A low-hydrogen-permeable polyolefin composite material, a preparation method and applications thereof

Abstract

The application discloses a kind of low hydrogen permeation polyolefin composite material and its preparation method and application, belong to sheet preparation technical field, ultra-high molecular weight polyethylene and modified petroleum resin are blended melt, after cooling, ultra-high molecular weight polyethylene modified composite material is prepared;High-density polyethylene and ultra-high molecular weight polyethylene modified composite material are mixed, nucleating agent and compatilizer are added to carry out mechanical mixing after, polyolefin composite material particle is prepared;Polyolefin composite material particle is pressed by flat vulcanizing machine, and low hydrogen permeation polyolefin composite material is prepared.The preparation process of low hydrogen permeation polyolefin composite material in the application, first by monoethanolamine petroleum resin is modified, then by modified petroleum resin is modified to ultra-high PE, can increase the fluidity of ultra-high PE, improve the nucleation crystallization ability of ultra-high PE, it is helpful to further enhance the hydrogen storage effect of polyolefin composite material.

Description

Technical Field

[0001] This invention belongs to the field of sheet material preparation technology, specifically relating to a low hydrogen permeability polyolefin composite material, its preparation method, and its application. Background Technology

[0002] Hydrogen is a renewable and clean energy carrier capable of storing and transporting large amounts of energy. To realize hydrogen energy systems in the near future, suitable hydrogen storage and transportation technologies must be established. Currently, gaseous, liquid, and solid-state hydrogen storage systems all use hydrogen storage tanks. However, compared to the heavy and costly metal hydrides, non-metallic tanks offer advantages such as light weight, high design flexibility, and high toughness, while also reducing carbon emissions. A typical example of a non-metallic tank is made of polyolefin materials. With the maturity of large-scale polyolefin production technology and the reduction in production costs, the application of polyolefins in packaging, containers, and pipelines has attracted widespread attention in recent years. However, polyolefin composites suffer from problems such as easy aging and low crystallinity.

[0003] Ultra-high molecular weight polyethylene (UHMWPE) is an excellent engineering plastic with high strength and abrasion resistance, good chemical stability and fatigue resistance, low friction, and excellent biocompatibility. This makes UHMWPE a promising candidate for applications in engineering bearings, valves, automotive parts, and biomedical implants. While the long chains endow UHMWPE with extremely high performance, its severe entanglement and the resulting extremely high melt viscosity also pose significant challenges to its processing. In contrast, high-density polyethylene (HDPE) is widely used in industry due to its excellent physical and mechanical properties. As a semi-crystalline polymer, the overall properties of HDPE are severely limited by its crystallinity and crystallization rate.

[0004] Numerous public reports exist on the preparation of UHMWPE / HDPE composite materials. CN109333897A discloses a dense, transcrystalline, ultra-strong, and ultra-wear-resistant polyethylene composite material and its preparation method. High-density polyethylene and ultra-high molecular weight polyethylene are dried and then mechanically mixed to obtain a premix. This premix is ​​then melt-blended using an extruder, granulated, and dried to obtain blend granules. The resulting blend granules are then molded using a method that superimposes oscillation and push-pull composite force fields during melt molding to prepare the dense, transcrystalline, ultra-strong, and ultra-wear-resistant polyethylene composite material.

[0005] CN104004253A discloses a high molecular weight polymer nucleating agent modified ultra-high molecular weight polyethylene (UHMWPE) blend material. In a 100-part mass fraction of the high molecular weight polymer, the mass fractions of each component are: UHMWPE 60-100 parts, HDPE 5-12 parts, LLDPE 6-16 parts, high molecular weight polymer nucleating agent 0.1-3 parts, and flow modifier 1.5-3 parts. The mixing ratio is arbitrary, resulting in a UHMWPE / HDPE composite material with good tensile properties and impact resistance. CN116874906A discloses a UHMWPE modified PE pipe material, using HDPE as the raw material, comprising 60-85 parts HDPE, 5-30 parts UHMWPE, 5-10 parts filler, 0.2-1 parts composite lubricant, 0.1-0.3 parts composite antioxidant, and 0.3 parts coupling agent. -1 part, by controlling the type of raw materials, the proportion of raw materials and the process parameters, the processing performance of the composite material was improved, and finally a special material for PE pipe with good heat resistance, pressure resistance and wear resistance was obtained; CN117024867A disclosed a method for preparing HDPE / UHMWPE / YPnm alloy material, wherein the components of the composite material are: 15-20 parts of nano-modified plastic composite material, 70-80 parts of high-density polyethylene and 15-20 parts of ultra-high molecular weight polyethylene, to obtain a composite material with good mechanical properties and high strength.

