Preparation method of glass fiber reinforced polypropylene composite material for outer barrel of washing machine

Abstract

The invention belongs to a polypropylene composite material, and particularly relates to a preparation method of a glass fiber reinforced polypropylene composite material for an outer barrel of a washing machine, which comprises the following steps: carrying out surface modification on glass fibers by using 3-chloropropyltrichlorosilane, mixing with polypropylene, a compatilizer, an antioxidant, a lubricant and a flexibilizer, and carrying out extrusion molding to obtain the glass fiber reinforced polypropylene composite material. And finally, carrying out a melting reaction through a double-screw extruder, and carrying out extrusion granulation to obtain the glass fiber reinforced polypropylene composite material. The problem of cracking caused by illumination aging and chemical inertness of the surface of the glass fiber is solved, surface modification is formed by using 3-chloropropyl trichlorosilane as a modifier, and meanwhile, chloropropyl is used as an extension side group for permeation connection and far-end chemical fixation, so that the connection stability of the glass fiber in the polypropylene composite material is improved, and the service life of the polypropylene composite material is prolonged. Therefore, the weather resistance of the composite material is improved.

Description

Technical Field

[0001] The invention belongs to polypropylene composite materials, and in particular relates to a preparation method of a glass fiber reinforced polypropylene composite material for a washing machine outer drum. Background Art

[0002] As a general engineering plastic, glass fiber reinforced polypropylene material has high strength, high stiffness, rigid impact strength, low density, low warping creep, and excellent dynamic fatigue resistance. It is widely used in household appliance parts. However, when glass fiber reinforced polypropylene material is used as the surface material of household appliances, the glass fiber ages rapidly under long-term light exposure. At the same time, the chemical inertness of the glass fiber surface leads to decreased stability and weather resistance of glass fiber reinforced polypropylene composite materials, and even cracks and cracks appear on the surface. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides a method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum, which solves the cracking problem caused by light aging and chemical inertness on the surface of the glass fiber, uses 3-chloropropyltrichlorosilane as a modifier to form surface modification, and simultaneously uses the chloropropyl group as an extended side group for penetration connection and remote chemical fixation, thereby improving the connection stability of the glass fiber in the polypropylene composite material, thereby improving the weather resistance of the composite material.

[0004] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0005] A method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum comprises the following steps:

[0006] Step 1, ultrasonically dispersing short glass fibers and long glass fibers in an ethanol aqueous solution for 20-30 minutes, filtering, drying, and soaking in a sodium hydroxide solution for 10-15 seconds, removing and standing for 2-3 hours to obtain mixed glass fibers, wherein the mass ratio of the short glass fibers to the long glass fibers is 1:2-4, and the length of the short glass fibers is 0.2-0.3 mm, the length of the long glass fibers is 10-15 mm, the volume fraction of ethanol in the ethanol aqueous solution is 40-50%, the concentration of the short glass fibers in the ethanol aqueous solution is 50-100 g / L, and the ultrasonically dispersed The temperature is 40-50°C, the ultrasonic frequency is 70-90kHz, the drying temperature is 120-130°C, the pH of the sodium hydroxide solution is 8-9, the immersion concentration is 100-300g / L, the temperature is 10-20°C, and the standing temperature is 60-80°C; in this step, the ethanol aqueous solution is used to clean the surface of the glass fiber, thereby reducing impurities on the surface and increasing the exposure of the glass fiber. After drying, a sodium hydroxide liquid film is formed on the surface of the glass fiber by rapid immersion, and the surface of the glass fiber is alkalized during the standing process, thereby achieving surface activation of the glass fiber;

