Zinc sulfide for glass fiber reinforced polyolefin composites and preparation method and application thereof

Abstract

The application provides vulcanized zinc special for glass fiber reinforced polyolefin composite materials and a preparation method and application thereof. The vulcanized zinc contains copper elements and manganese elements, the mass content of the copper elements in the vulcanized zinc is 5-25 ppm, the mass content of the manganese elements in the vulcanized zinc is 10-50 ppm, and the mass content of zinc in the vulcanized zinc and the D50 particle size of the vulcanized zinc satisfy the following relationship: 15<=W / (D zn / (D znS 0.3 ) <=23. By synergistically regulating the zinc content, particle size, and the content of doped copper elements and manganese elements in the vulcanized zinc, the mechanical properties, antistatic property, and wear resistance of the glass fiber reinforced polyolefin composite materials are significantly improved.

Description

Technical Field

[0001] This invention relates to the technical field of sulfides, and particularly to zinc sulfide for glass fiber reinforced polyolefin composites, its preparation method, and its application. Background Technology

[0002] Glass fiber reinforced polyolefin (GF / PO) composites are high-performance materials commonly used in the automotive, electronics, and construction industries. They are widely recognized for their excellent mechanical properties, low density, good corrosion resistance, and processability. As a reinforcing phase, glass fiber not only significantly improves the tensile strength, rigidity, and heat resistance of the polyolefin matrix material but also enhances its dimensional stability to some extent. However, despite these advantages, GF / PO composites still face some technical bottlenecks in certain specialized applications.

[0003] First, the polarity difference between glass fiber and polyolefin matrix leads to poor interfacial compatibility, making the fiber-matrix interface prone to stress concentration and inducing crack propagation under dynamic loads. Traditional silane coupling agent treatment can only improve interfacial adhesion to a limited extent, and the tensile strength and impact toughness of the composite material still fall short of theoretical values. Second, the intrinsic volume resistivity of polyolefin reaches 10⁻⁶. 16 ~10 18 While glass fiber reinforcement partially reduces resistance (Ω·cm), it still falls short of meeting the antistatic requirements (surface resistance ≤10 Ω·cm) for applications such as electronic packaging and mining equipment. 9 The addition of existing antistatic agents (such as carbon black and metal powders) often leads to a deterioration in material toughness or a decrease in processing fluidity. In addition, the low hardness of the polyolefin matrix makes it prone to abrasive and adhesive wear under long-term friction conditions. Although the hardness of glass fiber can partially improve wear resistance, the exposed fiber may act as an abrasive, exacerbating damage to the workpiece.

[0004] Therefore, there is an urgent need to improve glass fiber reinforced polyolefin composites to enhance their mechanical properties, antistatic properties, and wear resistance in order to meet the demand for high-performance materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a zinc sulfide specifically for glass fiber reinforced polyolefin composites, its preparation method, and its application.

[0006] This invention provides a zinc sulfide specifically for glass fiber reinforced polyolefin composites, wherein the zinc sulfide contains copper and manganese elements, and the mass content of copper in the zinc sulfide is 5~25 ppm, preferably 10~20 ppm;

[0007] The manganese element in the zinc sulfide has a mass content of 10~50 ppm, preferably 25~35 ppm;

[0008] The incorporation of copper and manganese can improve the dispersibility of zinc sulfide particles, prevent particle aggregation, and make the microstructure of the composite material more uniform. This helps to reduce crack initiation and propagation, and improve the toughness and overall mechanical properties of the composite material.

[0009] "Zinc sulfide" refers to an inorganic compound composed of zinc and sulfur elements, possessing excellent optical, electrical, and wear-resistant properties. In this invention, zinc sulfide is modified by co-doping with copper and manganese elements and used as a functional filler.

[0010] The zinc mass content in the zinc sulfide is related to the D of the zinc sulfide. 50 Particle size satisfies the following relationship:

[0011] ;

[0012] in, W zn The percentage of zinc in zinc sulfide materials is expressed as % (by mass). D znS The particle size of zinc sulfide particles, in nm; preferably... .

[0013] This formula is derived from the summarization of a large amount of experimental data and the fitting of performance curves, reflecting the law that zinc content and particle size have a synergistic regulatory effect on antistatic properties and wear resistance.

[0014] In this invention, the mass content of copper and manganese and the zinc content in zinc sulfide materials can be detected by atomic absorption spectrometry (AAS).

