A special resin for modified ultra-high molecular weight polyethylene lined oil pipe and its preparation method

Abstract

The present invention belongs to the technical field of ultra-high molecular weight polyethylene modification, and specifically relates to a modified ultra-high molecular weight polyethylene lined oil pipe special resin and a preparation method thereof. The modified ultra-high molecular weight polyethylene lined oil pipe special resin is made of the following raw materials in parts by mass: 65-80 parts of ultra-high molecular weight polyethylene, 5-10 parts of high-density polyethylene, 8-12 parts of modified polyaryletherketone, 4-7 parts of modified hyperbranched polyester, 0.3-2 parts of silicone masterbatch, and 0.1-0.5 parts of antioxidant. The lined oil pipe prepared by the modified ultra-high molecular weight polyethylene lined oil pipe special resin of the present invention has excellent wear resistance and high temperature resistance, and also has good mechanical properties such as tensile strength and impact strength.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-high molecular weight polyethylene modification, and in particular relates to a special resin for modified ultra-high molecular weight polyethylene lined oil pipe and a preparation method thereof. Background Art

[0002] Ultra-high molecular weight polyethylene exhibits the advantages of high strength, high wear resistance, excellent chemical corrosion resistance and good self-lubrication due to its extremely high molecular weight and highly entangled molecular structure. The oil pipes currently used in oil fields are generally lined with ultra-high molecular weight polyethylene pipes in ordinary oil pipes to reduce the wear between the sucker rod and the oil pipe and the corrosion of the inner wall of the oil pipe.

[0003] The disadvantages of ultra-high molecular weight polyethylene such as high difficulty in melt extrusion processing, low surface hardness and poor heat resistance make it unable to meet the specific requirements of the working environment. At present, the modification research on the performance defects of ultra-high molecular weight polyethylene mainly focuses on improving its wear resistance, etc., and there are few modification studies on its defects such as high temperature resistance.

[0004] The Chinese patent application document with publication number CN114409987A discloses a high-temperature resistant ultra-high molecular weight polyethylene composite pipe and a preparation method thereof. The high-temperature resistant ultra-high molecular weight polyethylene comprises: ultra-high molecular weight polyethylene with a mass fraction of 1.5% to 8%, high-density polyethylene with a mass fraction of 1.5% to 8%, maleic anhydride grafted polyethylene with a mass fraction of 1.5% to 8%, high-temperature resistant material with a mass fraction of 10% to 30%, lubricant with a mass fraction of 1% to 10%, and filler with a mass fraction of 5% to 20%, wherein the high-temperature resistant material is at least one of diatomaceous earth and talcum powder; the problem of low thermal deformation temperature of ultra-high molecular weight polyethylene composite pipe is solved, and the heat resistance of ultra-high molecular weight polyethylene is improved.

[0005] However, too much filler and high-temperature resistant materials such as diatomaceous earth and talcum powder are added to the composite pipe to improve its high-temperature resistance. The addition of too much filler will affect the performance of the material, and more inorganic fillers will seep out during long-term use, shortening its service life. Summary of the invention

[0006] The existing special resin for oil pipe lining has the problem of weak high temperature resistance. In order to solve this problem, the present invention provides a modified ultra-high molecular weight polyethylene special resin for oil pipe lining and a preparation method thereof.

[0007] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a modified ultra-high molecular weight polyethylene lined oil pipe special resin, which is made of the following raw materials in parts by weight:

[0009] 65-80 parts of ultra-high molecular weight polyethylene, 5-10 parts of high-density polyethylene, 8-12 parts of modified polyaryletherketone, 4-7 parts of modified hyperbranched polyester, 0.3-2 parts of silicone masterbatch, and 0.1-0.5 parts of antioxidant.

[0010] Preferably, the preparation method of the modified polyaryletherketone comprises the following steps:

[0011] (1) Under the protection of inert gas, [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 4,4'-(1,4-phenylenediisopropyl)diphenol, 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and potassium carbonate are uniformly mixed, N,N-dimethylformamide and a water-carrying agent are added, the temperature is raised to carry out reflux reaction, and after the water and the water-carrying agent are evaporated, the temperature is continued to be raised to carry out polymerization reaction to obtain a polymer;

[0012] (2) The polymer is washed by boiling in water, dried, added to diphenyl sulfone and mixed evenly, precipitated in anhydrous ethanol, filtered and dried to obtain modified polyaryletherketone.

