Polyphenylene sulfide composite material with low glass fiber precipitation and preparation method thereof

Abstract

The invention discloses a polyphenylene sulfide composite material with low glass fiber precipitation and a preparation method thereof, and belongs to the technical field of high polymer materials, the polyphenylene sulfide composite material comprises the following components by weight: 10-60 parts of polyphenylene sulfide, 10-50 parts of glass fiber, 0-10 parts of an elastomer, 5-10 parts of minerals, 0.1-5 parts of a coupling agent, and 0.1-5 parts of a pigment. The preparation method is simple to operate and short in production period, the mechanical property, the processing property and the appearance quality of the material are considered while precipitation of the glass fibers is inhibited through component design and process collaborative optimization, and the preparation method has remarkable technical progress and practical application value.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and in particular to a polyphenylene sulfide composite material with low glass fiber exudation and its preparation method. Background Technology

[0002] Currently, the production and demand for polymer materials are growing rapidly, and the consumption areas are constantly expanding. Plastics are gradually replacing various materials and playing an important role in all aspects of our lives. Polyphenylene sulfide (PPS), as a high-performance engineering plastic, has excellent high-temperature resistance, chemical corrosion resistance, and good electrical insulation, and is widely used in automobiles, electronics, aerospace, and other fields. Glass fiber modified PPS, as one of the most common composite materials, typically has an injection molding temperature of 130~140℃. Standard temperature measuring machines cannot reach this temperature range. When injection molding at low mold temperatures (below 80℃), the rapidly solidifying glass fibers freeze upon contact with the mold wall. If they are not fully surrounded by the melt in time, they will be exposed and form loose fibers. Glass fiber precipitation leads to a rough surface and reduced appearance quality of the composite material. It may also affect the material's weather resistance and electrical properties, and even cause poor assembly or functional failure in precision parts applications. To address the issue of glass fiber precipitation, pigments and mineral components can be added to improve the appearance and processing performance of the material. However, traditional methods still have limitations in reducing glass fiber precipitation. For example, the quantitative addition of components such as carbon black and calcium sulfate can significantly improve the appearance and mechanical properties of composite materials. The disadvantage is that if the addition exceeds a certain range, the mechanical properties of PPS composite materials will decrease. In addition, some modification methods may introduce complex processes or increase costs, making it difficult to balance material performance and production efficiency.

[0003] Based on the above problems, a polyphenylene sulfide composite material with low glass fiber precipitation and its preparation method are proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a polyphenylene sulfide composite material with low glass fiber exudation and its preparation method, so as to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides a polyphenylene sulfide composite material with low glass fiber exudation, comprising the following components by weight: 10-60 parts polyphenylene sulfide, 10-50 parts glass fiber, 0-10 parts elastomer, 5-10 parts mineral, 0.1-5 parts coupling agent, and 0.1-5 parts pigment.

[0006] Preferably, the polyphenylene sulfide is commercially available general-purpose PPS.

[0007] Preferably, the glass fiber is 2-3 mm alkali-free chopped glass fiber.

[0008] Preferably, the elastomer is one or more of the following: polyolefin elastomer, styrene elastomer, polyurethane elastomer, polyester elastomer, polyamide elastomer, and ethylene copolymer elastomer.

[0009] Preferably, the mineral is one or more of silicates, borates, carbonates, phosphates, arsenates, vanadates, sulfates, hydroxides, oxides, sulfides, and halides.

[0010] Preferably, the coupling agent is a silane coupling agent or a boric acid-containing organic compound. The silane coupling agent is one or more of aminosilane coupling agents, carboxylsilane coupling agents, epoxysilane coupling agents, etc.; the boric acid-containing organic compound is one or more of phenylboronic acid, 1,4-phenyldiboronic acid, 4-vinylphenylboronic acid, tetraphenylboronic acid, etc.

[0011] Preferably, the pigment is one or more of the following: carbon black, aniline black, carbon black masterbatch, cinnabar, red clay, realgar, malachite green, wollastonite, barite powder, talc powder, mica powder, and kaolin.

[0012] The present invention also provides a method for preparing the above-mentioned polyphenylene sulfide composite material with low glass fiber precipitation, characterized by comprising the following steps: S1. Pre-dried polyphenylene sulfide, minerals, elastomers, coupling agents, and pigments are placed in a high-speed mixer in proportion and mixed to obtain a mixture; S2. The mixture is added to the main feed port of the twin-screw extruder, and the glass fiber is added to the side feed port of the twin-screw extruder for extrusion granulation to obtain the polyphenylene sulfide composite material. Preferably, in S1, the mixing temperature is 50~80℃ and the time is 5~30min.

