Preparation method of functional polypropylene composite material with hydrophobic and toughening properties
By blending long-chain alkyl fluorinated polysiloxanes with polypropylene, the problems of insufficient hydrophobicity and toughness of polypropylene materials are solved, achieving efficient improvement in hydrophobicity and toughness, making it suitable for applications in multiple fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA THREE GORGES UNIV
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-09
AI Technical Summary
Existing polypropylene materials cannot simultaneously achieve hydrophobic and toughening properties. Traditional modification methods suffer from problems such as poor interfacial compatibility and insufficient durability, making it difficult to meet the needs of high-end applications.
Long-chain alkyl fluorinated polysiloxanes were used as hydrophobic and toughening modifiers and melt-blended with polypropylene. The low surface energy provided by the fluorinated alkyl groups and the flexibility of the polysiloxane segments improved the interfacial compatibility, thus preparing a functional polypropylene composite material with both hydrophobic and toughening properties.
It achieves high efficiency improvement in hydrophobicity and toughness of polypropylene materials, with a water contact angle ≥120°, fracture strain ≥550%, and toughness ≥100J/m3, making it suitable for applications in multiple fields.
Smart Images
Figure CN122167876A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of preparation of functional polymer composite materials, and specifically to a method for preparing a functional polypropylene composite material that combines hydrophobic and toughening properties. Background Technology
[0002] Hydrophobic and toughening functional additives play a significant role in improving the chemical resistance, hydrophobicity, and mechanical properties of conventional plastic products, greatly enhancing the stability and durability of materials in harsh environments. By endowing plastics with multifunctional properties such as waterproofing, oil resistance, and toughening through molecular design, it not only helps reduce plastic pollution and promotes the green transformation of the industry, but also expands its application scenarios and enhances its market competitiveness.
[0003] Polypropylene (PP) is one of the world's largest thermoplastics, holding a significant position in the packaging, textile, and automotive industries due to its lightweight, chemical resistance, and ease of processing and molding. However, the non-polar nature of its molecular chains results in surface energies as high as 29-30 mN / m, making it difficult to meet the hydrophobic performance requirements of high-end applications such as antifouling and self-cleaning, and also limiting the application of polar composite materials. On the other hand, with the development of polymer materials, their application in various industries that traditionally use metals or ceramics is rapidly increasing. In consumer industries such as automotive and home appliances, the application and market for polymers are expanding rapidly due to the demand for product weight reduction. Polypropylene is a low-cost commercial polymer with good mechanical properties and is widely used in many modern industries. However, its high molding shrinkage, high brittleness, and low notched impact strength make it difficult to meet various physical and mechanical performance requirements. Currently, strategies for hydrophobic toughening synergistic modification mainly include nanofiller composite methods, surface micro / nano structure construction methods, hydrophobic elastomer blending methods, multilayer / gradient structure design methods, and bio-based modification methods. However, while nanofiller composites achieve surface hydrophobicity by introducing hydrophobic nanoparticles (such as SiO2 and carbon nanotubes) and simultaneously toughen the surface using the stress transfer effect of nanoparticles, insufficient interfacial compatibility and particle dispersion can easily lead to stress concentration, thus reducing toughness. Superhydrophobicity can be achieved by constructing micro / nano-scale rough surfaces and combining them with low surface energy materials (such as fluorosilanes). However, these surface structures are prone to wear, have poor durability, rely on precision machining, are difficult to scale up, and the fluorination reagents are expensive and pose high environmental risks. Multilayer / gradient structure designs construct composite structures of hydrophobic surface layers and toughening bulk through co-extrusion or coating processes, but the interlayer interface bonding is weak, and delamination is likely after long-term use. Therefore, the development of a stable, simple, and scalable preparation technology for functional polypropylene composites with both hydrophobic and toughening properties is particularly urgent.
