Single-chain nanoparticle-composite reinforced and toughened plastic materials and methods for their preparation

Abstract

The application discloses a single-chain nanoparticle composite reinforced and toughened plastic material and a preparation method thereof, and belongs to the technical field of polymer plastics. The reinforced and toughened plastic material comprises the following raw materials in parts by weight: 10-20 parts of polymer monomers, 0.004-0.005 parts of an initiator, 0.05-0.06 parts of a chain transfer agent, 8-12 parts of a solvent and 0.1-0.2 parts of a functional filler. The preparation method specifically comprises the following steps: (1) weighing the raw materials; (2) uniformly mixing the raw materials, replacing the nitrogen atmosphere and performing polymerization reaction; and (3) reprecipitating and vacuum drying, so as to obtain the product. The reinforced and toughened plastic material not only has excellent tensile performance, but also has excellent mechanical response under bending load, and is suitable for engineering plastic application scenarios with high requirements for structural stability and use safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular plastics, and more particularly to a single-chain nanoparticle composite reinforced and toughened plastic material and a preparation method thereof. BACKGROUND

[0002] In the field of plastic materials, how to effectively solve the problem of "strong-tough mutual exclusion" has always been a core challenge in material performance optimization. Generally, enhancing the mechanical strength of plastics often leads to a decrease in toughness, and vice versa.

[0003] To address this problem, inorganic fillers (such as carbon black, silicon dioxide, clay, etc.) or blending modification methods are commonly used in the prior art to achieve reinforcement or toughening effects. However, these traditional methods generally have the following limitations: on the one hand, inorganic fillers can easily cause compatibility problems between the polymer matrix and the inorganic fillers, resulting in limited improvement in material mechanical properties; on the other hand, excessive addition of fillers can affect the processing performance and product quality of the material, and even cause embrittlement, limiting its practical application. In addition, this technology cannot simultaneously optimize strength and toughness, especially in the context of increasing demand for high-performance plastics, developing modified plastic materials with high strength and high toughness has important technical significance and broad application prospects.

[0004] Therefore, how to balance the strength and toughness of plastic materials is a problem that needs to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a single-chain nanoparticle composite reinforced and toughened plastic material and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A single-chain nanoparticle composite reinforced and toughened plastic material, comprising the following raw materials by weight: 10-20 parts of a polymer monomer, 0.004-0.005 parts of an initiator, 0.05-0.06 parts of a chain transfer agent, 8-12 parts of a solvent, and 0.1-0.2 parts of a functional filler.

[0008] The present application aims to solve the problem of balancing strength and toughness in existing plastic materials, and provides a plastic modification technology and material system based on single-chain nanoparticle (SCNPs) composite. By introducing SCNPs with molecular-scale dispersibility and excellent compatibility into the polymer matrix, the mechanical strength, fracture toughness, and ductility of the plastic material are simultaneously improved, thereby overcoming the performance trade-off and processing limitations faced by traditional inorganic fillers or blending modification, and meeting the application requirements for high-performance and high-reliability plastic materials.

[0009] Further, the above-mentioned single-chain nanoparticle-reinforced toughened plastic material comprises the following raw materials by weight: 15 parts of polymer monomer, 0.00427 parts of initiator, 0.0525 parts of chain transfer agent, 10 parts of solvent, and 0.15 parts of functional filler.

[0010] Further, the above-mentioned polymer monomer is widely applicable and can be selected from methyl methacrylate, ethyl methacrylate, or styrene, and is preferably ethyl methacrylate (EMA).

[0011] The above-mentioned further beneficial effect is that the method of the present application has strong universality and is applicable to any polymerizable polymer monomer, such as methyl methacrylate, ethyl methacrylate, styrene, etc., and the present application mainly demonstrates the results of using ethyl methacrylate as the monomer. EMA as a representative acrylate plastic monomer helps to embody the universality of the present application.

[0012] Further, the above-mentioned initiator is azobisisobutyronitrile (AIBN).

[0013] The above-mentioned further beneficial effect is that the initiation temperature of AIBN is moderate, controllability is good, applicability to various monomers is strong, and the initiation efficiency is high with few side reactions.

[0014] Further, the above-mentioned chain transfer agent is 4-cyano-4-[(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid (CTA).

