Anti-impact, anti-yellowing and weather-aging-resistant PP composite material and preparation method thereof

Abstract

The invention discloses an anti-impact, anti-yellowing and weather-aging-resistant PP composite material and a preparation technology thereof.The prepared PP composite material is simple in technology, the antibacterial effect of the PP composite material is improved through a chitosan derivative, meanwhile, the original tensile strength and bending performance of the PP composite material are kept, and the PP composite material has excellent mechanical performance and is suitable for being applied to the field of medical instruments. A specific stabilizer compounding system and a coating system established with the glass fiber powder are uniformly dispersed in the PP composite material, so that the weather aging resistance, the impact resistance and the yellowing resistance are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene materials, and in particular to an impact-resistant, yellowing-resistant, weathering-resistant and aging-resistant PP composite material and a preparation method thereof. Background Art

[0002] Polypropylene (PP) is widely used for its light weight, high crystallinity, easy processing, corrosion resistance, impact strength, flexural resistance and good electrical insulation. It has become one of the most used plastic materials for automotive parts, accounting for about 37% of automotive plastics. Polypropylene (PP) is mainly used in automotive interiors, exteriors and function keys, such as dashboards, door panels, bumpers, etc., of which interiors account for 55%. However, the unstable tertiary carbon groups in the PP molecular chain are easily broken by ultraviolet (UV) and thermal oxidation, resulting in a decrease in the mechanical properties of the material, surface powdering, and general heat resistance. At the same time, it is sensitive to the effects of oxygen, especially at high temperatures. The UV resistance is very poor, and the carbonyl compounds (such as ketones and aldehydes) generated by oxidation accumulate, causing the material to turn yellow, seriously affecting the appearance. Among them, when polypropylene is used in the automotive field, in hot weather, the car will continue to be irradiated by high temperature and ultraviolet rays, causing the parts to age. With people's emphasis on quality of life, it is suitable for automotive parts, home appliance housings, outdoor products and other fields that require high material weather resistance and color stability.

[0003] Traditional anti-aging agents (such as hindered amine light stabilizers HALS, ultraviolet absorbers UVA) are easy to migrate, volatilize or be consumed by the environment, resulting in insufficient long-term effectiveness. For example, the existing modification technology adds a single antioxidant system, such as adding antioxidants 1010 (phenols) or 168 (phosphites), which can only inhibit initial oxidation and cannot cope with long-term thermal oxidation and ultraviolet synergy. In addition, antioxidants are easy to decompose during high-temperature processing, and have poor compatibility with PP, which causes surface frosting after migration. In addition, adding light-stabilizing compounds such as HALS and UVA (such as UV-531) to synergize, delay yellowing through free radical capture and ultraviolet absorption, but HALS is easily inactivated in acidic environments (such as automobile exhaust, acid rain), and is sensitive to metal ions (such as copper and iron), resulting in a sharp drop in protective effect. Adding inorganic fillers such as titanium dioxide (TiO2), carbon black and other sunscreens can shield ultraviolet rays, but high additions (>5%) will reduce the toughness of the material and cannot inhibit internal oxidation yellowing.

[0004] Therefore, technicians in this field urgently need to develop impact-resistant, yellowing-resistant, and weather-resistant PP composite materials to improve the yellowing resistance of PP materials and maintain excellent material properties. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art, and provides a PP composite material with impact resistance, yellowing resistance and weathering aging resistance, and its preparation process. This material realizes efficient anti-aging and anti-yellowing while having excellent impact resistance and antibacterial properties.

[0006] Specifically, the present invention is realized through the following technologies:

[0007] A PP composite material with impact resistance, yellowing resistance and weathering aging resistance, the composite material comprises the following components in parts by weight: 50-80 parts by mass of PP, 5-15 parts by mass of chitosan or its derivatives, 1-10 parts by mass of glass fiber powder, 5-20 parts by mass of toughening agent, 1-2 parts by mass of stabilizer, 1-2 parts by mass of lubricant.

[0008] Preferably, the chitosan or its derivatives are selected from one or more of chitosan, hydroxypropyl chitosan, 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan (CTS18), 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan (CTS16), 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan (CTS5), O-carboxymethyl chitosan, N-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-alkylated chitosan, O-alkylated chitosan, N-dodecylated chitosan, N-hexadecylated chitosan, hydroxypropyl trimethyl ammonium chloride chitosan.

[0009] Preferably, the chitosan or its derivatives are selected from one or more of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan.

[0010] Preferably, the chitosan or its derivatives are selected from 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan.

