A polyphenylene sulfide composite pipe and a preparation method and application thereof

Abstract

This invention provides a polyphenylene sulfide (PPS) composite pipe and its preparation method. The PPS composite pipe comprises, from the inside out: a barrier-modified PPS layer, a reinforcement-modified PPS layer, and a toughening-modified PPS layer. The barrier-modified PPS layer is a PPS layer containing a barrier agent, the reinforcement-modified PPS layer is a PPS layer containing a reinforcement agent, and the toughening-modified PPS layer is a PPS layer containing a toughening agent. The PPS composite pipe of this invention features high toughness, high barrier performance, and high strength, meeting the comprehensive requirements of high-temperature oil and gas production and transportation for high temperature resistance, high barrier properties, and high strength.

Description

Technical Field

[0001] This invention belongs to the field of petroleum pipe technology, specifically relating to a polyphenylene sulfide composite pipe, its preparation method, and its application. Background Technology

[0002] With the continuous development of deep / ultra-deep oil and gas resources, petroleum engineering equipment faces harsh operating conditions such as high temperature and high pressure. Future wells reaching depths of 15,000 meters will face extreme conditions including 280℃~310℃ and 190MPa~220MPa. Non-metallic materials, due to their excellent corrosion resistance, are widely used in oil and gas field drilling and production equipment, logging instruments, and oil pipes, serving as key basic materials for petroleum engineering equipment. Currently, the temperature resistance, pressure resistance, and barrier properties of commonly used non-metallic materials such as fiberglass, fluororubber, polytetrafluoroethylene, and polyethylene cannot meet the application requirements of deep / ultra-deep oil and gas resource exploration and development. Therefore, research on high-temperature resistant, high-barrier choke manifold materials and pipes is urgently needed to address the application requirements of non-metallic wellheads in deep oil and gas production.

[0003] Currently, for the application requirements of high-barrier, high-temperature resistant, and high-strength non-metallic pipes in high-temperature gas production and transportation fields, the common practice is to select polymer materials with good gas barrier properties as inner linings, such as polyvinylidene fluoride (PVDF) and nylon (PA). However, the overall performance of the above-mentioned special high-performance materials is still insufficient, and the raw materials are all dependent on imports, resulting in high prices and low cost-effectiveness. Polyphenylene sulfide (PPS) has excellent high-temperature resistance and corrosion resistance, and the raw materials have now been domestically produced at a price of 60,000 to 80,000 yuan / ton, about half the price of imported materials, and it is widely used in the electronics, automotive, machinery, and chemical industries. However, the strength and barrier properties of existing PPS pipes still cannot meet the actual needs of oil and gas fields. Summary of the Invention

[0004] To further improve the strength and barrier properties of polyphenylene sulfide (PPS) pipes, the present invention aims to provide a PPS composite pipe and its preparation method, thereby addressing the shortcomings of currently used PPS pipes in terms of strength and barrier properties.

[0005] This invention is achieved through the following technical solution: This invention provides a polyphenylene sulfide composite pipe, which comprises, from the inside out: a barrier-modified PPS layer, a reinforcement-modified PPS layer, and a toughening-modified PPS layer; the barrier-modified PPS layer is a polyphenylene sulfide layer containing a barrier agent, the reinforcement-modified PPS layer is a polyphenylene sulfide layer containing a reinforcement agent, and the toughening-modified PPS layer is a polyphenylene sulfide layer containing a toughening agent.

[0006] Preferably, the barrier agent is graphene oxide.

[0007] Preferably, the components of the barrier-modified PPS layer, by weight, include: 60-100 parts of polyphenylene sulfide, 5-15 parts of barrier agent, and 0.01-0.2 parts of antioxidant.

[0008] Preferably, the reinforcing agent is chopped carbon fiber.

[0009] Preferably, the components of the reinforced modified PPS layer, by weight, include: 60-100 parts of polyphenylene sulfide, 5-15 parts of reinforcing agent, and 0.01-0.2 parts of antioxidant.

