron microscope image of the tensile section of the material of the present invention with a scale of 10 μm. DETAILED DESCRIPTION Example

[0017] (1) Add natural cotton wool and hydrochloric acid in a mass ratio of 1:3 into a beaker, stir and react at 50 °C for 24 h at a speed of 500 rpm. After the reaction, filter the acid-hydrolyzed cotton wool from the hydrochloric acid by suction, dilute and wash with ultrapure water for 4 times, and dry the sample in a drying oven at 60 °C for 24 h to obtain nanocellulose. (2) Ethylene glycol and dimethyl carbonate were mixed in a molar ratio of 1:1, and the mixture was stirred at 400 rpm for 30 min to obtain a composite active diluent; (3) Add hydroxyethyl acrylate monomer, polymerization inhibitor hydroquinone (hydroquinone accounts for 0.3 wt.% of the total amount of acrylate), and catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1 wt.% of the total amount of acrylate) into the reactor, heat the solution to 100 °C and stir for 12 h to obtain an acrylate prepolymer; (4) Under a nitrogen atmosphere, an acrylate prepolymer, a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, a reactive diluent, and nanocellulose were mixed in a weight ratio of 50:1:15:20, with a stirring speed of 1200 rpm and a stirring time of 12 h to obtain an acrylate photosensitive resin with self-healing properties; (5) The acrylic photosensitive resin was poured into the DLP 3D printing equipment for printing. The printing parameters were as follows: UV light band 405 nm, UV light power 9 mW / cm2, printing layer thickness 0.1 mm, single layer exposure time 2.5 s. After printing, the workpiece was cured at high temperature, the curing temperature was 80 °C, and the curing time was 6 h, thus obtaining a 3D printed self-healing acrylic elastomer. Example

[0018] (1) Add natural cotton wool and hydrochloric acid in a mass ratio of 1:3 into a beaker, stir and react at 50 °C for 24 h at a speed of 500 rpm. After the reaction, filter the acid-hydrolyzed cotton wool from the hydrochloric acid by suction, dilute and wash with ultrapure water for 4 times, and dry the sample in a drying oven at 60 °C for 24 h to obtain nanocellulose. (2) Ethylene glycol and dimethyl carbonate were mixed in a molar ratio of 1:1, and the mixture was stirred at 400 rpm for 30 min to obtain a composite active diluent; (3) Add hydroxyethyl acrylate monomer, polymerization inhibitor hydroquinone (hydroquinone accounts for 0.3 wt.% of the total amount of acrylate), and catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1 wt.% of the total amount of acrylate) into the reactor, heat the solution to 100 °C and stir for 12 h to obtain an acrylate prepolymer; (4) Under a nitrogen atmosphere, an acrylate prepolymer, a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, a reactive diluent, and nanocellulose were mixed in a ratio of 50:1:15:30 by weight, with a stirring speed of 1200 rpm and a stirring time of 12 h to obtain an acrylate photosensitive resin with self-healing properties; (5) The acrylic photosensitive resin was poured into the DLP 3D printing equipment for printing. The printing parameters were as follows: UV light band 405 nm, UV light power 9 mW / cm2, printing layer thickness 0.1 mm, single layer exposure time 2.5 s. After printing, the workpiece was cured at high temperature, the curing temperature was 80 °C, and the curing time was 6 h, thus obtaining a 3D printed self-healing acrylic elastomer. Example

[0019] (1) Add natural cotton wool and hydrochloric acid in a mass ratio of 1:3 into a beaker, stir and react at 50 °C for 24 h at a speed of 500 rpm. After the reaction, filter the acid-hydrolyzed cotton wool from the hydrochloric acid by suction, dilute and wash with ultrapure water for 4 times, and dry the sample in a drying oven at 60 °C for 24 h to obtain nanocellulose. (2) Ethylene glycol and dimethyl carbonate were mixed in a molar ratio of 1:1, and the mixture was stirred at 400 rpm for 30 min to obtain a composite active diluent; (3) Add hydroxyethyl acrylate monomer, polymerization inhibitor hydroquinone (hydroquinone accounts for 0.3 wt.% of the total amount of acrylate), and catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1 wt.% of the total amount of acrylate) into the reactor, heat the solution to 100 °C and stir for 12 h to obtain an acrylate prepolymer; (4) Under a nitrogen atmosphere, an acrylate prepolymer, a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, a reactive diluent, and nanocellulose were mixed in a weight ratio of 50:1:15:40, with a stirring speed of 1200 rpm and a stirring time of 12 h to obtain an acrylate photosensitive resin with self-healing properties; (5) The acrylic photosensitive resin was poured into the DLP 3D printing equipment for printing. The printing parameters were as follows: UV light band 405 nm, UV light power 9 mW / cm2, printing layer thickness 0.1 mm, single layer exposure time 2.5 s. After printing, the workpiece was cured at high temperature, the curing temperature was 80 °C, and the curing time was 6 h, thus obtaining a 3D printed self-healing acrylic elastomer. Example