[0007] Step 2, adding 3-chloropropyltrichlorosilane to ether and stirring evenly to form a dissolving solution, then adding the mixed glass fiber, ultrasonically dispersing for 30-60 minutes, and then taking it out and standing to obtain a coated glass fiber, wherein the concentration of the 3-chloropropyltrichlorosilane in the ether is 400-600 g / L, the concentration of the mixed glass fiber in the dissolving solution is 100-200 g / L, the ultrasonic frequency of the ultrasonic dispersion is 70-100 kHz, and the temperature is 5-10° C.; the standing atmosphere is nitrogen and water vapor The mixed atmosphere is characterized in that the volume ratio of nitrogen to water vapor is 10-12:1. In this step, 3-chloropropyltrichlorosilane has good solubility in ether, and its dissolved solution is used to soak the glass fiber, and a liquid film is formed on the surface of the glass fiber by ultrasonic dispersion. Finally, under the action of water vapor in the static atmosphere, 3-chloropropyltrichlorosilane is in situ converted into 3-hydroxypropyltrihydroxysilane, and at the same time, the alkalized hydroxyl groups on the surface of the mixed glass fiber form good adhesion, thereby eliminating the surface connection gaps caused by the holes on the surface of the glass fiber.

[0008] Step 3, ball-milling polypropylene and compatibilizer to form fine powder, then adding coated glass fiber, antioxidant, lubricant and toughening agent in sequence, and stirring at constant temperature to obtain a mixture, wherein the mass ratio of the mixture is: 80-90 parts of polypropylene, 2-3 parts of compatibility, 15-20 parts of coated glass fiber, 1-2 parts of antioxidant, 0.3-0.5 parts of lubricant, and 0.5-0.8 parts of toughening agent. The compatibilizer is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is one of GX-5, NT-C, and WBG-Ⅱ; the ball milling pressure is 0.4-0.6MPa, the temperature is 20-30°C, and the constant temperature stirring temperature is 40- 50℃; In this step, the polypropylene and the compatibilizer are fully mixed by ball milling, and other materials are blended with the mixed powder to obtain a mixture; wherein the maleic anhydride grafted polypropylene has good compatibility with the polypropylene structure, effectively improving its compatibility with the polypropylene, and at the same time, the maleic anhydride is connected to the polypropylene main chain in the form of a side group, which improves the connectivity between the polypropylene and other materials, especially the silanol and hydroxypropyl on the coated glass fiber, which can form a stable connection with the maleic anhydride, thereby improving the connectivity between the glass fiber and the polypropylene; the antioxidant adopts a composite antioxidant to improve the antioxidant properties from different angles, improve the aging resistance, and extend the service life of the material; the use of the toughening agent can enable the composite material to obtain excellent high impact resistance; the lubricant can not only effectively improve the lubricity, but also cooperate with the glass fiber to form good wear resistance;

[0009] Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material, the extrusion process parameters of the twin-screw extruder are: 170-180°C in zone one, 185-195°C in zone two, 190-200°C in zone three, 200-210°C in zone four, 205-215°C in zone five, 195-205°C in zone six, 185-200°C in zone seven, 180-195°C in zone eight, 175-185°C in zone nine, 180-200°C in die head, and 280-350r / min in screw speed.

[0010] It can be seen from the above description that the present invention has the following advantages:

[0011] 1. The present invention solves the cracking problem caused by light aging and chemical inertness on the surface of glass fiber, uses 3-chloropropyltrichlorosilane as a modifier to form surface modification, and uses chloropropyl as an extended side group for penetration connection and remote chemical fixation, thereby improving the connection stability of glass fiber in polypropylene composite materials, thereby improving the weather resistance of the composite materials.

[0012] 2. The present invention adopts in-situ alkalization and in-situ hydrolysis reaction, which not only improves the stable chemical fixation of 3-chloropropyltrichlorosilane, but also improves the wetting effect and the connection bite force by roughening the thin surface of the glass fiber.

[0013] 3. The present invention utilizes long glass fibers and short glass fibers to form a long-short staggered structure, which can not only form a staggered glass fiber network structure, but also reduce repeated cross-linking and improve the frame support; moreover, polypropylene forms excellent side group connection activity through the compatibilizer, can form chemical connection stability with the glass fiber frame, and reduce the crack problem on the glass fiber surface. DETAILED DESCRIPTION

[0014] The present invention is described in detail with reference to the embodiments, but no limitation is imposed on the claims of the present invention.