[0011] Preferably, the stabilizer is a compound system of 2,5-di-tert-butylhydroquinone and deoxycholic acid; the mass ratio of 2,5-di-tert-butylhydroquinone to deoxycholic acid is 1:0.1-1.

[0012] In a preferred embodiment, the glass fiber powder, the stabilizer and the chitosan or its derivatives form a coating.

[0013] Preferably, the toughening agent is selected from elastomer toughening agents, including but not limited to ethylene propylene rubber (EPR), ethylene propylene diene monomer rubber (EPDM), and cis-1,4-polybutadiene rubber (BR); thermoplastic elastomer toughening agents include but not limited to polyolefin elastomer (POE), styrene-butadiene block copolymer (SBS); plastic toughening agents include but not limited to low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA).

[0014] Furthermore, the toughening agent is preferably a combination of an elastomer toughening agent and a thermoplastic elastomer toughening agent; particularly preferably a combination of cis-1,4-polybutadiene rubber (BR) and polyolefin elastomer (POE).

[0015] Preferably, the mass ratio of the elastomer toughening agent to the thermoplastic elastomer toughening agent is 1:2 - 4.

[0016] Preferably, the lubricant is selected from one or a combination of vinyl bisstearamide, zinc stearate, magnesium stearate, oleamide, and stearamide; more preferably vinyl bisstearamide.

[0017] On the other hand, the present invention provides a method for preparing the above PP composite material, comprising the following steps:

[0018] Step 1: Weigh the prescribed amount of stabilizer and glass fiber powder, and ultrasonically disperse them in deionized water. Dissolve the prescribed amount of chitosan or its derivative in dilute hydrochloric acid, and slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer and glass fiber powder are dispersed while stirring. Control the temperature and continuously stir and react; after the reaction is completed, add an alkali solution dropwise, continue stirring, filter the slurry, wash the product with deionized water, and dry it in a vacuum drying oven to obtain a coated material;

[0019] Step 2: Weigh the prescribed amount of PP, toughening agent, and lubricant, and put them into a high-speed mixer to stir and mix at room temperature; add the coated material from Step 1 and continue to stir and mix to obtain a homogeneous mixture;

[0020] Step 3: Melt-blend and extrude the obtained mixture through a twin-screw extruder, cool it, and pelletize it to obtain a PP composite material.

[0021] In a preferred embodiment, the method for preparing the PP composite material specifically comprises the following steps:

[0022] Step 1: Weigh the prescribed amount of stabilizer and glass fiber powder, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of chitosan or its derivative in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and dry it in a vacuum at 80 °C for 12 hours to obtain the coating material.

[0023] Step 2: Weigh the prescribed amount of PP, toughening agent, and lubricant, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0024] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C. The screw rotation speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0025] Advantages of the present invention:

[0026] Compared with the prior art, the process for preparing the PP composite material of the present application is simple. By adding a specific amount of chitosan derivative to PP, its antibacterial effect is greatly improved, the tensile strength and bending properties are enhanced, and it has excellent mechanical properties. In addition, the compounding system of the specific stabilizer 2,5-di-tert-butylhydroquinone and deoxycholic acid and the establishment of a coating system with glass fiber powder are uniformly dispersed in the PP composite material, significantly improving the weathering resistance, impact resistance, and anti-yellowing ability. Specific embodiments

[0027] The present invention will be further illustrated by the following examples. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0028] In specific implementation schemes, refer to the components to prepare the PP composite material. The preparation method includes: ultrasonically disperse glass fiber and stabilizer in deionized water, dissolve chitosan or its derivative in dilute hydrochloric acid, and while stirring, slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer and glass fiber are dispersed to prepare the coating material. After mixing PP, toughening agent, and lubricant in a high-speed mixer, add the coating material evenly. The mixture is melt and co-extruded through a twin-screw extruder to obtain the PP composite material. Specific examples are listed in detail as follows.

[0029] Example 1

[0030] Components

[0031]

[0032] The specific preparation process is as follows:

[0033] Step 1: Weigh the prescribed amounts of 2,5-di-tert-butylhydroquinone, deoxycholic acid, and glass fiber powder, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for reaction; after the reaction is completed, while stirring, add an appropriate amount of sodium hydroxide solution dropwise to adjust to neutrality. After the addition is completed, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material;

[0034] Step 2: Weigh the prescribed amounts of PP, BR, POE, and vinyl bisstearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min; add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture;

[0035] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is: the first stage is 180 - 190 °C, the second stage is 190 - 200 °C, the third stage is 200 - 210 °C, and the die head is 190 - 200 °C; the screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0036] Example 2

[0037] Components

[0038]

[0039]

[0040] The specific preparation process is as follows:

[0041] Step 1: Weigh the prescribed amounts of 2,5-di-tert-butylhydroquinone, deoxycholic acid, and glass fiber powder, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for reaction; after the reaction is completed, while stirring, add an appropriate amount of sodium hydroxide solution dropwise to adjust to neutrality. After the addition is completed, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material;

[0042] Step 2: Weigh the prescribed amounts of PP, BR, POE, and vinyl bis-stearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min; add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a homogeneous mixture.