[0004] The core of hydrophobic modification is to impart low surface energy interfaces and micro / nano rough structures to materials through chemical modification or physical doping, such as introducing -CF3, -Si-O-Si- segments and inorganic fillers (SiO2, TiO2, etc.), thereby achieving hydrophobic, oil-repellent, corrosion-resistant, and self-cleaning properties. Compared to the poor durability of micro / nano rough structures, improving the low surface energy interface of composite materials is a potential approach. On the other hand, according to the energy dissipation mechanism, introducing flexible segments can utilize interfacial slippage to reduce stress concentration, thereby improving toughness. Therefore, this invention designs a class of long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifiers from a molecular design perspective, and then prepares modified composite materials by melt blending with polypropylene. This simplifies the process and saves production costs, eliminating the need for complex surface treatment or multi-layer composite processes, resulting in a high success rate for industrialization. Fluoroalkyl (-CF3) and polysiloxane segments can impart low surface energy to materials, increasing the contact angle to over 120°. The flexibility of the siloxane segments dissipates energy through molecular chain slip, inhibiting crack propagation. Furthermore, the introduction of long-chain alkyl groups optimizes substrate compatibility, improving its compatibility with the polypropylene matrix. Through rational molecular design, hydrophobicity and toughness are simultaneously enhanced, effectively avoiding the trade-offs inherent in traditional methods. Summary of the Invention
[0005] This invention proposes a solution that utilizes long-chain alkyl fluorinated polysiloxanes to synergistically enhance the hydrophobicity and toughness of polypropylene. The fluorinated alkyl (-CF3) and polysiloxane segments impart low surface energy to the material, improving the hydrophobicity of the polypropylene matrix. The flexibility of the siloxane segments dissipates energy through molecular chain slippage, inhibiting crack propagation and improving the crystallinity of the polypropylene matrix, thus achieving efficient toughening. The introduction of long-chain alkyl groups optimizes matrix compatibility, improving its compatibility with the polypropylene matrix and synergistically enhancing the hydrophobicity and toughness of polypropylene. This effectively avoids the "one-sided" contradiction of traditional methods, thereby expanding the functional applications of traditional polypropylene materials in high-tech fields such as home appliances, special fluid transport pipes, the 3C industry, daily consumer goods and cosmetics, and sporting goods.
[0006] The objective of this invention is achieved through the following technical solution:
[0007] A method for preparing a functional polypropylene composite material with both hydrophobic and toughening properties includes the following steps: (1) Preparation of alkaline gel: Cyclosiloxane and tetramethylammonium hydroxide are mixed evenly, heated to 70~100℃, and dehydrated under vacuum to obtain alkaline gel; (2) Synthesis of long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier: Cyclosiloxane, 1,3,5-trimethyl-1,3,5 (trifluoropropyl)cyclotrisiloxane, long-chain alkyltrimethoxysilane and alkali gum are mixed evenly, and after vacuum dehydration at 30~50 ℃, the temperature is raised to 90~120 ℃ for polymerization reaction. After the reaction is completed, the temperature is raised again to 160~180 ℃ to depressurize and remove unreacted low-boiling substances and alkali gum to obtain long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier; (3) Preparation of functional polypropylene composite material: Polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier and antioxidant prepared in step (2) are mixed evenly, and then granulated by extrusion through a twin-screw extruder at 180~280℃ to obtain functional polypropylene composite material.
[0008] The cyclosiloxanes mentioned in steps (1) and (2) are selected from one or more of octamethylcyclotetrasiloxane, hexaethylcyclotrisiloxane, octaphenylcyclotetrasiloxane, and methylphenylcyclosiloxane; preferably octamethylcyclotetrasiloxane.
[0009] In step (1), the mass ratio of cyclosiloxane to tetramethylammonium hydroxide is 75~95:1~5.
[0010] The long-chain alkyltrimethoxysilane mentioned in step (2) is selected from one or more of hexadecyltrimethoxysilane, dodecyltrimethoxysilane, n-decyltrimethoxysilane, n-octyltrimethoxysilane and n-hexyltrimethoxysilane; the long-chain alkyltrimethoxysilane has 6 to 16 alkyl carbons.
