A smooth surface ultra-high molecular polyethylene material and preparation method thereof

Abstract

The present invention provides a kind of ultra-high molecular polyethylene material with a smooth surface and its preparation method, the ultra-high molecular polyethylene material with a smooth surface is composed of the following components in parts by mass: 40-60 parts of ultra-high molecular polyethylene, 10-20 parts of modified polyethylene, 0.5-1 parts of antioxidant, 1-5 parts of lubricant, and 0.1-1 parts of nucleator; wherein the modified polyethylene is polyethylene glycol, epichlorohydrin and hydroxylated silica reaction, and then reacted with plasma surface treated ultra-high molecular polyethylene to obtain. The present invention first uses NH3 plasma to treat the surface of ultra-high molecular polyethylene, and successfully introduces polar groups such as amino and imino groups; subsequently, polyethylene glycol, epichlorohydrin and hydroxylated silica are combined to form a modified composite system; finally, it is grafted onto the surface of plasma treated ultra-high molecular polyethylene to obtain a modified polyethylene with excellent surface gloss and strong oleophobicity.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to an ultra-high molecular polyethylene material with a smooth surface and a preparation method thereof. Background Art

[0002] In the fields of industrial fluid transportation and engineering materials, ultra-high molecular weight polyethylene (UHMWPE) is widely used in pipes, rods, and wear-resistant components due to its excellent wear resistance, chemical stability, and low coefficient of friction. For example, in oil and gas production, this material is often used in the manufacture of oil rods and pumping pipes to withstand long-term use in complex media environments. However, as application scenarios diversify, the limitations of traditional materials in specific working conditions are gradually becoming apparent.

[0003] In the existing technology, ultra-high molecular weight polyethylene is often prepared into pipes or coatings through extrusion or molding processes. For example, a metal inner pipe is compounded with an outer layer of polyethylene to achieve both strength and corrosion resistance. In the anti-wax accumulation scenario, the mainstream solution relies on adding surfactants to petroleum to delay clogging by reducing the affinity between wax and the pipe wall, but such chemical additives have the problems of high cost, poor environmental compatibility and unstable long-term effects. Although the above problems can be partially alleviated by optimizing the molecular weight of polyethylene or adjusting the compounding process, the gloss and surface polarity of existing materials are still not enough to completely inhibit the adhesion of wax or other sticky substances. Therefore, the development of an ultra-high molecular weight polyethylene material with both high gloss and a polar surface has become a key technical challenge to improve the efficiency and durability of fluid transportation systems.

[0004] In summary, there is an urgent need to develop a new technical solution to solve the problems existing in the existing technology. Summary of the Invention

[0005] Based on this, the present invention provides a smooth-surfaced ultra-high molecular weight polyethylene material, which achieves improved performance by adding modified polyethylene. Specifically, the present invention first uses NH3 plasma to treat the surface of ultra-high molecular weight polyethylene, successfully introducing polar groups such as amino groups and imino groups, thereby giving the material surface higher polarity and reactivity; subsequently, polyethylene glycol and epichlorohydrin are reacted under catalyst and alkaline conditions, introducing epoxy groups into the polyethylene glycol molecular chain, and then combining with hydroxylated silica to form a modified composite system; finally, the above composite system is grafted onto the plasma-treated ultra-high molecular weight polyethylene surface through chemical bonding of epoxy groups, hydroxyl groups, amino groups, etc., forming an interface layer with a dense cross-linked structure, effectively increasing the gloss of the modified material. At the same time, due to the presence of extremely oleophobic polyethylene glycol, a modified polyethylene with excellent surface gloss and strong oleophobicity is finally obtained. This modified material can effectively reduce surface roughness and inhibit the adhesion of wax components in devices such as oil rods.

[0006] One object of the present invention is to provide an ultra-high molecular weight polyethylene material with a smooth surface, wherein the ultra-high molecular weight polyethylene material with a smooth surface is composed of the following components in parts by mass:

[0007]

[0008] in,

[0009] The modified polyethylene is obtained by reacting polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide, and then reacting with ultra-high molecular polyethylene treated with plasma surface treatment.

[0010] Furthermore, the antioxidant is antioxidant 1076.

[0011] Furthermore, the lubricant is polyethylene wax.

[0012] Furthermore, the nucleating agent is white carbon black.