[0013] Preferably, in step S2, the extrusion temperature is 160~340℃ and the screw speed is 100~400rpm.

[0014] Therefore, the polyphenylene sulfide composite material with low glass fiber exudation and its preparation method of the present invention have the following beneficial effects: (1) In this invention, short glass fibers with a length of 3 mm are selected. Compared with long glass fibers, short glass fibers are less likely to precipitate, which also helps to improve the fluidity of the product. At the same time, the high specific surface area of ​​short glass fibers can form a stable interface with PPS and coupling agent, making it difficult for glass fibers to precipitate on the surface of the composite material during injection molding, thus effectively reducing the phenomenon of glass fiber precipitation.

[0015] (2) Calcium carbonate and calcium sulfate are selected as minerals as additives. These mineral fillers can enhance the tensile strength, flexural modulus, and impact resistance of the composite material, as well as improve its thermal stability and heat resistance. On the other hand, the addition of minerals can also reduce the production cost of the composite material. For polyphenylene sulfide composites with low glass fiber precipitation, adding a certain amount of minerals can serve as a substitute for glass fiber, effectively reducing the precipitation phenomenon. In terms of low-temperature crystallization, the crystallization rate of calcium end groups is much higher than that of hydrogen or sodium end groups in PPS itself.

[0016] (3) Pigments can reduce the problem of product discoloration during processing and ensure the appearance of the product. Carbon black masterbatch is easier to disperse than carbon black, and low carbon black content can bring better composite material performance.

[0017] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0018] The technical solution of the present invention will be further described below through embodiments.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0020] Example 1 The raw materials in this embodiment include the following components by weight: 50 parts PPS-MAN015P, 40 parts glass fiber ECS10-03-584, 6 parts calcium sulfate, 1 part coupling agent OFS6040, 1 part carbon black masterbatch (the carbon black content in the carbon black masterbatch is 58%), and 2 parts elastomer BF-7M. The preparation steps are as follows: PPS was pre-dried at 140℃ for 2 hours, and then the materials were weighed according to the above weight ratio. After adding the coupling agent, the mixture was mixed at 60℃ for 2 minutes in a high-speed mixer. After adding the minerals, pigments and elastomers, the mixture was continued for 5 minutes.

[0021] The mixture was then co-extruded and granulated using a twin-screw extruder. The mixture was added to the feed inlet, and the glass fiber was added via side feeding. The extruder zone temperatures (from the feed inlet to the die) were set to 260℃, 310℃, 320℃, 320℃, 320℃, 315℃, 315℃, 310℃, 300℃, 300℃, and 320℃, respectively. The feed rate was 30 kg / h, and the extrusion screw speed was 300 rpm. The selected twin-screw extruder had a diameter of ϕ35 mm × 2 and an L / D ratio of 44.

[0022] Example 2 The preparation steps in this embodiment are the same as in Example 1, except that the raw materials are modified to include the following components by weight: 50 parts PPS-MAN015P, 40 parts glass fiber ECS10-03-584, 6 parts calcium sulfate, 1 part coupling agent OFS6040, 1 part carbon black, and 2 parts elastomer BF-7M.

[0023] Example 3 The raw materials used in this embodiment are the same as those in Embodiment 1, except that the extrusion screw speed is changed to 150 rpm.

[0024] Comparative Example 1 The preparation steps of this comparative example are the same as those of Example 1, except that the raw materials are modified to include the following components by weight: 50 parts PPS-MAN015P, 46 parts glass fiber ECS10-03-584, 1 part coupling agent OFS6040, 1 part carbon black masterbatch, and 2 parts elastomer BF-7M.

[0025] Comparative Example 2 The preparation steps of this comparative example are the same as those of Example 1, except that the raw materials are modified to include the following components by weight: 50 parts PPS-MAN015P, 46 parts glass fiber ECS10-03-584, 1 part coupling agent OFS6040, 1 part carbon black, and 2 parts elastomer BF-7M.

[0026] Comparative Example 3 The raw materials used in this comparative example are the same as those in Comparative Example 1, except that the extrusion screw speed is changed to 150 rpm.

[0027] The material granules obtained from Examples 1-3 and Comparative Examples 1-3 were added to an injection molding machine and molded into standard specimens for testing. Tensile strength and elongation were tested according to ISO 527 standard, flexural strength and flexural modulus were tested according to ISO 178 standard, and notched impact strength of simply supported beams was tested according to ISO 179 standard. The test results are shown in Table 1.