[0011] The molar ratio of cyclosiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, and long-chain alkyltrimethoxysilane is 0.8~1.2:0.8~1.2:0.04~0.2.
[0012] The polymerization reaction in step (2) is carried out under nitrogen protection.
[0013] The polypropylene resin mentioned in step (3) is one or both of homopolymer polypropylene and copolymer polypropylene, and the melt flow rate of the polypropylene resin is 2~10g / 10min (230℃, 2.16kg). The antioxidant is selected from one or more of hydroquinone, thiobisphenol, p-phenylenediamine, and butylated hydroxytoluene; preferably, it is a composite antioxidant composed of hydroquinone and thiobisphenol in a mass ratio of 1:1 to 3. The mass ratio of polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and antioxidant is 85~95:2~10:0.2~1.
[0014] The internal mixer in step (3) has a rotation speed of 50~80 r / min; the twin-screw extruder has a screw length-to-diameter ratio of 30~40:1, an extrusion temperature of 180~250℃, and a screw rotation speed of 200~300 r / min.
[0015] In some preferred embodiments, the preparation method of the aforementioned functional polypropylene composite material with both hydrophobic and toughening properties includes the following steps: (1) Preparation of alkaline adhesive: 75-95 parts by weight of cyclosiloxane and 1-5 parts by weight of tetramethylammonium hydroxide are mixed evenly and heated to 70-100°C. o C. Vacuum dehydration for 1-3 hours yields alkaline gum; (2) Synthesis of long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier: Cyclosiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane and long-chain alkyltrimethoxysilane were mixed in a molar ratio of 0.8~1.2:0.8~1.2:0.04~0.2. 1% of the material mass of alkali gum was added to the reaction system as a catalyst. The mixture was dehydrated under vacuum at 30~50℃ for 1~3h, then heated to 90~120℃ for 2~4h, and finally heated to 160~180℃ to remove unreacted low-boiling substances and alkali gum under reduced pressure to prepare the long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier. (3) Preparation of functional polypropylene composite materials: By weight, 85-95 parts of polypropylene resin, 2-10 parts of long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and 0.2-1 parts of antioxidant are mixed evenly and then mixed in an internal mixer at 180-280 °C. o The polypropylene composite material is obtained by fully mixing C for 0.5-1 hour and then extruding and granulating it through a twin-screw extruder.
[0016] In the above preparation steps, one portion can be converted into equivalent units of measurement such as 1KG or 1g.
[0017] The functional polypropylene composite material obtained by the above technical solution, which combines hydrophobic and toughening properties, has a water contact angle ≥120°, a fracture strain ≥550%, and a toughness ≥100 J / m. 3 .
[0018] Another technical solution of the present invention is to provide the application of the aforementioned functional polypropylene composite material, which is made into plastic products through calendering, injection molding, blow molding, and extrusion processes, and applied to the fields of household appliance shells, special fluid transportation pipes, 3C product accessories, daily consumer goods packaging, cosmetic packaging materials, sports equipment, and automotive interior and exterior parts.
[0019] The functional polypropylene composite material of the present invention, which combines hydrophobic and toughening properties, can be made into plastic products by calendering, injection molding, blow molding, extrusion and other methods. It has advantages such as good compatibility, excellent hydrophobic and oleophobic properties, and strong durability. It can be applied to many fields such as home appliances, special fluid transportation pipes, 3C industry, daily consumer goods and cosmetics, sports equipment and so on.
[0020] The preparation method of the functional PP composite material with both hydrophobic and toughening properties of the present invention has the following advantages compared with the prior art: (1) The use of fluoroalkyl (-CF3) and polysiloxane segments can impart low surface energy to the material and improve the hydrophobicity of the polypropylene matrix. The strong electronegativity of fluorine can strongly attract surrounding electron pairs to form stable covalent bonds, making the distribution of fluorine atoms in the molecule more uniform, reducing the intermolecular interaction force, and the surface free energy is also lower. The maximum hydrophobic angle of the composite material is 129.24°, which is 23% higher than that of the substrate.