[0015] In this invention, the mass content of copper and manganese elements and the zinc content in zinc sulfide materials can be adjusted by screening suitable zinc sulfide raw material ores; alternatively, a synthetic method can be used to select suitable zinc compounds and sulfides to synthesize zinc sulfide, and then adjust the content by adding a certain amount of copper and manganese elements through a deposition method.

[0016] In some embodiments, the dielectric constant of the zinc sulfide is 9 to 11.5.

[0017] In this invention, the "dielectric constant" represents the polarization ability of a material under the influence of an electric field and is an important parameter for evaluating the electrical properties of a material. The dielectric constant is tested using the capacitance method (parallel-plate capacitor method). The dielectric constant is related to the polarization ability of a material. If the dielectric constant is too low, the material will have a weak response to the applied electric field and surface charge will easily accumulate, which is not conducive to improving antistatic properties. If the dielectric constant is too high, the charge accumulation may lead to an excessively fast conduction rate, resulting in the risk of local leakage or breakdown, which will reduce the stability of the material.

[0018] In some embodiments, the zinc sulfide contains 60-70% zinc by mass; preferably 65-68%.

[0019] In some embodiments, the zinc sulfide has a D 50 The particle size is 50~150nm, preferably 50~120nm.

[0020] “D 50 "Particle size" refers to the median particle size of the zinc sulfide powder, meaning that 50% of the particles are smaller than this size. The unit is nanometers (nm). In this invention, the D50 particle size is controlled within the range of 50~150nm to optimize its dispersibility and interfacial compatibility.

[0021] The present invention also provides a method for preparing the zinc sulfide, comprising the following steps:

[0022] Zinc sulfate, copper sulfate, and manganese sulfate were dissolved in deionized water and heated. Sodium sulfide solution was slowly added dropwise to react the solutions. The mixture was cooled to room temperature, and the precipitates were collected by vacuum filtration. Dilute hydrochloric acid was added and stirred to remove surface impurities. The mixture was then washed with deionized water until neutral and dried at high temperature to obtain the zinc sulfide powder sample.

[0023] The present invention also provides the application of the zinc sulfide described herein in the preparation of glass fiber reinforced polyolefin composites.

[0024] The present invention also provides a glass fiber reinforced polyolefin composite material, comprising the following components in parts by weight:

[0025] 100 parts of glass fiber reinforced polyolefin composite material and 0.1 to 10 parts of zinc sulfide, preferably 2 to 8 parts.

[0026] In this invention, zinc sulfide is used as a reinforcing phase. When combined with glass fiber reinforced polyolefin matrix, it can increase the mechanical properties, antistatic properties and wear resistance of the material.

[0027] In some embodiments, the glass fiber content in the glass fiber reinforced polyolefin composite material is 10-40% by mass.

[0028] In some embodiments, the polyolefin in the glass fiber reinforced polyolefin composite material includes any one or more of polyethylene, polypropylene, polytetrafluoroethylene, and polyolefin elastomers.

[0029] In some embodiments, the glass fiber reinforced polyolefin composite material further includes 0 to 2 parts of other additives, wherein the other additives are selected from at least one of lubricants, antioxidants, impact modifiers, flame retardants, fluorescent whitening agents, plasticizers, thickeners, release agents, and nucleating agents.

[0030] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0031] This invention significantly improves the mechanical properties, antistatic properties, and wear resistance of glass fiber reinforced polyolefin composites by synergistically controlling the zinc content, particle size, and the content of copper and manganese doped in zinc sulfide. Specifically, the introduction of copper and manganese effectively enhances the interfacial activity and dispersion stability of the zinc sulfide particles, improving the strength, hardness, and wear resistance of the composite material. Furthermore, the appropriate matching of zinc content and particle size helps optimize the conductive path and interfacial bonding force of the composite system, significantly improving antistatic properties and overall structural stability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is an X-ray diffraction pattern of the zinc sulfide material in Example 1 of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0036] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0037] In this invention, there are no particular limitations on the specific dispersion and stirring methods.

[0038] Unless otherwise specified, all reagents or instruments used in this invention are commercially available products.

[0039] Unless otherwise specified, all components in the parallel embodiments and comparative examples of this invention are the same commercially available products.

