Thermal insulation high-pressure-resistant polypropylene material and preparation method thereof

Abstract

This invention relates to a thermally insulating and high-pressure resistant polypropylene material, comprising the following components in parts by weight: polypropylene resin, hollow glass fiber, modified nano-ATO, hollow glass microspheres, antioxidant, latex powder, nucleating agent, and lubricant; wherein the modified nano-ATO is a product obtained by coupling nano-ATO with MPS and then copolymerizing it with octadecene and acrylate. Because the modified nano-ATO introduces long alkyl chains of octadecene, which are similar in polarity to polypropylene, the two molecules are more tightly packed through intermolecular forces and entanglement between molecular chain segments. The modified nano-ATO contains ester groups and other oxygen-containing groups that form hydrogen bonds with the hydroxyl groups on the surface of the hollow glass fiber, resulting in strong interactions between the nano-ATO and both the polypropylene matrix and the hollow glass fiber. This gives the modified nano-ATO excellent compatibility and stability with other components, significantly improving the pressure resistance and other mechanical properties of the polypropylene material.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a thermally insulating and high-pressure resistant polypropylene material and its preparation method. Background Technology

[0002] In petrochemical transportation systems, pipeline materials must meet the requirements of extremely complex operating environments. Polypropylene (PP), due to its excellent chemical inertness and low density, has become a potential alternative material to metal pipelines. Compared with conventional metal pipelines, polypropylene pipelines have inherent corrosion resistance, resisting electrochemical corrosion from sulfur-containing media, acidic oil and gas mixtures, and seawater erosion environments during oil extraction, significantly extending pipeline service life. Simultaneously, its density is only 0.91-0.92 g / cm³, equivalent to one-eighth that of steel pipes, greatly reducing transportation and installation costs.

[0003] However, its application as a pipeline material in harsh conditions such as high-pressure transportation, extreme temperature differences, and corrosive media still faces significant challenges. Existing modification techniques often improve thermal insulation and dimensional stability by adding inorganic fillers or enhance mechanical strength by using fiber reinforcement. However, inorganic fillers, due to their high surface energy, tend to agglomerate in the non-polar PP matrix, leading to uneven dispersion, stress concentration points, and weakened material mechanical properties and thermal stability. Furthermore, agglomerates can easily cause a "thermal bridge effect," which reduces insulation efficiency. Meanwhile, while fiber reinforcement increases strength, it exacerbates material anisotropy, making it prone to delamination failure under alternating pressure. The significant difference in thermal expansion coefficients between fibers and resin can easily cause interfacial debonding under temperature cycling, resulting in decreased anti-leakage performance.

[0004] Furthermore, existing additive systems suffer from insufficient synergistic effects: conventional antioxidants are prone to failure in high-temperature, sulfur-containing environments, accelerating the thermo-oxidative aging of materials; nucleating agents and lubricants exhibit antagonistic effects, affecting crystallization control and causing processing defects; and most critically, the materials lack sufficient creep resistance, making it difficult to meet the low deformation requirements of pipelines under long-term pressure. Although some studies have attempted composite modification, problems such as poor interfacial compatibility and reduced processing fluidity make it difficult to synergistically optimize mechanical properties, processing efficiency, long-term durability, and thermal insulation effects, severely limiting the widespread application of high-performance polypropylene pipelines in the complex working conditions of the petroleum industry.

[0005] In conclusion, there is an urgent need to develop a new technical solution to address the problems existing in the current technology and meet the needs of the current market. Summary of the Invention

[0006] Therefore, it is necessary to provide a thermally insulating and high-pressure resistant polypropylene material. The polypropylene material of the present invention incorporates modified nano-ATO (nano-antimony-doped tin oxide), whose long alkyl chains have high compatibility with the polypropylene matrix, and whose ester groups form hydrogen bonds with hollow glass fibers to synergistically enhance the interfacial bonding, significantly improving the compressive strength. The three-dimensional network structure inhibits the migration and aggregation of modified nano-ATO at high temperatures. Combined with the infrared reflection characteristics of modified nano-ATO, the material has excellent thermal insulation and mechanical stability, thus overcoming the shortcomings of the prior art.

