Preparation method of modified polyphenylene sulfide composite master batch

Abstract

The preparation method comprises the following steps: weighing polyphenylene sulfide, hyperbranched polysiloxane, a core-shell filler, a carbon nanotube, a phosphorus-nitrogen flame retardant, a cross-linking agent, an antioxidant, a lubricant, a light stabilizer and a color master batch according to a set mass ratio, carrying out melt blending through a twin-screw extruder, and carrying out water-cooling pelletizing, so as to obtain the modified polyphenylene sulfide composite master batch. Modified polyphenylene sulfide composite master batches are obtained; the invention relates to the technical field of polyphenylene sulfide composite material preparation. According to the preparation method of the modified polyphenylene sulfide composite master batch, through the synergistic effect of hyperbranched polysiloxane and the cross-linking agent, the notch impact strength is improved, a rigid network is formed through the core-shell filler and the PPS matrix, the high-temperature working condition requirement is met, and the modified polyphenylene sulfide composite master batch has good heat conduction performance and electromagnetic shielding performance; effective support is provided for use and heat dissipation of high-power electronic devices, meanwhile, the melt processing characteristic of PPS is reserved, and good process compatibility is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene sulfide composite material preparation, in particular to a method for preparing a modified polyphenylene sulfide composite masterbatch. Background Art

[0002] Polyphenylene sulfide (PPS), a polymer containing repeating p-phenylene sulfide units, is a new type of functional engineering plastic. It exhibits excellent chemical resistance, dimensional stability, and electrical insulation properties, making it widely used in the automotive, electrical and electronics, and aerospace industries. However, traditional PPS has the following drawbacks: Insufficient toughness: notched impact strength is usually less than 2kJ / m 2 , which limits its application in structural parts; Low heat deformation temperature: The heat deformation temperature of traditional PPS generally does not exceed 260°C, which is difficult to meet the requirements of high-temperature working conditions; Functional singularity: Traditional modification technology can only improve a single property, such as flame retardancy or thermal conductivity, and cannot achieve multifunctional integration.

[0003] In view of this, a preparation method of modified polyphenylene sulfide composite masterbatch is proposed to improve the high toughness and high heat resistance of PPS and realize multifunctional integrated design. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a method for preparing a modified polyphenylene sulfide composite masterbatch, which solves the problems of insufficient toughness, low heat deformation temperature and single function of traditional PPS.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a modified polyphenylene sulfide composite masterbatch, comprising: With nano-ferroferric oxide as the core, it is coated with polydopamine, and then boron nitride nanosheets are bonded to the surface of polydopamine as core-shell filler. The raw materials are weighed according to a set mass ratio. The raw materials include polyphenylene sulfide, hyperbranched polysiloxane, core-shell filler, carbon nanotubes, phosphorus-nitrogen flame retardant, crosslinker, antioxidant, lubricant, light stabilizer and masterbatch. The raw materials are melt-blended through a twin-screw extruder. The temperature of zone 1 is 285-295°C, the temperature of zone 2 is 305-315°C, the temperature of zone 3 is 315-325°C, and the screw speed is 350-450rpm. The raw materials are then water-cooled and pelletized to obtain a modified polyphenylene sulfide composite masterbatch.

[0006] The present invention is further configured as follows: the raw materials include, by mass ratio: Polyphenylene sulfide: 40% to 55%; Hyperbranched polysiloxane: 9% to 12%; Core-shell filler: 13% to 20%; Carbon nanotubes: 3% to 6%; Phosphorus and nitrogen flame retardants: 6% to 12%; Cross-linking agent: 2% to 4%; Antioxidant: 0.5% to 1.5%; Lubricant: 1% to 3%; Light stabilizer: 0.5% to 1.5%; Masterbatch: 4%~7%.

[0007] The present invention is further configured as follows: the preparation method of the core-shell filler comprises: Nano-ferrosoferric oxide was dispersed in Tris buffer and ultrasonically treated for 10 minutes. Dopamine hydrochloride was added and magnetically stirred at room temperature for 24 hours. Dopamine hydrochloride was self-oxidatively polymerized to polydopamine. The product was washed with deionized water until neutral and vacuum dried at 60°C for 8 hours to obtain the coating to be shelled. Boron nitride nanosheets were dispersed in ethanol and ultrasonically treated for 2 h. The shelled material was added and ultrasonically treated for 1 h. The product was magnetically stirred at room temperature for 48 h. The product was centrifuged and washed three times with ethanol. The product was vacuum dried at 60°C for 8 h to obtain a core-shell filler.

