Polypropylene composite material and preparation method thereof

Abstract

The invention discloses a polypropylene composite material and a preparation method thereof, the polypropylene composite material comprises 65-90 parts by weight of polypropylene and 5-20 parts by weight of CaCO3 whisker slurry; the polypropylene comprises one or more of co-polypropylene and homo-polypropylene; the CaCO3 whisker slurry is prepared by the following steps: adding MgCl2 into a CaCl2 aqueous solution, stirring, introducing CO2 gas, carrying out carbonization reaction, stirring again, standing and mineralizing to prepare a CaCO3 whisker mixed solution; adding dopamine hydrochloride into the CaCO3 whisker mixed solution, stirring, adjusting the pH value, introducing oxygen, carrying out oxidative polymerization reaction, filtering, and washing to obtain surface-modified CaCO3 whiskers; deionized water and absolute ethyl alcohol are added, stirring is conducted again, and CaCO3 crystal whisker slurry is prepared; according to the polypropylene composite material, the VOC content in the material can be greatly reduced, and the odor of the material is reduced.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a polypropylene composite material and a preparation method thereof. Background Art

[0002] Lightweighting of automotive materials has become an important trend in the development of the industry. By using lightweight materials instead of traditional materials, the weight of the car can be reduced to achieve the purpose of saving fuel. The so-called low-density material means that the mineral filling is reduced, the density of the material is reduced, and the parts are lightweight without changing the shrinkage rate. For example: PP+EPDM-T05 replaces PP+EPDM-T16 material, and PP+EPDM-T10 replaces PP+EPDM-T20 material. The difficulty of this type of material is to reduce the mineral filling while maintaining the original rigidity and toughness of the material, and more importantly, the shrinkage rate of the material must remain unchanged.

[0003] In recent years, cars have been rapidly popularized in families, bringing great convenience to people and improving everyone's living standards. However, when automotive polymer materials are used as automotive interior parts, they will continuously release volatile organic compounds (VOCs) such as "pentaphenyltrialdehyde", causing the deterioration of the in-car environment and endangering human health. As people's awareness of health and environmental protection increases, the issue of in-car air quality has attracted more and more attention. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a polypropylene composite material and a preparation method thereof.

[0005] A polypropylene composite material comprising 71-85 parts by weight of polypropylene and 8-20 parts by weight of CaCO 3 Whisker slurry; the polypropylene includes one or more of copolymer polypropylene and homopolymer polypropylene; the CaCO 3 The whisker slurry comprises the following steps of preparation:

[0006] In CaCl 2 Add MgCl to the aqueous solution 2 , stirring, introducing CO 2 Gas, carbonization reaction, stirring, standing mineralization, CaCO 3 Whisker mixture;

[0007] To the above CaCO 3 Dopamine hydrochloride was added to the whisker mixture, stirred, the pH value was adjusted, oxygen was introduced, an oxidative polymerization reaction was carried out, and the surface-modified CaCO was obtained by filtering and washing. 3 whiskers; add deionized water and anhydrous ethanol, and stir to obtain CaCO 3 Whisker slurry.

[0008] Preferably, 5-9 parts by weight of a toughening agent is also included; the toughening agent includes one or more of propylene-α-olefin copolymer, ethylene-propylene copolymer and ethylene-octene copolymer.

[0009] Preferably, 1-3 parts by weight of a compatibilizer is further included; the compatibilizer includes one or more of maleic acid grafted polypropylene, maleic anhydride grafted polypropylene, acrylic acid grafted polypropylene and glycidyl acrylate grafted polypropylene.

[0010] Preferably, 0.2-0.5 parts by weight of an antioxidant is also included; the antioxidant includes one or more of antioxidant 1010, antioxidant 1076, antioxidant 626, antioxidant 168 and antioxidant DSTP.

[0011] Preferably, 0.2-0.5 parts by weight of a lubricant is also included; the lubricant includes one or more of zinc stearate, calcium stearate, ethylene bisstearamide and pentaerythritol stearate.

[0012] Preferably, the invention further comprises 0.4-0.8 parts by weight of a light stabilizer and 0.5-1 parts by weight of a colorant; the light stabilizer comprises a hindered amine light stabilizer.

[0013] Preferably, the MgCl 2 and CaCl 2 The molar ratio is 1:0.2-1:0.5.

[0014] Preferably, the CaCl 2 The concentration of the aqueous solution is 0.1-0.25 mol / L.

[0015] Preferably, the volume ratio of the deionized water to anhydrous ethanol is 19:1.