[0006] Although the above-mentioned known techniques can all prepare UHMWPE / HDPE blend composites, they still have problems such as low crystallization efficiency, poor crystallinity, and high hydrogen permeability of the sheets. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0009] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a low-hydrogen-permeability polyolefin composite material.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a low-hydrogen-permeability polyolefin composite material, comprising,

[0011] A xylene-petroleum resin mixed solution was prepared by mixing petroleum resin and xylene.

[0012] An oxidant was added to a xylene-petroleum resin mixture to carry out an oxidation reaction, and after cooling, it was hydrothermally reacted with monoethanolamine to obtain a modified petroleum resin.

[0013] Ultra-high molecular weight polyethylene and modified petroleum resin are blended and melted, and then cooled to obtain ultra-high molecular weight polyethylene modified composite material.

[0014] High-density polyethylene and ultra-high molecular weight polyethylene modified composite materials are mixed, nucleating agents and compatibilizers are added, and then mechanically mixed to obtain polyolefin composite material particles.

[0015] Low hydrogen permeability polyolefin composite material is obtained by pressing polyolefin composite particles through a flat vulcanizing machine.

[0016] In a preferred embodiment of the preparation method described in this invention, the petroleum resin comprises 9 to 13 parts and the xylene comprises 87 to 96 parts by mass of the raw materials.

[0017] In a preferred embodiment of the preparation method described in this invention, the oxidant is an oxygen-ozone mixture, wherein the O3 volume concentration is 2%.

[0018] In a preferred embodiment of the preparation method described in this invention, the oxidation reaction is carried out at a temperature of 3–8°C for a time of 20–50 min.

[0019] As a preferred embodiment of the preparation method of the present invention, the mass percentage of the monoethanol to the cooled xylene petroleum resin solution is 6-12%: 88-94%; the hydrothermal reaction is carried out at a temperature of 70-90°C for 1-3 hours.

[0020] In a preferred embodiment of the preparation method described in this invention, the ultra-high molecular weight polyethylene and modified petroleum resin are blended and melted, wherein the weight-average molecular weight of the ultra-high molecular weight polyethylene is 3 million to 9 million, and the weight-average molecular weight of the modified petroleum resin is 1,000 to 2,500; the blending and melting is carried out in the mixing chamber of a Hacker rheometer 300P, wherein the rotor speed is 50 to 70 rpm, the temperature is 150 to 170°C, and the time is 7 to 15 min.

[0021] As a preferred embodiment of the preparation method described in this invention, the ultra-high molecular weight polyethylene modified composite material comprises 10-50 parts by weight, the high-density polyethylene comprises 50-90 parts by weight, the nucleating agent comprises 0.003-1 parts by weight, and the compatibilizer comprises 0.4-2 parts by weight, based on the mass parts of the raw materials.

[0022] The weight-average molecular weight of the high-density polyethylene is 120,000 to 300,000.

[0023] As a preferred embodiment of the preparation method described in this invention, the mechanical mixing includes the following conditions for mixing and extrusion: rotor speed of 2000-4500 rpm, feed rate of 0.3-3 kg / h, and barrel temperature of 200-250°C.

[0024] The conditions for pressing the flat vulcanizing machine include: temperature of 180-220℃, pressure of 10-20MPa, and time of 5-20min.