[0013] The reaction formula of the modified polyaryletherketone is as follows:

[0014]

[0015] By adopting the above technical scheme, the two phenolic hydroxyl groups contained in 4,4'-(1,4-phenylene diisopropylidene)diphenol undergo a nucleophilic substitution reaction with the fluorine atom in [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone; the thiophene ring, benzene ring and other groups in 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene have a certain conjugated structure, and introducing them into the molecular main chain of the modified polyaryletherketone can slow down the thermal vibration of the polyaryletherketone molecules at high temperatures and the movement of the molecular chain, thereby improving the rigidity and high temperature stability of the molecular chain; the polyhydroxy structure of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene can also form crosslinking points with the molecular chain of the modified polyaryletherketone, thereby improving the mechanical properties of the material.

[0016] Preferably, in step (1), the molar ratio of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 4,4'-(1,4-phenylenediisopropylidene)diphenol and 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene is 1:(0.5-2):(0.3-0.6).

[0017] Preferably, in step (1), the molar ratio of potassium carbonate to 4,4'-(1,4-phenylenediisopropylidene)diphenol is (3.2-3.5):1.

[0018] By adopting the above technical scheme, the reaction rate is moderate under this ratio; when the amount of potassium carbonate used is small, the reaction rate is slow, which easily makes the molecular weight distribution of the generated modified polyaryletherketone uneven; excessive potassium carbonate may make the reaction difficult to control and affect the mechanical properties of the modified polyaryletherketone.

[0019] Preferably, in step (1), the temperature of the reflux reaction is 120-150° C., and the time of the reflux reaction is 2-4 h; the temperature of the polymerization reaction is 160-180° C., and the time of the polymerization reaction is 8-10 h.

[0020] Preferably, in step (1), the water-carrying agent is selected from toluene and xylene.

[0021] Preferably, in step (1), the amount of N,N-dimethylformamide used is such that the solid content of the reaction system is 10%-15%.

[0022] Preferably, the preparation method of the modified hyperbranched polyester comprises the following steps:

[0023] Tannic acid, terminal hydroxyl hyperbranched polyester and acetone are mixed at 40-50° C. for 2-5 hours, acetone is removed by rotary evaporation, and the modified hyperbranched polyester is obtained by drying.

[0024] By adopting the above technical scheme, the direct mixing compatibility of ultra-high molecular weight polyethylene and modified polyaryletherketone is poor, and the modified hyperbranched polyester can improve the compatibility between the two. The phenolic hydroxyl groups of tannic acid and the carbonyl, hydroxyl and other groups in the hyperbranched polyester molecules can form hydrogen bonds, so that tannic acid and hyperbranched polyester form a relatively stable complex. Tannic acid has a conjugated structure such as a benzene ring. After modifying the hyperbranched polyester, it can keep the resin stable in a higher temperature environment; secondly, the antioxidant property of tannic acid can inhibit the oxidative degradation reaction of the resin at high temperature to a certain extent, reduce the performance degradation rate of the resin in a hot oxygen environment, and extend the service life.

[0025] Preferably, the amount of tannic acid used is 3%-4.5% of the mass of the hydroxyl-terminated hyperbranched polyester.

[0026] By adopting the above technical solution, excessive use of tannic acid may affect the processing performance of the resin due to its strong adhesion.

[0027] Preferably, the viscosity average molecular weight of the ultra-high molecular weight polyethylene is 2.5 million to 3.5 million; and the viscosity average molecular weight of the high density polyethylene is 300,000 to 500,000.

[0028] In a second aspect, the present invention provides a method for preparing the modified ultra-high molecular weight polyethylene lined oil pipe special resin, comprising the following steps:

[0029] Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are uniformly mixed and placed in a twin-screw extruder for melting, extrusion, granulation, drying and crushing to obtain modified ultra-high molecular weight polyethylene special resin for oil pipe lining.

[0030] Preferably, the extrusion temperature is 125-135°C, 225-235°C, 265-270°C, 275-280°C, 285-290°C, respectively.

