Low-odor anti-floating fiber reinforced PA composite material and preparation method thereof

Abstract

The invention discloses a low-odor anti-floating fiber reinforced PA composite material and a preparation method thereof, and belongs to the field of composite technology materials. The material is prepared from the following raw materials: PA6 resin, modified glass fibers, an antioxidant, a lubricant and a compatilizer, polydopamine and a metal organic framework are loaded on the surface of the modified glass fiber. According to the preparation method disclosed by the invention, a multi-layer structure of GF-PDA-MOFs is constructed by utilizing the extremely strong modification capability of polydopamine on the surfaces of different materials, and the compatibility with PA is improved through polar groups on the surfaces of PDA and MOFs, so that the interface bonding force between the glass fiber and a PA matrix can be greatly increased, the fiber reinforcement effect is improved, and the problem of surface floating fiber is effectively solved; meanwhile, the MOFs material has high porosity, a porous structure, a polar group and a benzene ring structure, volatile odor substances in the extrusion process can be adsorbed through physical or chemical action, and the odor of particles or workpieces is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly relates to a low-odor, anti-floating fiber reinforced PA composite material and a preparation method thereof. Background Art

[0002] Nylon 6 (PA6), as the engineering plastic with the largest output, has good properties such as high wear resistance, self-lubrication, self-extinguishing, high oil resistance and high corrosion resistance, and is widely used in fields such as automobiles, airplanes, electronic and electrical, and railways. However, PA resin usually needs to add glass fiber to improve the strength of the overall composite material. With the increase of the glass fiber content, the dispersibility of the fiber in the system and its compatibility with the matrix gradually become worse, the interfacial bonding force decreases, and even if a multi-component compatibilizer is added to the system, problems such as strength reduction and surface floating fiber may still occur. In addition, the processing process and product parts of PA usually emit unpleasant odors, and a large amount of small molecule substances volatilize, directly affecting consumers' preference for the products manufactured by it, especially the application parts in the automotive interior. Therefore, it is of great significance to prepare a low-odor, anti-floating fiber reinforced PA composite material. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the present invention provides a low-odor, anti-floating fiber reinforced PA composite material and a preparation method thereof.

[0004] The object of the present invention can be achieved by the following technical solutions:

[0005] In the first aspect of the present invention, a PA composite material is provided, comprising the following raw materials:

[0006] PA6 resin, modified glass fiber, antioxidant, lubricant and compatibilizer;

[0007] The surface of the modified glass fiber is loaded with polydopamine and metal-organic framework.

[0008] Optionally, the preparation method of the modified glass fiber comprises the following steps:

[0009] Mix an aqueous solution of dopamine hydrochloride with glass fiber, add an oxidant, after oxidative polymerization reaction, filter and wash with deionized water to obtain glass fiber coated with polydopamine GF-PDA;

[0010] Mix a metal ion source and N, N-dimethylformamide, stir to form a homogeneous solution, then add the glass fiber coated with polydopamine and stir; then add an organic ligand, after the reaction, collect the product by centrifugation, and obtain the modified glass fiber with a GF-PDA-MOFs multi-layer structure after washing and drying.

[0011] Optionally, before adding the oxidant, an alkali solution is added to adjust the pH to 8-9.

[0012] Optionally, the oxidative polymerization reaction is carried out in an ultrasonic cleaner.

[0013] Optionally, the metal ion source is FeCl3, Fe(NO3)3, ZrCl4 or ZrOCl2·8H2O, and the organic ligand is 2-aminoterephthalic acid or 2,4-diaminoterephthalic acid; the mass ratio of the metal ion source, organic ligand, glass fiber, and N,N-dimethylformamide is 1:1:20:100.

[0014] Optionally, the oxidant includes one of H2O2, K2S2O8, (NH4)2S2O8, and the frequency range of the ultrasonic cleaner is 20KHz - 80KHz.

