Electroplatable polypropylene composite material, method for its production and use

Abstract

The application provides a platable polypropylene composite material. The platable polypropylene composite material comprises the following components in parts by weight: 40-60 parts of polypropylene, 30-50 parts of talcum powder, 3-8 parts of polyethylene glycol star polymer, 1-5 parts of lubricant, and 0.1-1 parts of antioxidant. The main chain of the polyethylene glycol star polymer is a copolymer chain formed by benzyl ether with one vinyl group on each benzene ring, and the branch chain is a chain formed by the reaction of aldehyde groups on the benzene ring with polyethylene glycol. The D50 particle size of the talcum powder is 1-5 microns. The weight average molecular weight of the polyethylene glycol star polymer is 10000-30000. By adding the polyethylene glycol star polymer with a specific structure and the small particle size talcum powder, the polypropylene composite material has high rigidity and excellent plating effect, meets the application requirements, and the shrinkage rate of the polypropylene composite material is close to that of ABS material, so that the polypropylene composite material can directly replace the ABS material without updating the mold, and has a good production application prospect.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to an electroplatable polypropylene composite material, its preparation method, and its application. Background Technology

[0002] Metallic materials possess excellent texture and a dazzling appearance, and are generally used in high-end products such as electronics, home appliances, and office supplies, offering a superior tactile experience and a premium feel. Polymer materials exhibit good chemical stability, are not easily corroded, and possess excellent processing and molding properties, along with advantages such as low cost and low density. Therefore, since their invention, polymer materials have been rapidly adopted across various industries. To further enhance the texture and aesthetics of plastic products, plastic electroplating processes have been developed, giving plastic parts a metallic appearance, and are widely used in numerous fields such as automobiles, electronics, and high-end jewelry.

[0003] The polymers used in electroplating processes are mainly polar polymers, such as ABS and polycarbonate plastics. Polypropylene plastic is a non-polar system, and its electroplating process is complex, resulting in problems such as easy paint peeling, surface pitting, and low yield. Therefore, it is rarely used in electroplated products. However, polypropylene materials have many advantages, such as low density, low and stable price, excellent chemical resistance, and good heat resistance. Therefore, developing electroplatable polypropylene materials with good electroplating performance has great commercial application value and huge economic benefits.

[0004] Chinese patent CN1110731150A discloses a dimensionally stable, electroplatable polypropylene composite material. This invention improves the dimensional stability of polypropylene materials by adding random copolymer polypropylene, nucleating agents, and high-mesh modified filler minerals. At the same time, it adds ethylene-octene copolymer as a toughening agent to increase the toughness of the material, and adds weakly alkaline wollastonite as an electroplating additive, so that the surface of the polypropylene material can be roughened in acidic solutions, realizing the feasibility of electroplating polypropylene materials. However, this invention has limited improvement on the impact resistance of polypropylene composite materials and its rigidity is low. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings and deficiencies of existing electroplatable polypropylene materials, such as poor electroplating appearance, low rigidity, and inability to meet application requirements. This invention provides an electroplatable polypropylene composite material in which the small-particle-size talc powder and polyethylene glycol star polymer have a synergistic effect, which can make the material have high rigidity while balancing the rigidity and toughness of the polypropylene composite material, and at the same time significantly improve the electroplating appearance of the polypropylene composite material.

[0006] A second objective of this invention is to provide a method for preparing an electroplatable polypropylene composite material.

[0007] A third objective of this invention is to provide an application of electroplatable polypropylene composite material in electronic product casings and cosmetic packaging.

[0008] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0009] An electroplatable polypropylene composite material, comprising the following components by weight:

[0010] 40-60 parts polypropylene, 30-50 parts talc, 3-8 parts polyethylene glycol star polymer, 1-5 parts lubricant, and 0.1-1 parts antioxidant;

[0011] The main chain of the polyethylene glycol star polymer is a copolymer main chain formed by two benzene rings each having a vinyl anisole, and the side chains of the polyethylene glycol star polymer are chains formed by the reaction of aldehyde groups on the benzene rings with polyethylene glycol.

[0012] The D50 particle size of the talc powder is 1–5 μm;

[0013] The weight-average molecular weight of the polyethylene glycol star polymer is 10,000 to 30,000.