[0016] A method for preparing a polypropylene composite material comprises the following steps:

[0017] Mix 71-85 parts by weight of polypropylene, 1-3 parts by weight of compatibilizer, 0.2-0.5 parts by weight of antioxidant, 5-9 parts by weight of toughening agent, 0.2-0.5 parts by weight of lubricant, 0.2-0.5 parts by weight of light stabilizer and 0.4-0.8 parts by weight of toner, and then add 8-20 parts of CaCO 3 The whisker slurry is melted, extruded and granulated to obtain a polypropylene composite material.

[0018] Beneficial effects of the present invention:

[0019] Calcium carbonate whiskers are used to reinforce polypropylene materials to prepare low-density and high-modulus composite materials. The advantages of the present invention are that, on the one hand, the present invention directly uses CaCO 3Whisker slurry can avoid the traditional drying process to prepare CaCO 3 Whisker powder causes powder agglomeration, affecting the dispersion of powder in the polymer matrix; on the other hand, VOC substances such as pentylene trialdehyde in polypropylene materials can be dissolved in CaCO 3 The aqueous solution in the whisker slurry and the anhydrous ethanol can be extracted through double vacuum, which can greatly reduce the VOC content of the composite material and alleviate the odor of the composite material. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Comparative Example 1:

[0022] The method for preparing a low-odor, low-density, high-modulus polypropylene composite material comprises the following steps:

[0023] Step 1: Add 200L of 0.1mol / L CaCl into the reactor. 2 aqueous solution, start the stirrer at 200 rpm and control the temperature at 70°C; then add the crystal control agent MgCl 2 , crystal control agent and CaCl 2 The molar ratio was 0.2. After stirring for 30 min, CO was introduced. 2 The gas was added until the pH value of the reaction solution reached 7-8, then the aeration was stopped to complete the carbonization reaction. The stirring was continued for 1 hour, and the CaCO was obtained after standing for 6 hours. 3 Whisker mixture;

[0024] Step 2: Add the CaCO obtained in step 1 3 Add 10 g of dopamine hydrochloride to the whisker mixture, start the stirrer at 50 rpm, control the temperature at 30 °C and stir for 5 min, then add Na 2 CO 3 When the pH value of the aqueous solution was adjusted to 8-9, oxygen was introduced, and the oxidative polymerization reaction was carried out for 1 hour, followed by filtration, washing, and drying to obtain surface-modified CaCO 3 Whisker powder;

[0025] Step 3: Weigh polypropylene, compatibilizer, antioxidant, lubricant, light stabilizer, and color powder by weight, mix them evenly in a high-speed mixer, and then add them into a twin-screw extruder through the main feed. 3The whisker powder was added into the twin-screw extruder through the side feed port. The screw speed was 300 r / min, the extrusion temperature was 210°C, and the vacuum degree of the two vacuum pumps was -0.08 MPa to prepare a low-odor, low-density, high-modulus polypropylene composite material.

[0026] Comparative Example 2:

[0027] The method for preparing a low-odor, low-density, high-modulus polypropylene composite material comprises the following steps:

[0028] Step 1: Add 200L of 0.2mol / L CaCl into the reactor. 2 aqueous solution, start the stirrer at 300 rpm and control the temperature at 80°C; then add the crystal control agent MgCl 2 , crystal control agent and CaCl 2 The molar ratio was 0.4. After stirring for 30 min, CO was introduced. 2 The gas was added until the pH value of the reaction solution reached 7-8, then the aeration was stopped to complete the carbonization reaction. The stirring was continued for 1 hour, and the CaCO was obtained after standing for 8 hours. 3 Whisker mixture;

[0029] Step 2: Add the CaCO obtained in step 1 3 Add 30 g of dopamine hydrochloride to the whisker mixture, start the stirrer at 100 rpm, control the temperature at 50 °C and stir for 5 min, then add Na 2 CO 3 When the pH value of the aqueous solution was adjusted to 8-9, oxygen was introduced, and the oxidative polymerization reaction was carried out for 2 hours, followed by filtration, washing, and drying to obtain surface-modified CaCO 3 Whisker powder;

[0030] Step 3: Weigh polypropylene, compatibilizer, antioxidant, lubricant, light stabilizer, and color powder by weight, mix them evenly in a high-speed mixer, and then add them into a twin-screw extruder through the main feed. 3 The whisker powder was added into the twin-screw extruder through the side feed port. The screw speed was 250 r / min, the extrusion temperature was 200°C, and the vacuum degree of the two vacuum pumps was -0.09 MPa to prepare a low-odor, low-density, high-modulus polypropylene composite material.