[0007] One object of the present invention is to provide a thermally insulating and high-pressure resistant polypropylene material, comprising the following components in parts by weight:

[0008] 50-60 parts of polypropylene resin

[0009] 15-20 parts of hollow glass fiber

[0010] Modified nano-ATO 2-4 parts

[0011] 3-5 parts of hollow glass microspheres

[0012] Antioxidant 0.1-0.5 parts

[0013] 1-2 parts latex powder

[0014] Nucleating agent 0.1-0.5 parts

[0015] Lubricant 0.1-1 part

[0016] 1-2 parts compatibilizer;

[0017] The modified nano-ATO is a product obtained by coupling nano-ATO with MPS and then copolymerizing it with octadecene and acrylate.

[0018] Furthermore, the antioxidant is selected from one or more of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 4,4'-bis[4-(1-phenyl-isopropyl)-phenyl]amine, and tris[2,4-di-tert-butylphenyl]phosphite.

[0019] Furthermore, the melt index of the polypropylene resin is 20-100 g / 10 min.

[0020] Furthermore, the nucleating agent is selected from one or more of TMP-1, TMB-5, and TMA-3.

[0021] Furthermore, the lubricant is selected from one or more of ethylene bis-stearamide, erucamide, polyethylene wax powder, and maleic acid-grafted polyethylene wax.

[0022] Furthermore, the particle size of the nano-ATO is 20-80 nm.

[0023] This invention also provides a method for preparing the aforementioned thermally insulating and high-pressure resistant polypropylene material, the method comprising the following steps:

[0024] S1. Graft MPS onto the surface of ATO to obtain an intermediate product;

[0025] S2. The intermediate product, octadecene, and acrylate are subjected to free radical polymerization under nitrogen protection and with BPO as the initiator to obtain modified nano-ATO.

[0026] S3. Mix the modified nano-ATO with other components evenly, feed it into the twin-screw extruder through the main feed port, feed the hollow glass fiber into the extruder through the side feed port, melt and extrude, and then granulate to obtain a heat-insulating and high-pressure resistant polypropylene material.

[0027] Furthermore, in step S2, the temperature of the free radical polymerization is 75-85°C.

[0028] Further, in step S2, the mass ratio of the intermediate product, octadecene, and acrylate is 1-3:2-4:1-3.

[0029] Furthermore, in step S3, the extrusion temperature of the twin-screw extruder is 200-220℃.

[0030] The present invention also provides the application of the aforementioned thermal insulation and high-pressure resistant polypropylene material in chemical pipelines, oil pipelines, heating pipelines, and gas supply pipelines.

[0031] Specifically, the present invention also provides an oil well downhole pipeline, which comprises, in sequence, a steel pipe, an inner polypropylene layer, an insulating polypropylene layer, and an outer polypropylene layer.

[0032] The material of the thermal insulation polypropylene layer is the thermal insulation, heat insulation and high pressure resistant polypropylene material.

[0033] The present invention has the following beneficial effects:

[0034] The thermal insulation and high-pressure resistant polypropylene material of this invention is a compound of polypropylene resin, hollow glass fiber, and modified nano-ATO. First, the nano-ATO is treated with MPS (methacryloyloxypropyltrimethoxysilane) coupling agent to introduce unsaturated double bonds into the nano-ATO. Then, it undergoes free radical polymerization with octadecene and acrylate under the catalysis of BPO to obtain modified nano-ATO, a star-shaped network polymer with ATO as the core. On the one hand, because the modified nano-ATO introduces long alkyl chains of octadecene, which are similar in polarity to polypropylene, the two are more tightly arranged through intermolecular forces and entanglement and cross-linking between molecular chain segments. The modified nano-ATO contains ester groups and other oxygen-containing groups that form hydrogen bonds with the hydroxyl groups on the surface of hollow glass fiber, so that the nano-ATO interacts with both the polypropylene matrix and the hollow glass fiber. This gives the modified nano-ATO excellent compatibility and stability with other components, significantly improving the mechanical properties of the polypropylene material. On the other hand, since modified nano-ATO is a star-shaped network polymer with ATO as the core and acrylate-octadecene copolymer grafted on the periphery to form a star-shaped network structure, its three-dimensional network structure can effectively prevent the migration and aggregation of modified nano-ATO at high temperatures and effectively limit the thermal motion of molecular chains. This allows modified nano-ATO to maintain good dispersibility at high temperatures, enabling it to maintain excellent shielding and infrared reflection properties. It effectively maintains the good thermal insulation and pressure resistance of polypropylene materials, and has a wide range of applications, including chemical pipelines, oil pipelines, heating pipelines, and gas supply pipelines. Detailed Implementation

[0035] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0036] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0037] It should be understood that, except in any operational instance or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term "about". Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximations varying with the desired performance to be obtained according to the invention.