[0025] Another objective of this invention is to overcome the shortcomings of the prior art and provide a low-hydrogen-permeability polyolefin composite material, wherein: the low-hydrogen-permeability polyolefin composite material has a tensile strength of 1.6–4.2 cN / dtex, an elongation at break of 30%–62%, a modulus of 27–68 cN / dtex, and a hydrogen permeability of 1.56 × 10⁻⁶. -16 ~4.687×10 -16 mol / (m·s·Pa).

[0026] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of a low-hydrogen-permeability polyolefin composite material in the preparation of hydrogen storage containers.

[0027] Beneficial effects of this invention:

[0028] (1) In the preparation process of the low hydrogen permeation polyolefin composite material of the present invention, the petroleum resin is first modified by monoethanolamine, and then the ultra-high PE is modified by the modified petroleum resin. This can increase the fluidity of ultra-high PE, improve the nucleation and crystallization ability of ultra-high PE, and help to further enhance the hydrogen storage effect of the polyolefin composite material.

[0029] (2) The low hydrogen permeability polyolefin composite material of the present invention is also filled with composite material. The nucleating material is composed of nucleating agent (barium sulfate and calcium carbonate) and compatibilizer (maleic anhydride), which helps to increase the crystallization rate and crystallinity of polyolefin composite material. Maleic anhydride grafted polyolefin helps to increase the dispersion performance of composite filler.

[0030] (3) In the preparation process of low hydrogen permeability polyolefin composite material, the present invention modifies ultra-high PE and HDPE by ultra-high speed screw blending melt extrusion. Because the speed is much higher than that of traditional screws, it helps the dispersion of ultra-high PE and inorganic fillers in HDPE, promotes the crystallinity of the system, and further improves the mechanical properties and low hydrogen permeability of polyolefin composite material. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0032] Figure 1 The images show the viscoelastic diagrams of the materials obtained in Examples 1 to 6 of this invention.

[0033] Figure 2 The images show the viscoelastic diagrams of the materials obtained in Examples 7 to 12 of this invention.

[0034] Figure 3 The images show the viscoelastic diagrams of the materials prepared in Comparative Examples 1 to 5 of this invention. Detailed Implementation

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0038] In this invention, unless otherwise stated, “UHMWPE” refers to high molecular weight polyethylene; “HDPE” refers to high density polyethylene; “PR” refers to petroleum resin; and “MEA” refers to monoethanolamine (2-hydroxyethylamine).

[0039] In this embodiment of the invention, the molecular weight of the petroleum resin is 300-3000, purchased from Puyang Zhongke Xinyuan Petrochemical Co., Ltd.; the molecular weight of the monoethanolamine is 61.08, purchased from Nanjing Lexuan Chemical Co., Ltd.; and the molecular weight of the HDPE is 120,000-300,000, purchased from Dongguan Weicai Plastic Raw Materials Co., Ltd.

[0040] The method for determining tensile strength in this embodiment of the invention:

[0041] Mechanical properties (including tensile strength, elongation at break, and modulus) were measured using a universal tensile testing machine (refer to national standard GB / T 14344); hydrogen permeability was measured using a hydrogen permeability tester (refer to national standard GB / T42610-2023).

[0042] Example 1

[0043] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, the main steps of which are:

[0044] (1) Take 13 parts by weight of petroleum resin and 87 parts by weight of xylene solvent to obtain a xylene-petroleum resin mixed solution.

[0045] A xylene petroleum resin solution was added to a bubble reactor, and then an ozone-oxygen mixture (O3-2% volume concentration) was introduced at a rate of 0.07 s⁻¹. -1 The mixture was introduced into a reactor and reacted at 8°C for 50 minutes. After cooling, the xylene petroleum resin solution was mixed with monoethanolamine at a mass ratio of 94% and 6%, and then added to a glass reactor equipped with a reflux condenser and a stirrer. The mixture was reacted at 90°C for 2.5 hours to obtain a modified petroleum resin.

