3D printable water-enhanced polymer material and method of making and use thereof

Abstract

The present application relates to a kind of 3D printable water reinforced polymer material and its preparation method and application, by the molar ratio of 1-5:1-5:0.5-1:6-8 Polyether polyol or polyester polyol, monofunctional oxime chain extender, crosslinking agent, polyisocyanate is obtained under catalyst condition.The reversibility of oxime urethane group in the material of the present application gives the material good 3D printing performance and self-repairing performance at high temperature, using its self-repairing performance can be assembled into printed products with complex geometric structure by simple printing parts;Through the spontaneous multi-step cascade reaction of oxime urethane group and water, the self-reinforcement of polymer material can be realized, and has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, and specifically relates to a 3D printable water-reinforced polymer material, its preparation method, and its application. Background Technology

[0002] Polymer materials are important materials with diverse structures and highly tunable properties, finding wide applications in numerous fields. Polymer materials are generally classified into two categories: thermoplastic polymers and thermosetting polymers. The linear structure of thermoplastic polymers allows them to melt at high temperatures and offers various processing and molding methods. However, while common thermoplastic polymers such as polyethylene, polypropylene, and polycaprolactone have good processing properties, their mechanical properties are unsatisfactory. High-performance thermoplastic polymers, such as polyetheretherketone, polyimide, and thermotropic liquid crystal polyarylates, have very high melting points, typically above 300°C, and high melt viscosity with poor flowability. Therefore, their processing usually requires harsh conditions. Thermosetting polymers possess relatively superior mechanical properties, high wear resistance, and heat resistance, and are typically processed using injection molding or compression molding techniques, during which the material gradually cross-links and solidifies. However, this simultaneous processing and solidification method limits the applicable processing methods for thermosetting polymers. Furthermore, molds are indispensable in traditional processing methods such as injection molding, which not only increases processing costs but also greatly limits the geometry of the finished product. In general, there is an inherent contradiction between the processing performance and mechanical properties of polymer materials, urgently requiring new strategies to reconcile this contradiction.

[0003] Cement, a common material in daily life, becomes a semi-fluid when mixed with water, exhibiting excellent processing properties. The resulting product gradually strengthens itself, eventually meeting application requirements. In recent years, 3D printing of cement has brought about a significant revolution in the construction industry. Introducing cement's excellent 3D printing properties and gradual self-strengthening capabilities into polymers, especially thermosetting polymers—for example, using fused deposition modeling (FDM) to process thermosetting polymers into objects with complex three-dimensional structures, followed by self-reinforcement through structural evolution—could effectively reconcile the inherent contradiction between the processing and mechanical properties of polymer materials. Previous research has shown that introducing reversible dynamic bonds into thermosetting polymer networks, and utilizing the dissociation of these dynamic bonds under external stimuli, can endow polymers with FDM processing properties. However, these dynamic thermosetting materials suitable for FDM processing do not possess self-reinforcing properties. Currently, no thermosetting polymer materials that can be manufactured via FDM and exhibit self-reinforcing properties after processing have been reported. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a 3D printable water-reinforced polymer material, its preparation method and application. The reversibility of the oxime ester group in the material endows the material with good 3D printing performance and self-healing performance at high temperature.

[0005] This invention provides a 3D printable water-reinforced polymer material, which is obtained by reacting polyether polyol or polyester polyol, monofunctional oxime chain extender, crosslinking agent and polyisocyanate in a molar ratio of 1-5:1-5:0.5-1:1-10 under catalytic conditions.

[0006] Preferably, the polyether polyol includes one or more of polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, and polyglycerol; the weight-average molecular weight of the polyether polyol is 500-10000; the polyester polyol includes one or more of polyhexyl adipate diol, polybutylene adipate diol, polypropylene adipate diol, polyethylene adipate diol, polybutylene phthalate diol, polycaprolactone diol, and polycaprolactone triol; the weight-average molecular weight of the polyester polyol is 500-10000.

[0007] Preferably, the monofunctional oxime chain extender includes one or more of 1-(2-hydroxyphenyl)-1-propanone oxime, 4-hydroxyacetophenone oxime, 3-hydroxy-3-methyl-2-butanone oxime, 4-(4-hydroxy-3-methoxyphenyl)butane-2-one oxime, and (9ci)-1-(3-hydroxy-2-pyridine)-acetophenone oxime.

[0008] Preferably, the polyisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate, phenylmethylene diisocyanate, triphenylmethane triisocyanate, L-lysine triisocyanate, and polymethylene polyphenyl polyisocyanate.

[0009] Preferably, the crosslinking agent is one or more of glycerol, water, 1,2,3-butanetriol, 1,2,4-butanetriol, pentaerythritol, diethanolamine, trimethylolpropane, sorbitol, melamine, diethylenetriamine, and castor oil.

[0010] Preferably, the catalyst comprises one or more of dibutyltin dilaurate, stannous octoate, triethylamine, dimethylaminoethyl ether, N-ethylmorpholine, and triethylenediamine.