[0038] Polypropylene resin, PP K9026, melt index 25g / 10min, purchased from Yanshan Petrochemical.

[0039] Hollow fiberglass, alkali-resistant hollow fiberglass, purchased from Beijing Saint-Gobain Vitex Co., Ltd.

[0040] Nano-ATO, nano-antimony-doped tin oxide.

[0041] Hollow glass microspheres, purchased from Shanxi Hainuo HN60.

[0042] Antioxidant, tris[2,4-di-tert-butylphenyl]phosphite.

[0043] Latex powder, purchased from Langfang Tuosheng Insulation Materials Co., Ltd.

[0044] Nucleating agent, TMA-3.

[0045] Lubricant, ethylene bis-stearamide.

[0046] MPS, Methacryloxypropyltrimethoxysilane.

[0047] BPO, benzoyl peroxide.

[0048] Compatibilizer, PP-g-MAH, CAS No.: 25722-45-6, purchased from Sigma. Example 1

[0049] A thermal insulation and high-pressure resistant polypropylene material, comprising the following components in parts by weight:

[0050] 50 parts of polypropylene resin

[0051] 16 parts of hollow fiberglass

[0052] 2 parts of modified nano-ATO

[0053] 3 portions of hollow glass microspheres

[0054] 0.2 parts antioxidant

[0055] 1.3 parts latex powder

[0056] 0.2 parts nucleating agent

[0057] 0.5 parts lubricant

[0058] 1 part compatibilizer;

[0059] The preparation method of the above-mentioned thermal insulation and high-pressure resistant polypropylene material includes the following steps:

[0060] S1. Disperse 10 parts of nano-ATO in 100 parts of anhydrous ethanol, add 5 parts of deionized water and 1 part of MPS, mix well, add ammonia to adjust the pH to 8, ball mill at 2000 rpm for 6 hours, centrifuge, wash and dry to obtain intermediate product.

[0061] S2. Using toluene as solvent, 5 parts of intermediate product, 10 parts of 1-octadecene and 5 parts of butyl acrylate were mixed. Under nitrogen protection, 1 part of BPO was added as an initiator and the mixture was reacted at 80°C for 5 hours for free radical polymerization. After cooling, the mixture was filtered, washed and dried to obtain the modified nano-ATO.

[0062] S3. According to the above mass proportions, the modified nano-ATO is mixed evenly with other components except hollow glass fiber, and fed into the twin-screw extruder through the main feed port. The hollow glass fiber is fed into the extruder through the side feed port. Under the condition of extrusion temperature of 220℃, the material is melt-extruded and then pelletized to obtain a heat-insulating and high-pressure resistant polypropylene material. Example 2

[0063] A thermal insulation and high-pressure resistant polypropylene material, comprising the following components in parts by weight:

[0064] 55 parts of polypropylene resin

[0065] 18 parts of hollow fiberglass

[0066] Modified nano-ATO 3 parts

[0067] 3 portions of hollow glass microspheres

[0068] 0.3 parts antioxidant

[0069] 1.5 parts latex powder

[0070] 0.2 parts nucleating agent

[0071] 0.7 parts lubricant

[0072] 1 part compatibilizer;

[0073] The preparation method of the above-mentioned thermal insulation and high-pressure resistant polypropylene material includes the following steps:

[0074] S1. Disperse 10 parts of nano-ATO in 100 parts of anhydrous ethanol, add 5 parts of deionized water and 1 part of MPS, mix well, add ammonia to adjust the pH to 8, ball mill at 2000 rpm for 6 hours, centrifuge, wash and dry to obtain intermediate product.

[0075] S2. Using toluene as a solvent, 5 parts of intermediate product, 10 parts of 1-octadecene and 5 parts of butyl acrylate were mixed. Under nitrogen protection, 0.5 parts of BPO were added as an initiator, and the mixture was subjected to free radical polymerization at 80°C for 5 hours. After cooling, the mixture was filtered, washed and dried to obtain the modified nano-ATO.