[0046] (2) Take ultra-high molecular weight polyethylene with a weight average molecular weight of 9 million and modified petroleum resin with a weight average molecular weight of 2500. The above composition is blended and melted in the mixing chamber of a Hacker rheometer 300P. After cooling, ultra-high molecular weight polyethylene modified composite material is obtained. The rotor speed is 70 rpm, the temperature is 170℃, and the time is 15 min.

[0047] (3) HDPE is 60 parts by weight and UHMWPE modified composite material is 40 parts by weight; based on 100 parts by weight of HDPE and UHMWPE, the components of nucleating agent barium sulfate and calcium carbonate, and compatibilizer maleic anhydride are mechanically mixed in proportions of 0.04 parts by weight, 0.06 parts by weight and 1 part by weight, respectively. The rotor speed is 4000 rpm, the feed rate is 0.5 kg / h and the barrel temperature is 235℃.

[0048] The polyolefin composite material particles are pressed into polyolefin composite material sheets (length*width 1.8×12m, thickness 20-30mm) by a flat vulcanizing machine at a temperature of 190℃, a pressure of 12MPa, and a time of 7min.

[0049] The properties of the polyolefin composite sheet were tested, and the test results are shown in Table 1.

[0050] Example 2

[0051] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, which differs from the method in Example 1 in that:

[0052] In step (3): Based on 100 parts by weight of the modified HDPE and UHMWPE composite material, the nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.2 parts by weight of barium sulfate, 0.3 parts by weight of calcium carbonate, and 1.2 parts by weight of maleic anhydride, respectively. The test results are shown in Table 1.

[0053] Example 3

[0054] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, the main steps of which are:

[0055] (1) Take 9 parts by weight of petroleum resin and 96 parts by weight of xylene solvent to obtain a xylene-petroleum resin mixed solution.

[0056] A xylene petroleum resin solution was added to a bubble reactor, and then an ozone-oxygen mixture (O3-2% volume concentration) was introduced at a rate of 0.03 s⁻¹. -1 The mixture was introduced into a reactor and reacted at 3°C ​​for 40 minutes. After cooling, the xylene petroleum resin solution was mixed with monoethanolamine at a mass ratio of 88% and 12%, and then added to a glass reactor equipped with a reflux condenser and a stirring device. The mixture was reacted at 70°C for 2 hours to obtain the modified petroleum resin.

[0057] (2) Take ultra-high molecular weight polyethylene with a weight average molecular weight of 3 million and modified petroleum resin with a weight average molecular weight of 1000. The above composition is blended and melted in the mixing chamber of a Hacker rheometer 300P. After cooling, ultra-high molecular weight polyethylene modified composite material is obtained. The rotor speed is 50 rpm, the temperature is 150℃, and the time is 7 min.

[0058] (3) HDPE is 85 parts by weight, and UHMWPE modified composite material is 15 parts by weight;

[0059] Based on 100 parts by weight of HDPE and UHMWPE, the components of nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.02 parts by weight of barium sulfate, 0.04 parts by weight of calcium carbonate and 0.8 parts by weight of maleic anhydride, respectively. The rotor speed was 4000 rpm, the feed rate was 1 kg / h, and the barrel temperature was 235℃.

[0060] The polyolefin composite material particles are pressed into polyolefin composite material sheets by a flat vulcanizing machine at a temperature of 180°C, a pressure of 10 MPa, and a time of 5 min.

[0061] The test results are shown in Table 1.

[0062] Example 4

[0063] The preparation of the low-hydrogen-permeability polyolefin composite material in this embodiment follows the method of Example 3, except that:

[0064] In step (3): Based on 100 parts by weight of HDPE and UHMWPE modified composite material, nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.11 parts by weight of barium sulfate, 0.09 parts by weight of calcium carbonate and 1.1 parts by weight of maleic anhydride, respectively. The test results are shown in Table 1.

[0065] Example 5

[0066] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, the main steps of which are:

[0067] (1) Take 10 parts by weight of petroleum resin and 90 parts by weight of xylene solvent to obtain a xylene-petroleum resin mixed solution.