[0040] The embodiments and comparative examples of the present invention respectively prepare zinc sulfide materials, including the following steps:

[0041] (1) Weigh zinc sulfate (ZnSO4·7H2O), copper sulfate (CuSO4·5H2O) and manganese sulfate (MnSO4·H2O), dissolve them in deionized water, heat to 60℃, slowly add Na2S·9H2O solution, control the reaction temperature at 60℃, and react for 2 hours;

[0042] (2) Cool down to room temperature, collect the precipitate by vacuum filtration, add dilute hydrochloric acid (0.1 mol / L, 200 mL), stir for 30 minutes to remove surface impurities;

[0043] (3) The sample was then washed three times with deionized water until neutral, and dried at 80°C to obtain ZnS powder sample;

[0044] (4) Use ultrasonic waves to disperse agglomerated particles, and then centrifuge and classify them to select specific particle sizes.

[0045] The D50 particle size was measured using a Horiba LA-960V2 laser particle size analyzer.

[0046] The X-ray diffraction (XRD) pattern of the zinc sulfide material prepared in Example 1 is shown below. Figure 1 As shown, no new impurity peaks were added after Cu and Mn doping, the sample had good crystallinity and few impurity phases, indicating that the preparation method of the present invention can achieve effective doping of Cu and Mn elements without introducing impurity phases, and maintain the good crystal structure and purity of the material.

[0047] The mass content of iron, copper, and zinc in the zinc sulfide materials prepared in each example and comparative example was determined by atomic absorption spectrometry (AAS). The results are shown in Table 1. Zn (%).

[0048] Table 1. Test parameter values ​​for zinc sulfide materials

[0049]

[0050] Using the zinc sulfide materials obtained in the various embodiments and comparative examples, glass fiber reinforced polypropylene composite materials were prepared according to the following parts by weight:

[0051] 100 parts polypropylene, 15 parts glass fiber, 3 parts zinc sulfide, 1 part antioxidant 1010;

[0052] The resin composition is prepared according to the following steps:

[0053] Polypropylene, glass fiber, zinc sulfide, and antioxidant 1010 are added to a twin-screw extruder in one step and mixed at 1000 rpm. The material temperature rises to 240°C, and after melt mixing, extrusion granulation, the resin composition is obtained.

[0054] Test method:

[0055] 1. Mechanical properties:

[0056] The notched impact strength of the cantilever beam was tested according to ASTM D256 / (GB / T1843) standard (KJ / M2);

[0057] Tensile properties were tested according to ASTM D638 / (GB / T1040) standard (MPa);

[0058] Bending performance was tested according to ASTM D790 / (GB / T9341) standard (MPa).

[0059] 2. Antistatic properties

[0060] Sheets produced by a Bravender single-screw extruder T-die were cut to dimensions of 5 cm wide and 5 cm long, and treated according to ASTM D618-61 at 23°C and 50% relative humidity. The resulting sheets were used as samples, and their surface resistivity was measured according to ASTM D257 using a surface resistivity measuring instrument (Adventest, Japan). The results are listed in Table 1.

[0061] 3. Wear resistance

[0062] The abrasion resistance was determined using a needle scraping test. The specific steps are as follows: a 710g weight was placed on a 0.45sq needle, and the needle was moved back and forth 300 times on a test sample that was 2mm wide, 1mm thick, and 100mm long, thereby measuring the thickness of the worn test sample.

[0063] The test results are shown in Table 2:

[0064] Table 2 Test results of various properties of glass fiber reinforced polypropylene composites

[0065]

[0066] As shown in Table 2, the glass fiber reinforced polypropylene composites prepared in Examples 1-11 of this application exhibit excellent mechanical properties, with tensile strength exceeding 170 MPa and notched impact strength exceeding 24.5 KJ / M. 2 It has a flexural strength of over 270 MPa, and also possesses low electrical resistance and excellent wear resistance.

[0067] To investigate the performance regulation of zinc sulfide materials under doping conditions, test data from each example in Table 2 were collected, and regression analysis was performed on the data using OriginLab. The analysis results show that the zinc elemental mass content (W...) Zn ) and zinc sulfide D 50 Particle size (D) ZnS There is a significant nonlinear coupling relationship between them.

[0068] To achieve synergistic optimization of antistatic and wear resistance properties, an empirical correlation function of the following form is constructed:

[0069] ;

[0070] Fitting analysis of different indices n showed that when n = 0.3, both the antistatic properties and wear resistance of the material were within their optimal performance range. Therefore, the indices in this empirical formula were set to 0.3, and the performance correlation factor R was defined as follows:

[0071] .