[0010] Preferably, the toughening agent is an epoxy-functionalized bio-based furfuryl elastomer.

[0011] Preferably, the toughened modified PPS layer comprises, by weight parts: 60-100 parts of polyphenylene sulfide, 10-40 parts of toughening agent, 0.01-0.2 parts of antioxidant, and 2-5 parts of carbon black masterbatch.

[0012] Furthermore, by mass percentage, the carbon black masterbatch comprises: 40%~45% carbon black, 50% inorganic filler, and 5%~10% resin carrier, wherein the inorganic filler is calcium carbonate and the resin carrier is linear polyphenylene sulfide resin with a weight average molecular weight of 10,000~30,000.

[0013] The present invention also provides a method for preparing the polyphenylene sulfide composite pipe, comprising: S1, respectively prepare barrier modified PPS premix, reinforced modified PPS premix and toughened modified PPS premix; S2, the barrier modified PPS premix, the reinforced modified PPS premix and the toughened modified PPS premix are plasticized and melt-blended respectively to obtain barrier modified PPS melt, reinforced modified PPS melt and toughened modified PPS melt respectively. S3 uses multi-layer co-extrusion molding technology to form high-barrier, high-strength polyphenylene sulfide composite pipes by combining barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt.

[0014] The present invention also provides the application of the polyphenylene sulfide composite pipe in the oil and gas field.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The polyphenylene sulfide composite pipe of the present invention consists of three layers from the inside out, with each layer having polyphenylene sulfide as the matrix, ensuring that the polyphenylene sulfide composite pipe has high temperature resistance. Secondly, the innermost layer is modified with a barrier agent, the middle layer is modified with a reinforcing agent, and the outermost layer is modified with a toughening agent. The three work together to give the polyphenylene sulfide composite pipe high toughness, high barrier performance, and high strength, meeting the comprehensive requirements of high temperature oil and gas production and transportation for high temperature resistance, high barrier performance, and high strength.

[0016] This invention relates to polyphenylene sulfide (PPS) composite pipes, which can be manufactured using multi-layer co-extrusion molding technology. This technology achieves multifunctional modification and integrated molding of PPS resin, producing non-metallic pipes with high temperature resistance, high barrier properties, and high strength. These pipes can be mass-produced using existing thermoplastic pipe production lines. This promotes the widespread application of non-metallic pipes in high-temperature (80℃~130℃) oil and gas production and transportation in oil and gas fields. Detailed Implementation

[0017] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0018] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0019] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not intended to limit the order of the method steps or define the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0020] The high-barrier, high-strength polyphenylene sulfide composite pipe of the present invention comprises, from the inside out: a barrier-modified PPS layer, a reinforcing modified PPS layer, and a toughening modified PPS layer; the barrier-modified PPS layer is a polyphenylene sulfide layer containing a barrier agent, the reinforcing modified PPS layer is a polyphenylene sulfide layer containing a reinforcing agent, and the toughening modified PPS layer is a polyphenylene sulfide layer containing a toughening agent.

[0021] In some preferred embodiments of the present invention, the matrix of the polyphenylene sulfide layer is a high molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 50,000 to 70,000.

[0022] In some preferred embodiments of the present invention, the barrier agent is graphene oxide, which is a single layer or few layers of graphene oxide with fewer than 5 layers and a diameter of 10-50 μm. The nanosheet-like graphene oxide is uniformly dispersed in the polyphenylene sulfide matrix, and its barrier properties can be improved based on the reduced permeation area and multi-path effect.

[0023] Specifically, by weight, the components of the barrier-modified PPS layer preferably include: 60-100 parts of polyphenylene sulfide, 5-15 parts of barrier agent, and 0.01-0.2 parts of antioxidant.

[0024] In some preferred embodiments of the present invention, the reinforcing agent is chopped carbon fiber with a length of 0.2~0.5mm and a surface activated.