[0013] Another object of the present invention is to provide a method for preparing the above-mentioned ultra-high molecular weight polyethylene material with a smooth surface, comprising the following steps:

[0014] S1, treating ultra-high molecular weight polyethylene with NH3 plasma to obtain plasma surface-treated ultra-high molecular weight polyethylene;

[0015] S2, adding strong acid and hydrogen peroxide to treat silica to obtain hydroxylated silica;

[0016] S3, mixing polyethylene glycol with epichlorohydrin, adding a phase transfer catalyst and sodium hydroxide, heating and stirring to react, then mixing with hydroxylated silica, adding a catalyst, and reacting after heating to obtain an intermediate product;

[0017] S4, blending the plasma surface-treated ultrahigh molecular weight polyethylene and the intermediate product, heating and reacting to obtain modified polyethylene;

[0018] S5. Blending the modified polyethylene, ultra-high molecular weight polyethylene, antioxidant, lubricant, and nucleating agent, stirring evenly, and then adding the mixture to a screw extruder for extrusion and granulation to obtain an ultra-high molecular weight polyethylene material with a smooth surface.

[0019] Furthermore, in step S1, the power of the plasma treatment is 100-300 W, the discharge time is 5-15 min, and the gas flow rate is 200-400 mL / min.

[0020] Furthermore, in step S3, the mass ratio of the polyethylene glycol, epichlorohydrin and hydroxylated silica is 2:(0.1-1):(0.5-1.5).

[0021] Furthermore, in step S3, the heating temperature is 40-60°C, and the temperature of the temperature increase is 130-180°C.

[0022] Furthermore, in step S3, the phase transfer catalyst is tetra-n-butylammonium chloride, and the catalyst is 2-methyl-4-ethylimidazole.

[0023] Furthermore, in step S4, the mass ratio of the plasma surface treated ultrahigh molecular weight polyethylene to the intermediate product is (5-10):(1-2).

[0024] Furthermore, in step S4, the heating temperature is 50-70°C.

[0025] Another object of the present invention is to provide the use of the above-mentioned ultra-high molecular polyethylene material with a smooth surface in oil rods, oil pumping pipes or engineering plastics.

[0026] The present invention has the following beneficial effects:

[0027] The present invention provides a smooth-surfaced ultra-high molecular weight polyethylene (UHMWPE) material, which achieves improved performance by adding modified polyethylene. Specifically, the present invention first uses NH3 plasma to treat the UHMWPE surface, successfully introducing polar groups such as amino and imino groups, thereby giving the material surface higher polarity and reactivity. Subsequently, polyethylene glycol and epichlorohydrin are reacted under catalyst and alkaline conditions to introduce epoxy groups into the polyethylene glycol molecular chain, which are then combined with hydroxylated silica to form a modified composite system. Finally, the composite system is grafted onto the plasma-treated UHMWPE surface through crosslinking of epoxy groups, hydroxyl groups, and amino groups, forming an interface layer with a dense network structure, effectively increasing the gloss of the modified material. At the same time, due to the presence of oleophobic polyethylene glycol, a modified polyethylene with excellent surface gloss and wax resistance is finally obtained. This modified material can effectively reduce surface roughness and inhibit the adhesion of wax components in devices such as oil rods. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0029] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0030] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0031] The following materials are used in the embodiments of the present invention:

[0032] Ultra-high molecular weight polyethylene, weight average molecular weight 250×10 4 , purchased from Beijing Oriental Petrochemical Additives Co., Ltd.

[0033] Polyethylene glycol, PEG600, was purchased from Tianda Chemical Reagent Factory, Dongli District, Tianjin.

[0034] Antioxidant: Antioxidant 1076.

[0035] Lubricant: polyethylene wax.

[0036] Nucleating agent: white carbon black.

[0037] The water in the embodiments of the present invention is deionized water.

[0038] The “parts” in the embodiments of the present invention refer to parts by mass.

[0039] Example 1

[0040] A smooth-surface ultra-high molecular polyethylene material, wherein the smooth-surface ultra-high molecular polyethylene material is composed of the following components in parts by mass:

[0041]

[0042] in,

[0043] The modified polyethylene is obtained by reacting polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide, and then reacting with ultra-high molecular polyethylene treated with plasma surface treatment.

[0044] The method for preparing the above-mentioned ultra-high molecular weight polyethylene material with a smooth surface comprises the following steps:

[0045] S1. Place ultra-high molecular weight polyethylene in a plasma treatment apparatus, evacuate to 10 Pa at 25°C, introduce NH3 at a gas flow rate of 300 mL / min, control the discharge power to 200 W, and the discharge time to 10 min for plasma treatment to obtain plasma surface-treated ultra-high molecular weight polyethylene;

[0046] S2, adding silica to a mixed solution of concentrated sulfuric acid and hydrogen peroxide (the mass ratio of concentrated sulfuric acid to hydrogen peroxide is m:m=7:3, and the concentration of the hydrogen peroxide is 30%), reacting at 80° C. for 1 hour, and washing to remove unreacted concentrated sulfuric acid and hydrogen peroxide to obtain hydroxylated silica;