[0015] Optionally, the weight part ratio of the raw materials is set as:

[0016]

[0017] Optionally, the antioxidant is one or more of antioxidant 1076, antioxidant 1010, antioxidant 168, antioxidant 1098;

[0018] The lubricant is one or more of ethylene bisstearamide, modified ethylene bisfatty acid amide, silicone powder, paraffin wax;

[0019] In the second aspect of the present invention, a method for preparing a PA composite material is provided, including the following steps: mixing PA6, antioxidant, lubricant, and compatibilizer evenly, and adding them to a twin-screw extruder through the main feeder; adding the modified glass fiber to the twin-screw extruder through the side feeder for melt extrusion granulation; the length-diameter ratio of the twin-screw extruder is 40:1, the screw speed is 200 - 400r / min, the extrusion temperature is 230 - 250°C, and the vacuum degree is -0.1 - -0.05MPa to obtain the PA composite material;

[0020] Among them, the surface of the modified glass fiber is loaded with polydopamine and metal-organic framework.

[0021] In the third aspect of the present invention, the above-mentioned PA composite material is applied to the preparation of automotive interior trim.

[0022] The beneficial effects of the present invention:

[0023] 1. By adding an oxidant to the reaction system in combination with ultrasonic treatment, the reactivity of dopamine on the surface of glass fiber is enhanced, the polymerization process is accelerated, and the formation of a uniform PDA coating is promoted. There are a large number of amino and hydroxyl groups in PDA molecules, which serve as in-situ growth points for the assembly of MOFs materials, and enhance the binding force between MOFs and PDA in the form of covalent and non-covalent adhesion, forming a firm and unified structure.

[0024] 2. By utilizing the strong modification ability of polydopamine on the surfaces of materials with different materials, the present invention constructs a multi-layer structure of GF-PDA-MOFs. By means of the polar groups on the surfaces of PDA and MOFs, including primary amino groups and secondary amino groups, the compatibility between glass fiber and PA is enhanced, the interfacial binding force between glass fiber and PA matrix can be greatly increased, the fiber reinforcement effect is improved, and the problem of surface floating fibers is effectively solved.

[0025] 3. MOFs materials have a high porosity, porous structure, polar groups and benzene ring structure, and can adsorb volatile odor substances during the extrusion process through physical action, electrostatic action or conjugation action, improving the odor of particles or parts. Specific embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0027] Example 1

[0028] This example provides a modified glass fiber and a preparation method, which are prepared through the following steps:

[0029] Step 1: Add 1 L of hydrochloric acid dopamine aqueous solution (1 g / L) and 50 g of glass fiber into a beaker, stir for 30 min under the conditions of a rotation speed of 200 rpm and a temperature of 50 °C, then add 1 mol / L of Na2CO3 aqueous solution to adjust the pH value to 8-9, add 0.1 mol / L of (NH4)2S2O8, place the beaker in an ultrasonic cleaner (50 KHz), carry out an oxidation polymerization reaction for 4 h, and then filter and wash with deionized water to obtain polydopamine-coated glass fiber GF-PDA;

[0030] Step 2: Add ZrCl4 (1 g) and DMF (100 g) into a flask, stir to form a homogeneous solution, then add 20 g of glass fiber, stir for 2 h, then add 2-aminoterephthalic acid (1 g), after complete dissolution, react at 120 °C for 24 h, after the reaction, collect by centrifugation at 3000 rpm, then wash with acetone and deionized water, and finally dry at 100 °C to obtain glass fiber with GF-PDA-MOFs multi-layer structure.