[0043] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C; the screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0044] Example 3

[0045] Components

[0046]

[0047] The specific preparation process is as follows:

[0048] Step 1: Weigh the prescribed amounts of 2,5-di-tert-butylhydroquinone, deoxycholic acid, and glass fiber powder and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the chitosan solution to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for reaction; after the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0049] Step 2: Weigh the prescribed amounts of PP, BR, POE, and vinyl bis-stearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min; add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a homogeneous mixture.

[0050] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C; the screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0051] Example 4

[0052] Components

[0053]

[0054] The specific preparation process is as follows:

[0055] Step 1: Weigh the prescribed amounts of 2,5-di-tert-butylhydroquinone, deoxycholic acid, and glass fiber powder, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for the reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0056] Step 2: Weigh the prescribed amounts of PP, POE, and vinyl bis-stearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a homogeneous mixture.

[0057] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C. The screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0058] Comparative Example 1

[0059] Component

[0060]

[0061] The specific preparation process is as follows:

[0062] Step 1: Weigh the prescribed amounts of PP, glass fiber powder, 2,5-di-tert-butylhydroquinone, deoxycholic acid, BR, POE, and vinyl bis-stearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min to obtain a homogeneous mixture.

[0063] Step 2: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C. The screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0064] Comparative Example 2

[0065] Component

[0066]

[0067]

[0068] The specific preparation process is as follows:

[0069] Step 1: Weigh the prescribed amounts of 2,5-di-tert-butylhydroquinone, titanium dioxide, and glass fiber powder, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan to the deionized water in which the stabilizer and glass fiber powder are dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0070] Step 2: Weigh the prescribed amounts of PP, BR, POE, and vinyl bisstearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0071] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 180 - 190 °C, the second section is 190 - 200 °C, the third section is 200 - 210 °C, and the die head is 190 - 200 °C. The screw speed of the extruder is 300 - 400 r / min. Cool and pelletize to obtain the PP composite material.

[0072] Accelerated aging experiment:

[0073] Use the specification of ASTM G154-23 for the accelerated aging test for testing.

[0074] Sample preparation: Take the PP composite materials of Examples 1 - 5 and Comparative Examples 1 - 4, and make weather-resistant test pieces of 70×45×30 mm.

[0075] Light source and irradiance: Select a UVB-313 fluorescent ultraviolet lamp (main wavelength 313 nm, simulating short-wave ultraviolet for accelerated degradation) as the light source, and control the irradiation intensity at 0.6 - 0.7 W / m 2 / nm (calibrate the lamp tube to meet the requirements of ASTM G154).

[0076] Temperature and cycle parameters: During the light irradiation stage, the temperature is 60 °C (blackboard temperature or test chamber air temperature), and continuous ultraviolet irradiation is carried out for 4 hours. During the non-irradiated stage, the temperature is 50 °C (turn off the ultraviolet lamp and maintain the temperature to simulate the night environment), and it is maintained for 4 hours. Each 8 hours is a complete cycle (4 h of light irradiation + 4 h of non-irradiation).

[0077] Sampling and Testing: Fix the PP spline (or other materials) on the specimen holder, avoiding blocking the light source. Conduct color difference tests every 100 hours for 600 hours. (1. The ΔE value represents the overall difference in material color change, calculated based on the changes in L* (lightness), a* (red-green axis), and b* (yellow-blue axis) in the CIELab color space ΔL* is the change in lightness (L* value after aging - initial L* value), Δa* is the change in the red-green axis (a* value after aging - initial a* value), Δb* is the change in the yellow-blue axis (b* value after aging - initial b* value). ΔE < 1 indicates that the human eye can hardly detect color differences. 1 ≤ ΔE < 3 indicates slight differences that require professional instruments to identify. ΔE ≥ 3 indicates obvious visible color changes; 2. The ΔY1 yellowness index represents the change in yellowness degree before and after aging. The simplified formula is ΔY1 ≈ 100×(1.28×Δa* - 1.06×Δb*). ΔY1 > 5 indicates significant yellowing, and ΔY1 < 2 indicates acceptable yellowness degree)

[0078] Tensile Strength Test: Refer to the standard of GB / T 1040.1 - 2018, use a universal testing machine to test the tensile strength at a testing rate of 50 mm / min. Test the tensile strength before accelerated aging, after 300 hours of accelerated aging, and after 600 hours of accelerated aging respectively.