[0015] Example 1

[0016] A method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum comprises the following steps:

[0017] Step 1, putting short glass fiber and long glass fiber into ethanol aqueous solution for ultrasonic dispersion for 20 minutes, filtering and drying, and soaking in sodium hydroxide solution for 10 seconds, removing and standing for 2 hours to obtain mixed glass fiber, the mass ratio of the short glass fiber to the long glass fiber is 1:2, and the length of the short glass fiber is 0.2-0.3mm, the length of the long glass fiber is 10-15mm, the volume fraction of ethanol in the ethanol aqueous solution is 40%, the concentration of the short glass fiber in the ethanol aqueous solution is 50g / L, the temperature of the ultrasonic dispersion is 40°C, the ultrasonic frequency is 70kHz, the drying temperature is 120°C, the pH of the sodium hydroxide solution is 8, the immersion concentration is 100-300g / L, the temperature is 10°C, and the standing temperature is 60-80°C;

[0018] Step 2, adding 3-chloropropyltrichlorosilane to ether and stirring evenly to form a dissolving solution, then adding the mixed glass fiber, ultrasonically dispersing for 30 minutes and then taking it out and letting it stand to obtain a coated glass fiber, the concentration of the 3-chloropropyltrichlorosilane in the ether is 400g / L, the concentration of the mixed glass fiber in the dissolving solution is 100g / L, the ultrasonic frequency of the ultrasonic dispersion is 70kHz, and the temperature is 5°C; the standing atmosphere is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1;

[0019] Step 3, ball-milling polypropylene and compatibilizer to form fine powder, then adding coated glass fiber, antioxidant, lubricant and toughening agent in sequence, stirring at constant temperature to obtain a mixture, wherein the mass ratio of the mixture is: 80 parts of polypropylene, 2 parts of compatibilizer, 15 parts of coated glass fiber, 1 part of antioxidant, 0.3 parts of lubricant, and 0.5 parts of toughening agent, the compatibilizer is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is GX-5; the ball milling pressure is 0.4MPa, the temperature is 20°C, and the constant temperature stirring temperature is 40°C;

[0020] Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material, the extrusion process parameters of the twin-screw extruder are: 170-180°C in zone one, 185-195°C in zone two, 190-200°C in zone three, 200-210°C in zone four, 205-215°C in zone five, 195-205°C in zone six, 185-200°C in zone seven, 180-195°C in zone eight, 175-185°C in zone nine, 180-200°C in die head, and 280-350r / min in screw speed.

[0021] Example 2

[0022] A method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum comprises the following steps:

[0023] Step 1, putting short glass fiber and long glass fiber into ethanol aqueous solution for ultrasonic dispersion for 30 minutes, filtering and drying, and soaking in sodium hydroxide solution for 15 seconds, removing and standing for 3 hours to obtain mixed glass fiber, the mass ratio of the short glass fiber to the long glass fiber is 1:4, and the length of the short glass fiber is 0.2-0.3mm, the length of the long glass fiber is 10-15mm, the volume fraction of ethanol in the ethanol aqueous solution is 50%, the concentration of the short glass fiber in the ethanol aqueous solution is 100g / L, the temperature of the ultrasonic dispersion is 50°C, the ultrasonic frequency is 90kHz, the drying temperature is 130°C, the pH of the sodium hydroxide solution is 9, the immersion concentration is 300g / L, the temperature is 20°C, and the standing temperature is 80°C;

[0024] Step 2, adding 3-chloropropyltrichlorosilane to ether and stirring evenly to form a dissolving solution, then adding the mixed glass fiber, taking it out and standing it after ultrasonic dispersion for 60 minutes to obtain a coated glass fiber, the concentration of the 3-chloropropyltrichlorosilane in the ether is 600g / L, the concentration of the mixed glass fiber in the dissolving solution is 200g / L, the ultrasonic frequency of the ultrasonic dispersion is 100kHz, and the temperature is 10°C; the standing atmosphere is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 12:1;

[0025] Step 3, ball-milling polypropylene and compatibilizer to form fine powder, then adding coated glass fiber, antioxidant, lubricant and toughening agent in sequence, stirring at constant temperature to obtain a mixture, wherein the mass ratio of the mixture is: 90 parts of polypropylene, 3 parts of compatibilizer, 20 parts of coated glass fiber, 2 parts of antioxidant, 0.5 parts of lubricant, and 0.8 parts of toughening agent, the compatibilizer is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is NT-C; the ball milling pressure is 0.6MPa, the temperature is 30°C, and the constant temperature stirring temperature is 50°C;