[0014] The inventors unexpectedly discovered that adding small-particle-size talc and a small amount of the aforementioned hydroxyl-containing polyethylene glycol star polymer to polypropylene is beneficial for polypropylene electroplating, further improving the electroplating yield of polypropylene composites, while also increasing the rigidity of the material. Polyethylene glycol and polypropylene have excellent compatibility, which can improve the toughness of the substrate and compensate for the decrease in impact strength caused by the addition of talc. Simultaneously, compared to macromolecules with linear segmental structures, the star polymer of this invention has a smaller volume and better flowability. The polar polyethylene glycol segments are well compatible with polypropylene, and the polyethylene glycol segments on the surface of the composition can reduce the surface resistance of polypropylene, thereby allowing the electroplated metal layer to adhere better to the surface of the polypropylene composite. On the other hand, in the polyethylene glycol star polymer containing multiple hydroxyl groups, the hydroxyl groups of the polyethylene glycol segments can bind with the hydroxyl groups on the surface of talc through hydrogen bonds, allowing the talc to be better dispersed in the polypropylene substrate, reducing surface pitting and defects in the polypropylene composite, and significantly improving the electroplating yield of the polypropylene composite system.

[0015] Talc possesses a lamellar structure, allowing talc particles to effectively fill the gaps between polypropylene polymer chains, forming a denser network structure. This talc filling not only reduces the free volume between polypropylene molecular chains but also restricts chain movement through physical cross-linking points, thus improving material rigidity. Adding a small amount of talc to polypropylene also acts as a nucleating agent, promoting crystallization and refining grain size. This grain refinement means an increased number of grain boundaries within the same volume, enhancing the resistance to chain movement and further improving rigidity. The nucleating agent effect also increases the crystallinity of polypropylene, further enhancing rigidity. By adding a certain amount of talc to polypropylene, the flexural modulus and flexural strength of the composite can be significantly improved, while reducing shrinkage to near that of ABS material. In some scenarios, the composite can directly replace ABS material without the need for re-molding. In addition, the addition of small-particle-size talc can create a fine and uniform roughening on the surface of the polypropylene material, which is beneficial to the subsequent electroplating process, and the metal layer is uniformly adhered to the surface of the part.

[0016] Preferably, the weight-average molecular weight of the polyethylene glycol star polymer is 15,000 to 25,000.

[0017] The polyethylene glycol star polymer was prepared by the following steps:

[0018] S1. Synthesis of aldehyde-containing divinyl monomers: 1,2-dibromoethane reacts with 2-hydroxy-5-vinylbenzaldehyde, and after the reaction is completed, the divinyl monomer containing aldehyde groups is obtained by purification.

[0019] S2. Polymerization reaction of aldehyde-containing divinyl monomer: The aldehyde-containing divinyl monomer obtained in step S1 is subjected to a polymerization reaction. After the reaction is completed, it is purified and dried to obtain a crosslinked polymer containing aldehyde.

[0020] S3. Synthesis of polyethylene glycol star polymer: The aldehyde-containing crosslinked polymer obtained in step S2 is polymerized with polyethylene glycol, and the polyethylene glycol star polymer is obtained after purification after the reaction.

[0021] Preferably, in this invention, the weight-average molecular weight of the polyethylene glycol used to prepare the branched chain is preferably 1500-4000. More preferably, the weight-average molecular weight of the polyethylene glycol used to prepare the branched chain is more preferably 2000-3000. Preferably, the average molecular weight of the aldehyde-containing crosslinked polymer in step S2 is 3000-5000.

[0022] The average molecular weight of the aldehyde-containing crosslinked polymer and the polyethylene glycol star polymer can be determined using a Waters-Breeze GPC instrument (Waters styragel HR1, HR3 and HR4 columns, effective measurement range 100-5000, 500-30000 and 5000-600000; standard sample: polystyrene; Waters 1515 pump; Waters 2414 refractive index detector), the test temperature is 35℃, THF is the mobile phase, and the flow rate is 1 mL / min.

[0023] Preferably, the melt flow rate of the polypropylene at 230°C and 2.16 kg is 30-80 g / 10 min.

[0024] In this invention, the melt flow rate of the polypropylene can be 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, 65 g / 10 min, 70 g / 10 min, 75 g / 10 min, 80 g / 10 min, etc., or any range formed by the above values, such as 40-50 g / 10 min, 45-55 g / 10 min, etc., but is not limited thereto.

[0025] When the melt flow rate of the polypropylene is within this range, the polypropylene composite system exhibits good fluidity, which is beneficial for the uniform mixing of the raw material components and the preparation of polypropylene with both excellent electroplating appearance and high impact resistance. The melt flow rate of the polypropylene was determined according to the standard method of ISO 1133-1:2011.