[0008] The present invention is further configured as follows: the nano-ferrosoferric oxide is dispersed in a Tris buffer at a ratio of 1 g:1 L, and the concentration of the Tris buffer is 10 mM and the pH is 8.5; The dopamine hydrochloride is added to the Tris buffer at a ratio of 2 g:1 L; The mass ratio of the boron nitride nanosheets to the shelled coating is 2:1, and the concentration of the ethanol is 6% vol.

[0009] The present invention is further configured as follows: the cross-linking agent is selected from diphenylmethane bismaleimide and furfuryl methacrylate, and the mass ratio of the diphenylmethane bismaleimide to furfuryl methacrylate is 2:1.

[0010] The present invention is further configured such that the diameter of the carbon nanotubes is 10-20 nm.

[0011] The present invention is further configured as follows: the phosphorus-nitrogen flame retardant is DOPO-HQ; The antioxidant is antioxidant 168; The lubricant is pentaerythritol stearate; The light stabilizer is UV-3853 hindered amine light stabilizer.

[0012] The present invention is further configured as follows: the masterbatch is a black masterbatch with a carbon content of 30%.

[0013] The present invention provides a method for preparing a modified polyphenylene sulfide composite masterbatch, which has the following beneficial effects: The present invention improves the notched impact strength through the synergistic effect of hyperbranched polysiloxane and cross-linking agent, and forms a rigid network through the core-shell filler and PPS matrix to achieve an ultra-heat-resistant design to meet the requirements of high-temperature working conditions. At the same time, it has good thermal conductivity and electromagnetic shielding performance, providing effective support for the use and heat dissipation of high-power electronic devices, while retaining the melt processing characteristics of PPS. It can be formed through conventional processes such as injection molding and extrusion, lowering the industrialization threshold and having good process compatibility. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0015] The embodiments of the present invention provide the following technical solutions: Example 1 A method for preparing a modified polyphenylene sulfide composite masterbatch is used to improve the high toughness and high heat resistance of PPS and achieve a multifunctional integrated design. The raw materials used include: Polyphenylene sulfide: 8.0kg; Hyperbranched polysiloxane: 2.4 kg; Core-shell filler: 2.6kg; Carbon nanotubes: 1.2 kg, the diameter of the carbon nanotubes is 20 nm; Phosphorus and nitrogen flame retardant: 2.4kg; Cross-linking agent: 0.8 kg; Antioxidant: 0.3kg, antioxidant is antioxidant 168; Lubricant: 0.6 kg, the lubricant is pentaerythritol stearate; Light stabilizer: 0.3kg, the light stabilizer is UV-3853 hindered amine light stabilizer; Masterbatch: 1.4kg, black masterbatch with 30% carbon content.

[0016] Further description, the preparation method of hyperbranched polysiloxane is: 1.0 mol of γ-chloropropylmethyldiethoxysilane, 2.0 mol of dimethyldimethoxysilane and 0.01 mol of tetramethylammonium hydroxide were added to 500 mL of tetrahydrofuran, and stirred at 60°C under nitrogen for 24 h. Deionized water was added to terminate the reaction, and the organic phase was separated and the solvent was removed by rotary evaporation to obtain a siloxane monomer; 100 g of siloxane monomer and 5 g of hexamethyldisiloxane were added to a reaction kettle, and the atmosphere was replaced with nitrogen three times. 0.1 g of trifluoromethanesulfonic acid was added, and the temperature was raised to 80° C. and stirred for 48 h. Sodium bicarbonate was added to neutralize the trifluoromethanesulfonic acid. The mixture was filtered and vacuum dried to obtain a hyperbranched polysiloxane.

[0017] As a detailed description, the preparation method of the core-shell filler includes: 289 g of nano-ferrosoferric oxide was dispersed in 289 L of Tris buffer with a concentration of 10 mM and a pH of 8.5. The solution was ultrasonically treated for 10 min. 578 g of dopamine hydrochloride was added to the Tris buffer. After magnetic stirring at room temperature for 24 h, dopamine hydrochloride was auto-oxidatively polymerized to form polydopamine. The product was washed with deionized water until neutral and vacuum dried at 60 ° C for 8 h to obtain the coating to be shelled; 1.733 kg of boron nitride nanosheets were dispersed in 173.3 L of 6% vol ethanol and ultrasonically treated for 2 h. The shelled material was added and ultrasonically treated for 1 h. The product was magnetically stirred at room temperature for 48 h. The product was centrifuged and washed three times with ethanol. It was then vacuum dried at 60°C for 8 h to obtain a core-shell filler.