[0026] Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material, the extrusion process parameters of the twin-screw extruder are: 170-180°C in zone one, 185-195°C in zone two, 190-200°C in zone three, 200-210°C in zone four, 205-215°C in zone five, 195-205°C in zone six, 185-200°C in zone seven, 180-195°C in zone eight, 175-185°C in zone nine, 180-200°C in die head, and 280-350r / min in screw speed.

[0027] Example 3

[0028] A method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum comprises the following steps:

[0029] Step 1, putting short glass fiber and long glass fiber into ethanol aqueous solution for ultrasonic dispersion for 25 minutes, filtering and drying, and soaking in sodium hydroxide solution for 12 seconds, removing and standing for 3 hours to obtain mixed glass fiber, wherein the mass ratio of the short glass fiber to the long glass fiber is 1:3, and the length of the short glass fiber is 0.2-0.3mm, the length of the long glass fiber is 10-15mm, the volume fraction of ethanol in the ethanol aqueous solution is 45%, the concentration of the short glass fiber in the ethanol aqueous solution is 80g / L, the temperature of the ultrasonic dispersion is 45°C, the ultrasonic frequency is 80kHz, the drying temperature is 125°C, the pH of the sodium hydroxide solution is 8, the immersion concentration is 200g / L, the temperature is 15°C, and the standing temperature is 70°C;

[0030] Step 2, adding 3-chloropropyltrichlorosilane to ether and stirring evenly to form a dissolving solution, then adding the mixed glass fiber, ultrasonically dispersing for 50 minutes, taking it out and letting it stand to obtain a coated glass fiber, the concentration of the 3-chloropropyltrichlorosilane in the ether is 500g / L, the concentration of the mixed glass fiber in the dissolving solution is 150g / L, the ultrasonic frequency of the ultrasonic dispersion is 80kHz, and the temperature is 8°C; the standing atmosphere is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 11:1;

[0031] Step 3, ball-milling polypropylene and compatibilizer to form fine powder, then adding coated glass fiber, antioxidant, lubricant and toughening agent in sequence, stirring at constant temperature to obtain a mixture, wherein the mass ratio of the mixture is: 85 parts of polypropylene, 3 parts of compatibility, 18 parts of coated glass fiber, 2 parts of antioxidant, 0.4 parts of lubricant, and 0.7 parts of toughening agent, the compatibilizer is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is WBG-Ⅱ; the ball milling pressure is 0.5MPa, the temperature is 25°C, and the constant temperature stirring temperature is 45°C;

[0032] Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material, the extrusion process parameters of the twin-screw extruder are: 170-180°C in zone one, 185-195°C in zone two, 190-200°C in zone three, 200-210°C in zone four, 205-215°C in zone five, 195-205°C in zone six, 185-200°C in zone seven, 180-195°C in zone eight, 175-185°C in zone nine, 180-200°C in die head, and 280-350r / min in screw speed.

[0033] Comparative Example 1

[0034] A method for preparing a glass fiber reinforced polypropylene composite material comprises the following steps:

[0035] Step 1, ball-milling polypropylene and compatibilizer to form fine powder, then adding glass fiber, antioxidant, lubricant and toughening agent in sequence, stirring at constant temperature to obtain a mixture, wherein the mass ratio of the mixture is: 85 parts of polypropylene, 3 parts of compatibilizer, 18 parts of glass fiber, 2 parts of antioxidant, 0.4 parts of lubricant, and 0.7 parts of toughening agent, the compatibilizer is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is WBG-Ⅱ; the ball milling pressure is 0.5MPa, the temperature is 25°C, and the constant temperature stirring temperature is 45°C;

[0036] Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material, the extrusion process parameters of the twin-screw extruder are: 170-180°C in zone one, 185-195°C in zone two, 190-200°C in zone three, 200-210°C in zone four, 205-215°C in zone five, 195-205°C in zone six, 185-200°C in zone seven, 180-195°C in zone eight, 175-185°C in zone nine, 180-200°C in die head, and 280-350r / min in screw speed.

