UHMWPE (Ultra High Molecular Weight Polyethylene) material with smooth surface and preparation method thereof

Abstract

The invention provides an ultra-high molecular weight polyethylene material with a smooth surface and a preparation method thereof. The ultra-high molecular weight polyethylene material with the smooth surface is prepared from the following components in parts by mass: 40-60 parts of ultra-high molecular weight polyethylene, 10-20 parts of modified polyethylene, 0.5-1 part of an antioxidant, 1-5 parts of a lubricant and 0.1-1 part of a nucleating agent, wherein the modified polyethylene is obtained by reacting polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide and then reacting with ultra-high molecular weight polyethylene subjected to plasma surface treatment. The method comprises the following steps: firstly, treating the surface of ultra-high molecular weight polyethylene by adopting NH3 plasma, and successfully introducing polar groups such as amino groups and imino groups; then, polyethylene glycol, epoxy chloropropane and hydroxylated silicon dioxide are combined, and a modified composite system is formed; and finally, grafting to the surface of the plasma-treated ultra-high molecular weight polyethylene to obtain the modified polyethylene with excellent surface glossiness and strong oleophobicity.

Description

Technical Field

[0001] The 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 field of industrial fluid transportation and engineering materials, ultra-high molecular weight polyethylene is widely used in pipes, rods and wear-resistant parts due to its excellent wear resistance, chemical stability and low friction coefficient. For example, in oil and gas production, this material is often used in the manufacture of oil rods and pumping pipes to meet the long-term use requirements in complex media environments. However, with the diversification of application scenarios, the limitations of traditional materials under specific working conditions have gradually emerged.

[0003] In the prior art, ultra-high molecular weight polyethylene is often prepared into pipes or coatings through extrusion or molding processes, such as compounding a metal inner tube with an outer layer of polyethylene to take into account 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 polar surface has become a key technical challenge to improve the efficiency and durability of fluid delivery systems.

[0004] In summary, it is urgent to develop a new technical solution to solve the problems existing in the prior art. Summary of the invention

[0005] Based on this, the present invention provides an ultra-high molecular weight polyethylene material with a smooth surface, which achieves improved performance by adding modified polyethylene. Specifically, the present invention first uses NH 3 Plasma treatment was used to successfully introduce polar groups such as amino and imino groups onto the surface of ultra-high molecular weight polyethylene, thereby giving the material surface higher polarity and reactivity. Subsequently, polyethylene glycol was reacted with epichlorohydrin under catalyst and alkaline conditions to introduce epoxy groups into the polyethylene glycol molecular chain, which was then combined with hydroxylated silica to form a modified composite system. Finally, the composite system was grafted onto the surface of ultra-high molecular weight polyethylene treated with plasma through chemical bonding of epoxy groups, hydroxyl groups, amino groups, etc., to form an interface layer with a dense cross-linked structure, which effectively increased the gloss of the modified material. At the same time, due to the presence of extremely oleophobic polyethylene, a modified polyethylene with excellent surface gloss and strong oleophobicity was finally obtained. The modified material can effectively reduce surface roughness and inhibit the adhesion of wax components in devices such as oil rods.

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

[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, NH 3 Performing plasma treatment to obtain ultra-high molecular weight polyethylene treated with plasma surface;

[0015] S2, adding strong acid and hydrogen peroxide to silicon dioxide for treatment to obtain hydroxylated silicon dioxide;

[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, reacting after heating to obtain an intermediate product;

[0017] S4, blending the plasma surface treated ultra-high 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 them into 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 silicon dioxide is 2:(0.1-1):(0.5-1.5).