[0021] (2) The flexibility of long-chain alkyl-modified siloxane segments dissipates energy through the slippage of alkyl molecular chains of suitable length, inhibits crack propagation, improves the crystallinity of polypropylene matrix, and achieves high-efficiency toughening. Long-chain alkyl chains of suitable length are easy to migrate and embed into PP matrix, forming an interpenetrating network structure with PP molecular chains, enhancing the interfacial bonding strength, and changing the local crystallization behavior of PP. The strain of the composite material is higher than 800%, which is more than 30 times higher than that of blank PP. Attached Figure Description
[0022] Figure 1 The image shows the 1H NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 1.
[0023] Figure 2 The image shows the silicon NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 1.
[0024] Figure 3 The image shows the NMR fluorine spectrum of the long-chain alkyl fluorinated polysiloxane in Example 1.
[0025] Figure 4 The image shows the 1H NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 2.
[0026] Figure 5 The image shows the silicon NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 2.
[0027] Figure 6 The image shows the NMR fluorine spectrum of the long-chain alkyl fluorinated polysiloxane in Example 2.
[0028] Figure 7 The image shows the 1H NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 3.
[0029] Figure 8 The image shows the silicon NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 3.
[0030] Figure 9 The image shows the NMR fluorine spectrum of the long-chain alkyl fluorinated polysiloxane in Example 3.
[0031] Figure 10 The image shows the 1H NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 4.
[0032] Figure 11 The image shows the silicon NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 4.
[0033] Figure 12 The image shows the NMR fluorine spectrum of the long-chain alkyl fluorinated polysiloxane in Example 4.
[0034] Figure 13 The image shows the 1H NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 7.
[0035] Figure 14 The image shows the silicon NMR spectrum of the long-chain alkyl fluorinated polysiloxane in Example 7.
[0036] Figure 15 The image shows the NMR fluorine spectrum of the long-chain alkyl fluorinated polysiloxane in Example 7. Detailed Implementation
[0037] To better understand the present invention, the following description, in conjunction with embodiments, further illustrates the present invention. However, the scope of protection claimed by the present invention is not limited to the scope described in the embodiments.
[0038] Example 1: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 1.
[0039] Table 1:
[0040] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0041] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 2.
[0042] Table 2:
[0043] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, hexadecyltrimethoxysilane, and alkali gum were added in parts by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued for another 2 hours. The temperature was then raised to 175°C, and the low-boiling point was removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to continue for another 2 hours. After the reaction was complete, the apparatus was closed. The final product was a transparent, viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane. Its proton, silicon, and fluorine spectra are shown below. Figure 1-3 As shown.
[0044] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 3.
[0045] Table 3:
[0046] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0047] Example 2: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 4.
[0048] Table 4:
[0049] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0050] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 5.
[0051] Table 5:
[0052] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, dodecyltrimethoxysilane, and alkali gum were added by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued for another 2 hours. The temperature was then raised to 175°C, and the low-boiling point was removed. Reflux was observed at the vacuum pump connection, and the reaction was allowed to continue for another 2 hours. After the reaction was complete, the apparatus was closed. The final product was a transparent, viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane. Its proton, silicon, and fluorine spectra are as follows: Figure 4-6 As shown.
[0053] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 6.
[0054] Table 6:
[0055] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and 0.2 parts hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o After being thoroughly mixed for 0.5 hours, the mixture was then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0056] Example 3: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 7.
[0057] Table 7:
[0058] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0059] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 8.
[0060] Table 8:
[0061] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-decyltrimethoxysilane, and alkali gum were added by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued for another 2 hours. The temperature was then raised to 175°C, and the low-boiling point was removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to continue for another 2 hours. After the reaction was complete, the apparatus was closed. The final product was a transparent, viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane. Its proton, silicon, and fluorine spectra are as follows: Figure 7-9 As shown.