[0031] In summary, the beneficial effects of the present invention are:

[0032] (1) The modified polyaryletherketone prepared by the present invention can improve the high temperature resistance and wear resistance of ultra-high molecular weight polyethylene; the present invention introduces structures such as biphenyl units and thiophene rings into the main chain of the modified polyaryletherketone molecule, so that it has better high temperature resistance; secondly, the alkyl group in 4,4'-(1,4-phenylenediisopropylidene)diphenol can reduce the intermolecular force, thereby improving the fluidity of the modified polyaryletherketone while maintaining the rigidity of the main chain of the molecule;

[0033] (2) The molecular shape of the modified hyperbranched polyester prepared by the present invention is closer to a sphere, and can be interspersed between the ultra-high molecular weight polyethylene and the modified polyaryletherketone molecular chains, thereby increasing the contact area between different molecular chains, thereby improving the compatibility of the system to a certain extent; at the same time, the addition of the modified hyperbranched polyester enhances the interaction between the molecular chains of the system and improves the stability;

[0034] (3) The introduction of the silicone masterbatch of the present invention can reduce the melt viscosity, making the resin flow more easily during processing; secondly, the silicone masterbatch can appropriately improve the surface hardness and wear resistance of the resin, reduce the wear and scratching of the lining oil pipe during use, and extend the service life of the material;

[0035] (4) The oil lined pipe prepared by the modified ultra-high molecular weight polyethylene oil lined pipe special resin of the present invention has excellent wear resistance and high temperature resistance, and also has good mechanical properties such as tensile strength and impact strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the infrared spectrum of the modified polyaryletherketone in Example 1 of the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is explained in detail below with reference to several representative embodiments of the present invention.

[0038] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0039] The antioxidant in the examples and comparative examples of the present invention can be any common antioxidant without special limitation. The following antioxidant is antioxidant 1010; the terminal hydroxyl hyperbranched polyesters are all aliphatic terminal hydroxyl hyperbranched polyesters with a number average molecular weight of 5000±50.

[0040] Example 1

[0041] A modified ultra-high molecular weight polyethylene lined oil pipe special resin in this embodiment is made of the following raw materials:

[0042] 75kg of ultra-high molecular weight polyethylene with a viscosity average molecular weight of 3 million, 8kg of high-density polyethylene with a viscosity average molecular weight of 450,000, 8kg of modified polyaryletherketone, 5kg of modified hyperbranched polyester, 1kg of silicone masterbatch, and 0.3kg of antioxidant.

[0043] The specific steps of the preparation method of the modified polyaryletherketone of this embodiment are as follows:

[0044] (1) Under argon protection, 3.984 g of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 3.467 g of 4,4'-(1,4-phenylenediisopropyl)diphenol, 2.583 g of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and 4.43 g of potassium carbonate were added to a three-necked flask in sequence and stirred for 5 min. 65 g of N,N-dimethylformamide and 100 mL of toluene with water were added. The temperature was raised to 135°C and refluxed for 3 h. After the water and the water-carrying agent were evaporated, the temperature was continued to be raised to 170°C and polymerized for 9 h to obtain a polymer.

[0045] (2) The polymer was added to water and boiled and washed 10 times to remove salts and solvents. The polymer was dried at 80°C for 10 h and then added to 60 mL of diphenyl sulfone and stirred for 10 min. The polymer was precipitated in anhydrous ethanol, filtered, and dried at 80°C for 12 h to obtain modified polyaryletherketone.

[0046] The modified polyaryletherketone prepared in Example 1 was tested by infrared spectrometer to obtain its infrared spectrum, as shown in FIG. Figure 1 As shown. Figure 1 It can be seen that 2970cm -1 -CH 3 Stretching vibration absorption peak, 1652cm -1 The characteristic absorption peak of ketone carbonyl is 1591cm -1 , 1500cm -1 The absorption peak of the skeleton vibration of the benzene ring is 1232cm -1 The asymmetric stretching vibration absorption peak of aromatic ether is 1050cm -1 The symmetrical stretching vibration absorption peak of aromatic ether is 886 cm-1 The CS stretching vibration absorption peak is at 835 cm -1 The absorption peak is the para-substitution absorption peak of the benzene ring.

[0047] The specific steps of the preparation method of the modified hyperbranched polyester of this embodiment are as follows:

[0048] In a three-necked flask, 0.2 g of tannic acid, 5 g of terminal hydroxyl hyperbranched polyester and 15 mL of acetone were added in sequence, stirred at 40° C. for 5 h, the acetone was removed by rotary evaporation, and the modified hyperbranched polyester was obtained by drying at 60° C. for 10 h.