[0079] Table 1 Results of Accelerated Light Resistance and Yellowing Test

[0080]

[0081] Table 2 Results of Tensile Strength Test

[0082]

[0083] The above results show that adding specific stabilizers to the PP of the present invention improves its excellent mechanical properties. Adding chitosan or its derivatives can greatly improve the antibacterial effect. The establishment of a coating system of glass fiber powder, stabilizer, and chitosan or its derivatives and their uniform dispersion in the PP composite significantly enhances the impact resistance, weather aging resistance, and yellowing resistance.

[0084] It should be noted here that the embodiments of the present invention are only used to illustrate the present invention, rather than to limit the present invention. Therefore, simple improvements to the present invention under the premise of the method of the present invention fall within the scope protected by the present invention.

Claims

1. A PP composite material that is impact-resistant, yellow-resistant and weather-resistant, characterized in that: The composite material comprises the following components in parts by weight: 50-80 parts by weight of PP, 5-15 parts by weight of chitosan or its derivatives, 1-10 parts by weight of glass fiber powder, 5-20 parts by weight of toughening agent, 1-2 parts by weight of stabilizer, and 1-2 parts by weight of lubricant.

2. The PP composite material according to claim 1, characterized in that: The chitosan or its derivative is selected from one or more of chitosan, hydroxypropyl chitosan, 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan (CTS18), 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan (CTS16), 3-O-acetyl-6-O-valeroyl-N-phthaloyl chitosan (CTS5), O-carboxymethyl chitosan, N-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-alkylated chitosan, O-alkylated chitosan, N-dodecylated chitosan, N-hexadecylated chitosan, and hydroxypropyltrimethylammonium chloride chitosan.

3. The PP composite material according to claim 1, characterized in that: The chitosan or its derivative is selected from one or more of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan and 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan.

4. The PP composite material according to claim 1, characterized in that: The chitosan or its derivative is selected from 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan.

5. The PP composite material according to claim 1, characterized in that: The stabilizer is a composite system of 2,5-di-tert-butylhydroquinone and deoxycholic acid; the mass ratio of the 2,5-di-tert-butylhydroquinone to the deoxycholic acid is 1:0.1-1.

6. The PP composite material according to claim 1, characterized in that: The glass fiber powder, stabilizer and chitosan or its derivatives form a coating.

7. The PP composite material according to claim 1, characterized in that: The toughening agent is selected from one or a combination of an elastomer toughening agent, a thermoplastic elastomer toughening agent, and a plastic toughening agent; more preferably, it is a combination of an elastomer toughening agent and a thermoplastic elastomer toughening agent.

8. The PP composite material according to claim 1, characterized in that: The toughening agent is selected from one or a combination of ethylene propylene rubber (EPR), ethylene propylene diene monomer rubber (EPDM), butadiene rubber (BR), polyolefin elastomer (POE), styrene-butadiene block copolymer (SBS), low-density polyethylene (LDPE), and ethylene-vinyl acetate copolymer (EVA); more preferably, it is a combination of butadiene rubber (BR) and polyolefin elastomer (POE).

9. The PP composite material according to claim 1, characterized in that The lubricant is selected from one or a combination of vinyl bisstearamide, zinc stearate, magnesium stearate, oleic acid amide and stearamide.

10. The PP composite material according to claim 1, characterized in that: The specific steps of the preparation method include: Step 1: weigh the prescribed amount of stabilizer and glass fiber powder and ultrasonically disperse them in deionized water, dissolve the prescribed amount of chitosan or its derivatives in dilute hydrochloric acid, slowly add the solution of chitosan or its derivatives into the deionized water dispersed with the stabilizer and glass fiber powder while stirring, and control the temperature and continue to stir the reaction; after the reaction is completed, add alkali solution dropwise, continue to stir, filter the slurry, wash the product with deionized water, and dry it in a vacuum drying oven to obtain a coating material; Step 2: Weigh the prescribed amount of PP, toughening agent, and lubricant and put them into a high-speed mixer, and stir and mix them at room temperature; add the coating material in step 1 and continue stirring and mixing to obtain a uniform mixture; Step 3: The obtained mixture is melt-blended and extruded through a twin-screw extruder, cooled, and pelletized to obtain a PP composite material.

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