[0062] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 9.
[0063] Table 9:
[0064] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0065] Example 4: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 10.
[0066] Table 10:
[0067] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0068] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 11.
[0069] Table 11:
[0070] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-octyltrimethoxysilane, and alkali gum were added by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued for another 2 hours. The temperature was then raised to 175°C, and the low-boiling point was removed. Reflux was observed at the vacuum pump connection, and the reaction was allowed to continue for another 2 hours. After the reaction was complete, the apparatus was closed. The final product was a transparent viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane. Its proton, silicon, and fluorine spectra are shown below. Figure 10-12 As shown.
[0071] The preparation of functional polypropylene composite materials, the types and amounts of raw materials for each component are shown in Table 12.
[0072] Table 12:
[0073] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0074] Example 5: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 13.
[0075] Table 13:
[0076] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0077] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 14.
[0078] Table 14:
[0079] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-octyltrimethoxysilane, and alkali gum were added in parts by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. Subsequently, the temperature was raised to 100°C, and the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was applied again, and the reaction was allowed to proceed for 2 hours. The temperature was raised to 175°C, and the low-boiling-point substances were removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to proceed for 2 hours. After the reaction was completed, the apparatus was closed. The final product was a transparent viscous fluid. After the product cooled to room temperature, it was removed and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane.
[0080] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 15.
[0081] Table 15:
[0082] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0083] Example 6: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 16.
[0084] Table 16:
[0085] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0086] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 17.
[0087] Table 17:
[0088] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-octyltrimethoxysilane, and alkali gum were added in parts by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. Subsequently, the temperature was raised to 100°C, and the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was applied again, and the reaction was allowed to proceed for 2 hours. The temperature was raised to 175°C, and the low-boiling-point substances were removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to proceed for 2 hours. After the reaction was completed, the apparatus was closed. The final product was a transparent viscous fluid. After the product cooled to room temperature, it was removed and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane.
[0089] The preparation of functional polypropylene composite materials, the types and amounts of raw materials for each component are shown in Table 18.
[0090] Table 18:
[0091] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and thiobisphenol are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0092] Example 7: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 19.
[0093] Table 19:
[0094] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0095] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 20.
[0096] Table 20:
[0097] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-hexyltrimethoxysilane, and alkali gum were added in parts by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued for another 2 hours. The temperature was then raised to 175°C, and the low-boiling point was removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to continue for another 2 hours. After the reaction was complete, the apparatus was closed. The final product was a transparent, viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane. Its proton, silicon, and fluorine spectra are as follows: Figure 13-15 As shown.
[0098] The preparation of functional polypropylene composite materials, the types and amounts of raw materials for each component are shown in Table 21.
[0099] Table 21:
[0100] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and thiobisphenol are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0101] Comparative Example 1: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 22.
[0102] Table 22:
[0103] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0104] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 23.
[0105] Table 23:
[0106] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, and alkali gum were added in parts by weight. A stirring rod was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, and the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued, and the reaction was allowed to proceed for 2 hours. The temperature was then raised to 175°C, and the low-boiling-point substances were removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to proceed for 2 hours. After the reaction was completed, the apparatus was closed. The final product was a transparent viscous fluid. After the product cooled to room temperature, it was removed and transferred to a sample bottle to obtain a fluorinated polysiloxane.
[0107] The preparation of functional polypropylene composite materials, the types and amounts of raw materials for each component are shown in Table 24.
[0108] Table 24:
[0109] Preparation process: By mass, polypropylene resin, fluorinated polysiloxane hydrophobic toughening modifier, and thiobisphenol are mixed evenly and then mixed in an internal mixer at 250-280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0110] Comparative Example 2: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 25.
[0111] Table 25:
[0112] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0113] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 26.