[0025] Specifically, by weight, the components of the reinforced modified PPS layer include: 60-100 parts of polyphenylene sulfide, 5-15 parts of reinforcing agent, and 0.01-0.2 parts of antioxidant.

[0026] In some preferred embodiments of the present invention, the toughening agent is an epoxy-functionalized bio-based furfuryl elastomer. The epoxy functional groups can react with polyphenylene sulfide (PPS), enabling the toughening agent to chemically bond with the PPS backbone, thereby improving both the uniformity of dispersion and the stability of the toughening agent in the PPS matrix.

[0027] Specifically, by weight, the toughened modified PPS layer comprises: 60-100 parts of polyphenylene sulfide, 10-40 parts of toughening agent, 0.01-0.2 parts of antioxidant, and 2-5 parts of carbon black masterbatch.

[0028] The carbon black masterbatch comprises, by weight percentage: 40%–45% carbon black, 50% inorganic filler, and 5%–10% resin carrier. The inorganic filler is calcium carbonate, and the resin carrier is low molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 10,000–30,000. The carbon black masterbatch can significantly improve the anti-aging properties and wear resistance of pipes, extending their service life.

[0029] In each layer of this invention, the antioxidant is composed of a primary antioxidant and a secondary antioxidant, wherein the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(0.5~5). The primary antioxidant is preferably antioxidant 1010, and the secondary antioxidant is preferably antioxidant 168. The primary antioxidant is a chain-terminating antioxidant, meaning it can terminate the propagation and growth of free radical chains during oxidation; the secondary antioxidant is a preventative antioxidant, meaning it can prevent or delay the generation of free radicals during the oxidative degradation of polymer materials.

[0030] The polyphenylene sulfide (PPS) composite pipe of the present invention consists of three PPS layers. The outermost toughening modified PPS layer uses a toughening agent to toughen and modify the PPS. The middle reinforcing modified PPS layer uses a reinforcing agent to reinforce and modify the PPS. The innermost barrier modified PPS layer uses a barrier agent to modify the PPS. Ultimately, the PPS pipe is toughened, reinforced, and modified to provide barrier protection. This results in the PPS composite pipe having high toughness, high barrier properties, and high strength, meeting the comprehensive requirements of high-temperature oil and gas production and transportation for high temperature resistance, high barrier properties, and high strength.

[0031] The high-barrier, high-strength polyphenylene sulfide composite pipe of the present invention is prepared by multi-layer co-extrusion molding technology, and the specific preparation method includes: S1, respectively prepare barrier modified PPS premix, reinforced modified PPS premix and toughened modified PPS premix; S2, the barrier modified PPS premix, the reinforced modified PPS premix and the toughened modified PPS premix are plasticized and melt-blended respectively to obtain barrier modified PPS melt, reinforced modified PPS melt and toughened modified PPS melt respectively. S3 uses multi-layer co-extrusion molding technology to form high-barrier, high-strength polyphenylene sulfide composite pipes by combining barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt.

[0032] In some preferred embodiments of the present invention, the barrier-modified PPS premix comprises, by weight parts: 60-100 parts of polyphenylene sulfide, 5-15 parts of a barrier agent, and 0.01-0.2 parts of an antioxidant. The polyphenylene sulfide is a high molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 50,000-70,000. The barrier agent is graphene oxide, which is a single-layer or few-layer graphene oxide with fewer than 5 layers and a diameter of 10-50 μm. The antioxidant consists of a primary antioxidant and a secondary antioxidant, wherein the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(0.5-5). The primary antioxidant is preferably antioxidant 1010, and the secondary antioxidant is preferably antioxidant 168.