[0015] The above-mentioned further beneficial effect is that CTA significantly inhibits the diradical termination side reaction through a reversible chain transfer equilibrium, realizes controllable polymer molecular weight, and makes the polydispersity index (PDI) as low as about 1.0, which is crucial for the mechanical properties of plastic materials.

[0016] Further, the above-mentioned solvent is 1,4-dioxane.

[0017] The above-mentioned further beneficial effect is that the boiling point of 1,4-dioxane is moderate, and the operation is safe.

[0018] Further, the above-mentioned functional filler is a single-chain nanoparticle (SCNP) with the structural formula .

[0019] The above-mentioned further beneficial effect is that single-chain nanoparticles, as a new emerging high polymer-based nanomaterial, have good molecular size compatibility and can realize molecular-level uniform dispersion in the polymer matrix without macroscopic phase separation.

[0020] A preparation method of a single-chain nanoparticle-reinforced toughened plastic material, specifically comprising the following steps:

[0021] (1) The weight parts of each raw material of the single-chain nanoparticle composite reinforced and toughened plastic material are taken according to the above;

[0022] (2) Each raw material is uniformly mixed, replaced in a nitrogen atmosphere, polymerized to obtain a reaction product;

[0023] (3) The reaction product is reprecipitated in a poor solvent, vacuum dried, and the single-chain nanoparticle composite reinforced and toughened plastic material is obtained.

[0024] The present application proposes a new technical route based on SCNPs composite modification for the performance regulation problem of plastic materials. This method can improve the strength and toughness of plastic materials without significantly sacrificing other properties, meeting the application requirements of high-performance engineering plastics in the fields of automobiles, electronics, packaging, etc.

[0025] Further, in the above step (2), the replacement time is 30 min; the polymerization reaction temperature is 80℃, and the time is 12h.

[0026] Further, in the above step (3), the poor solvent is methanol; the vacuum drying temperature is 70℃, and the time is one week.

[0027] Through the above technical solution, compared with the prior art, the present application realizes the synergistic optimization of the strength and toughness of plastic materials by introducing single-chain nanoparticles (SCNPs) into the plastic matrix, and has the following significant technical effects and practical advantages:

[0028] 1. Synergistic improvement of strength and toughness: SCNPs, as highly flexible and deformable nanoparticles, can be uniformly dispersed in the plastic matrix and promote the synergistic movement between polymer chain segments. This mechanism effectively improves the tensile strength, elongation at break and impact toughness of the plastic material, which is significantly better than the traditional inorganic filler reinforcement system, effectively breaking through the material performance bottleneck of "strong-tough mutual exclusion".

[0029] 2. Synchronous enhancement of bending strength: The reinforced and toughened plastic material of the present application not only performs excellently in tensile properties, but also exhibits excellent mechanical response under bending load, which is suitable for engineering plastic application scenarios with high requirements for structural stability and use safety.

[0030] 3. Simple process, strong universality: The modification method adopted by the present application is simple and controllable, and is compatible with existing polymerization or blending processing procedures, without the need for additional complex equipment or high-energy consumption conditions. It is suitable for a variety of general plastics and engineering plastic systems, and has good universality and industrialization prospects.

[0031] 4. In summary, the present application discloses a kind of single-chain nanoparticle (SCNPs) composite based on enhanced toughening plastic material and its preparation method, suitable for the mechanical property optimization of polymethyl methacrylate (PMMA), poly (methyl methacrylate) (PEMA), polystyrene (PS) and other thermoplastic plastic systems. Among them, SCNPs are flexible high molecular single-chain nanoparticles formed by internal cross-linking, which can be uniformly dispersed in the plastic polymer matrix at molecular scale, thereby significantly improving the toughness and ductility on the basis of improving the overall strength of the material, so that the resulting composite material exhibits excellent tensile strength, fracture toughness, ductility and bending strength. The present application of reinforced and toughened plastic material is suitable for a variety of plastic mechanical performance requirements of higher application scenarios, including but not limited to automotive interior and exterior parts, electronic product shell, sports equipment, household appliance structural parts, high-strength packaging materials and building decoration materials and other fields, has a wide range of industrial application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 Synthesis route of single-chain nanoparticles;

[0033] Figure 2 Nuclear magnetic resonance hydrogen spectrum (H NMR) diagram of single-chain nanoparticles; 1 H NMR) diagram;