[0031] Example 2

[0032] This example provides a modified glass fiber and its preparation method, which is prepared through the following steps:

[0033] Step 1: Add 1 L of hydrochloric acid dopamine aqueous solution (0.5 g / L) and 50 g of glass fiber into a beaker, stir at a rotation speed of 300 rpm and a temperature of 50 °C for 20 min, then add 1 mol / L of Na2CO3 aqueous solution to adjust the pH value to 8 - 9, add 0.05 mol / L of H2O2, place the beaker in an ultrasonic cleaner (50 KHz), carry out an oxidation polymerization reaction for 4 h, then filter and wash with deionized water to obtain polydopamine-coated glass fiber GF-PDA;

[0034] Step 2: Add FeCl3 (1 g) and DMF (100 g) into a flask, stir to form a homogeneous solution, then add 20 g of glass fiber, stir for 2 h, then add 2-aminoterephthalic acid (1 g), after complete dissolution, react at 120 °C for 24 h, after the reaction, collect by centrifugation at 3000 rpm, then wash with acetone and deionized water, and finally dry at 100 °C to obtain glass fiber with GF-PDA-MOFs multi-layer structure.

[0035] Example 3

[0036] This example provides a low-odor, anti-floating fiber reinforced PA composite material and its preparation method, including the following steps:

[0037] The antioxidant is a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1, the lubricant is ethylene bis-stearamide, and the modified glass fiber in Example 2 is used as the filling phase;

[0038] According to the ratio in Table 1, stir PA6 resin, modified glass fiber, antioxidant, and lubricant at a speed of 200 r / min for 10 min to obtain a mixture;

[0039] Put the mixture into a parallel twin-screw extruder, the barrel temperature is 230 °C, the screw speed is 400 r / min, and the vacuum degree is -0.06 MPa. Through melting and extrusion granulation, the low-odor, anti-floating fiber reinforced PA composite material is obtained.

[0040] Example 4

[0041] This example provides a low-odor, anti-floating fiber reinforced PA composite material, and the preparation method includes the following steps:

[0042] The antioxidant is a compound of antioxidant 1076 and antioxidant 168 with a mass ratio of 1:1, the lubricant is silicone powder, and the modified glass fiber in Example 1 is used as the filler phase;

[0043] According to the ratio in Table 1, PA6 resin, modified glass fiber, antioxidant, and lubricant are stirred at a speed of 200 r / min for 10 min to obtain a mixture;

[0044] The mixture is put into a parallel twin-screw extruder, the barrel temperature is 230 °C, the screw speed is 400 r / min, and the vacuum degree is -0.06 MPa. Through melting and extrusion granulation, the low-odor, anti-floating fiber reinforced PA composite material is obtained.

[0045] Example 5

[0046] This example provides a low-odor, anti-floating fiber reinforced PA composite material, and the preparation method includes the following steps:

[0047] The antioxidant is a compound of antioxidant 1076 and antioxidant 168 with a mass ratio of 1:1, the lubricant is silicone powder, and the modified glass fiber in Example 1 is used as the filler phase;

[0048] According to the ratio in Table 1, PA6 resin, modified glass fiber, antioxidant, and lubricant are stirred at a speed of 200 r / min for 10 min to obtain a mixture;

[0049] The mixture is put into a parallel twin-screw extruder, the barrel temperature is 230 °C, the screw speed is 400 r / min, and the vacuum degree is -0.05 MPa. Through melting and extrusion granulation, the low-odor, anti-floating fiber reinforced PA composite material is obtained.

[0050] Example 6

[0051] This example provides a low-odor, anti-floating fiber reinforced PA composite material, and the preparation method includes the following steps:

[0052] The antioxidant is antioxidant 1098, the lubricant is silicone powder, the compatibilizer is maleic anhydride grafted ethylene-octene copolymer, and the modified glass fiber in Example 1 is used as the filler phase;

[0053] According to the ratio in Table 1, PA6 resin, modified glass fiber, antioxidant, lubricant, and compatibilizer are stirred at a speed of 200 r / min for 10 min to obtain a mixture;

[0054] Put the mixture into a parallel twin-screw extruder. The barrel temperature is 230 °C, the screw speed is 400 r / min, and the vacuum degree is -0.05 MPa. Through melting and extrusion granulation, a low-odor, anti-floating fiber reinforced PA composite material is obtained.