[0026] The particle size of talc powder affects the subsequent electroplating effect. If the talc powder particle size is too large, the surface of the injection-molded parts made of composite materials tends to have more particles, making it difficult for the electroplating layer to adhere to the surface of these small particles, resulting in easy peeling of the plating layer or the formation of small defects. Conversely, if the talc powder particle size is too small, it is difficult to disperse well and is prone to forming agglomerated particles, which affects the subsequent electroplating process. In addition, talc powder with a very small particle size is less effective in improving the rigidity of polypropylene substrates than talc powder with a large particle size.

[0027] This invention selects talc powder with a D50 particle size of 1–5 μm. Talc powder with this D50 particle size range can significantly reduce surface defects in composite materials and further improve the yield of subsequent electroplating processes.

[0028] More preferably, the D50 particle size of the talc powder is 1.5 to 3.5 μm.

[0029] The D50 particle size of the talc powder can be determined according to GB / T 19077.1-2008 "Particle Size Analysis by Laser Diffraction".

[0030] Preferably, the talc powder is added to the composite material in the form of a masterbatch. Adding it as a masterbatch allows for more uniform dispersion of the talc powder in the composite material. The masterbatch can be prepared by referring to existing technologies, by mixing talc powder with a portion of polypropylene and a lubricant.

[0031] Preferably, the lubricant is an ester-based lubricant.

[0032] More preferably, the lubricant is an aliphatic stearate, such as an oleic acid-based aliphatic polyester or an erucic acid-based aliphatic polyester.

[0033] Preferably, the antioxidant is at least one of hindered amines, hindered phenols, phosphites, or thioesters.

[0034] In a specific embodiment, the hindered amine antioxidant may be UV-3808, LA-402XP, LA-402AF, etc.;

[0035] The hindered phenolic antioxidant may be antioxidant 1098, antioxidant 1010, antioxidant 259, antioxidant 1076, or spiroethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (ADK AO-80), etc.;

[0036] The phosphite antioxidant may be antioxidant 168, antioxidant PEP-36, or 627A, etc.

[0037] The thioester antioxidants may be distearate, dilaurate, or pentaerythritol-based dodecathiopropyl ester, etc.

[0038] A method for preparing an electroplatable polypropylene composite material includes the following steps:

[0039] After the raw materials are mixed evenly, they are added to an extruder, melt-extruded, granulated, and dried to obtain the electroplatable polypropylene composite material.

[0040] More preferably, the method for preparing the electroplatable polypropylene composite material includes the following steps: S1. Preparing talc powder, an appropriate amount of polypropylene and a lubricant into talc powder masterbatch;

[0041] S2. Mix the talc masterbatch with the remaining components evenly, melt-extrude, granulate, and dry to obtain the electroplatable polypropylene composite material.

[0042] Preferably, in step S1, the mass ratio of talc to polypropylene is 4:1.

[0043] Preferably, the melt extrusion temperature in step S1 is 160–210°C.

[0044] Preferably, in step S1, the extruder is a twin-screw extruder with a screw length-to-diameter ratio of 48:1 and a screw speed of 100 r / min.

[0045] Preferably, the temperature of the melt extrusion in step S2 is 160–210°C.

[0046] Preferably, in step S2, the extruder is a twin-screw extruder with a screw length-to-diameter ratio of 40:1 and a screw speed of 300 r / min.

[0047] The above-mentioned electroplatable polypropylene composite material is used in electronic product casings and cosmetic packaging.

[0048] More specifically, the electroplatable high-rigidity polypropylene composite material itself contains a large amount of talc powder, which gives it good rigidity. The shrinkage rate of the composite material is close to that of ABS material, so it can directly replace ABS material without updating the mold, and has broad application prospects and practical value.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] This invention improves the surface polarity and electroplating metal adhesion of polypropylene materials by incorporating specific polyethylene glycol star polymers, resulting in composite materials with excellent electroplating properties. Simultaneously, because polyethylene glycol star polymers are flexible, three-dimensional polymer materials, they possess excellent flowability and can improve the dispersibility of talc. The polyethylene glycol segments have excellent compatibility with the polypropylene matrix, and the flexible segments enhance the toughness of the composite system, overcoming the decrease in notched impact resistance of the polypropylene matrix caused by the addition of talc. This results in a polypropylene composite material that balances rigidity and toughness while exhibiting outstanding rigidity and excellent electroplating appearance, meeting application requirements. Furthermore, its shrinkage rate is close to that of ABS materials, allowing it to directly replace ABS materials without requiring mold updates, demonstrating promising production prospects. Detailed Implementation

[0051] To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention.