[0033] In some preferred embodiments of the present invention, the reinforced modified PPS premix comprises, by weight parts: 60-100 parts of polyphenylene sulfide, 5-15 parts of reinforcing agent, and 0.01-0.2 parts of antioxidant. The polyphenylene sulfide is a high molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 50,000-70,000. The reinforcing agent is preferably chopped carbon fiber with a length of 0.2-0.5 mm and a surface activated. The antioxidant consists of a primary antioxidant and a secondary antioxidant, wherein the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(0.5-5). The primary antioxidant is preferably antioxidant 1010, and the secondary antioxidant is preferably antioxidant 168.

[0034] In some preferred embodiments of the present invention, the toughened modified PPS premix comprises, by weight parts: 60-100 parts of polyphenylene sulfide, 10-40 parts of toughening agent, 0.01-0.2 parts of antioxidant, and 2-5 parts of carbon black masterbatch. The polyphenylene sulfide is preferably a high molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 50,000-70,000. The toughening agent is preferably an epoxy-functionalized bio-based tannin elastomer, i.e., a product obtained by copolymerizing tannin ester, butadiene, and an olefin containing epoxy functional groups, which is a commercially available product; wherein the Mooney viscosity is 40±5 ML (1+4) 100℃, and the bio-based tannin elastomer contains not less than 50% tannin ester by weight and not less than 2% olefin monomer containing epoxy functional groups by weight. The antioxidant consists of a primary antioxidant and a secondary antioxidant, wherein the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(0.5~5). The primary antioxidant is preferably antioxidant 1010, and the secondary antioxidant is preferably antioxidant 168. The carbon black masterbatch contains 40%~45% carbon black, 50% inorganic filler, and 5%~10% resin carrier. The inorganic filler is calcium carbonate with a fineness of 1000 mesh, and the resin carrier is low molecular weight linear polyphenylene sulfide resin with a weight-average molecular weight of 10,000~30,000.

[0035] In the specific implementation process, the preparation methods of the barrier modified PPS premix, the reinforced modified PPS premix, and the toughened modified PPS premix are as follows: according to the raw material ratio, each raw material is premixed in a high-speed mixer with a speed of not less than 400 r / min and a mixing time of not less than 30 min, to obtain toughened modified PPS premix, reinforced modified PPS premix, and barrier modified PPS premix respectively; the three premixes are dried at a temperature of 120~130℃ for 3~5 h.

[0036] In specific implementation, S2 of the present invention is as follows: the three premixed materials are plasticized and melt-blended using three conical counter-rotating twin-screw extruders respectively. The temperatures of the six-stage extruder barrel and extruder head are set in stages to 155~160℃, 240~260℃, 290~310℃, 290~310℃, 290~310℃ and 300~310℃, the screw speed is 20~30 r / min, and the extrusion pressure is 3~7 MPa.

[0037] In specific implementation, S3 of the present invention is as follows: barrier modified PPS melt, reinforcement modified PPS melt, and toughening modified PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside to the outside, they are barrier modified PPS melt, reinforcement modified PPS melt, and toughening modified PPS melt. During the forming process in the die head, the interfaces between the three structural layer melts are fused together to form a three-layer composite pipe. After extrusion, the three-layer composite pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing chamber, where the pipe is sizing using a sizing sleeve and then cooled with a cooling medium at a temperature of 240~260℃. The second stage is in a spray chamber, where the pipe is cooled with a cooling medium at a temperature of 150~200℃. The third stage is in a spray chamber, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain high-barrier, high-strength polyphenylene sulfide composite pipe.

[0038] The following are specific embodiments of the present invention.

[0039] Example 1 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix According to the mass fraction, 60 parts of linear polyphenylene sulfide with a weight average molecular weight of 50,000, 5 parts of graphene oxide (average particle size of 10 μm), and 0.01 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were added to a high-speed mixer for premixing. The high-speed mixer speed was 400 r / min and the mixing time was 30 min. Then, it was dried at 120℃ for 3 h to obtain barrier modified PPS premix.