[0018] As a detailed description, the crosslinking agent is selected from diphenylmethane bismaleimide and furfuryl methacrylate, wherein diphenylmethane bismaleimide is 532 g and furfuryl methacrylate is 266 g.

[0019] Polyphenylene sulfide, hyperbranched polysiloxane, core-shell filler, carbon nanotubes, phosphorus-nitrogen flame retardant, crosslinker, antioxidant, lubricant, light stabilizer and masterbatch were weighed according to the above mass ratio and melt-blended through a twin-screw extruder, wherein the temperature of zone 1 was 285° C., the temperature of zone 2 was 305° C., the temperature of zone 3 was 315° C., and the screw speed was 450 rpm. The mixture was then water-cooled and pelletized to obtain a modified polyphenylene sulfide composite masterbatch.

[0020] Example 2 The difference between this embodiment and embodiment 1 is that the raw materials used in this embodiment include, by mass ratio: Polyphenylene sulfide: 25kg; Hyperbranched polysiloxane: 5 kg; Core-shell filler: 7.5kg; Carbon nanotubes: 2.5 kg, the diameter of the carbon nanotubes is 15 nm; Phosphorus and nitrogen flame retardant: 4kg; Cross-linking agent: 1.5 kg; Antioxidant: 0.5kg; Lubricant: 1kg; Light stabilizer: 0.5kg; Masterbatch: 2.5kg.

[0021] Twin-screw extruder: zone 1 temperature 290°C, zone 2 temperature 310°C, zone 3 temperature 320°C, screw speed 400 rpm.

[0022] Example 3 The difference between this embodiment and embodiment 1 is that the raw materials used in this embodiment include, by mass ratio: Polyphenylene sulfide: 110kg; Hyperbranched polysiloxane: 18 kg; Core-shell filler: 40kg; Carbon nanotubes: 6 kg, the diameter of the carbon nanotubes is 10 nm; Phosphorus and nitrogen flame retardant: 12kg; Cross-linking agent: 4kg; Antioxidant: 1kg; Lubricant: 2kg; Light stabilizer: 1kg; Masterbatch: 6kg.

[0023] Twin-screw extruder: zone 1 temperature 295°C, zone 2 temperature 315°C, zone 3 temperature 325°C, screw speed 350 rpm.

[0024] The differences in mass percentage of the raw materials used in Examples 1-3 are shown in Table 1: Table 1 Example 1 Example 2 Example 3 Polyphenylene sulfide / kg 8.0 25 110 Hyperbranched polysiloxane / kg 2.4 5 18 Core-shell filler / kg 2.6 7.5 40 Carbon nanotubes / kg 1.2 2.5 6 Phosphorus and nitrogen flame retardants / kg 2.4 4 12 Cross-linking agent / kg 0.8 1.5 4 Antioxidant / kg 0.3 0.5 1 Lubricant / kg 0.6 1 2 Light stabilizer / kg 0.3 0.5 1 Masterbatch / % 1.4 2.5 6 Simulation experiment After obtaining the modified polyphenylene sulfide composite masterbatch according to the above embodiment, in order to verify the advantages of these modified polyphenylene sulfide composite masterbatch in notched impact strength, heat deformation temperature, thermal conductivity, electromagnetic shielding effectiveness and density, Solvay's Ryton R-4-230 model PPS was used as a comparative example. The notched impact strength was measured by the Izod impact test according to ISO 180 standard, the heat deformation temperature was measured by thermomechanical analysis according to ISO 75 standard, the thermal conductivity was measured by a laser thermal conductivity meter according to ASTM E1461 standard, the electromagnetic shielding effectiveness was measured by the waveguide method according to ASTM D4935 standard, and the density was measured by the gas pycnometer method according to ISO 1183 standard. The measurement results are shown in Table 2: Table 2 Comparative Example The present invention <![CDATA[Izod impact strength (kJ / m 2 )]]> 1.8 22.5 Heat deformation temperature (℃) 260 310 Thermal conductivity (W / (m·K)) 0.25 4.9 Electromagnetic shielding effectiveness (dB) - 55 <![CDATA[Density (g / cm 3 ).]]> 1.34 1.15 As can be seen from Table 2, the modified polyphenylene sulfide composite masterbatch prepared in the present invention has significantly improved performance in terms of impact strength, heat deformation temperature, thermal conductivity, electromagnetic shielding effectiveness and density compared with traditional PPS materials.