[0049] The specific steps of the preparation method of a modified ultra-high molecular weight polyethylene lined oil pipe special resin of this embodiment are as follows:

[0050] Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are added to a mixer and stirred for 2 hours, then transferred to a twin-screw extruder, melted, extruded and granulated. The pellets are placed in a vacuum oven and dried at 80°C for 12 hours, and crushed to obtain a modified ultra-high molecular weight polyethylene resin for oil lined pipes; the five extrusion temperatures are 130°C, 230°C, 270°C, 280°C and 285°C respectively.

[0051] Example 2

[0052] A modified ultra-high molecular weight polyethylene lined oil pipe special resin in this embodiment is made of the following raw materials:

[0053] 65kg of ultra-high molecular weight polyethylene with a viscosity-average molecular weight of 3.5 million, 5kg of high-density polyethylene with a viscosity-average molecular weight of 300,000, 12kg of modified polyaryletherketone, 4kg of modified hyperbranched polyester, 1.5kg of silicone masterbatch, and 0.5kg of antioxidant.

[0054] The specific steps of the preparation method of the modified polyaryletherketone of this embodiment are as follows:

[0055] (1) Under argon protection, 3.984 g of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 5.196 g of 4,4'-(1,4-phenylenediisopropyl)diphenol, 1.55 g of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and 6.841 g of potassium carbonate were added to a three-necked flask in sequence and stirred for 5 min. 72 g of N,N-dimethylformamide and 100 mL of toluene with water were added, the temperature was raised to 120°C and refluxed for 3 h. After the water and the water-carrying agent were evaporated, the temperature was continued to be raised to 180°C and polymerized for 10 h to obtain a polymer;

[0056] (2) The polymer was added to water and boiled and washed 10 times to remove salts and solvents. The polymer was dried at 80°C for 10 h and then added to 60 mL of diphenyl sulfone and stirred for 10 min. The polymer was precipitated in anhydrous ethanol, filtered, and dried at 80°C for 12 h to obtain modified polyaryletherketone.

[0057] The specific steps of the preparation method of the modified hyperbranched polyester of this embodiment are as follows:

[0058] In a three-necked flask, 0.15 g of tannic acid, 5 g of terminal hydroxyl hyperbranched polyester and 15 mL of acetone were added in sequence, stirred at 45° C. for 3 h, the acetone was removed by rotary evaporation, and the modified hyperbranched polyester was obtained by drying at 60° C. for 10 h.

[0059] The specific steps of the preparation method of a modified ultra-high molecular weight polyethylene lined oil pipe special resin of this embodiment are as follows:

[0060] Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are added to a mixer and stirred for 2 hours, then transferred to a twin-screw extruder, melted at 210°C, extruded and granulated, and the pellets are placed in a vacuum oven at 80°C for 12 hours and crushed to obtain modified ultra-high molecular weight polyethylene special resin for oil pipe lining; the five extrusion temperatures are 125°C, 235°C, 265°C, 275°C and 290°C respectively.

[0061] Example 3

[0062] A modified ultra-high molecular weight polyethylene lined oil pipe special resin in this embodiment is made of the following raw materials:

[0063] 70kg of ultra-high molecular weight polyethylene with a viscosity-average molecular weight of 2.5 million, 10kg of high-density polyethylene with a viscosity-average molecular weight of 500,000, 12kg of modified polyaryletherketone, 7kg of modified hyperbranched polyester, 2kg of silicone masterbatch, and 0.1kg of antioxidant.

[0064] The specific steps of the preparation method of the modified polyaryletherketone of this embodiment are as follows:

[0065] (1) Under argon protection, 3.984 g of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 1.732 g of 4,4'-(1,4-phenylenediisopropyl)diphenol, 2.077 g of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and 2.418 g of potassium carbonate were added to a three-necked flask in sequence and stirred for 5 min. 57 g of N,N-dimethylformamide and 100 mL of xylene with water were added. The temperature was raised to 150°C and refluxed for 2 h. After the water and the water-carrying agent were evaporated, the temperature was continued to be raised to 160°C and polymerized for 10 h to obtain a polymer.

[0066] (2) The polymer was added to water and boiled and washed 10 times to remove salts and solvents. The polymer was dried at 80°C for 10 h and then added to 60 mL of diphenyl sulfone and stirred for 10 min. The polymer was precipitated in anhydrous ethanol, filtered, and dried at 80°C for 12 h to obtain modified polyaryletherketone.