[0040] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 60 parts of linear polyphenylene sulfide with a weight average molecular weight of 50,000, 5 parts of 0.2 mm short-cut carbon fiber, and 0.01 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were added to a high-speed mixer for premixing at a speed of 400 r / min for 30 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0041] (3) Preparation of toughened modified PPS premix According to the mass percentages, 60 parts of linear polyphenylene sulfide with a weight average molecular weight of 50,000, 10 parts of epoxy-functionalized bio-based caprylate elastomer, 0.01 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1), and 2 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 400 r / min for 30 min, and then dried at 120℃ for 3 h to obtain toughened modified PPS premix. The carbon black masterbatch consisted of 40% carbon black, 50% calcium carbonate, and 10% linear polyphenylene sulfide resin with a weight average molecular weight of 10,000.

[0042] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0043] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0044] Example 2 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 70 parts of linear polyphenylene sulfide with a weight average molecular weight of 60,000, 7 parts of graphene oxide (average particle size 15 μm), and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing. The high-speed mixer speed was 600 r / min, and the mixing time was 60 min. Then, the mixture was dried at 120℃ for 3 h to obtain barrier modified PPS premix.

[0045] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 70 parts of linear polyphenylene sulfide with a weight average molecular weight of 60,000, 7 parts of 0.3 mm short-cut carbon fibers, and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 600 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0046] (3) Preparation of toughened modified PPS premix Based on mass parts, 70 parts of linear polyphenylene sulfide with a weight average molecular weight of 60,000, 15 parts of epoxy-functionalized bio-based caprylate elastomer, 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5), and 3 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 600 r / min for 60 min, followed by drying at 120℃ for 3 h to obtain toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0047] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0048] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0049] Example 3 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 9 parts of graphene oxide (average particle size of 20 μm), and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain barrier-modified PPS premix.

[0050] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 9 parts of 0.4 mm short-cut carbon fiber, and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0051] (3) Preparation of toughened modified PPS premix Based on mass parts, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 25 parts of epoxy-functionalized bio-based caprylate elastomer, 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5), and 4 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0052] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0053] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0054] Example 4 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 90 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 12 parts of graphene oxide (average particle size of 30 μm), and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2) were added to a high-speed mixer for premixing. The high-speed mixer speed was 1000 r / min, and the mixing time was 60 min. Then, the mixture was dried at 120℃ for 3 h to obtain barrier modified PPS premix.

[0055] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 90 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 12 parts of 0.4 mm short-cut carbon fiber, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2) were added to a high-speed mixer for premixing at a speed of 1000 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0056] (3) Preparation of toughened modified PPS premix Based on mass parts, 90 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 35 parts of epoxy-functionalized bio-based caprylate elastomer, 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2), and 5 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 1000 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0057] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0058] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0059] Example 5 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 100 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 15 parts of graphene oxide (average particle size of 50 μm), and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:5) were added to a high-speed mixer for premixing. The high-speed mixer speed was 1200 r / min, and the mixing time was 60 min. Then, the mixture was dried at 120℃ for 3 h to obtain barrier modified PPS premix.

[0060] (2) Preparation of reinforced modified PPS premix Based on mass parts, take 100 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 15 parts of 0.5 mm short-cut carbon fiber, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:5), add them to a high-speed mixer for premixing at a speed of 1200 r / min for 60 min, and then dry at 120℃ for 3 h to obtain reinforced modified PPS premix.

[0061] (3) Preparation of toughened modified PPS premix Based on mass parts, 100 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 40 parts of epoxy-functionalized bio-based caprylate elastomer, 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:5), and 4 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 1200 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 30,000.

[0062] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0063] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0064] Example 6 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 5 parts of graphene oxide (average particle size of 20 μm), and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain barrier-modified PPS premix.

