Preparation method of PVC composite material based on waste fan blades, obtained product and application

Abstract

The invention belongs to the field of solid recycling and polymer composite materials, and particularly relates to a preparation method of a PVC composite material based on waste fan blades, an obtained product and application. The method comprises the following steps: (1) preheating part of waste fan blade powder, adding a modifier, and stirring at a high speed to obtain modified fan blade powder 1; (2) preheating the residual waste fan blade powder, then adding a liquid coupling agent, and stirring at a high speed to obtain modified fan blade powder 2; and (3) mixing the modified fan blade powder 1 and the modified fan blade powder 2, then adding the mixed powder, a stabilizer, PE wax, titanium dioxide and an impact modifier into PVC resin, blending and plasticizing, and then carrying out hot press molding. According to the invention, a technical system of'modification technology + coupling agent modification technology + MBS / ACR synergistic toughening 'is constructed, and chemical bonding with a PVC matrix is enhanced through combined pretreatment of WFRP, meanwhile, the prepared material improves the addition amount of fan blade powder, the use of calcium carbonate is avoided, the synergism of light weight and high performance is realized, the density is reduced by 7.1%, the tensile strength is improved by 26.4% (up to 55.3 MPa), and the service life of the fan blade powder is prolonged. And the vicat softening temperature is increased to 90.3 DEG C.

Description

Technical Field

[0001] The present invention belongs to the field of solid resource utilization and polymer composite materials, and particularly relates to a preparation method of a PVC composite material based on waste fan blades, and the obtained products and applications. Background Art

[0002] The rapid growth of the wind power industry has led to a large number of retired wind turbine blades. These blades are primarily made of glass fiber-reinforced epoxy resin composites, whose chemical cross-linking properties make traditional landfill and incineration processes inefficient. Industry statistics predict that by 2030, the global volume of retired blades will reach millions of tons. Securing their high-value utilization has become a major industry challenge.

[0003] Currently, the main methods for processing retired wind turbine blades include mechanical pulverization, pyrolysis, and chemical decomposition. However, the powder produced by mechanical pulverization is mostly used in low-value-added applications (such as sand control materials and building fillers), failing to fully realize its reinforcing potential. Chinese patent CN118950671A provides a method for recycling retired wind turbine blades, but this method only involves mechanically segmenting the turbine. This recycling technology has significant limitations and a limited application scenario.

[0004] In the field of plastic pipes, calcium carbonate (CaCO3) is a commonly used filler, but its high density leads to heavy pipes and high transportation costs, and excessive filling will significantly reduce the toughness of the material. In addition, in the current process of utilizing waste wind turbine blades, the polarity difference between thermoplastic resins (such as PVC) and thermosetting powders leads to interface defects, traditional coupling agents are difficult to effectively bridge, the interface modification process is single, and the amount of wind turbine blade powder added is extremely low, which limits the increase in filling amount. At the same time, the composite materials currently prepared using wind turbine blade powder are prone to brittle fracture, and the prepared pipes have insufficient stiffness and impact resistance. Therefore, finding a method to efficiently utilize waste wind turbine blades and prepare pipes with excellent performance has become an urgent problem to be solved. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for preparing a PVC composite material based on waste fan blades.

[0006] The present invention also provides a PVC composite material obtained by the above preparation method.

[0007] Another object of the present invention is to provide an application of the above PVC composite material in the preparation of high-performance pipes.

[0008] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are as follows: The present invention provides a method for preparing a PVC composite material based on waste fan blades, comprising the following steps: (1) Preheating a portion of waste fan blade powder, adding a modifier, and stirring at high speed to obtain modified fan blade powder 1; (2) Preheating the remaining waste fan blade powder, then adding a liquid coupling agent and stirring at high speed to obtain modified fan blade powder 2; (3) The modified fan blade powder 1 and the modified fan blade powder 2 are mixed, and then the mixed powder, stabilizer, PE wax, titanium dioxide and impact modifier are added to the PVC resin, and after blending and plasticizing, hot pressing is performed.

[0009] Preferably, in step (1), the amount of the modifier added is 3-3.5% of the waste fan blade powder; the modifier is composed of 3-(mercaptopropyl)trimethylsilane and methyltrichlorosilane in a mass ratio of 1:0.3-0.5.

[0010] Preferably, in step (2), the liquid coupling agent accounts for 6-20% of the waste fan blade powder; and the liquid coupling agent is KH-550.