[0047] S3. Polyethylene glycol, tetra-n-butylammonium chloride, epichlorohydrin, and NaOH were mixed (polyethylene glycol: tetra-n-butylammonium chloride: epichlorohydrin: NaOH = 2:0.02:0.4:0.2, m / m / m / m), stirred at 55° C. for 1.5 h, cooled to room temperature, added with chloroform, filtered, adjusted to neutral with 10% sulfuric acid, and distilled under reduced pressure to obtain a liquid product;

[0048] The liquid product and hydroxylated silica (polyethylene glycol 50% by weight) were blended, 2-methyl-4-ethylimidazole (1% by weight of the reactant) was added, and the mixture was reacted at 150° C. for 5 h. After filtering, an intermediate product was obtained;

[0049] S4. Using xylene as a solvent, the plasma surface treated ultrahigh molecular weight polyethylene and the intermediate product (plasma surface treated ultrahigh molecular weight polyethylene:intermediate product=5:1, m / m) were blended and reacted at 60° C. for 3 h to obtain modified polyethylene;

[0050] S5. Blend the modified polyethylene, ultra-high molecular weight polyethylene, antioxidant, lubricant, and nucleating agent according to the above-mentioned parts by mass, stir evenly, then add them to a screw extruder, and extrude and granulate them at 180-220° C. to obtain an ultra-high molecular weight polyethylene material with a smooth surface.

[0051] Example 2

[0052] A smooth-surface ultra-high molecular polyethylene material, wherein the smooth-surface ultra-high molecular polyethylene material is composed of the following components in parts by mass:

[0053]

[0054] in,

[0055] The modified polyethylene is obtained by reacting polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide, and then reacting with ultra-high molecular polyethylene treated with plasma surface treatment.

[0056] The preparation method of the above-mentioned ultra-high molecular weight polyethylene material with a smooth surface is the same as that in Example 1.

[0057] Example 3

[0058] A smooth-surface ultra-high molecular polyethylene material, wherein the smooth-surface ultra-high molecular polyethylene material is composed of the following components in parts by mass:

[0059]

[0060] in,

[0061] The modified polyethylene is obtained by reacting polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide, and then reacting with ultra-high molecular polyethylene treated with plasma surface treatment.

[0062] The preparation method of the above-mentioned ultra-high molecular weight polyethylene material with a smooth surface is the same as that in Example 1.

[0063] Comparative Example 1

[0064] A smooth-surface ultra-high molecular weight polyethylene material. The difference between this comparative example and Example 1 is that step S3 is replaced by: mixing polyethylene glycol, hydroxylated silica, and 2-methyl-4-ethylimidazole in a mass ratio of 2:1:0.03, reacting at 150°C for 5 hours, and filtering to obtain an intermediate product. The other ingredients and preparation method are the same as those in Example 1.

[0065] Comparative Example 2

[0066] A ultra-high molecular weight polyethylene material with a smooth surface. The difference between this comparative example and Example 1 is that no hydroxylated silica is added during the preparation of the modified polyethylene. Other components and preparation methods are the same as those in Example 1.

[0067] Application Example 1

[0068] An oil rod, comprising the ultra-high molecular polyethylene material with a smooth surface according to Example 1, wherein the preparation method thereof comprises the following steps:

[0069] The ultra-high molecular polyethylene material with a smooth surface of Example 1 was injection molded to form a 2.5 mm coating layer on the surface of the oil rod to obtain the oil rod.

[0070] Comparative Application Example 1

[0071] A fuel rod comprises the ultra-high molecular polyethylene material with a smooth surface according to Comparative Example 1, and its preparation method is the same as that of Application Example 1.

[0072] Comparative Application Example 2

[0073] An oil rod comprises the ultra-high molecular polyethylene material with a smooth surface of Comparative Example 2, and its preparation method is the same as that of Application Example 1.

[0074] Comparative Application Example 3

[0075] Ordinary oil rod, not coated with ultra-high molecular weight polyethylene material.

[0076] Test Example 1

[0077] With reference to ISO2813, the smooth-surfaced ultra-high molecular weight polyethylene materials of Examples 1-3 and Comparative Examples 1-2 were dried at 60°C for 6 h, respectively added to a twin-screw extruder and extruded into pellets at 200°C, and then the pellets were injection-molded into plates with a plate mold thickness of 2 mm to obtain ultra-high molecular weight polyethylene sheets, which were then subjected to a gloss performance test.