[0114] Table 26:
[0115] Synthesis process: In a three-necked flask equipped with a thermometer, octamethylcyclotetrasiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, n-hexyltrimethoxysilane, and alkali gum were added in parts by weight. A stir bar was inserted, and a vacuum pump was connected. Vacuum was applied at 50°C, and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, at which point the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was continued, and the reaction was allowed to proceed for another 2 hours. The temperature was then raised to 175°C, and the low-boiling components were removed. Reflux was observed at the vacuum pump connection, and the reaction was allowed to proceed for another 2 hours. After the reaction was completed, the apparatus was closed. The final product was a transparent, viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a long-chain alkyl fluorinated polysiloxane.
[0116] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 27.
[0117] Table 27:
[0118] Preparation process: By mass, polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and hydroquinone are mixed evenly and then mixed in an internal mixer at 250~280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0119] Comparative Example 3: The synthesis of alkali gum, the types of raw materials and the amount of each component are shown in Table 28.
[0120] Table 28:
[0121] Synthesis process: In a three-necked flask equipped with a thermometer, add octamethylcyclotetrasiloxane and tetramethylammonium hydroxide by weight, evacuate, dehydrate, heat and maintain at 50°C, then heat to 80°C, continuously evaporate water, increase the viscosity of the reactants until the reaction solution becomes transparent and viscous, cool and discharge to obtain alkaline glue, seal and store at 2-8°C for later use.
[0122] The synthesis of long-chain alkyl fluorinated polysiloxanes, and the types and amounts of raw materials for each component are shown in Table 29.
[0123] Table 29:
[0124] Synthesis process: Octamethylcyclotetrasiloxane and alkali gum were added in a three-necked flask equipped with a thermometer, by weight. A stir bar was inserted and a vacuum pump was connected. Vacuum was applied at 50°C and the reaction was allowed to proceed for 1 hour. The temperature was then raised to 100°C, and the system changed from turbid to transparent, accompanied by an increase in viscosity. Vacuum was applied again and the reaction was allowed to proceed for 2 hours. The temperature was then raised to 175°C, and the low-boiling-point substances were removed. Reflux condensation was observed at the vacuum pump connection, and the reaction was allowed to proceed for 2 hours. After the reaction was completed, the apparatus was closed. The final product was a transparent viscous fluid. The product was cooled to room temperature and transferred to a sample bottle to obtain a fluorinated polysiloxane.
[0125] The preparation of functional polypropylene composite materials, including the types and amounts of raw materials for each component, are shown in Table 30.
[0126] Table 30:
[0127] Preparation process: By mass, polypropylene resin, fluorinated polysiloxane hydrophobic toughening modifier, and thiobisphenol are mixed evenly and then mixed in an internal mixer at 250-280°C. o The mixture was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain a functional polypropylene composite material. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0128] Comparative Example 4: The preparation of polypropylene without added modifiers, and the types and amounts of raw materials for each component are shown in Table 31: Table 31:
[0129] Preparation process: Polypropylene resin and thiobisphenol A are mixed evenly by mass parts and then mixed in an internal mixer at 250~280°C. o C was thoroughly mixed for 0.5 hours, and then extruded and granulated using a twin-screw extruder to obtain polypropylene without added modifiers. Its hydrophobic properties are shown in Appendix Table 32, and its mechanical properties are shown in Appendix Table 33.
[0130] The hydrophobic properties are shown in Table 32:
[0131] The mechanical properties are shown in Table 33:
[0132] Hydrophobic properties showed that fluoroalkyl (-CF3) and polysiloxane segments could impart low surface energy to the material, improving the hydrophobicity of the polypropylene matrix by more than 23%. Toughening properties showed that alkyl chains of suitable length dissipated energy through slip, inhibiting crack propagation, improving the crystallinity of the polypropylene matrix, and achieving efficient toughening. Long alkyl chains readily migrated and embedded into the PP matrix, forming an interpenetrating network structure with the PP molecular chains, enhancing interfacial bonding strength, and simultaneously altering the local crystallization behavior of PP. The strain of the composite material was higher than 800%, more than 30 times higher than that of the blank PP. Fluorinated polysiloxanes with suitable long-chain alkyl groups can significantly and simultaneously improve the hydrophobicity and toughening properties of composite PP.