[0068] A xylene petroleum resin solution was added to a bubble reactor, and then an ozone-oxygen mixture (O3-2% volume concentration) was introduced at a rate of 0.07 s⁻¹. -1 The mixture was introduced into a reactor and reacted at 8°C for 50 minutes. After cooling, the xylene petroleum resin solution was mixed with monoethanolamine at a mass ratio of 94% and 6%, and then added to a glass reactor equipped with a reflux condenser and a stirring device. The mixture was reacted at 90°C for 2.5 hours to obtain the modified petroleum resin.

[0069] (2) Take ultra-high molecular weight polyethylene with a weight average molecular weight of 6 million and modified petroleum resin with a weight average molecular weight of 1800. The above composition is blended and melted in the mixing chamber of a Hacker rheometer 300P. After cooling, ultra-high molecular weight polyethylene modified composite material is obtained. The rotor speed is 60 rpm, the temperature is 160℃, and the time is 10 min.

[0070] (3) HDPE is 70 parts by weight and UHMWPE modified composite material is 30 parts by weight; based on 100 parts by weight of HDPE and UHMWPE, the components of nucleating agent and compatibilizer are mechanically mixed in the proportion of 0.03 parts by weight of barium sulfate, 0.04 parts by weight of calcium carbonate and 1 part by weight of maleic anhydride, respectively. The rotor speed is 3800 rpm, the feed rate is 0.5 kg / h, and the barrel temperature is 240℃.

[0071] The polyolefin composite material particles were pressed into polyolefin composite material sheets by a flat vulcanizing machine at a temperature of 200℃, a pressure of 15MPa, and a time of 10min. The test results are shown in Table 1.

[0072] Example 6

[0073] The preparation of the low-hydrogen-permeability polyolefin composite material in this embodiment follows the method of Example 5, except that:

[0074] In step (3): Based on 100 parts by weight of HDPE and UHMWPE modified composite material, nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.02 parts by weight of barium sulfate, 0.03 parts by weight of calcium carbonate and 0.5 parts by weight of maleic anhydride, respectively. The test results are shown in Table 1.

[0075] The viscoelastic diagrams of the materials obtained in Examples 1-6 are shown below. Figure 1 As can be seen from the figure, the high modulus of the sheet obtained by modifying ultra-high PE with modified petroleum resin and the effect of ultra-high speed screw indicates a synergistic effect in promoting crystallization. At the same time, it can be seen from Examples 1-2 that nucleating agents and compatibilizers can also promote crystallization. Examples 3-4 show that the use of modified petroleum resin can promote HDPE crystallization. The comparison between Examples 5-6 and Examples 1-4 proves the promoting effect of high speed of ultra-high speed screw on crystallization.

[0076] Example 7

[0077] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, the main steps of which are:

[0078] (1) Take 8 parts by weight of petroleum resin and 92 parts by weight of xylene solvent to obtain a xylene-petroleum resin mixed solution; add the xylene-petroleum resin solution to a bubble reactor, and then add an ozone-oxygen mixture (O3-2% volume concentration) at a rate of 0.07s. -1 The mixture was introduced into a reactor and reacted at 8°C for 50 minutes. After cooling, the xylene petroleum resin solution was mixed with monoethanolamine at a mass ratio of 94% and 6%, and then added to a glass reactor equipped with a reflux condenser and a stirring device. The mixture was reacted at 90°C for 2.5 hours to obtain the modified petroleum resin.

[0079] (2) Take ultra-high molecular weight polyethylene with a weight average molecular weight of 1.5 million and modified petroleum resin with a weight average molecular weight of 300. The above composition is blended and melted in the mixing chamber of a Hacker rheometer 300P. After cooling, ultra-high molecular weight polyethylene modified composite material is obtained. The rotor speed is 40 rpm, the temperature is 130℃, and the time is 5 min.