[0078] The test results are shown in Table 1.

[0079] Table 1 Glossiness performance test results of Example 1 and Comparative Examples 1-2

[0080] project Glossiness (60°) Example 1 89 Example 2 88 Example 3 85 Comparative Example 1 78 Comparative Example 2 72

[0081] It can be seen from the above test results that the ultra-high molecular weight polyethylene materials with smooth surfaces prepared in Examples 1-3 of the present invention have relatively high gloss.

[0082] Test Example 2

[0083] The oil rods of Application Example 1 and Comparative Application Examples 1-3 were weighed and immersed in the same volume of waxy crude oil. After standing at 18°C ​​for 72 hours, the oil rods were taken out and washed with isopropyl alcohol to remove the crude oil. After standing and drying for 2 hours, the rods were weighed. The amount of wax deposited on the oil rods within 72 hours was calculated. The amount of wax deposited in Application Example 1, Comparative Application Example 1 or Comparative Application Example 2 was recorded as A, and the amount of wax deposited in Comparative Application Example 3 was recorded as B. The wax prevention rate was calculated as follows:

[0084] Wax resistance rate = (BA) / B.

[0085] The test results are shown in Table 2.

[0086] Table 2 Wax resistance test results

[0087] project Wax content (g) Wax resistance rate (%) Application Example 1 0.28 96.14 Comparative Application Example 1 2.49 65.66 Comparative Application Example 2 2.24 69.10 Comparative Application Example 3 7.25 /

[0088] It can be seen from the above test results that the present invention has a good anti-wax effect.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0090] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A smooth surface ultra-high molecular polyethylene material, characterized in that: The ultra-high molecular weight polyethylene material with a smooth surface is composed of the following components in parts by mass: composition: in, The preparation method of the modified polyethylene comprises the following steps: S1, treating ultra-high molecular weight polyethylene with NH3 plasma to obtain plasma surface-treated ultra-high molecular weight polyethylene; S2, adding strong acid and hydrogen peroxide to treat silica to obtain hydroxylated silica; S3, mixing polyethylene glycol with epichlorohydrin, adding a phase transfer catalyst and sodium hydroxide, heating and stirring to react, then mixing with hydroxylated silica, adding a catalyst, and reacting after heating to obtain an intermediate product; S4, blending the plasma surface-treated ultrahigh molecular weight polyethylene and the intermediate product, heating and reacting to obtain modified polyethylene; In step S3, the mass ratio of the polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide is 2:(0.1-1):(0.5-1.5); In step S4, the mass ratio of the plasma surface treated ultrahigh molecular weight polyethylene to the intermediate product is (5-10):(1-2).

2. The ultra-high molecular weight polyethylene material with a smooth surface according to claim 1, characterized in that: The antioxidant is antioxidant 1076.

3. The ultra-high molecular weight polyethylene material with a smooth surface according to claim 1, characterized in that: The lubricant is polyethylene wax.

4. The ultra-high molecular weight polyethylene material with a smooth surface according to claim 1, characterized in that: The nucleating agent is white carbon black.

5. The method for preparing the ultra-high molecular weight polyethylene material with a smooth surface according to any one of claims 1 to 4, characterized in that: The steps include: S1, treating ultra-high molecular weight polyethylene with NH3 plasma to obtain plasma surface-treated ultra-high molecular weight polyethylene; S2, adding strong acid and hydrogen peroxide to treat silica to obtain hydroxylated silica; S3, mixing polyethylene glycol with epichlorohydrin, adding a phase transfer catalyst and sodium hydroxide, heating and stirring to react, then mixing with hydroxylated silica, adding a catalyst, and reacting after heating to obtain an intermediate product; S4, blending the plasma surface-treated ultrahigh molecular weight polyethylene and the intermediate product, heating and reacting to obtain modified polyethylene; S5. Blending the modified polyethylene, ultra-high molecular weight polyethylene, antioxidant, lubricant, and nucleating agent, stirring evenly, and then adding the mixture to a screw extruder for extrusion and granulation to obtain an ultra-high molecular weight polyethylene material with a smooth surface.

6. The method for preparing the ultra-high molecular weight polyethylene material with a smooth surface according to claim 5, characterized in that: In step S1, the power of the plasma treatment is 100-300 W, the discharge time is 5-15 min, and the gas flow rate is 200-400 mL / min.

7. The method for preparing the ultra-high molecular weight polyethylene material with a smooth surface according to claim 5, characterized in that: In step S4, the heating temperature is 50-70°C.

8. Use of the ultra-high molecular weight polyethylene material with a smooth surface according to any one of claims 1 to 4 in oil rods and oil pumping pipes.

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