[0067] The specific steps of the preparation method of the modified hyperbranched polyester of this embodiment are as follows:

[0068] In a three-necked flask, 0.15-0.225 g of tannic acid, 5 g of terminal hydroxyl hyperbranched polyester and 15 mL of acetone were added in sequence, stirred at 40-50° C. for 2-5 h, the acetone was removed by rotary evaporation, and the modified hyperbranched polyester was obtained by drying at 60° C. for 10 h.

[0069] The specific steps of the preparation method of a modified ultra-high molecular weight polyethylene lined oil pipe special resin of this embodiment are as follows:

[0070] Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are added to a mixer and stirred for 2 hours, then transferred to a twin-screw extruder, melted at 170-210°C, extruded and granulated, and the pellets are placed in a vacuum oven at 80°C for 12 hours and crushed to obtain a modified ultra-high molecular weight polyethylene resin for oil lined pipes; the five extrusion temperatures are 125°C, 230°C, 270°C, 280°C and 290°C respectively.

[0071] Example 4

[0072] A modified ultra-high molecular weight polyethylene lined oil pipe special resin in this embodiment is made of the following raw materials:

[0073] 80kg of ultra-high molecular weight polyethylene with a viscosity average molecular weight of 3 million, 10kg of high-density polyethylene with a viscosity average molecular weight of 500,000, 10kg of modified polyaryletherketone, 6kg of modified hyperbranched polyester, 0.3kg of silicone masterbatch, and 0.2kg of antioxidant.

[0074] The specific steps of the preparation method of the modified polyaryletherketone of this embodiment are as follows:

[0075] (1) Under argon protection, 3.984 g of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 6.929 g of 4,4'-(1,4-phenylenediisopropyl)diphenol, 2.077 g of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and 8.85 g of potassium carbonate were added to a three-necked flask in sequence and stirred for 5 min. 88 g of N,N-dimethylformamide and 100 mL of xylene with water were added. The temperature was raised to 135°C and refluxed for 4 h. After the water and the water-carrying agent were evaporated, the temperature was continued to be raised to 170°C and polymerized for 8 h to obtain a polymer.

[0076] (2) The polymer was added to water and boiled and washed 10 times to remove salts and solvents. The polymer was dried at 80°C for 10 h and then added to 60 mL of diphenyl sulfone and stirred for 10 min. The polymer was precipitated in anhydrous ethanol, filtered, and dried at 80°C for 12 h to obtain modified polyaryletherketone.

[0077] The specific steps of the preparation method of the modified hyperbranched polyester of this embodiment are as follows:

[0078] In a three-necked flask, 0.18 g of tannic acid, 5 g of terminal hydroxyl hyperbranched polyester and 15 mL of acetone were added in sequence, stirred at 50° C. for 3 h, the acetone was removed by rotary evaporation, and the modified hyperbranched polyester was obtained by drying at 60° C. for 10 h.

[0079] The specific steps of the preparation method of a modified ultra-high molecular weight polyethylene lined oil pipe special resin of this embodiment are as follows:

[0080] Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are added to a mixer and stirred for 2 hours, then transferred to a twin-screw extruder, melted at 170°C, extruded and granulated, and the pellets are placed in a vacuum oven at 80°C for 12 hours and crushed to obtain modified ultra-high molecular weight polyethylene special resin for oil pipe lining; the five extrusion temperatures are 135°C, 225°C, 270°C, 275°C and 285°C respectively.

[0081] Comparative Example 1

[0082] The difference from Example 1 is that the amount of silicone masterbatch used in this comparative example is 7 kg, and the rest is the same as Example 1.

[0083] Comparative Example 2

[0084] The difference from Example 1 is that the viscosity average molecular weight of the ultra-high molecular weight polyethylene in this comparative example is 8 million, and the rest is the same as Example 1.

[0085] Comparative Example 3

[0086] The difference from Example 1 is that the mass of 4,4'-(1,4-phenylenediisopropylidene)diphenol in this comparative example is 17.323 g, the mass of 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene is 20.66 g, and the rest is the same as Example 1.

[0087] Comparative Example 4

[0088] The difference from Example 1 is that the mass of tannic acid in this comparative example is 0.5 g, and the rest is the same as Example 1.