[0080] (3) HDPE is 50 parts by weight, and UHMWPE modified composite material is 50 parts by weight;

[0081] Based on 100 parts by weight of HDPE and UHMWPE, the components of nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.004 parts by weight of barium sulfate, 0.004 parts by weight of calcium carbonate and 0.4 parts by weight of maleic anhydride, respectively. The rotor speed was 3000 rpm, the feed rate was 0.3 kg / h and the barrel temperature was 200℃.

[0082] The polyolefin composite material particles were pressed into polyolefin composite material sheets by a flat vulcanizing machine at a temperature of 180℃, a pressure of 10MPa, and a time of 5min. The test results are shown in Table 1.

[0083] Example 8

[0084] This embodiment prepares polyolefin composite sheet according to the method of Example 7, except that:

[0085] In step (3): Based on 100 parts by weight of HDPE and UHMWPE modified composite material, nucleating agent and compatibilizer were mechanically mixed with 0.4 parts by weight of barium sulfate, 0.6 parts by weight of calcium carbonate and 2 parts by weight of maleic anhydride, respectively; the rotor speed was 4000 rpm, the feed rate was 8 g / min, the barrel temperature was 230℃, and the test results are shown in Table 1.

[0086] Example 9

[0087] This embodiment provides a method for preparing a low-hydrogen-permeability polyolefin composite material, the main steps of which are:

[0088] (1) Take 15 parts by weight of petroleum resin and 85 parts by weight of xylene solvent to obtain a xylene-petroleum resin mixed solution; add the xylene-petroleum resin solution to a bubble reactor, and then add an ozone-oxygen mixture (O3-2% volume concentration) at a rate of 0.03s. -1 The mixture was introduced into a reactor and reacted at 8°C for 50 minutes. After cooling, the xylene petroleum resin solution was mixed with monoethanolamine at a mass ratio of 84% and 16%, and then added to a glass reactor equipped with a reflux condenser and a stirring device. The mixture was reacted at 90°C for 2.5 hours to obtain the modified petroleum resin.

[0089] (2) Take ultra-high molecular weight polyethylene with a weight average molecular weight of 10.2 million and modified petroleum resin with a weight average molecular weight of 3000. The above composition is blended and melted in the mixing chamber of a Hacker rheometer 300P, and then cooled to obtain ultra-high molecular weight polyethylene modified composite material. The rotor speed is 80 rpm, the temperature is 200℃, and the time is 20 min.

[0090] (3) HDPE is 90 parts by weight and UHMWPE modified composite material is 10 parts by weight; based on 100 parts by weight of HDPE and UHMWPE, the components of nucleating agent and compatibilizer are mechanically mixed in the proportion of 0.4 parts by weight of barium sulfate, 0.6 parts by weight of calcium carbonate and 2 parts by weight of maleic anhydride, respectively. The rotor speed is 4500 rpm, the feed rate is 3 kg / h, and the barrel temperature is 250℃.

[0091] The polyolefin composite material particles were pressed into polyolefin composite material sheets by a flat vulcanizing machine at a temperature of 220℃, a pressure of 20MPa, and a time of 20min. The test results are shown in Table 1.

[0092] Example 10

[0093] This embodiment prepares a low-hydrogen-permeability polyolefin composite material, following the method of Example 9, except that:

[0094] In step (3): Based on 100 parts by weight of HDPE and UHMWPE modified composite material, nucleating agent and compatibilizer were mechanically mixed in the proportions of 0.3 parts by weight of barium sulfate, 0.5 parts by weight of calcium carbonate and 0.5 parts by weight of maleic anhydride, respectively; the rotor speed was 4500 rpm, the feed rate was 3 g / min, the barrel temperature was 230℃, and the test results are shown in Table 1.

[0095] Example 11

[0096] The method is the same as in Example 1, except that calcium carbonate is replaced with an equal part by weight of SiO2.

[0097] Example 12

[0098] The method is the same as in Example 7, except that no compatibilizer is added.