[0065] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 5 parts of 0.4 mm short-cut carbon fiber, and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0066] (3) Preparation of toughened modified PPS premix Based on mass parts, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 10 parts of epoxy-functionalized bio-based caprylate elastomer, 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5), and 4 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0067] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0068] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0069] Example 7 The high-barrier, high-strength polyphenylene sulfide composite pipe of this embodiment is prepared by the following steps: Step 1, Prepare the premix (1) Preparation of barrier-modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 15 parts of graphene oxide (average particle size of 20 μm), and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain barrier-modified PPS premix.

[0070] (2) Preparation of reinforced modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 15 parts of 0.4 mm short-cut carbon fiber, and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0071] (3) Preparation of toughened modified PPS premix Based on mass parts, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 40 parts of epoxy-functionalized bio-based caprylate elastomer, 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5), and 4 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0072] Step 2, melt blending Barrier-modified PPS premix, reinforced PPS premix, and toughened PPS premix were plasticized and melt-blended using three conical counter-rotating twin-screw extruders. The barrel and extruder temperatures of the six extruder sections were set at 160℃, 240℃, 290℃, 300℃, 310℃, and 310℃, respectively. The screw speed was 2 r / min, and the extrusion pressure was 3 MPa, resulting in barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively.

[0073] Step 3, multi-layer co-extrusion molding Barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt are injected into a three-layer co-extrusion die head for pipe forming. From the inside out, the layers are barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt, respectively, and then extruded. After extrusion, the pipe undergoes three stages of temperature-controlled gradient cooling. The first stage is in a vacuum sizing box, where the pipe is sized using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray box, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray box, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a high-barrier, high-strength polyphenylene sulfide composite pipe.

[0074] Comparative Example 1: Pure Polyphenylene Sulfide Pipe The polyphenylene sulfide pipe of this comparative example is prepared by the following steps: Step 1, Prepare PPS premix Based on mass fractions, take 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000 and 0.1 parts of antioxidant (the mass ratio of antioxidant 1010 and antioxidant 168 is 1:0.5), add them to a high-speed mixer for premixing at a speed of 800 r / min for 60 min, and then dry at 120℃ for 3 h to obtain PPS premix.

[0075] Step 2, melt blending PPS premix was plasticized and melt-blended using a conical counter-rotating twin-screw extruder. The temperatures of the six-stage extruder barrel and extruder head were set to 160℃, 240℃, 290℃, 300℃, 310℃ and 310℃ respectively. The screw speed was 2r / min and the extrusion pressure was 3MPa, which yielded PPS melt.

[0076] Step 3, Extrusion molding PPS melt is injected into an extruder head for pipe forming and extruded. After extrusion, it undergoes three-stage temperature-controlled gradient cooling. The first stage is in a vacuum sizing chamber, where the pipe is sizing using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray chamber, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray chamber, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain polyphenylene sulfide pipe.

[0077] Comparative Example 2: Composite pipes made of polyphenylene sulfide and carbon fiber The composite pipe of polyphenylene sulfide and carbon fiber in this comparative example is prepared by the following steps: Step 1, Prepare reinforced modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 9 parts of 0.4 mm short-cut carbon fiber, and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the reinforced modified PPS premix.

[0078] Step 2, melt blending The reinforced modified PPS premix was plasticized and melt-blended using a conical counter-rotating twin-screw extruder. The extruder barrel temperature and extruder head temperature were set in stages to 160℃, 240℃, 290℃, 300℃, 310℃ and 310℃, the screw speed was 2 r / min and the extrusion pressure was 3 MPa, to obtain the reinforced modified PPS melt.

[0079] Step 3, Extrusion molding The enhanced modified PPS melt is injected into an extruder head for pipe forming and extruded. After extrusion, it undergoes three-stage temperature-controlled gradient cooling. The first stage is in a vacuum sizing chamber, where the pipe is sizing using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray chamber, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray chamber, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain a composite pipe of polyphenylene sulfide and carbon fiber.