[0072] According to the data in Table 2, the R values ​​of each embodiment and comparative example are shown in Table 3:

[0073] Table 3 R values

[0074]

[0075] The R value proposed above can effectively characterize the coordination window between particle size and zinc content in zinc sulfide materials. In all embodiments of the present invention, the R value is within... Within the specified range, the material exhibits excellent overall performance. Conversely, in Comparative Examples 1 and 2, when the R value deviates from this range, the glass fiber reinforced polypropylene composite material shows a significant deterioration trend in performance. Specifically, when the R value is too large, the ZnS particle size and zinc content are mismatched, easily leading to particle agglomeration and decreased dispersion, forming stress concentration areas in the composite system, which in turn causes a decrease in the mechanical properties of the material. At the same time, agglomerated particles hinder the construction of effective conductive channels, causing unstable or failed antistatic properties. In addition, interface inhomogeneity also exacerbates the friction and wear process, resulting in a significant decrease in wear resistance. When the R value is too small, the ZnS particle size is too large and the zinc content is too low, resulting in weakened effective polar interactions in the material, insufficient reinforcement effect of the filler on the matrix, manifested as a decrease in the mechanical strength of the composite material. At the same time, the electrostatic conductivity of ZnS in the composite system is weakened, unable to effectively release surface charge, leading to severe static accumulation and poor antistatic properties. Furthermore, excessively large filler particle size can also easily cause accelerated wear, resulting in reduced wear resistance.

[0076] It should be noted that although only polypropylene resin is used as the resin component of the resin composition in the embodiments of the present invention, in fact, when polypropylene resin is replaced with other polyolefin materials, such as polyethylene, polypropylene, polytetrafluoroethylene and polyolefin elastomers, similar effects of improving mechanical properties, antistatic properties and wear resistance can be achieved.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Zinc sulfide specifically for glass fiber reinforced polyolefin composites, characterized in that, The zinc sulfide contains copper and manganese, and the copper content in the zinc sulfide is 5-25 ppm by mass. The manganese element in the zinc sulfide has a mass content of 10~50 ppm; The zinc mass content in the zinc sulfide is related to the D of the zinc sulfide. 50 Particle size satisfies the following relationship: in, W zn The percentage of zinc in zinc sulfide materials is expressed as % (by mass). D znS The particle size of zinc sulfide particles, in nm; The zinc sulfide contains 60-70% zinc by mass. The zinc sulfide D 50 The particle size is 50~150nm.

2. The zinc sulfide according to claim 1, characterized in that, The dielectric constant of the zinc sulfide is 9 to 11.

5.

3. The method for preparing zinc sulfide according to any one of claims 1 to 2, characterized in that, Includes the following steps: Zinc sulfate, copper sulfate, and manganese sulfate were dissolved in deionized water and heated. Sodium sulfide solution was slowly added dropwise to react the solutions. The mixture was cooled to room temperature, and the precipitates were collected by vacuum filtration. Dilute hydrochloric acid was added and stirred to remove surface impurities. The mixture was then washed with deionized water until neutral and dried at high temperature to obtain the zinc sulfide powder sample.

4. The use of zinc sulfide according to any one of claims 1 to 2 in the preparation of glass fiber reinforced polyolefin composites.

5. A glass fiber reinforced polyolefin composite material, characterized in that, Based on parts by weight, it comprises the following components: 100 parts of glass fiber reinforced polyolefin composite material and 0.1 to 10 parts of zinc sulfide as described in claim 1.

6. The glass fiber reinforced polyolefin composite material according to claim 5, characterized in that, In the glass fiber reinforced polyolefin composite material, the mass content of glass fiber is 10-40%.

7. The glass fiber reinforced polyolefin composite material according to claim 5, characterized in that, The glass fiber reinforced polyolefin composite material contains any one or more of polyethylene, polypropylene, polytetrafluoroethylene, and polyolefin elastomers.

8. The glass fiber reinforced polyolefin composite material according to claim 5, characterized in that, The glass fiber reinforced polyolefin composite material also includes 0 to 2 parts of other additives, wherein the other additives are selected from at least one of lubricants, antioxidants, impact modifiers, flame retardants, fluorescent whitening agents, plasticizers, thickeners, release agents, and nucleating agents.

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