Claims
1. A method for preparing a functional polypropylene composite material with hydrophobic and toughening properties, characterized in that, Includes the following steps: (1) Preparation of alkaline gel: Cyclosiloxane and tetramethylammonium hydroxide are mixed evenly, heated to 70~100℃, and dehydrated under vacuum to obtain alkaline gel; (2) Synthesis of long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier: Cyclosiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, long-chain alkyltrimethoxysilane and alkali gum are mixed evenly, and after vacuum dehydration at 30~50 ℃, the temperature is raised to 90~120 ℃ for polymerization reaction. After the reaction is completed, the temperature is raised again to 160~180 ℃ to remove unreacted low-boiling substances and alkali gum under reduced pressure to obtain long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier; (3) Preparation of functional polypropylene composite material: Polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier and antioxidant prepared in step (2) are mixed evenly, and then granulated by extrusion through a twin-screw extruder at 180~280℃ to obtain functional polypropylene composite material.
2. The method of claim 1, wherein, The cyclosiloxanes mentioned in steps (1) and (2) are selected from one or more of octamethylcyclotetrasiloxane, hexaethylcyclotrisiloxane, octaphenylcyclotetrasiloxane, and methylphenylcyclosiloxane; preferably octamethylcyclotetrasiloxane.
3. The method of claim 2, wherein, In step (1), the mass ratio of cyclosiloxane to tetramethylammonium hydroxide is 75~95:1~5.
4. The method of claim 2, wherein, The long-chain alkyltrimethoxysilane mentioned in step (2) is selected from one or more of hexadecyltrimethoxysilane, dodecyltrimethoxysilane, n-decyltrimethoxysilane, n-octyltrimethoxysilane and n-hexyltrimethoxysilane; the long-chain alkyltrimethoxysilane has 6 to 16 alkyl carbons.
5. The preparation method according to claim 4, characterized in that, The molar ratio of cyclosiloxane, 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane, and long-chain alkyltrimethoxysilane is 0.8~1.2:0.8~1.2:0.04~0.
2.
6. The method of claim 1, wherein, The polymerization reaction described in step (2) is carried out under nitrogen protection.
7. The method of claim 1, wherein the method is performed in a single step. The polypropylene resin mentioned in step (3) is one or both of homopolymer polypropylene and copolymer polypropylene, and the melt flow rate of the polypropylene resin is 2~10g / 10min. The antioxidant is selected from one or more of hydroquinone, thiobisphenol, p-phenylenediamine, and butylated hydroxytoluene; preferably, it is a composite antioxidant composed of hydroquinone and thiobisphenol in a mass ratio of 1:1 to 3. The mass ratio of polypropylene resin, long-chain alkyl fluorinated polysiloxane hydrophobic toughening modifier, and antioxidant is 85~95:2~10:0.2~1.
8. The method of claim 1, wherein, The internal mixer in step (3) has a rotation speed of 50~80 r / min; the twin-screw extruder has a screw length-to-diameter ratio of 30~40:1, an extrusion temperature of 180~250℃, and a screw rotation speed of 200~300 r / min.
9. A functional polypropylene composite material with both hydrophobic and toughening properties, characterized in that, obtained by the production process according to any one of claims 1 to 8; the composite material has a water contact angle of > 120°, a strain at break of > 550%, and a toughness of > 100 J / m 3 .
10. The application of the functional polypropylene composite material according to claim 9, characterized in that, The composite material is processed into plastic products through calendering, injection molding, blow molding, and extrusion processes, and applied to the fields of household appliance shells, special fluid transportation pipes, 3C product accessories, daily consumer goods packaging, cosmetic packaging materials, sports equipment, and automotive interior and exterior parts.