[0037] Comparative Example 2

[0038] Comparative Example 2 uses conventional fiber-reinforced polypropylene pellets.

[0039] Performance Testing

[0040] The products of Examples 1-3 and Comparative Examples 1-2 were used as test products to conduct performance tests on glass fiber reinforced polypropylene composite materials. The results are as follows:

[0041]

[0042] The above data show that the glass fiber reinforced polypropylene composite material in the present technical solution has certain improvements in mechanical properties, and the surface activity of the glass fiber is effectively improved by modification with 3-chloropropyltrichlorosilane, which effectively improves its fixation and stability in the polypropylene composite material.

[0043] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for preparing a glass fiber reinforced polypropylene composite material for a washing machine outer drum, characterized in that: The steps include: Step 1, putting the short glass fiber and the long glass fiber into an ethanol aqueous solution for ultrasonic dispersion for 20-30 minutes, filtering, drying and soaking in a sodium hydroxide solution for 10-15 seconds, removing and standing for 2-3 hours to obtain a mixed glass fiber; Step 2, adding 3-chloropropyltrichlorosilane to ether and stirring evenly to form a solution, then adding the mixed glass fiber, ultrasonically dispersing for 30-60 minutes, then taking it out and letting it stand to obtain a coated glass fiber; Step 3, ball-milling the polypropylene and the compatibilizer to form fine powder, then sequentially adding the coated glass fiber, antioxidant, lubricant and toughening agent, and stirring at a constant temperature to obtain a mixture; Step 4, putting the mixed material into a twin-screw extruder, extruding and granulating after melting and reaction, to obtain a glass fiber reinforced polypropylene composite material.

2. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The mass ratio of the short glass fibers to the long glass fibers in step 1 is 1:2-4, and the length of the short glass fibers is 0.2-0.3 mm, and the length of the long glass fibers is 10-15 mm.

3. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The volume fraction of ethanol in the ethanol aqueous solution in step 1 is 40-50%, the concentration of the short glass fibers in the ethanol aqueous solution is 50-100 g / L, the temperature of the ultrasonic dispersion is 40-50° C., and the ultrasonic frequency is 70-90 kHz.

4. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The drying temperature in step 1 is 120-130° C., the pH of the sodium hydroxide solution is 8-9, the immersion concentration is 100-300 g / L, the temperature is 10-20° C., and the standing temperature is 60-80° C.

5. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The concentration of 3-chloropropyltrichlorosilane in diethyl ether in step 2 is 400-600 g / L, the concentration of the mixed glass fiber in the dissolving solution is 100-200 g / L, the ultrasonic frequency of the ultrasonic dispersion is 70-100 kHz, and the temperature is 5-10°C.

6. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The static atmosphere in step 2 is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10-12:

1.

7. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The mass ratio of the mixture in step 3 is: 80-90 parts of polypropylene, 2-3 parts of compatibility, 15-20 parts of coated glass fiber, 1-2 parts of antioxidant, 0.3-0.5 parts of lubricant, and 0.5-0.8 parts of toughening agent.

8. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 7, characterized in that: The compatibilizer in step 3 is maleic anhydride grafted polypropylene, the antioxidant is a composite antioxidant composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1, the lubricant is polyethylene wax, and the toughening agent is one of GX-5, NT-C, and WBG-Ⅱ.

9. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The ball milling pressure in step 3 is 0.4-0.6 MPa, the temperature is 20-30°C, and the constant temperature stirring temperature is 40-50°C.

10. The method for preparing the glass fiber reinforced polypropylene composite material for the outer drum of a washing machine according to claim 1, characterized in that: The extrusion process parameters of the twin-screw extruder in the step 4 are: zone 1 170-180°C, zone 2 185-195°C, zone 3 190-200°C, zone 4 200-210°C, zone 5 205-215°C, zone 6 195-205°C, zone 7 185-200°C, zone 8 180-195°C, zone 9 175-185°C, die head 180-200°C, and screw speed 280-350r / min.

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