[0011] This invention also provides a method for preparing a 3D-printable water-reinforced polymer material, comprising the following steps:

[0012] According to the molar ratio, polyether polyol or polyester polyol, monofunctional oxime chain extender, and crosslinking agent are placed in a container and dissolved in a solvent; then polyisocyanate and catalyst are added, and the mixture is stirred at 40-60℃ for 1-5 hours to obtain a mixture; then the mixture is poured into a mold, and the mixture is allowed to react fully at 40-60℃ for 24-48 hours, and then dried and cured to obtain a water-reinforced polymer material that can be 3D printed.

[0013] This invention also provides the application of a 3D printable water-reinforced polymer material in the preparation of 3D printed articles.

[0014] Furthermore, the parameters for preparing the 3D printed product are as follows: the extrusion chamber temperature and nozzle temperature are set to 160℃ and 150℃ respectively, and heated for 10-20 minutes; then, under the control of the computer operating platform, the sample is extruded through the nozzle device and deposited, and the print head movement speed is set to 1 mm / s. -1 The screw extrusion speed is set to 0.01 mm / s. -1 .

[0015] Beneficial effects

[0016] The reversibility of the oxime ester group in the material of this invention endows the material with good 3D printing performance and self-healing properties at high temperatures. Figure 1 Its self-healing properties allow simple printed parts to be assembled into printed products with complex geometries; through the spontaneous multi-step tandem reaction of oxime ester groups with water, self-reinforcement of polymer materials can be achieved, showing good application prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the performance of the water-reinforced polymer material of the present invention.

[0018] Figure 2 (A) Photographs of the original, cut and healed WS-CPOU samples. The healed sample can be stretched to more than 500% of its original length. (B) Stress-strain curves of WS-CPOU before and after self-healing.

[0019] Figure 3 The image shows the heated infrared spectrum of WS-CPOU.

[0020] Figure 4 (A) Temperature scanning rheological measurement results of WS-CPOU; (B) Viscosity of WS-CPOU as a function of shear rate; (C) Assembled-healed WS-CPOU 3D printed parts.

[0021] Figure 5(A) Changes in tensile strength, elongation, toughness and Young's modulus of WS-CPOU film before and after immersion; (B) Changes in tensile strength, elongation, toughness and Young's modulus of WS-CPOU 3D printed products before and after immersion; (C) Infrared spectra of WS-CPOU samples immersed in water for different times; (D) Schematic diagram of WS-CPOU water enhancement process. Detailed Implementation

[0022] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0023] Example 1

[0024] I. Experimental Materials

[0025] Polypropylene glycol (PPG, Mn = ~2000 g mol) -1 Aladdin), polytetramethylene ether glycol (PTMEG, Mn = ~1000 gmol) -1 Aladdin), isophorone diisocyanate (IPDI, 99%, Aladdin), dibutyltin dilaurate (DBTDL, 95%, Aladdin); 3-hydroxy-3-methyl-2-butanone oxime (HMBO, 98%, Tokyo Chemical Industry), glycerol (GLY, 99%, Sinopharm Group). Acetone (99.8%, Yung-Cheng Chemical).

[0026] II. Preparation Method

[0027] Material synthesis: Polypropylene glycol (PPG, 1.4 g, 1 mmol), polytetrahydrofuran glycol (PTMG, 1.4 g, 2 mmol), 3-hydroxy-3-methyl-2-butanone oxime (HMBO, 0.246 g, 3 mmol), and glycerol (GLY, 0.0322 g, 0.5 mmol) were placed in a glass container equipped with a magnetic stirrer and dissolved in 10 ml of acetone. Then, isophorone diisocyanate (IPDI, 1.049 g, 6.75 mmol) and dibutyltin dilaurate (DBTDL, 0.04 g, 1 wt%) were added and stirred at 50 °C for 2 h. The mixture was then quickly poured into a PTFE mold and placed in an oven at 50 °C for 24 h to allow the mixture to react fully. Finally, it was cured in a vacuum oven at 70 °C for another 24 h to obtain the water-reinforced polymer material.

[0028] 3D Printing: The water-reinforced polymer material described above was loaded into the 3D printer barrel. The extrusion chamber temperature and nozzle temperature were set to 160℃ and 150℃ respectively, and heated for 10 minutes. Then, under the control of the computer operating platform, the sample was extruded and deposited through the nozzle device (inner diameter: 0.65mm), and the print head movement speed was set to 1mm / s. -1 The screw extrusion speed is set to 0.01 mm / s. -1 The printing path is controlled by an externally connected computer control system.

[0029] Water-reinforced performance characterization: The synthesized water-reinforced polymer material and the 3D-printed polyurethane product were immersed in deionized water for different time periods, then removed from the water and vacuum dried at room temperature for 24 hours. The mechanical properties of the dried samples were then tested.