[0076] S3. According to the above mass proportions, the modified nano-ATO is mixed evenly with other components except hollow glass fiber, and fed into the twin-screw extruder through the main feed port. The hollow glass fiber is fed into the extruder through the side feed port. Under the condition of extrusion temperature of 220℃, the material is melt-extruded and then pelletized to obtain a heat-insulating and high-pressure resistant polypropylene material. Example 3

[0077] A thermal insulation and high-pressure resistant polypropylene material, comprising the following components in parts by weight:

[0078] 58 parts of polypropylene resin

[0079] 20 parts of hollow fiberglass

[0080] 4 parts of modified nano-ATO

[0081] 4 portions of hollow glass microspheres

[0082] 0.3 parts antioxidant

[0083] 2 parts latex powder

[0084] 0.2 parts nucleating agent

[0085] 0.9 parts lubricant

[0086] 1 part compatibilizer;

[0087] The preparation method of the above-mentioned thermal insulation and high-pressure resistant polypropylene material includes the following steps:

[0088] S1. Disperse 10 parts of nano-ATO in 100 parts of anhydrous ethanol, add 5 parts of deionized water and 1 part of MPS, mix well, add ammonia to adjust the pH to 8, ball mill at 2000 rpm for 6 hours, centrifuge, wash and dry to obtain intermediate product.

[0089] S2. Using toluene as a solvent, 5 parts of intermediate product, 10 parts of 1-octadecene and 5 parts of butyl acrylate were mixed. Under nitrogen protection, 0.5 parts of BPO were added as an initiator, and the mixture was subjected to free radical polymerization at 80°C for 5 hours. After cooling, the mixture was filtered, washed and dried to obtain the modified nano-ATO.

[0090] S3. According to the above mass proportions, the modified nano-ATO is mixed evenly with other components except hollow glass fiber, and fed into the twin-screw extruder through the main feed port. The hollow glass fiber is fed into the extruder through the side feed port. Under the condition of extrusion temperature of 220℃, the material is melt-extruded and then pelletized to obtain a heat-insulating and high-pressure resistant polypropylene material.

[0091] Comparative Example 1

[0092] A polypropylene material, the difference between this comparative example and Example 1 is that in step S2, 1-octadecene is replaced with an equal mass of hexadecene, while the other components and preparation methods are the same.

[0093] Comparative Example 2

[0094] A polypropylene material, the difference between this comparative example and Example 1 is that in step S2, 1-octadecene is removed, that is, only butyl acrylate is used to react with the intermediate product, and the other components and preparation methods are the same.

[0095] Application Example 1

[0096] An oil well downhole pipeline comprises, in sequence, a steel pipe, an inner polypropylene layer (2 mm), an insulating polypropylene layer (3 mm), and an outer polypropylene layer (2 mm).

[0097] The materials of the inner and outer polypropylene layers include polypropylene (Korean Hyosung R200P, melt flow rate 0.22g / 10min), antioxidant 1076, and color masterbatch DSTDP.

[0098] The mass ratio of the polypropylene, antioxidant, and color masterbatch is 10:2:0.1;

[0099] The material of the thermal insulation polypropylene layer is the thermal insulation and high pressure resistant polypropylene material described in Example 1;

[0100] The method for preparing the downhole pipeline includes the following steps: the inner polypropylene layer, the thermal insulation polypropylene layer and the outer polypropylene layer are loaded into a co-extrusion device, and co-extrusion is started at an extrusion temperature of 230°C. The extruded material is placed in a steel pipe forming mold for forming, and the pipeline is obtained after shaping, cooling, traction and cutting.

[0101] Comparative Application Example 1

[0102] A material for oil well downhole pipelines. The difference between this comparative application example and application example 1 is that the material of the thermal insulation polypropylene layer is replaced with the polypropylene material of comparative example 1, while the other components and preparation methods are the same.

[0103] Comparative Application Example 2

[0104] A material for oil well downhole pipelines. The difference between this comparative application example and application example 1 is that the material of the thermal insulation polypropylene layer is replaced with the polypropylene material of comparative example 2, while the other components and preparation methods are the same.

[0105] Test Example 1

[0106] The performance of the polypropylene materials prepared in Example 1 and Comparative Examples 1-2 was tested.