[0034] Figure 3 Tensile stress-strain curves (a) and tensile mechanical property statistical data (b) of comparative example 1 and example 1 samples;

[0035] Figure 4 Three-point bending stress-strain curves of comparative example 1 and example 1 samples;

[0036] Figure 5 Scanning electron microscope fracture surface image of example 1 sample. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0038] Example 1

[0039] The single-chain nanoparticle composite reinforced and toughened plastic material comprises the following raw materials by weight: ethyl methacrylate (0.13 mol, 15 g), azobisisobutyronitrile (0.026 mmol, 4.27 mg), 4-cyano-4-[(dodecylthioalkylthiocarbonyl)thioalkyl]valeric acid (0.13 mmol, 52.5 mg), 1,4-dioxane (10 mL), and single-chain nanoparticles (150 mg, approximately 1 wt% of the system mass).

[0040] Among them, the synthesis route of single-chain nanoparticles is as follows: Figure 1 As shown, the specific steps include: styrene (0.095 mol, 9.9 g), 4-acryloyloxybenzophenone (crosslinking agent, 5 mmol, 1.26 g), azobisisobutyronitrile (0.05 mmol, 8.2 mg), cyanomethyl dodecyl trithiocarbonate (0.25 mmol, 79.4 mg), and 1,4-dioxane (10 mL) are uniformly mixed, purged with nitrogen, and polymerized at 90 °C for 24 h. After the polymerization is completed, the mixture is reprecipitated in the unsuitable solvent methanol and dried under vacuum at 50 °C for 24 h.

[0041] 1H NMR spectrum of single-chain nanoparticles 1 H NMR) such as Figure 2 As shown. By Figure 2 The spectral analysis shows that the characteristic peaks of styrene and 4-acryloyloxybenzophenone are present, confirming that the two have successfully achieved random copolymerization, and the unit structure content of 4-acryloyloxybenzophenone is (0.11 / 9) / ((0.11 / 9)+(1 / 5))=5.7%.

[0042] The preparation method of the above-mentioned single-chain nanoparticle composite reinforced and toughened plastic material specifically includes the following steps:

[0043] (1) Weigh each raw material according to the weight of the above-mentioned single-chain nanoparticle composite reinforced and toughened plastic material;

[0044] (2) Mix all raw materials evenly, replace with nitrogen atmosphere for 30 min, and then polymerize at 80℃ for 12 h to obtain reaction product;

[0045] (3) The reaction product is redeposited in methanol and then vacuum dried at 70°C for one week to obtain a single-chain nanoparticle composite reinforced and toughened plastic material.

[0046] Comparative Example 1

[0047] Plastic material, comprising raw materials in the following weights: ethyl methacrylate (0.13 mol, 15 g), azobisisobutyronitrile (0.026 mmol, 4.27 mg), 4-cyano-4-[(dodecylsulfanylthio) sulfanyl] pentanoic acid (0.13 mmol, 52.5 mg) and 1,4-dioxane (10 mL);

[0048] The preparation method of the above plastic material, specifically comprising the following steps:

[0049] (1) Each raw material is weighed according to the weight of the above plastic material;

[0050] (2) Each raw material is uniformly mixed, replaced with nitrogen atmosphere for 30 min, and then polymerized at 80°C for 12 h to obtain a reaction product;

[0051] (3) The reaction product is reprecipitated in methanol, and then vacuum dried at 70°C for one week to obtain the plastic material.

[0052] Performance test

[0053] Each of the plastic material (PEMA) prepared in Comparative Example 1 and the reinforced and toughened plastic material (PEMA-SCNPs) prepared in Example 1 is subjected to injection molding to obtain a dumbbell-shaped sample, and then subjected to plastic mechanical property test and fracture surface morphology characterization.

[0054] 1. Tensile property test

[0055] At room temperature, the dumbbell-shaped sample is subjected to tensile test on a universal material testing machine (Instron 68TM-5 double column, 5kN) at a tensile speed of 10 mm / min, and the effective tensile area of the dumbbell-shaped sample is 20 mm x 4.0 mm x 2.0 mm (ISO 527-2-5A). Each sample is subjected to at least five individual tensile tests.

[0056] The results are shown in Table 1 and Figure 3 based on the test data of five parallel samples.