[0031] Embodiment 1:

[0032] The method for preparing a low-odor, low-density, high-modulus polypropylene composite material comprises the following steps:

[0033] Step 1: Add 200L of 0.1mol / L CaCl into the reactor. 2 aqueous solution, start the stirrer at 200 rpm and control the temperature at 70°C; then add the crystal control agent MgCl2 , crystal control agent and CaCl 2 The molar ratio was 0.2. After stirring for 30 min, CO was introduced. 2 The gas was added until the pH value of the reaction solution reached 7-8, then the aeration was stopped to complete the carbonization reaction. The stirring was continued for 1 hour, and the CaCO was obtained after standing for 6 hours. 3 Whisker mixture;

[0034] Step 2: Add the CaCO obtained in step 1 3 Add 10 g of dopamine hydrochloride to the whisker mixture, start the stirrer at 50 rpm, control the temperature at 50 °C and stir for 5 min, then add Na 2 CO 3 When the pH value of the aqueous solution was adjusted to 8-9, oxygen was introduced, and the oxidative polymerization reaction was carried out for 1 hour, and then the surface-modified CaCO was obtained by filtration and washing. 3 whiskers; then add a certain amount of deionized water and anhydrous ethanol (the volume ratio of deionized water to anhydrous ethanol is 19:1), rotate at 200 rpm, stir for 30 minutes, and obtain CaCO with a solid content of 60%. 3 Whisker slurry;

[0035] Step 3: Weigh polypropylene, compatibilizer, antioxidant, toughening agent, lubricant, light stabilizer, and color powder by weight, mix them evenly in a high-speed mixer, and then add them into a twin-screw extruder through the main feed. 3 The whisker slurry was pumped into a twin-screw extruder through a side feed port using a melt pump. The screw speed was 300 r / min, the extrusion temperature was 210°C, and the vacuum degree of the two vacuum pumps was -0.08 MPa to prepare a low-odor, low-density, high-modulus polypropylene composite material.

[0036] Embodiment 2:

[0037] The method for preparing a low-odor, low-density, high-modulus polypropylene composite material comprises the following steps:

[0038] Step 1: Add 200L of 0.2mol / L CaCl into the reactor. 2 aqueous solution, start the stirrer at 300 rpm and control the temperature at 80°C; then add the crystal control agent MgCl 2 , crystal control agent and CaCl 2 The molar ratio was 0.4. After stirring for 30 min, CO was introduced. 2 The gas was added until the pH value of the reaction solution reached 7-8, then the aeration was stopped to complete the carbonization reaction. The stirring was continued for 1 hour, and the CaCO was obtained after standing for 8 hours. 3 Whisker mixture;

[0039] Step 2: Add the CaCO obtained in step 13 Add 30 g of dopamine hydrochloride to the whisker mixture, start the stirrer at 100 rpm, control the temperature at 50 °C and stir for 5 min, then add Na 2 CO 3 When the pH value of the aqueous solution was adjusted to 8-9, oxygen was introduced, and the oxidative polymerization reaction was carried out for 2 hours, and then the surface-modified CaCO was obtained by filtration and washing. 3 whiskers; then add a certain amount of deionized water and anhydrous ethanol (the volume ratio of deionized water to anhydrous ethanol is 19:1), rotate at 250 rpm, stir for 30 minutes, and obtain CaCO with a solid content of 60%. 3 Whisker slurry;

[0040] Step 3: Weigh polypropylene, compatibilizer, antioxidant, toughening agent, lubricant, light stabilizer, and color powder by weight, mix them evenly in a high-speed mixer, and then add them into a twin-screw extruder through the main feed. 3 The whisker slurry was pumped into a twin-screw extruder through a side feed port using a melt pump. The screw speed was 250 r / min, the extrusion temperature was 200°C, and the vacuum degree of the two vacuum pumps was -0.09 MPa to prepare a low-odor, low-density, high-modulus polypropylene composite material.

[0041] Embodiment 3:

[0042] The method for preparing a low-odor, low-density, high-modulus polypropylene composite material comprises the following steps:

[0043] Step 1: Add 200L of 0.25mol / L CaCl into the reactor. 2 aqueous solution, start the stirrer at 300 rpm and control the temperature at 90°C; then add the crystal control agent MgCl 2 , crystal control agent and CaCl 2 The molar ratio was 0.5. After stirring for 30 min, CO was introduced. 2 The gas was added until the pH value of the reaction solution reached 7-8, then the aeration was stopped to complete the carbonization reaction. The stirring was continued for 1 hour, and the CaCO was obtained after standing for 9 hours. 3 Whisker mixture;

[0044] Step 2: Add the CaCO obtained in step 1 3 Add 40 g of dopamine hydrochloride to the whisker mixture, start the stirrer at 100 rpm, control the temperature at 40 °C and stir for 5 min, then add Na 2 CO 3 When the pH value of the aqueous solution was adjusted to 8-9, oxygen was introduced, and the oxidative polymerization reaction was carried out for 2 hours, and then the surface-modified CaCO was obtained by filtration and washing. 3whiskers; then add a certain amount of deionized water and anhydrous ethanol (the volume ratio of deionized water to anhydrous ethanol is 19:1), rotate at 200 rpm, stir for 30 minutes, and obtain CaCO with a solid content of 60%. 3 Whisker slurry;

[0045] Step 3: Weigh polypropylene, compatibilizer, antioxidant, toughening agent, lubricant, light stabilizer, and color powder by weight, mix them evenly in a high-speed mixer, and then add them into a twin-screw extruder through the main feed. 3 The whisker slurry was pumped into a twin-screw extruder through a side feed port using a melt pump. The screw speed was 400 r / min, the extrusion temperature was 210°C, and the vacuum degree of the two vacuum pumps was -0.09 MPa to prepare a low-odor, low-density, high-modulus polypropylene composite material.