[0107] Pressure resistance test: The polypropylene materials prepared in Example 1 and Comparative Examples 1-2 were injection molded into boxes of 60×100×100mm and top covers of 60×100×10mm respectively. After welding, water pressure was applied to the inside until the parts cracked. The water pressure strength tested was the pressure resistance strength.

[0108] Tensile property test:

[0109] The tensile strength of the polypropylene materials prepared in Example 1 and Comparative Examples 1-2 before and after high-temperature treatment was tested in accordance with ISO 527-2 standard.

[0110] The high-temperature treatment conditions were 120°C for 7 days.

[0111] Thermal insulation performance test:

[0112] The polypropylene materials prepared in Example 1 and Comparative Examples 1-2 were respectively injection molded into 100×100×100mm square boxes with a wall thickness of 3mm and a built-in temperature sensor. The boxes with an initial room temperature of 25°C were placed in a 60°C constant temperature chamber for 4 hours. The temperature change inside the box was detected and the temperature data was recorded. The higher the temperature, the worse the heat insulation effect.

[0113] The test results are shown in Table 1.

[0114] Table 1. Performance test results of polypropylene materials in Examples 1 and 1-2

[0115]

[0116] According to Table 1, the polypropylene material of the present invention has better heat insulation, pressure resistance and mechanical properties, and also has good tensile properties after high temperature testing, and its tensile properties have not decreased significantly.

[0117] Test Example 2

[0118] The pipelines prepared for use case 1 and comparative application example 1-2 were subjected to performance testing.

[0119] Thermal conductivity: Tested using GB / T 5990 method.

[0120] The test results are shown in Table 2.

[0121] Table 2 Performance test results of the pipes prepared in Application Example 1 and Comparative Application Examples 1-2

[0122] As can be seen from Table 2, the pipes made of the polypropylene material of the present invention have good heat insulation effect.

[0123] 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 implemented 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 exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0124] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A thermally insulating and high-pressure resistant polypropylene material, characterized in that, The ingredients include the following parts by weight: 50-60 parts of polypropylene resin 15-20 parts of hollow glass fiber Modified nano-ATO 2-4 parts 3-5 parts of hollow glass microspheres Antioxidant 0.1-0.5 parts 1-2 parts latex powder Nucleating agent 0.1-0.5 parts Lubricant 0.1-1 part 1-2 parts compatibilizer; The modified nano-ATO is a product obtained by coupling nano-ATO with methacryloyloxypropyltrimethoxysilane and then copolymerizing it with octadecene and acrylate. The preparation method of the thermal insulation and high-pressure resistant polypropylene material includes the following steps: S1. Grafting methacryloyloxypropyltrimethoxysilane onto the surface of ATO yields an intermediate product; S2. The intermediate product, octadecene, and acrylate are subjected to free radical polymerization under nitrogen protection and with BPO as the initiator to obtain modified nano-ATO. S3. Mix the modified nano-ATO with other components evenly, feed it into the twin-screw extruder through the main feed port, feed the hollow glass fiber into the extruder through the side feed port, melt and extrude, and then granulate to obtain a heat-insulating and high-pressure resistant polypropylene material.

2. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, The particle size of the nano-ATO is 20-80 nm.

3. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, The antioxidant is selected from one or more of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 4,4'-bis[4-(1-phenyl-isopropyl)-phenyl]amine, and tris[2,4-di-tert-butylphenyl]phosphite.

4. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, The melt flow index of the polypropylene resin is 20-100 g / 10 min.

5. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, The nucleating agent is selected from one or more of TMP-1, TMB-5, and TMA-3.

6. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, The lubricant is selected from one or more of ethylene bis-stearamide, erucamide, polyethylene wax powder, and maleic acid-grafted polyethylene wax.

7. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, In step S2, the temperature of the free radical polymerization is 75-85℃.

8. The thermal insulation and high-pressure resistant polypropylene material according to claim 1, characterized in that, In step S2, the mass ratio of the intermediate product, octadecene, and acrylate is 1-3:2-4:1-3.

9. The application of the thermal insulation and high-pressure resistant polypropylene material according to any one of claims 1-6 in chemical pipelines, oil pipelines, heating pipelines, and gas supply pipelines.

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