[0052] The embodiments of the present invention use the following raw materials:

[0053] Polypropylene 1: PP H9018, purchased from Lanzhou Petrochemical Company of China National Petroleum Corporation, with a melt flow rate of 54 g / 10 min at 230℃ and 2.16 kg load;

[0054] Polypropylene 2: PPH-MN70, purchased from China Petroleum & Chemical Corporation, with a melt flow rate of 78 g / 10 min at 230℃ and 2.16 kg load;

[0055] Polypropylene 3: PP N-Z30S was purchased from China Petroleum & Chemical Corporation. The melt flow rate at 30℃ and 2.16kg load was 28g / 10min.

[0056] Talc-1: Talc HTP Ultra 5, purchased from Liaoning Aihaiyi Mining Co., Ltd., with a D50 particle size of 2.8 μm;

[0057] Talc-2: Talc TYT-777A, purchased from Haicheng Tianyuan Chemical Co., Ltd., with a D50 particle size of 14μm;

[0058] Talc-3 and talc TY90-20-A were purchased from Dongguan Sanzhi New Material Technology Co., Ltd., with a D50 particle size of 35μm.

[0059] Calcium carbonate, MLT-2800C, purchased from Dongguan Meilitai Chemical Co., Ltd., with a D50 particle size of 1.4μm;

[0060] Polyethylene glycol star copolymer-1: The weight average molecular weight of the polyethylene glycol star copolymer is 10,000, of which the weight average molecular weight of the cross-linked polymer containing aldehyde groups in its preparation process is 5,000.

[0061] The polyethylene glycol star copolymer-1 was prepared by the following method:

[0062] S1. Synthesis of aldehyde-containing divinyl monomers: 1 mol of 2-hydroxy-5-vinylbenzaldehyde was dissolved in N,N-dimethylformamide, potassium carbonate was added, and the mixture was stirred to obtain a mixture. 0.5 mol of 1,2-dibromoethane was dissolved in N,N-dimethylformamide and added dropwise to the mixture. The reaction was carried out under an inert atmosphere. After the reaction was completed, the mixture was purified to obtain aldehyde-containing divinyl monomers.

[0063] S2. Polymerization of aldehyde-containing divinyl monomers: The aldehyde-containing divinyl monomers obtained in step S1 and azobisisobutyronitrile (AIBN) were dissolved in tetrahydrofuran and stirred. After the reaction was completed, tetrahydrofuran was added for dilution, methanol was used to precipitate the polymer, and finally the mixture was dried under vacuum to constant weight to obtain the aldehyde-containing crosslinked polymer with a weight-average molecular weight of 5000. (This aldehyde-containing crosslinked polymer is also used to prepare polyethylene glycol star copolymer-2, polyethylene glycol star copolymer-3, polyethylene glycol star copolymer-4, and polyethylene glycol star copolymer-5.)

[0064] S3. Synthesis of polyethylene glycol star copolymer: 1 mol of the aldehyde-containing crosslinked polymer obtained in step S2 was mixed with 2.5 mol of polyethylene glycol (weight average molecular weight of 2000) and tetrahydrofuran. The mixture was stirred and reacted at room temperature. After the reaction was completed, the mixture was poured into ice-cold methanol to precipitate the polymer. The resulting polymer was redissolved in tetrahydrofuran and precipitated again with ice-cold methanol. This process was repeated 3 times to remove unreacted polyethylene glycol, thus obtaining a polyethylene glycol star copolymer with an average molecular weight of 10000.

[0065] Polyethylene glycol star copolymer-2: Its preparation steps are the same as those of polyethylene glycol star copolymer-1, except that the amount of polyethylene glycol (weight average molecular weight of 2000) added is increased to 7.5 mol, so that the weight average molecular weight of polyethylene glycol star copolymer is 20000.

[0066] Polyethylene glycol star copolymer-3: Its preparation steps are the same as those of polyethylene glycol star copolymer-1, except that the amount of polyethylene glycol (weight average molecular weight of 2000) added is increased to 12.5 mol, so that the weight average molecular weight of polyethylene glycol star copolymer is 30000.

[0067] Polyethylene glycol star copolymer-4: Its preparation steps are the same as those of polyethylene glycol star copolymer-1; the difference is that the amount of polyethylene glycol (weight average molecular weight of 2000) added is reduced to 1.5 mol, so that the weight average molecular weight of polyethylene glycol star copolymer is 8000.