[0020] (1) Add natural cotton wool and hydrochloric acid in a mass ratio of 1:3 into a beaker, stir and react at 50 °C for 24 h at a speed of 500 rpm. After the reaction, filter the acid-hydrolyzed cotton wool from the hydrochloric acid by suction, dilute and wash with ultrapure water for 4 times, and dry the sample in a drying oven at 60 °C for 24 h to obtain nanocellulose. (2) Ethylene glycol and dimethyl carbonate were mixed in a molar ratio of 1:1, and the mixture was stirred at 400 rpm for 30 min to obtain a composite active diluent; (3) Add hydroxyethyl acrylate monomer, polymerization inhibitor hydroquinone (hydroquinone accounts for 0.3 wt.% of the total amount of acrylate), and catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1 wt.% of the total amount of acrylate) into the reactor, heat the solution to 100 °C and stir for 12 h to obtain an acrylate prepolymer; (4) Under a nitrogen atmosphere, an acrylate prepolymer, a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, a reactive diluent, and nanocellulose were mixed in a ratio of 50:1:15:50 by weight, with a stirring speed of 1200 rpm and a stirring time of 12 h to obtain an acrylate photosensitive resin with self-healing properties; (5) The acrylic photosensitive resin was poured into the DLP 3D printing equipment for printing. The printing parameters were as follows: UV light band 405 nm, UV light power 9 mW / cm2, printing layer thickness 0.1 mm, single layer exposure time 2.5 s. After printing, the workpiece was cured at high temperature, the curing temperature was 80 °C, and the curing time was 6 h, thus obtaining a 3D printed self-healing acrylic elastomer. Example

[0021] (1) Add natural cotton wool and hydrochloric acid in a mass ratio of 1:3 into a beaker, stir and react at 50 °C for 24 h at a speed of 500 rpm. After the reaction, filter the acid-hydrolyzed cotton wool from the hydrochloric acid by suction, dilute and wash with ultrapure water for 4 times, and dry the sample in a drying oven at 60 °C for 24 h to obtain nanocellulose. (2) Ethylene glycol and dimethyl carbonate were mixed in a molar ratio of 1:1, and the mixture was stirred at 400 rpm for 30 min to obtain a composite active diluent; (3) Add hydroxyethyl acrylate monomer, polymerization inhibitor hydroquinone (hydroquinone accounts for 0.3 wt.% of the total amount of acrylate), and catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1 wt.% of the total amount of acrylate) into the reactor, heat the solution to 100 °C and stir for 12 h to obtain an acrylate prepolymer; (4) Under a nitrogen atmosphere, an acrylate prepolymer, a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, a reactive diluent, and nanocellulose were mixed in a weight ratio of 50:1:15:60, with a stirring speed of 1200 rpm and a stirring time of 12 h to obtain an acrylate photosensitive resin with self-healing properties; (5) The acrylic photosensitive resin was poured into the DLP 3D printing equipment for printing. The printing parameters were as follows: UV light band 405 nm, UV light power 9 mW / cm2, printing layer thickness 0.1 mm, single layer exposure time 2.5 s. After printing, the workpiece was cured at high temperature, the curing temperature was 80 °C, and the curing time was 6 h, thus obtaining a 3D printed self-healing acrylic elastomer.