[0011] Preferably, in steps (1) and (2), the preheating temperature is 50-55° C.; and the high-speed stirring time is 10-15 minutes.

[0012] Preferably, in step (3), the mass ratio of the modified fan blade powder 1 to the modified fan blade powder 2 is 1:3-5.

[0013] Preferably, in step (3), the mass ratio of the mixed powder, stabilizer, PE wax, titanium dioxide, impact modifier and PVC resin is 10-30:4:0.8:2:2.5:100.

[0014] Preferably, in step (3), the stabilizer is a calcium zinc stabilizer; and the impact modifier is composed of MBS and ACR in a mass ratio of 1.5:1.

[0015] Preferably, in step (3), the blending and plasticizing is carried out at a temperature of ≤80°C and high-speed mixing for 15 minutes; the hot pressing molding is carried out by pre-pressing for 5 minutes under the conditions of 170°C and 2MPa on a flat vulcanizing machine, then maintaining the pressure for 15 minutes at a pressure of 20MPa, and cooling to set the shape.

[0016] The present invention also provides a PVC composite material based on waste fan blades prepared by the above preparation method.

[0017] The present invention further provides the use of the above-mentioned PVC composite material based on waste fan blades in the preparation of drainage, sewage pipes, and power pipes.

[0018] The beneficial effects of the present invention are: (1) The present invention constructs a "modification technology + coupling agent modification technology + MBS / ACR synergistic toughening" technology system, and strengthens the chemical bonding with the PVC matrix by jointly pretreating WFRP. At the same time, the prepared material increases the amount of fan blade powder added and avoids the use of calcium carbonate, achieving lightweight and high performance synergy, reducing the density by 7.1%, increasing the tensile strength by 26.4% (reaching 55.3 MPa), and increasing the Vicat softening temperature to 90.3℃.

[0019] (2) The preparation method provided by the present invention reduces costs: the cost of a single piece of material is reduced by 0.32 yuan / m (compared with the CaCO3 system). This technology can be widely used in the fields of sewage, drainage pipes and power pipelines, filling the gap in existing technologies in high-value recycling and high-performance pipe preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the infrared spectrum; Figure 2 This is a physical picture of the prepared PVC pipe. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below with reference to specific embodiments.

[0022] In the following examples, the raw materials, main instruments and equipment are: PVC resin (SG-5): Henan Lianchuang Chemical Co., Ltd. Waste fan blade powder (300 mesh, Guoneng (Shandong) Energy and Environment Co., Ltd.); Additives: calcium zinc stabilizer (Wenzhou Zhengbang Chemical Co., Ltd.), PE wax, titanium dioxide, 3-(mercaptopropyl)trimethylsilane, methyltrichlorosilane, KH550, impact modifier MBS (methyl methacrylate-butadiene-styrene copolymer) (Japan Kaneka Chemical), ACR (acrylate processing aid) (Zibo Huaxing Additive Co., Ltd.).

[0023] Table 1 Main instruments and equipment Example 1 (1) Preheat a portion of waste fan blade powder to 50°C, add a modifier (3-(mercaptopropyl)trimethylsilane and methyltrichlorosilane in a mass ratio of 1:0.5) accounting for 3.5% of the waste fan blade powder, and stir evenly at high speed (1600 rpm) to obtain modified fan blade powder 1; (2) Preheat the remaining waste fan blade powder for 2 minutes, then add the liquid coupling agent KH550 and stir at high speed for 10 minutes to obtain modified fan blade powder 2; (3) Mix 4 parts of modified fan blade powder 1 and 16 parts of modified fan blade powder 2 (the mass ratio of 1 to 2 is 1:4), then add 20 parts of the mixed powder, 4 parts of calcium zinc stabilizer, 0.8 parts of PE wax, 2 parts of titanium dioxide and impact modifier (1.5 parts of MBS and 1 part of ACR) to 100 parts of PVC resin, blend and plasticize (at a temperature of ≤80℃, high-speed mixing for 15 minutes), and then hot press molding (pre-pressing for 5 minutes at a flat vulcanizing machine at 170℃ and 2MPa, and then maintaining the pressure at 20MPa for 15 minutes). Actual picture as shown Figure 2 shown.

[0024] Infrared characterization (FTIR): A small amount of WFRP powder and dry potassium bromide (KBr) powder were ground in a certain ratio (1:100), mixed evenly, placed in a mold, and maintained at a pressure of 10 MPa for 30 s on a tablet press. After being taken out, it was placed in an infrared spectrometer for testing.