[0057] Table 1. Tensile mechanical property statistical data of samples of Comparative Example 1 and Example 1

[0058] Sample Yield strength (MPa) Breaking strength (MPa) Toughness (MPa) Breaking elongation (%) Comparative Example 1 31.42±0.36 21.08±0.55 13.78±1.81 60.60±9.06 Example 1 39.45±0.39 28.36±0.40 22.63±1.52 78.20±5.37

[0059] As can be seen from Table 1 and Figure 3 compared with Comparative Example 1, the yield strength (increased by about 26%), fracture strength, toughness (increased by about two times) and elongation at break of the sample of Example 1 are all obviously improved, which indicates that the strength and toughness of the plastic material can be simultaneously improved by the present application, and the "strength-toughness" of the plastic material is simultaneously optimized.

[0060] 2. Three-point bending (flexural properties) test

[0061] The Autograph AG-I 20kN universal material testing machine produced by Shimadzu (Japan) was used at room temperature, and the sample preparation and bending strength calculation were strictly in accordance with the national standard GB / T 9341-2000.

[0062] The results are shown in Table 2 and Figure 4 .

[0063] Table 2 Flexural properties statistics of the sample of Comparative Example 1 and Example 1

[0064] Sample Maximum bending strength (MPa) Comparative Example 1 47.43±0.81 Example 1 55.19±1.05

[0065] As can be seen from Table 2, compared with Comparative Example 1, the maximum bending strength of the sample of Example 1 is increased by about 20%, which shows that the flexural properties of the plastic material are also improved synchronously by the present application.

[0066] 3. Fracture surface morphology characterization

[0067] The scanning electron microscope fracture surface image of the sample of Example 1 is shown in Figure 5 .

[0068] As can be seen from Figure 5 , the fracture surface of the sample of Example 1 is uniform and presents a network structure that can realize energy dissipation, which shows the characteristics of ductile fracture.

[0069] The above description of the disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single chain nanoparticle complexed reinforced and toughened plastic material, characterized in that, The raw materials include the following components by weight: polymer monomer 10-20 parts, initiator 0.004-0.005 parts, chain transfer agent 0.05-0.06 parts, solvent 8-12 parts, and functional filler 0.1-0.2 parts; The functional filler is a single-chain nanoparticle, and the structural formula is .

2. A single-stranded nanoparticle-composite reinforced and toughened plastic material according to claim 1, characterized in that, The raw materials include the following components by weight: polymer monomer 15 parts, initiator 0.00427 parts, chain transfer agent 0.0525 parts, solvent 10 parts, and functional filler 0.15 parts.

3. A single-walled nanoparticle-composite reinforced and toughened plastic material according to claim 1 or 2, characterized in that The polymer monomer is methyl methacrylate, ethyl methacrylate, or styrene.

4. A single-walled nanoparticle-composite reinforced and toughened plastic material according to claim 1 or 2, characterized in that The initiator is azobisisobutyronitrile.

5. A single-walled nanoparticle-composite reinforced and toughened plastic material according to claim 1 or 2, characterized in that The chain transfer agent is 4-cyano-4-[(dodecylsulfanylthio) sulfanyl] pentanoic acid.

6. A single-chain nanoparticle-composite reinforced and toughened plastic material according to claim 1 or 2, characterized in that, The solvent is 1,4-dioxane.

7. A process for the preparation of a single-stranded nanoparticle-composite reinforced and toughened plastic material, characterized in that, The method specifically includes the following steps: (1) taking each raw material according to the weight fraction of the single-chain nanoparticle composite reinforced and toughened plastic material according to any one of claims 1-6; (2) uniformly mixing each raw material, replacing the atmosphere with nitrogen, and performing polymerization reaction to obtain a reaction product; (3) reprecipitating the reaction product in a poor solvent and vacuum drying to obtain the single-chain nanoparticle composite reinforced and toughened plastic material.

8. A process for the preparation of a single-stranded nanoparticle-composite reinforced and toughened plastic material according to claim 7, characterized in that, In step (2), the replacement time is 30 min; the polymerization reaction temperature is 80°C, and the time is 12 h.

9. A process for the preparation of a single-stranded nanoparticle-composite reinforced and toughened plastic material according to claim 7, characterized in that, In step (3), the poor solvent is methanol; the vacuum drying temperature is 70°C, and the time is one week.

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