[0030] III. Self-healing and 3D printing properties of water-reinforced polymer materials

[0031] Dynamic oxime ester bonds can dissociate into isocyanate and oxime groups at higher temperatures, and then recombine to form oxime ester bonds upon cooling. Therefore, polyurethane materials containing oxime ester bonds exhibit good self-healing properties. To demonstrate the self-healing properties of the prepared water-reinforced polymer material (WS-CPOU), the material was completely cut and spliced ​​together, then left to stand at 70°C for 24 hours without external force. The healed material could be stretched to more than 500% of its original length without breaking. Figure 2 A). The self-healing property of WS-CPOU was further quantitatively evaluated using uniaxial tensile testing, and the self-healing efficiency was defined as the ratio of the toughness of the original sample to the toughness of the repaired sample. Test results showed that the self-healing efficiency of WS-CPOU could reach over 80% after being placed in a 70℃ environment for 24 hours. Figure 2 B).

[0032] The dissociation of dynamic oxime ester bonds at high temperatures can disrupt the cross-linked structure of WS-CPOU, thus enabling the material to be processed using FDM technology at higher temperatures. The heated infrared spectrum shows that when the temperature reaches 150℃, the 2258 cm⁻¹... -1 The characteristic peak of the isocyanate group begins to appear at the temperature, and the intensity of the isocyanate absorption peak gradually increases with increasing temperature, indicating that the increase in temperature promotes the dissociation of the oxime ester bond. Figure 3 ).

[0033] Rheological testing results show that as the temperature increases, the storage modulus (G′), loss modulus (G″), and complex viscosity of WS-CPOU continuously decrease. When the temperature reaches approximately 160℃, G′ and G″ intersect, indicating a transition of the polymer from a solid to a liquid state, and WS-CPOU exhibits a certain degree of fluidity. Figure 4 A). At 160℃, the viscosity of WS-CPOU decreases with increasing shear rate, indicating that the polymer exhibits shear-thinning properties, which is beneficial for extrusion printing. Figure 4 B). Therefore, based on the dynamics of oxime esters, WS-CPOU material can be used for FDM 3D printing at a temperature of 160°C. Furthermore, the printed parts can be assembled, utilizing the self-healing properties of WS-CPOU to fuse the joints together, resulting in products with more complex structures. Figure 4 C).

[0034] IV. Water-reinforced properties of water-reinforced polymer materials

[0035] The water-enhancing properties of WS-CPOU were systematically characterized by studying the changes in mechanical properties and chemical structure of WS-CPOU thin film samples and 3D-printed samples after immersion in water for different times. The results are as follows: Figure 5 As shown, it can be observed that the mechanical properties of the dried film samples gradually improve with increasing soaking time. After soaking for 55 days, the tensile strength, elongation, toughness, and Young's modulus of the dried film samples increased to 165.6%, 111.4%, 149.1%, and 112.8% of the original samples, respectively. Figure 5 (A)). The tensile strength, elongation, toughness, and Young's modulus of the 3D-printed sample increased to 140.7%, 110.8%, 130.1%, and 108.8% of the original sample, respectively, after immersion in water for 35 days. Figure 5 (B) The structural changes of WS-CPOU before and after immersion in water were studied using infrared spectroscopy. Comparison revealed that after immersion in water for 7 days, the WS-CPOU structure at 1651 cm⁻¹... -1 A new characteristic peak appeared at the location, corresponding to the C=O group of the urea bond, and its intensity increased with increasing soaking time. Figure 5 C).

[0036] These results demonstrate the feasibility of the proposed strategy of initiating polymer network structure changes and progressively strengthening the polymer based on a multi-step tandem reaction of dynamic bonds. The isocyanate groups generated by the dissociation of dynamic oxime ester bonds react with water molecules to generate free amine groups, which further react with isocyanate groups to form urea bonds. Figure 5 D). Bidentate hydrogen bonds formed between polar urea bonds are stronger than hydrogen bonds between urethane bonds, which can significantly improve the mechanical properties of the polymer.

Claims

1. A 3D-printable water-reinforced polymer material, characterized in that: It is prepared by reacting polypropylene glycol, polytetrahydrofuran glycol, 3-hydroxy-3-methyl-2-butanone oxime, glycerol, and isophorone diisocyanate in a molar ratio of 1:2:3:0.5:6.75 under dibutyltin dilaurate conditions.

2. A method for preparing a 3D-printable water-reinforced polymer material as described in claim 1, comprising the following steps: According to the molar ratio, polypropylene glycol, polytetrahydrofuran glycol, 3-hydroxy-3-methyl-2-butanone oxime, and glycerol are placed in a container and dissolved in a solvent; then isophorone diisocyanate and dibutyltin dilaurate are added, and the mixture is stirred at 40-60℃ for 1-5 hours to obtain a mixture; then the mixture is poured into a mold, and the mixture is allowed to react fully at 40-60℃ for 24-48 hours, and then dried and cured to obtain a water-reinforced polymer material that can be 3D printed.

3. The application of the 3D printable water-reinforced polymer material as described in claim 1 in the preparation of 3D printed articles.

4. The application according to claim 3, characterized in that: The parameters for preparing the 3D printed product are as follows: the extrusion chamber temperature and nozzle temperature are set to 160℃ and 150℃ respectively, and heated for 10-20 minutes; then, under the control of the computer operating platform, the sample is extruded and deposited through the nozzle device, and the print head movement speed is set to 1 mm / s. -1 The screw extrusion speed is set to 0.01 mm / s. -1 .

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