[0068] Polyethylene glycol star copolymer-5: Its preparation steps are the same as those of polyethylene glycol star copolymer-1, except that the amount of polyethylene glycol (weight average molecular weight of 2000) added is increased to 47.5 mol, so that the molecular weight of polyethylene glycol star copolymer is 100000.

[0069] Lubricant: Ester-based lubricant, commercially available;

[0070] Antioxidant: Antioxidant 1010 and Antioxidant 168 are compounded in a mass ratio of 1:1. Commercially available.

[0071] Unless otherwise specified, all components used in the parallel embodiments and comparative examples are the same commercially available products.

[0072] Example 1

[0073] An electroplatable polypropylene composite material, the weight parts of the raw materials used are shown in Table 1.

[0074] The preparation method of the above-mentioned electroplatable polypropylene composite material includes the following steps:

[0075] S1. Weigh 25% polypropylene and 0.3% lubricant by weight of talc powder, mix them evenly with talc powder, melt extrude, granulate, and dry to obtain talc powder masterbatch.

[0076] S2. The talc masterbatch obtained in step S1 is mixed evenly with the remaining polypropylene, polyethylene glycol star polymer, lubricant, and antioxidant. The mixture is then added to an extruder, melt-extruded, granulated, and dried to obtain the electroplatable polypropylene composite material.

[0077] In both steps S1 and S2, the extruders used are twin-screw extruders. In step S1, the screw length-to-diameter ratio of the extruder is 48:1, the screw speed is 100 r / min, and the melt extrusion temperature is 160–210℃. In step S2, the screw length-to-diameter ratio of the extruder is 40:1, the screw speed is 300 r / min, and the melt extrusion temperature is 160–210℃.

[0078] Examples 2 to 9

[0079] The weight proportions of the raw materials used in Examples 2 through 9 are shown in Table 1. The preparation steps for Examples 2 through 9 are the same as those for Example 1.

[0080] Table 1 Formulation components of Examples 1 to 9

[0081]

[0082] Table 2 Formulation components of Comparative Examples 1 to 11

[0083]

[0084]

[0085] Performance testing

[0086] The properties of the polypropylene composite materials obtained in the above embodiments and comparative examples were characterized. The specific test items, test methods, and results are as follows:

[0087] (1) Cantilever beam notched impact strength test: The ZBC1400-B LCD plastic pendulum impact tester (Meters Industrial Systems (China) Co., Ltd.) was used to conduct the cantilever beam notched impact strength test. The test standard was ISO180-2019, type A notch, the test conditions were room temperature, and the sample size was 80mm×10mm×4mm.

[0088] (2) Bending modulus test: The test was conducted in accordance with the standard ISO178-2019. The sample size was 80mm×10mm×4mm. The test equipment was KRT-W20kN, manufactured by Kunshan Keruit Test Instrument Co., Ltd.

[0089] (3) Electroplating Appearance: The sample material is 100mm×100mm×3mm in size. After degreasing, roughening, neutralization, sensitization, activation, degumming, and electroless nickel plating, the appearance is visually inspected using a 5x magnifying glass. Excellent appearance is defined as: uniform plating, no pits or dents, and uniform, bright luster. Good appearance is defined as: uniform plating, fewer than 5 pits or dents on the surface, and a diameter of less than 0.3mm. Poor appearance is defined as: uneven plating, localized wrinkling, or more than 5 pits or dents, and a diameter of greater than 0.3mm.

[0090] Table 3 Performance test results of Examples 1-9 and Comparative Examples 1-11

[0091]

[0092]

[0093] As can be seen from the performance test results of the electroplatable polypropylene composite materials of each embodiment in Table 2, the polypropylene composite materials prepared by the present invention have high rigidity while achieving an excellent balance between toughness and rigidity. The flexural modulus of the polypropylene materials can all reach more than 3300 MPa, and they all have excellent electroplating appearance.

[0094] A comparison of Examples 1 and 5 shows that increasing the proportion of talc powder increases the rigidity of the system, but slightly reduces the notched impact strength.

[0095] Comparative Examples 1 and 2 show the addition of talc powder with excessively large D50 particle size. The rigidity of the composite is improved, but the notched impact resistance is significantly reduced. Furthermore, due to the excessively large filler particles, the coating is difficult to distribute evenly on the surface of the part, which easily leads to pits and wrinkles, resulting in a decrease in electroplating performance.

[0096] Comparative Example 3 uses a star-shaped polyethylene glycol polymer with an excessively low molecular weight. While it exhibits good surface electroplating, the low molecular weight of the polyethylene glycol results in a weak dispersion effect on talc and a significant decrease in the toughness of the material.