[0028] Table 1 Performance Indicators

[0029] As shown in Table 1, the low-glass fiber precipitation polyphenylene sulfide composite material prepared by the method provided by the present invention, compared with the same PPS, glass fiber, and glass fiber plus mineral ratios, shows a significant improvement in tensile strength, flexural strength, impact strength, and elongation at break after mineral substitution of some glass fibers, while maintaining a relatively stable flexural modulus. This indicates that the minerals in the formulation system can improve tensile strength, flexural strength, impact strength, and elongation at break while keeping the flexural modulus constant. This is because a lower screw speed results in less shearing of the glass fibers, allowing for the retention of longer glass fiber lengths and maximizing the preservation of the mechanical properties provided by chopped glass fibers.

[0030] In this invention, 2-3 mm alkali-free chopped glass fibers are used. The fibers have a moderate length and uniform surface activity. When combined with silane coupling agents or boric acid-containing organic compounds as coupling agents, they can form strong chemical bonds with PPS resin, effectively improving the interfacial bonding force between the glass fiber and the resin matrix, and fundamentally inhibiting the precipitation problem caused by interfacial peeling of the glass fiber during processing. The introduction of elastomers (such as polyolefin elastomers, styrene elastomers, etc.) can adjust the toughness and melt flow of composite materials, reduce glass fiber breakage caused by excessive shear stress during processing, and further reduce the risk of precipitation; mineral fillers (such as silicates, carbonates, etc.) are uniformly dispersed in the resin matrix to form a stable support structure, synergistically enhance interfacial stability, and improve the rigidity and dimensional stability of the material.

[0031] Therefore, the present invention provides a polyphenylene sulfide composite material with low glass fiber precipitation and its preparation method, which significantly solves the technical problem of glass fiber precipitation in traditional PPS composite materials through reasonable component design and process optimization.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A polyphenylene sulfide composite material with low glass fiber exudation, characterized in that, The following components are included in parts by weight: 10-60 parts polyphenylene sulfide, 10-50 parts glass fiber, 0-10 parts elastomer, 5-10 parts mineral, 0.1-5 parts coupling agent, and 0.1-5 parts pigment.

2. The polyphenylene sulfide composite material with low glass fiber exudation according to claim 1, characterized in that: The glass fiber is 2-3 mm alkali-free chopped glass fiber.

3. The polyphenylene sulfide composite material with low glass fiber exudation according to claim 1, characterized in that: The elastomer is one or more of the following: polyolefin elastomers, styrene elastomers, polyurethane elastomers, polyester elastomers, polyamide elastomers, and ethylene copolymer elastomers.

4. The polyphenylene sulfide composite material with low glass fiber exudation according to claim 1, characterized in that: The mineral is one or more of the following: silicate, borate, carbonate, phosphate, arsenate, vanadate, sulfate, hydroxide, oxide, sulfide, and halide.

5. The polyphenylene sulfide composite material with low glass fiber exudation according to claim 1, characterized in that: The coupling agent is a silane coupling agent or a boric acid-containing organic compound. The silane coupling agent is one or more of aminosilane coupling agents, carboxylsilane coupling agents, epoxysilane coupling agents, etc.; the boric acid-containing organic compound is one or more of phenylboronic acid, 1,4-phenyldiboronic acid, 4-vinylphenylboronic acid, tetraphenylboronic acid, etc.

6. The polyphenylene sulfide composite material with low glass fiber exudation according to claim 1, characterized in that: The pigment is one or more of the following: carbon black, aniline black, carbon black masterbatch, cinnabar, red clay, realgar, malachite green, wollastonite, barite powder, talc powder, mica powder, and kaolin.

7. A method for preparing a polyphenylene sulfide composite material with low glass fiber exudation as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Pre-dried polyphenylene sulfide, minerals, elastomers, coupling agents, and pigments are placed in a high-speed mixer in proportion and mixed to obtain a mixture; S2. Add the mixture to the main feed port of the twin-screw extruder, and add the glass fiber to the side feed port of the twin-screw extruder for extrusion granulation to obtain polyphenylene sulfide composite material.

8. The method for preparing the low glass fiber exudation polyphenylene sulfide composite material according to claim 7, characterized in that: In step S1, the mixing temperature is 50~80℃ and the time is 5~30min.

9. The method for preparing the low glass fiber exudation polyphenylene sulfide composite material according to claim 8, characterized in that: In S2, the extrusion temperature is 160~340℃ and the screw speed is 100~400rpm.

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