[0025] Figure 1 The infrared spectrum of the modified WFRP / PVC composite material shows distinct infrared peaks characteristic of polyvinyl chloride. The absorption peaks at 688 cm⁻¹ and 620 cm⁻¹ are characteristic of polyvinyl chloride, corresponding to carbon-chloride vibration absorption. Peaks at 2966 cm⁻¹, 2916 cm⁻¹, and 2853 cm⁻¹ correspond to the symmetric and asymmetric stretching vibrations of the methylene (-CH₂-) and methine (-CH₂-) groups, respectively. Peaks at 1429 cm⁻¹ correspond to the bending vibration of the methylene (-CH₂-) group.

[0026] Comparative Example 1 (1) Preheat the waste fan blade powder for 2 minutes, then add the liquid coupling agent KH550 and stir at high speed for 10 minutes to obtain the modified fan blade powder; (2) 20 parts of modified fan blade powder, 4 parts of calcium zinc stabilizer, 0.8 parts of PE wax, 2 parts of titanium dioxide and impact modifier (1.5 parts of MBS and 1 part of ACR) were added to 100 parts of PVC resin, blended and plasticized (mixed at high speed for 15 minutes at a temperature of ≤80°C), and then hot-pressed (pre-pressed for 5 minutes at a flat vulcanizing press at 170°C and 2 MPa, and then maintained at a pressure of 20 MPa for 15 minutes).

[0027] Effect Example 1 The composite materials prepared in Example 1 and Comparative Example 1 were tested for their properties; at the same time, a relevant control group was set up. The specific composition of the control group is shown in Table 1. The waste glass fiber powder used in the control group was prepared according to the method provided in Example 1, with powder 1 and powder 2 being composed in a ratio of 1:4.

[0028] Table 2 The specific detection methods are: Density: Test in accordance with GB / T 1033.1-2008.

[0029] Vicat softening temperature: Test according to GB / T 8802-2001. Set the Vicat softening tester to a heating rate of 50°C / h, a standard deflection of 1.00 mm, a constant temperature of 23.5°C, and a constant temperature time of 5 minutes.

[0030] Mechanical properties test: Longitudinal shrinkage: in accordance with GB / T 6671-2001. Tensile strength and elongation at break tests are carried out in accordance with GB / T 1040.2-2006; The test results are shown in Table 3.

[0031] Table 3 1. Density: When fillers are added to PVC, the density of the material increases, as calcium carbonate and WFRP inherently have greater densities than PVC. However, adding fillers can reduce costs. As shown in the table, the density gradually increases with increasing WFRP content. Due to the presence of lightweight, high-strength glass fiber in WFRP, the density of WFRP / PE is lower than that of CaCO3 / PE at the same filler content. This can reduce production costs later in production.

[0032] 2. Vicat Softening Point: A higher Vicat softening point indicates a material's greater heat resistance and less deformation. The Vicat softening temperature of the material increases with increasing modified WFRP content, but when the addition reaches 30wt%, the Vicat softening temperature actually decreases. This is primarily due to the following: Glass fiber possesses high strength and heat resistance. When added to PVC pipes, at low glass fiber content, it is evenly dispersed within the PVC matrix, forming a skeleton-like structure. This structure restricts and hinders the movement of PVC molecular chains, making it difficult for them to slide and deform freely when heated, thereby raising the material's Vicat softening temperature. Furthermore, a certain interfacial bonding between the glass fiber and PVC exists. When subjected to external forces or heat, this interfacial bonding effectively transfers stress, enhancing the material's overall load-bearing capacity. At low glass fiber content, increasing the interfacial bonding strengthens, and the material's heat resistance also improves. However, when the glass fiber content is too high, the increased interaction between the glass fibers can lead to poor dispersion within the PVC matrix, making it prone to agglomeration. These agglomerated glass fiber particles become weak links in the material. When heated, the PVC molecular chains in these areas are prone to deformation and flow, thereby lowering the material's Vicat softening temperature. Furthermore, excessive glass fiber addition increases the material's viscosity, making it more difficult to process. During processing, this can lead to structural inhomogeneities within the material, such as voids and defects, which can also adversely affect the material's Vicat softening temperature.

[0033] When examining different material types at a fixed filler level, WFRP as a filler exhibits a greater effect on increasing the Vicat softening temperature than CaCO₃. This is due to the presence of glass fiber in WFRP. Glass fiber offers significant advantages over calcium carbonate in mechanical, thermal, and processing properties, resulting in a more pronounced increase in the Vicat softening temperature.