[0089] Comparative Example 5

[0090] The difference from Example 1 is that the modified ultra-high molecular weight polyethylene lined oil pipe special resin in this comparative example is made of raw materials of the following mass: 100 kg of ultra-high molecular weight polyethylene with a viscosity-average molecular weight of 3 million, 10 kg of high-density polyethylene with a viscosity-average molecular weight of 500,000, 3 kg of modified polyaryletherketone, 12 kg of modified hyperbranched polyester, 0.3 kg of silicone masterbatch, and 0.2 kg of antioxidant, and the rest are the same as Example 1.

[0091] Comparative Example 6

[0092] The difference from Example 1 is that the modified ultra-high molecular weight polyethylene lined oil pipe special resin in this comparative example is made of raw materials of the following mass: 40 kg of ultra-high molecular weight polyethylene with a viscosity-average molecular weight of 3 million, 10 kg of high-density polyethylene with a viscosity-average molecular weight of 500,000, 5 kg of modified polyaryletherketone, 1 kg of modified hyperbranched polyester, 0.3 kg of silicone masterbatch, and 0.2 kg of antioxidant, and the rest are the same as Example 1.

[0093] Comparative Example 7

[0094] The difference from Example 1 is that in this comparative example, an equal amount of polyaryletherketone is used instead of modified polyaryletherketone; the polyaryletherketone is prepared from 4'4-difluorobenzophenone and p-diphenol according to a conventional method, and the molar ratio of 4'4-difluorobenzophenone to p-diphenol is 1:1. The rest is the same as in Example 1.

[0095] Comparative Example 8

[0096] The difference from Example 1 is that no modified polyaryletherketone is added in this comparative example, and the rest is the same as Example 1.

[0097] Comparative Example 9

[0098] The difference from Example 1 is that no modified hyperbranched polyester is added in this comparative example, and the rest is the same as Example 1.

[0099] Related tests

[0100] The modified ultra-high molecular weight polyethylene special resin for oil lining pipes prepared in Example 1 to Example 4 and Comparative Example 1 to Comparative Example 9 were respectively extruded into oil lining pipes through an extruder; the oil lining pipes prepared in Example 1 to Example 4 and Comparative Example 1 to Comparative Example 9 were cut into test samples for relevant tests, and the test results are shown in Table 1.

[0101] Table 1 Related test results

[0102]

[0103] By comparing Comparative Example 1 with Example 1, it can be seen that as the content of silicone masterbatch increases, the tensile strength and wear resistance of the oil lining pipe decrease. This may be because the excessive silicone masterbatch is unevenly dispersed and agglomerated in the oil lining pipe material, resulting in the silicone masterbatch being unable to form a uniform lubricating layer on the surface of the oil lining pipe material, thereby reducing the wear resistance.

[0104] From the comparison between Comparative Example 2 and Example 1, it can be seen that the wear resistance is not greatly improved; during the extrusion process, due to the increase in the molecular weight of the ultra-high molecular weight polyethylene, the higher melt viscosity makes it difficult for the resin to flow, and the processing performance deteriorates.

[0105] By comparing Comparative Example 3 with Example 1, it can be seen that excessive introduction of 4,4'-(1,4-phenylenediisopropyl)diphenol and 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene may induce side reactions, affect the cross-linking process, and cause a decrease in the mechanical properties of the final lined oil pipe; secondly, the introduction of too much rigid structure causes the resin fluidity to deteriorate and the processing performance to decrease.

[0106] By comparing Comparative Example 4 with Example 1, it can be seen that excessive tannic acid may weaken the interaction between the molecular chains of the hyperbranched polyester, destroy the molecular structure of the hyperbranched polyester, affect the compatibility of the hyperbranched polyester, and have a slight effect on the processing properties of the resin; however, for the raw materials used for the entire modified ultra-high molecular weight polyethylene lined oil pipe special resin, the amount of tannic acid used is relatively small, and has little effect on the overall performance of the lined oil pipe.

[0107] By comparing Comparative Examples 5 and 6 with Example 1, it can be seen that by adjusting the raw material ratio of the modified ultra-high molecular weight polyethylene lined oil pipe special resin, the wear resistance, processability and other related properties are reduced, indicating that the raw material ratio of the modified ultra-high molecular weight polyethylene lined oil pipe special resin in the present invention has been optimized.