[0097] Comparative Example 4 contains a star-shaped polyethylene glycol polymer with an excessively large molecular weight. It has a good toughening effect on the material, but the material lacks rigidity.

[0098] Comparative Example 5, without the addition of talc, showed a low flexural modulus of the polypropylene composite material, only 1420 MPa, indicating poor system rigidity.

[0099] Comparative Example 6, which did not include polypropylene glycol star polymer, showed a notched impact strength of only 3.11 KJ / m² for the polypropylene composite material. 2 The electroplating effect is poor.

[0100] Comparative Example 7 showed insufficient talc addition. The polypropylene composite material had good toughness and a good electroplating appearance, but the material's rigidity was insufficient, and the shrinkage rate of the composite material increased significantly, differing greatly from ABS, making subsequent co-molding production impossible.

[0101] Comparative Example 8 showed that the polypropylene composite material with excessive talc had a good electroplating appearance, but the material lacked toughness and had low notched impact strength.

[0102] In Comparative Example 9, when too little polyethylene glycol star polymer was added, the wetting and coating of talc was insufficient, the hydroxyl groups on the surface of the composite material were also fewer, the appearance of the electroplating effect was reduced, and the mechanical properties were also reduced.

[0103] Comparative Example 10 showed that too much polyethylene glycol star polymer was added, which had a significant impact on the overall rigidity of the composite material and resulted in a substantial decrease in flexural modulus.

[0104] Comparative Example 11 shows that although using small-particle calcium carbonate to replace talc results in better electroplating performance, the flexural modulus is significantly reduced.

[0105] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electroplatable polypropylene composite material, characterized in that, By weight, it includes the following components: 40-60 parts polypropylene, 30-50 parts talc, 3-8 parts polyethylene glycol star polymer, 1-5 parts lubricant, and 0.1-1 parts antioxidant; The main chain of the polyethylene glycol star polymer is a copolymer main chain formed by two benzene rings each having a vinyl anisole, and the side chains of the polyethylene glycol star polymer are chains formed by the reaction of aldehyde groups on the benzene rings with polyethylene glycol. The D50 particle size of the talc powder is 1–5 μm; The weight-average molecular weight of the polyethylene glycol star polymer is 10,000 to 30,000. The polyethylene glycol star polymer was prepared by the following steps: S1. Synthesis of aldehyde-containing divinyl monomers: 1,2-dibromoethane reacts with 2-hydroxy-5-vinylbenzaldehyde, and after the reaction is completed, the divinyl monomer containing aldehyde groups is obtained by purification. S2. Polymerization reaction of aldehyde-containing divinyl monomer: The aldehyde-containing divinyl monomer obtained in step S1 is subjected to a polymerization reaction. After the reaction is completed, it is purified and dried to obtain a crosslinked polymer containing aldehyde. S3. Synthesis of polyethylene glycol star polymer: The aldehyde-containing crosslinked polymer obtained in step S2 is polymerized with polyethylene glycol, and the polyethylene glycol star polymer is obtained after purification after the reaction.

2. The electroplatable polypropylene composite material according to claim 1, characterized in that, The weight-average molecular weight of the polyethylene glycol star polymer is 15,000 to 25,000.

3. The electroplatable polypropylene composite material according to claim 1, characterized in that, The polypropylene has a melt flow rate of 30-80 g / 10 min at 230°C and 2.16 kg.

4. The electroplatable polypropylene composite material according to claim 1, characterized in that, The D50 particle size of the talc powder is 1.5–3.5 μm.

5. The electroplatable polypropylene composite material according to claim 1, characterized in that, The talc powder is added to the composite material in the form of masterbatch.

6. The electroplatable polypropylene composite material according to claim 1, characterized in that, The antioxidant is at least one of hindered amines, hindered phenols, phosphites, or thioesters.

7. The method for preparing the electroplatable polypropylene composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: After the raw materials are mixed evenly, they are melt-extruded, granulated, and dried to obtain the electroplatable polypropylene composite material.

8. The method for preparing the electroplatable polypropylene composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Prepare talc masterbatch by mixing talc powder, an appropriate amount of polypropylene, and a lubricant; S2. Mix the talc masterbatch with the remaining components evenly, melt-extrude, granulate, and dry to obtain the electroplatable polypropylene composite material.

9. The application of the electroplatable polypropylene composite material according to any one of claims 1 to 6 in electronic product casings and cosmetic packaging.

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