[0025] In addition, a self-healing test was carried out on the modified polyphenylene sulfide composite masterbatch prepared by the present invention. The scratch depth was 50 μm, the repair temperature was 160° C., and the repair time was 30 minutes. The scratch changes before and after the repair were observed using an optical microscope, and it was found that 95% of the area was repaired, indicating that the modified polyphenylene sulfide composite masterbatch provided by the present invention has good self-healing ability, that is, a reversible covalent bond is generated through the Diels-Alder reaction of diphenylmethane bismaleimide and furfuryl methacrylate. When the material is impacted or scratched, the covalent bond breaks under the action of stress, absorbs energy and prevents crack propagation; under heating conditions at 60° C., the covalent bond is reformed, the crack is repaired and the integrity of the material is restored.

[0026] As an extended explanation, when the modified polyphenylene sulfide composite masterbatch prepared by the present invention is used to prepare the target product by 3D printing, an external magnetic field (0.5T) is applied during the printing process to orient the core-shell filler and form a continuous heat conduction path. Tests have found that the thermal conductivity coefficient reaches 6.8W / (m·K).

[0027] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a modified polyphenylene sulfide composite masterbatch, characterized in that: include: With nano-ferroferric oxide as the core, it is coated with polydopamine, and then boron nitride nanosheets are bonded to the surface of polydopamine as core-shell filler. The raw materials are weighed according to a set mass ratio. The raw materials include polyphenylene sulfide, hyperbranched polysiloxane, core-shell filler, carbon nanotubes, phosphorus-nitrogen flame retardant, crosslinker, antioxidant, lubricant, light stabilizer and masterbatch. The raw materials are melt-blended through a twin-screw extruder. The temperature of zone 1 is 285-295°C, the temperature of zone 2 is 305-315°C, the temperature of zone 3 is 315-325°C, and the screw speed is 350-450rpm. The raw materials are then water-cooled and pelletized to obtain a modified polyphenylene sulfide composite masterbatch.

2. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The raw materials include, by mass ratio: Polyphenylene sulfide: 40% to 55%; Hyperbranched polysiloxane: 9% to 12%; Core-shell filler: 13% to 20%; Carbon nanotubes: 3% to 6%; Phosphorus and nitrogen flame retardants: 6% to 12%; Cross-linking agent: 2% to 4%; Antioxidant: 0.5% to 1.5%; Lubricant: 1% to 3%; Light stabilizer: 0.5% to 1.5%; Masterbatch: 4%~7%.

3. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The preparation method of the core-shell filler comprises: Nano-ferrosoferric oxide was dispersed in Tris buffer and ultrasonically treated for 10 minutes. Dopamine hydrochloride was added and magnetically stirred at room temperature for 24 hours. Dopamine hydrochloride was self-oxidatively polymerized to polydopamine. The product was washed with deionized water until neutral and vacuum dried at 60°C for 8 hours to obtain the coating to be shelled. Boron nitride nanosheets were dispersed in ethanol and ultrasonically treated for 2 h. The shelled material was added and ultrasonically treated for 1 h. The product was magnetically stirred at room temperature for 48 h. The product was centrifuged and washed three times with ethanol. The product was vacuum dried at 60°C for 8 h to obtain a core-shell filler.

4. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 3, characterized in that: The nano-ferroferric oxide is dispersed in a Tris buffer at a ratio of 1 g:1 L, and the concentration of the Tris buffer is 10 mM and the pH is 8.5; The dopamine hydrochloride is added to the Tris buffer at a ratio of 2 g:1 L; The mass ratio of the boron nitride nanosheets to the shelled coating is 2:1, and the concentration of the ethanol is 6% vol.

5. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The cross-linking agent is selected from diphenylmethane bismaleimide and furfuryl methacrylate, and the mass ratio of the diphenylmethane bismaleimide to furfuryl methacrylate is 2:

1.

6. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The diameter of the carbon nanotube is 10-20 nm.

7. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The phosphorus-nitrogen flame retardant is DOPO-HQ; The antioxidant is antioxidant 168; The lubricant is pentaerythritol stearate; The light stabilizer is UV-3853 hindered amine light stabilizer.

8. The method for preparing a modified polyphenylene sulfide composite masterbatch according to claim 1, characterized in that: The masterbatch is a black masterbatch with a carbon content of 30%.