[0021] Furthermore, in step S3, the heating temperature is 40-60°C, and the heating temperature 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 ultra-high 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 ultra-high molecular weight 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 an ultra-high molecular weight polyethylene material with a smooth surface, which achieves improved performance by adding modified polyethylene. Specifically, the present invention first adopts NH 3 Plasma treatment was used to successfully introduce polar groups such as amino and imino groups onto the surface of ultra-high molecular weight polyethylene, thereby giving the material surface higher polarity and reactivity. Subsequently, polyethylene glycol was reacted with epichlorohydrin under catalyst and alkaline conditions to introduce epoxy groups into the polyethylene glycol molecular chain, which was then combined with hydroxylated silica to form a modified composite system. Finally, the composite system was grafted onto the surface of ultra-high molecular weight polyethylene treated with plasma through cross-linking of epoxy groups, hydroxyl groups, amino groups, etc., to form an interface layer with a dense network structure, which effectively increased 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 anti-wax was finally obtained. The 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 solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0029] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0030] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on 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, the smooth-surface ultra-high molecular polyethylene material comprising 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 the ultra-high molecular weight polyethylene in a plasma treatment apparatus, evacuate to 10Pa at 25°C, and introduce NH 3 , gas flow rate 300mL / min, discharge power controlled to 200W, discharge time to 10min, plasma treatment to obtain plasma surface treated ultra-high molecular polyethylene;

[0046] S2, adding silicon dioxide 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, washing and removing unreacted concentrated sulfuric acid and hydrogen peroxide, to obtain hydroxylated silicon dioxide;

[0047] S3, mixing polyethylene glycol, tetra-n-butylammonium chloride, epichlorohydrin and NaOH (polyethylene glycol: tetra-n-butylammonium chloride: epichlorohydrin: NaOH = 2: 0.02: 0.4: 0.2, m / m / m / m), stirring at 55 ° C for 1.5 h, cooling to room temperature, adding chloroform and filtering, adjusting to neutrality with 10% sulfuric acid, and distilling under reduced pressure to obtain a liquid product;

[0048] The liquid product and hydroxylated silica (polyethylene glycol 50% by mass) were mixed, 2-methyl-4-ethylimidazole (reactant 1% by mass) 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 solvent, blending the plasma surface treated ultra-high molecular weight polyethylene and the intermediate product (plasma surface treated ultra-high molecular weight polyethylene: intermediate product=5:1, m / m), reacting 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 mass fractions, stir evenly, then add them into a screw extruder, 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, the smooth-surface ultra-high molecular polyethylene material comprising 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, the smooth-surface ultra-high molecular polyethylene material comprising 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 ultra-high molecular weight polyethylene material with a smooth surface. The difference between this comparative example and Example 1 is that step S3 is replaced by: polyethylene glycol, hydroxylated silica and 2-methyl-4-ethylimidazole in a mass ratio of 2:1:0.03 are mixed, reacted at 150°C for 5h, and filtered to obtain an intermediate product. Other ingredients and preparation methods 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 silicon dioxide is added during the preparation of the modified polyethylene, and other components and preparation methods are the same as those of 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, and a preparation method thereof comprises the following steps:

[0069] The ultra-high molecular polyethylene material with a smooth surface of Example 1 is 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] An oil rod comprises the ultra-high molecular polyethylene material with a smooth surface of 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 hours, respectively added to a twin-screw extruder for extrusion granulation 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 tested for gloss performance.

[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 higher glossiness.

[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, the crude oil was washed off with isopropanol, and the rods were weighed after standing and drying for 2 hours. 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 obtained, and the calculation method was 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0090] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description 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 may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A smooth surface ultra-high molecular weight 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 weight: composition: in, 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.

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 ultra-high molecular weight polyethylene treated with plasma surface treatment; S2, adding strong acid and hydrogen peroxide to silicon dioxide for treatment to obtain hydroxylated silicon dioxide; 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, reacting after heating to obtain an intermediate product; S4, blending the plasma surface treated ultra-high 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 them into 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 S3, the mass ratio of the polyethylene glycol, epichlorohydrin and hydroxylated silicon dioxide is 2:(0.1-1):(0.5-1.5).

8. 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 mass ratio of the plasma surface treated ultra-high molecular weight polyethylene to the intermediate product is (5-10):(1-2).

9. 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.

10. Use of the ultra-high molecular polyethylene material with a smooth surface as claimed in any one of claims 1 to 4 in oil rods, oil pumping pipes or engineering plastics.

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