[0055] Example 7

[0056] This example provides a low-odor, anti-floating fiber reinforced PA composite material. The preparation method includes the following steps:

[0057] The antioxidant is antioxidant 1098, the lubricant is silicone powder, the compatibilizer is maleic anhydride grafted ethylene-octene copolymer, and the GF-PDA glass fiber in step one of Example 1 is used as the filler phase;

[0058] According to the ratio in Table 1, stir PA6 resin, modified glass fiber, antioxidant, lubricant, and compatibilizer at a speed of 200 r / min for 10 min to obtain a mixture;

[0059] Put the mixture into a parallel twin-screw extruder. The barrel temperature is 230 °C, the screw speed is 400 r / min, and the vacuum degree is -0.05 MPa. Through melting and extrusion granulation, a low-odor, anti-floating fiber reinforced PA composite material is obtained.

[0060] Table 1 Weight parts of each component added in Examples 3 - 7

[0061]

[0062] Comparative Example 1

[0063] This example provides a glass fiber reinforced PA composite material. The preparation method includes the following steps:

[0064] Compared with Example 4, glass fiber is used as the filler phase, and the compatibilizer is maleic anhydride grafted ethylene-octene copolymer. Add each component according to the ratio in Table 2, and the remaining raw materials and preparation process are the same as those in Example 4.

[0065] Comparative Example 2

[0066] This example provides a glass fiber reinforced PA composite material and a preparation method, including the following steps:

[0067] Compared with Comparative Example 1, add each component according to the ratio in Table 2, and the remaining raw materials and preparation process are the same.

[0068] Comparative Example 3

[0069] This example provides a glass fiber reinforced PA composite material. The preparation method includes the following steps:

[0070] Compared with Comparative Example 1, the components were added according to the ratios in Table 2, and the remaining raw materials and the preparation process were the same.

[0071] Table 2 Parts by weight of each component added in Comparative Examples 1 to 3

[0072] Component Comparative Example 1 Comparative Example 2 Comparative Example 3 PA6 65 75 70 GF 30 20 30 Antioxidant 0.3 0.3 0.5 Lubricant 0.2 0.5 0.4 Compatibilizer 8 8 /

[0073] The properties of the composite materials prepared in Examples 3 to 7 and Comparative Examples 1 to 3 were respectively tested for tensile strength, flexural strength, and notched Izod impact strength according to the GB / T standard; the floating fiber situation was judged visually; the odor level test method referred to the test method of German Volkswagen PV3900 to test the odor level. The specific method of the odor level test is as follows:

[0074] Put 20 g of the above sample into a test vessel, place it in an oven for 2 h, and set the temperature of the oven at (80 ± 2) °C. Ensure that the test vessel is sealed tightly. After the test vessel is taken out of the oven and cooled to 60 °C, slightly open the lid, and let professional odor assessment personnel evaluate its odor. The odor level of the material is classified according to the standard as follows: Grade 1: odorless; Grade 2: having an odor, but no interfering odor; Grade 3: having an obvious odor, but no interfering odor; Grade 4: having an interfering odor; Grade 5: having a strong interfering odor; Grade 6: having an intolerable odor. All test results are shown in Table 3 and Table 4.