[0108] By comparing Comparative Example 7 with Example 1, it can be seen that the wear resistance is reduced, which proves that the introduction of biphenyl units, thiophene rings and other structures in the modified polyaryletherketone can further improve the rigidity of the molecular chain and thus improve the wear resistance and high temperature resistance of the lined oil pipe.

[0109] By comparing Comparative Example 8 with Example 1, it can be seen that the raw materials of the lining oil pipe in Comparative Example 8 do not contain modified polyaryletherketone, so the Vicat softening temperature, mortar wear amount, etc. are lower than those of the lining oil pipe in Example 1, which indicates that the addition of modified polyaryletherketone effectively improves the high temperature resistance and wear resistance of the lining oil pipe.

[0110] By comparing Comparative Example 9 with Example 1, it can be seen that the raw materials of the oil pipe lining in Comparative Example 9 do not contain modified hyperbranched polyester. Since the molecular structures and polarities of ultra-high molecular weight polyethylene and modified polyaryletherketone are quite different, it is difficult for the two to form a good compatible interface without adding modified hyperbranched polyester, and the mechanical properties such as tensile strength and impact strength are reduced. At the same time, the processing performance of the modified ultra-high molecular weight polyethylene oil pipe lining special resin is affected.

[0111] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or equivalent replacement that can be done by other technicians in this field without expending creative labor falls within the protection scope of the present invention.

Claims

1. A modified ultra-high molecular weight polyethylene lined oil pipe special resin, characterized in that: The invention is prepared from the following raw materials in parts by weight: 65-80 parts of ultra-high molecular weight polyethylene, 5-10 parts of high-density polyethylene, 8-12 parts of modified polyaryletherketone, 4-7 parts of modified hyperbranched polyester, 0.3-2 parts of silicone masterbatch, and 0.1-0.5 parts of antioxidant; The preparation method of the modified hyperbranched polyester comprises the following steps: Mixing tannic acid, terminal hydroxyl hyperbranched polyester and acetone at 40-50° C. for 2-5 hours, removing acetone by rotary evaporation, and drying to obtain modified hyperbranched polyester; The preparation method of the modified polyaryletherketone comprises the following steps: (1) Under the protection of inert gas, [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 4,4'-(1,4-phenylenediisopropyl)diphenol, 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene and potassium carbonate are uniformly mixed, N,N-dimethylformamide and a water-carrying agent are added, the temperature is raised to carry out reflux reaction, and after the water and the water-carrying agent are evaporated, the temperature is continued to be raised to carry out polymerization reaction to obtain a polymer; (2) The polymer is washed by boiling in water, dried, added to diphenyl sulfone and mixed evenly, precipitated in anhydrous ethanol, filtered and dried to obtain modified polyaryletherketone.

2. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: In the step (1), the molar ratio of [4-[4-(4-fluorobenzoyl)phenyl]phenyl]-(4-fluorophenyl)methanone, 4,4'-(1,4-phenylenediisopropylidene)diphenol and 2,3,4,5-tetrakis(3,4-dihydroxyphenyl)thiophene is 1:(0.5-2):(0.3-0.6).

3. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: In the step (1), the molar ratio of potassium carbonate to 4,4'-(1,4-phenylenediisopropylidene)diphenol is (3.2-3.5):

1.

4. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: In the step (1), the temperature of the reflux reaction is 120-150° C., and the time of the reflux reaction is 2-4 hours; the temperature of the polymerization reaction is 160-180° C., and the time of the polymerization reaction is 8-10 hours.

5. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: In the step (1), the water-carrying agent is selected from toluene and xylene.

6. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: The amount of the tannic acid used is 3%-4.5% of the mass of the terminal hydroxyl hyperbranched polyester.

7. The modified ultra-high molecular weight polyethylene lined oil pipe special resin according to claim 1, characterized in that: The viscosity average molecular weight of the ultra-high molecular weight polyethylene is 2.5 million to 3.5 million; the viscosity average molecular weight of the high density polyethylene is 300,000 to 500,000.

8. A method for preparing the modified ultra-high molecular weight polyethylene lined oil pipe special resin according to any one of claims 1 to 7, characterized in that: The steps include: Ultra-high molecular weight polyethylene, high-density polyethylene, modified polyaryletherketone, modified hyperbranched polyester, silicone masterbatch and antioxidant are uniformly mixed and placed in a twin-screw extruder for melting, extrusion, granulation, drying and crushing to obtain modified ultra-high molecular weight polyethylene special resin for oil pipe lining.

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