[0034] 3. Longitudinal Shrinkage: The results show that the type and amount of filler significantly influence the mechanical properties of plastic products. Specifically, as the amount of modified WFRP filler increases, the longitudinal shrinkage of the composite material gradually decreases, while the tensile strength initially increases and then decreases. Comparing several composite materials, the 20wt% WFRP / PVC / MBS / ACR composite (Example 1) exhibits the best longitudinal shrinkage and the highest tensile strength.

[0035] 4. Tensile strength: The modified WFRP powder can improve its compatibility with the matrix, and can make the powder disperse evenly in the matrix, reducing the agglomeration of the material. From the perspective of material type, the tensile strength of several composite materials is compared. The composite material that has been modified twice and modified synergistically by MBS and ACR has the best performance. Compared with the spherical structure of calcium carbonate, the glass fiber in WFRP has a certain aspect ratio, which plays the role of supporting skeleton and filling in the sample, so that the strain of the sample is reduced when it is deformed. The present invention can improve the interfacial bonding force between WFRP and the matrix, improve the toughness and impact resistance of the material, improve the processing performance, promote the plasticization of the material, and help improve production efficiency by pretreating the exhaust fan blade powder.

[0036] 5. Estimation of material cost per piece: Based on the production of one piece (physical figure as shown in the figure) Figure 2 1m, 110mm diameter, 3.2mm wall thickness PVC hard pipe, The mass required for a 1m piece is: Weight per meter (kg / m) = (outer diameter - wall thickness) × wall thickness × 3.14 × density / 1000 Compared to pure PVC and 20wt% CaCO3 composites, the 20wt% modified WFRP / PVC composites offer lower unit material costs. For every meter of pipe produced, the 20wt% modified WFRP / PVC composite saves 0.32 yuan compared to the 20wt% CaCO3 / PVC composite.

Claims

1. A method for preparing a PVC composite material based on waste fan blades, characterized in that: The following steps are involved: (1) Preheating a portion of waste fan blade powder, adding a modifier, and stirring at high speed to obtain modified fan blade powder 1; (2) Preheating the remaining waste fan blade powder, then adding a liquid coupling agent and stirring at high speed to obtain modified fan blade powder 2; (3) The modified fan blade powder 1 and the modified fan blade powder 2 are mixed, and then the mixed powder, stabilizer, PE wax, titanium dioxide and impact modifier are added to the PVC resin, and after blending and plasticizing, hot pressing is performed.

2. The preparation method according to claim 1, characterized in that In step (1), the amount of the modifier added is 3-3.5% of the waste fan blade powder; the modifier is composed of 3-(mercaptopropyl)trimethylsilane and methyltrichlorosilane in a mass ratio of 1:0.3-0.

5.

3. The preparation method according to claim 1, characterized in that In step (2), the liquid coupling agent accounts for 6-20% of the waste fan blade powder; the liquid coupling agent is KH-550.

4. The preparation method according to any one of claims 1 to 3, characterized in that In steps (1) and (2), the preheating temperature is 50-55° C.; and the high-speed stirring time is 10-15 minutes.

5. The preparation method according to any one of claims 1 to 4, characterized in that In step (3), the mass ratio of the modified fan blade powder 1 to the modified fan blade powder 2 is 1:3-5.

6. The preparation method according to claim 1 or 5, characterized in that In step (3), the mass ratio of the mixed powder, stabilizer, PE wax, titanium dioxide, impact modifier and PVC resin is 10-30:4:0.8:2:2.5:

100.

7. The preparation method according to claim 1 or 6, characterized in that In step (3), the stabilizer is a calcium zinc stabilizer; and the impact modifier is composed of MBS and ACR in a mass ratio of 1.5:

1.

8. The preparation method according to claim 1 or 7, characterized in that In step (3), the blending and plasticizing is carried out at a temperature of ≤80°C and high-speed mixing for 15 minutes; the hot pressing molding is carried out by pre-pressing for 5 minutes under the conditions of 170°C and 2MPa on a flat vulcanizing machine, then maintaining the pressure for 15 minutes at a pressure of 20MPa, and cooling to set the shape.

9. A PVC composite material based on waste fan blades prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the PVC composite material based on waste fan blades as claimed in claim 9 in the preparation of drainage, sewage pipes and power pipes.

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