[0080] Comparative Example 3: Composite pipe of polyphenylene sulfide and graphene oxide The composite pipe of polyphenylene sulfide and graphene oxide in this comparative example is prepared by the following steps: Step 1, Prepare barrier-modified PPS premix Based on mass fractions, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 9 parts of graphene oxide (average particle size of 20 μm), and 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5) were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain barrier-modified PPS premix.

[0081] Step 2, melt blending The barrier-modified PPS premix was plasticized and melt-blended using a conical counter-rotating twin-screw extruder. The barrel and extruder head temperatures of the six extruder sections were set to 160℃, 240℃, 290℃, 300℃, 310℃ and 310℃ in stages, the screw speed was 2 r / min and the extrusion pressure was 3 MPa, and barrier-modified PPS melt was obtained respectively.

[0082] Step 3, Extrusion molding The barrier-modified PPS melt is injected into an extruder head for pipe forming and extruded. After extrusion, it undergoes three-stage temperature-controlled gradient cooling. The first stage is in a vacuum sizing chamber, where the pipe is sizing using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray chamber, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray chamber, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain polyphenylene sulfide composite pipe.

[0083] Comparative Example 4: Composite pipes made of polyphenylene sulfide and elastomer The composite pipe of polyphenylene sulfide and elastomer in this comparative example is prepared by the following steps: Step 1: Prepare toughened modified PPS premix Based on mass parts, 80 parts of linear polyphenylene sulfide with a weight average molecular weight of 70,000, 25 parts of epoxy-functionalized bio-based caprylate elastomer, 0.1 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:0.5), and 4 parts of carbon black masterbatch were added to a high-speed mixer for premixing at a speed of 800 r / min for 60 min. The mixture was then dried at 120℃ for 3 h to obtain the toughened modified PPS premix. The carbon black masterbatch consisted of 45% carbon black, 50% calcium carbonate, and 5% linear polyphenylene sulfide resin with a weight average molecular weight of 20,000.

[0084] Step 2, melt blending The toughened modified PPS premix was plasticized and melt-blended using a conical counter-rotating twin-screw extruder. The temperatures of the six-stage extruder barrel and extruder head were set to 160℃, 240℃, 290℃, 300℃, 310℃ and 310℃ respectively. The screw speed was 2r / min and the extrusion pressure was 3MPa, which yielded toughened modified PPS melt.

[0085] Step 3, Extrusion molding Toughened modified PPS melt is injected into an extruder head for pipe forming and extruded. After extrusion, it undergoes three-stage temperature-controlled gradient cooling. The first stage is in a vacuum sizing chamber, where the pipe is sizing using a sizing sleeve and then cooled with a cooling medium at 240°C. The second stage is in a spray chamber, where the pipe is cooled with a cooling medium at 150°C. The third stage is in a spray chamber, where the pipe is cooled with room temperature water. The pipe, cooled to room temperature, is then cut to a fixed length to obtain polyphenylene sulfide composite pipe.

[0086] Mechanical properties and barrier properties were tested on Examples 1-7 and Comparative Examples 1-4. The test results are shown in Table 1.

[0087]

[0088] As shown in Table 1, the polyphenylene sulfide composite pipes prepared in the various embodiments of the present invention possess high strength, high barrier properties, and high toughness. Comparative Example 1 prepared a pure polyphenylene sulfide pipe, which, compared to Example 3, had lower yield strength and elongation at break, but a very high nitrogen permeability coefficient. Comparative Example 2 was a composite pipe of polyphenylene sulfide and reinforcing agent chopped carbon fibers. It can be seen that the yield strength of the composite pipe of Comparative Example 2 was significantly improved compared to Comparative Example 1, indicating that introducing chopped carbon fibers into the polyphenylene sulfide pipe can significantly improve the yield strength of the pipe. Comparative Example 3 was a composite pipe of polyphenylene sulfide and graphene oxide. It can be seen that the nitrogen permeability coefficient of the composite pipe of Comparative Example 3 was significantly reduced compared to Comparative Example 1, indicating that the introduction of graphene oxide can improve the barrier properties of the polyphenylene sulfide pipe. Comparative Example 4 is a composite pipe made of polyphenylene sulfide and bio-based tannin elastomer. It can be seen that the elongation at break of the composite pipe in Comparative Example 4 is much higher than that in Comparative Example 1, indicating that the introduction of bio-based tannin elastomer can greatly improve the toughness of polyphenylene sulfide pipe.