[0075] Table 3

[0076]

[0077] Table 4

[0078]

[0079] It can be seen from the test results of Comparative Examples 1 to 3 that the addition of unmodified glass fibers will result in fiber floating, with a relatively poor smell. After adding a multi-component compatibilizer, the fiber floating problem will be improved to some extent, but it cannot be completely eliminated, and the smell becomes even worse, reaching level 4.5. It can be seen from the test results of Examples 3 to 6 that as the addition amount of the modified glass fiber GF-PDA-MOFs increases, no fiber floating occurs even without a compatibilizer, and the tensile properties and flexural properties gradually increase. The smell situation is also improved, reaching level 3.5, which is better than that of Comparative Examples 1 to 3. In addition, by comparing Example 7 with other examples, it can be seen that the introduction of the MOFs material further increases the polar groups on the surface of the glass fiber, improves the compatibility, solves the fiber floating problem, and greatly improves the smell of the composite material, significantly reducing the level. Taking advantage of the strong adhesion and reactivity of polydopamine on the surfaces of materials with different materials, a multi-layer structure of integral GF-PDA-MOFs is constructed. The abundant polar groups on the surfaces of PDA and MOFs have good compatibility with PA, which can greatly increase the interfacial bonding force between the glass fiber and the PA matrix. Even under the condition of no compatibilizer, the fiber reinforcement effect can still be improved, the tensile and flexural properties are greatly enhanced, and there is no fiber floating on the surface of the composite material. At the same time, the high porosity, porous structure, and polar groups of the MOFs material can adsorb volatile odor substances during the extrusion or injection molding process, thereby improving the smell of the particles or products.

[0080] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0081] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A PA composite material, characterized in that: Including the following ingredients: PA6 resin, modified glass fiber, antioxidant, lubricant and compatibilizer; The surface of the modified glass fiber is loaded with polydopamine and a metal organic framework.

2. The PA composite material according to claim 1, characterized in that: The preparation method of the modified glass fiber comprises the following steps: The dopamine hydrochloride aqueous solution is mixed with glass fiber, an oxidant is added, and after oxidative polymerization, the mixture is filtered and washed with deionized water to obtain polydopamine-coated glass fiber GF-PDA; The metal ion source and N,N-dimethylformamide are stirred to form a uniform solution, and then the polydopamine-coated glass fiber is added and stirred; then the organic ligand is added, and the product is collected by centrifugation after the reaction, and the modified glass fiber with GF-PDA-MOFs multilayer structure is obtained after washing and drying.

3. The PA composite material according to claim 1, characterized in that: Before adding the oxidant, an alkali solution is added to adjust the pH to 8-9.

4. The PA composite material according to claim 1, characterized in that: The oxidative polymerization reaction is carried out in an ultrasonic cleaning machine.

5. The PA composite material according to claim 1, characterized in that: The metal ion source is FeCl3, Fe(NO3)3, ZrCl4 or ZrOCl2·8H2O, and the organic ligand is 2-aminoterephthalic acid or 2,4-diaminoterephthalic acid; the mass ratio of the metal ion source, the organic ligand, the glass fiber and N,N-dimethylformamide is 1:1:20:

100.

6. The PA composite material according to claim 4, characterized in that: The oxidant includes one of H2O2, K2S2O8, and (NH4)2S2O8, and the frequency range of the ultrasonic cleaning machine is 20KHz to 80KHz.

7. The PA composite material according to claim 1, characterized in that: The weight proportion of the raw materials is set as: 60-80 parts of PA6 resin; 8. The PA composite material according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1076, antioxidant 1010, antioxidant 168, and antioxidant 1098; The lubricant is one or more of ethylene bisstearamide, modified ethylene bisfatty acid amide, silicone powder and paraffin.

9. A method for preparing a PA composite material, characterized in that: The following steps are involved: After PA6, antioxidant, lubricant and compatibilizer are evenly mixed, they are added into the twin-screw extruder through the main feed; The modified glass fiber is added to a twin-screw extruder through side feeding for melt extrusion granulation; the twin-screw extruder has an aspect ratio of 40:1, a screw speed of 200 to 400 r / min, an extrusion temperature of 230 to 250° C., and a vacuum degree of -0.1 to -0.05 MPa, to obtain the PA composite material; Wherein, the surface of the modified glass fiber is loaded with polydopamine and a metal organic framework.

10. Use of the PA composite material according to any one of claims 1 to 8 in the preparation of automobile interior decoration.

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