[0022] The self-repairing acrylic photosensitive resins of Examples 1-5 were respectively poured into a DLP 3D printing device for printing, and after printing, the parts were cured at high temperature to obtain elastic parts with self-repairing ability. The performance test conditions are as follows: Tensile properties: According to GB / T 1040.1-2018 Determination of tensile properties of plastics Part 1: General Principles, the mechanical properties of the printed specimens were measured using a CTM8010 microcomputer-controlled electronic universal material testing machine (Xie Qiang Instrument Manufacturing (Shanghai) Co., Ltd.), with a gauge length of 40 mm and a tensile rate of 20 mm / min. Self-repairing performance: self-repairing efficiency = σ tensile strength after self-repairing / σ tensile strength before self-repairing. According to GB / T 9341-2008 Determination of bending properties of plastics, when using a CTM8010 microcomputer-controlled electronic universal material testing machine for the bending resistance test, the bending angle was 90° and the bending speed was 1 time / second. According to GB / T 22314-2008 Plastic epoxy resin viscosity determination method, the resin viscosity test was performed using an LC-NDJ-5T digital display viscometer (Hunan Lichen Instrument Technology Co., Ltd.).

[0023] Table 1 shows the main performance indicators of the self-repairing photosensitive resins of Examples 1-5 Performance viscosity (cp·s) Tensile strength (MPa) Elongation at break (%) Self-repair efficiency (%) Bending times Example 1 2300 4.55 1350 91 40000 Example 2 2650 6.03 1100 89 38000 Example 3 2930 10.06 760 88 35000 Example 4 3050 14.74 360 90 31000 Example 5 3400 11.40 720 76 27000 It can be seen from Table 1 that the self-healing acrylic photosensitive resin material for 3D printing prepared by the present invention has good mechanical properties and self-healing efficiency, and can be used as a raw material for 3D printing elastic components to provide better strength, toughness and service life.

[0024] The above description of the disclosed embodiments is intended only to enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-repairing acrylate photosensitive resin for 3D printing, the self-repairing acrylate photosensitive resin comprising filler nanocellulose and polymer matrix acrylate, Features: The nanocellulose is nanocellulose with surface hydroxyl groups and nano-sized structure, and a hydrogen bond network exists at the interface between the surface hydroxyl groups of the nanocellulose and the end hydroxyl groups of the acrylate molecular chain. The preparation method of the self-repairing acrylate photosensitive resin includes the following stages: S1: Nanocellulose Preparation ① Add natural cotton wool and saturated hydrochloric acid in a mass ratio of 1: (2.8-3.5) into a reaction vessel, heat to 50℃-60℃ and mechanically stir for 24h at a mechanical stirring rate of 500rpm-550rpm; ② After filtering the solid after acid hydrolysis from the hydrochloric acid using a suction filtration device, dilute and wash it with deionized water for 4-6 times, and then place the washed solid in a drying oven and dry it at 60°C-65°C for 18h-24h to obtain nanocellulose with a length and diameter of 20nm-200nm; S2: Preparation of self-healing acrylic photosensitive resin ① Filling nitrogen into a reaction container, and in a nitrogen atmosphere, uniformly mixing acrylate, photoinitiator, active diluent, and nanocellulose in a mass ratio of 100: (1-5): (15-30): (20-60) to obtain the desired self-healing acrylate photosensitive resin for 3D printing; wherein the active diluent is specifically an active diluent mixed with alcohol and ester.

2. The self-repairing acrylic photosensitive resin for 3D printing according to claim 1, Features: The acrylic acid ester is hydroxyethyl acrylate.

3. The self-repairing acrylic photosensitive resin for 3D printing according to claim 1, Features: The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

4. The self-repairing acrylic photosensitive resin for 3D printing according to claim 1, Features: The active diluent component is obtained by compounding ethylene glycol and dimethyl carbonate in a molar ratio of 1:

1.

5. The self-repairing acrylic photosensitive resin for 3D printing according to claim 1, Features: The method for preparing the self-repairing acrylate photosensitive resin comprises the following steps: S3: Preparation of self-healing acrylic photosensitive resin ① Add hydroxyethyl acrylate monomer, inhibitor hydroquinone, and catalyst 4-dimethylaminopyridine into a reaction kettle, heat the solution to 100°C, stir and react for 12 hours to obtain an acrylate prepolymer; wherein the hydroquinone accounts for 0.28% of the total amount of acrylate wt. %-0.35 wt. %, 4-dimethylaminopyridine dosage is 0.8% of the total amount of acrylate wt. %-1.5 wt. %; Under a nitrogen atmosphere, acrylate prepolymer, photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, active diluent and nanocellulose are mixed in a ratio of (50-60) by weight: (1-1.5) by weight: (15-20) by weight: (20-30) by stirring at a speed of 1200 rpm for 12 h to obtain an acrylate photosensitive resin with self-healing properties.

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