[0089] Furthermore, it can be noted that although the yield strength of the polyphenylene sulfide (PPS) pipe increased after the introduction of chopped carbon fibers in Comparative Example 2, the elongation at break and nitrogen permeability coefficient deteriorated. Similarly, it can be observed that while the barrier properties of the pipe improved after the introduction of graphene oxide in Comparative Example 3, the toughness significantly decreased. Comparative Example 4, while improving the barrier properties of the pipe, also had a certain impact on its toughness and strength. This indicates that introducing reinforcing agents, barrier agents, and toughening agents alone cannot yield PPS composite pipes with excellent overall performance. This invention introduces reinforcing agents, barrier agents, and toughening agents simultaneously into PPS pipes, forming a three-layer composite pipe structure. The synergistic effect among the three overcomes the negative effects of introducing only one substance, thus obtaining a PPS composite pipe with excellent overall performance.

Claims

1. A polyphenylene sulfide composite pipe, characterized in that, The polyphenylene sulfide composite pipe comprises, from the inside out: a barrier-modified PPS layer, a reinforcement-modified PPS layer, and a toughening-modified PPS layer; the barrier-modified PPS layer is a polyphenylene sulfide layer containing a barrier agent, the reinforcement-modified PPS layer is a polyphenylene sulfide layer containing a reinforcement agent, and the toughening-modified PPS layer is a polyphenylene sulfide layer containing a toughening agent.

2. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The barrier agent is graphene oxide.

3. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The components of the barrier-modified PPS layer, by weight, include: 60-100 parts of polyphenylene sulfide, 5-15 parts of barrier agent, and 0.01-0.2 parts of antioxidant.

4. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The reinforcing agent is short-cut carbon fiber.

5. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The components of the reinforced modified PPS layer, by weight, include: 60-100 parts of polyphenylene sulfide, 5-15 parts of reinforcing agent, and 0.01-0.2 parts of antioxidant.

6. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The toughening agent is an epoxy-functionalized bio-based furfuryl elastomer.

7. The polyphenylene sulfide composite pipe according to claim 1, characterized in that, The toughened modified PPS layer comprises, by weight, 60-100 parts of polyphenylene sulfide, 10-40 parts of toughening agent, 0.01-0.2 parts of antioxidant, and 2-5 parts of carbon black masterbatch.

8. The polyphenylene sulfide composite pipe according to claim 7, characterized in that, The carbon black masterbatch comprises, by weight percentage: 40% to 45% carbon black, 50% inorganic filler, and 5% to 10% resin carrier, wherein the inorganic filler is calcium carbonate and the resin carrier is linear polyphenylene sulfide resin with a weight average molecular weight of 10,000 to 30,000.

9. The method for preparing the polyphenylene sulfide composite pipe according to any one of claims 1 to 8, characterized in that, include: S1, respectively prepare barrier modified PPS premix, reinforced modified PPS premix and toughened modified PPS premix; S2, the barrier modified PPS premix, the reinforced modified PPS premix and the toughened modified PPS premix are plasticized and melt-blended respectively to obtain barrier modified PPS melt, reinforced modified PPS melt and toughened modified PPS melt respectively. S3 uses multi-layer co-extrusion molding technology to form high-barrier, high-strength polyphenylene sulfide composite pipes by combining barrier-modified PPS melt, reinforced PPS melt, and toughened PPS melt.

10. The application of the polyphenylene sulfide composite pipe according to any one of claims 1 to 8 in the oil and gas field.

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