[0046] The compositions of the raw materials prepared in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1 below:

[0047] Table 1 Composition of raw materials

[0048]

[0049] The glass fiber reinforced polypropylene composite materials obtained in Comparative Examples 1-2 and Examples 1-3 were subjected to mechanical property tests according to relevant testing standards. The test results are shown in Table 2 below:

[0050] Table 2 Physical properties test results

[0051]

[0052]

[0053] The test results of Comparative Example 1 and Example 1, and Comparative Example 2 and Example 2 show that directly using CaCO 3 Whisker slurry can avoid the traditional drying process to prepare CaCO 3 Whisker powder causes powder agglomeration, which can evenly disperse the powder in the polymer matrix, greatly improving the mechanical properties of the composite material. In addition, VOC substances such as pentylene trialdehyde in polypropylene materials can be dissolved in CaCO 3 The aqueous solution in the whisker slurry and the anhydrous ethanol, combined with the double vacuum extraction process, can greatly reduce the VOC content of the composite material and alleviate the odor of the composite material.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A polypropylene composite material, characterized in that: The method comprises 71-85 parts by weight of polypropylene and 8-20 parts by weight of CaCO3 whisker slurry; the polypropylene comprises one or more of copolymer polypropylene and homopolymer polypropylene; the CaCO3 whisker slurry comprises the following preparation steps: Add MgCl2 to the CaCl2 aqueous solution, stir, introduce CO2 gas, carbonize, stir again, let stand for mineralization, and obtain a CaCO3 whisker mixture; Add dopamine hydrochloride to the above-mentioned CaCO3 whisker mixture, stir, adjust the pH value, introduce oxygen, carry out oxidative polymerization reaction, filter and wash to obtain surface-modified CaCO3 whiskers; add deionized water and anhydrous ethanol, stir again to obtain CaCO3 whisker slurry.

2. The polypropylene composite material according to claim 1, characterized in that: The invention also includes 5-9 parts by weight of a toughening agent; the toughening agent includes one or more of propylene-alpha olefin copolymer, ethylene-propylene copolymer and ethylene-octene copolymer.

3. The polypropylene composite material according to claim 1, characterized in that: The invention also includes 1-3 parts by weight of a compatibilizer; the compatibilizer includes one or more of maleic acid grafted polypropylene, maleic anhydride grafted polypropylene, acrylic acid grafted polypropylene and glycidyl acrylate grafted polypropylene.

4. The polypropylene composite material according to claim 1, characterized in that: The invention also includes 0.2-0.5 parts by weight of an antioxidant; the antioxidant includes one or more of antioxidant 1010, antioxidant 1076, antioxidant 626, antioxidant 168 and antioxidant DSTP.

5. The polypropylene composite material according to claim 1, characterized in that: The invention also includes 0.2-0.5 parts by weight of a lubricant; the lubricant includes one or more of zinc stearate, calcium stearate, ethylene bis stearamide and pentaerythritol stearate.

6. The polypropylene composite material according to claim 1, characterized in that: The invention also comprises 0.4-0.8 parts by weight of a light stabilizer and 0.5-1 parts by weight of a color powder; the light stabilizer comprises a hindered amine light stabilizer.

7. The polypropylene composite material according to claim 1, characterized in that: The molar ratio of MgCl2 to CaCl2 is 1:0.2-1:0.

5.

8. The polypropylene composite material according to claim 1, characterized in that: The concentration of the CaCl2 aqueous solution is 0.1-0.25 mol / L.

9. The polypropylene composite material according to claim 1, characterized in that: The volume ratio of the deionized water to anhydrous ethanol is 19:

1.

10. A method for preparing a polypropylene composite material, characterized in that: The following steps are involved: 71-85 parts by weight of polypropylene, 1-3 parts by weight of compatibilizer, 0.2-0.5 parts by weight of antioxidant, 5-9 parts by weight of toughening agent, 0.2-0.5 parts by weight of lubricant, 0.2-0.5 parts by weight of light stabilizer and 0.4-0.8 parts by weight of color powder are mixed, and then 8-20 parts of CaCO3 whisker slurry are added, and a polypropylene composite material is obtained by melting and extruding granulation.

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