[0099] The viscoelastic diagrams of the materials obtained in Examples 7-12 are shown below. Figure 2 Examples 7-9 clearly show the promoting effect of ultra-high speed of ultra-high speed screw on crystallization; Example 10 shows that decreasing speed and temperature will reduce crystallinity; Examples 11-12 show the synergistic promoting effect of calcium carbonate and barium sulfate nucleating agents, and the promoting effect of compatibilizer on crystallization.

[0100] Comparative Example 1

[0101] The method of Example 7 is followed, except that "the cooled xylene petroleum resin solution and monoethanolamine are mixed at a mass ratio of 94% and 6%" is replaced with "the cooled xylene petroleum resin solution and monoethanolamine are mixed at a mass ratio of 85% and 15%".

[0102] All other conditions are the same as in Example 7.

[0103] Comparative Example 2

[0104] The method of Example 7 is followed, except that no nucleating agent or compatibilizer is added; all other conditions are the same as in Example 7.

[0105] Comparative Example 3

[0106] The method of Example 7 was followed, except that monoethanolamine was not added; all other conditions were the same as in Example 7.

[0107] Comparative Example 4

[0108] The method is the same as in Example 9, except that monoethanolamine is replaced with an equal weight of triethanolamine.

[0109] Comparative Example 5

[0110] Based on Example 2, step (1) of not modifying the petroleum resin is omitted, and the petroleum resin is directly mixed with ultra-high molecular weight polyethylene. Everything else is the same as in Example 2.

[0111] See the viscoelastic diagrams of the materials prepared in Comparative Examples 1-5. Figure 3 Comparative Example 1 illustrates the nucleating agent, compatibilizer, and modification of petroleum resin to promote crystallization. In Comparative Example 4, triethanolamine was used instead, increasing the number of hydroxyl groups and promoting the fluidity of ultra-high PE, thereby promoting crystallization.

[0112] Table 1

[0113]

[0114] As can be seen from the results in Table 1, the present invention improves the tensile strength of polyolefin composites by combining modified petroleum resins and ultra-high PE with specific component contents, that is, it improves the elongation at break of polyolefin composites.

[0115] Examples 5-6 and 7-9 show that modifying ultra-high PE with modified petroleum resin helps increase the fluidity of ultra-high PE and promotes crystallization; at the same time, the ultra-high speed screw has a much higher rotational speed than the traditional twin-screw screw, which can improve the fluidity of ultra-high PE in HDPE, thereby promoting crystallization.

[0116] Examples 1-3 show that the hydrogen permeability is lower, and the ultra-high PE modified composite material can better promote dispersion in HDPE, thereby promoting crystallization. Comparative Examples 3, 4, 11, 12 and the comparative examples show that without the addition of monoethanolamine, nucleating agent and compatibilizer, the hydrogen permeability is higher, making it difficult to obtain polyolefin composite materials with high hydrogen storage efficiency.

[0117] Comparative Example 5 shows that when the petroleum resin is not modified, the performance of the resulting composite sheet decreases. Modifying the petroleum resin with monoethanolamine, and then modifying the ultra-high PE with the modified petroleum resin, can increase the fluidity of the ultra-high PE and improve its nucleation and crystallization ability, which helps to further enhance the hydrogen storage effect and mechanical properties of the polyolefin composite material.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a low-hydrogen-permeability polyolefin composite material, characterized in that: include, A xylene-petroleum resin mixed solution was prepared by mixing petroleum resin and xylene. An oxidant is added to a xylene petroleum resin mixture to carry out an oxidation reaction. After cooling, the mixture is hydrothermally reacted with monoethanolamine to obtain a modified petroleum resin. The mass percentage of monoethanolamine to the cooled xylene petroleum resin mixture is 6-12%: 88-94%. Ultra-high molecular weight polyethylene and modified petroleum resin are blended and melted, and then cooled to obtain ultra-high molecular weight polyethylene modified composite material. High-density polyethylene and ultra-high molecular weight polyethylene modified composite materials are mixed, and nucleating agents and compatibilizers are added before mechanical mixing to obtain polyolefin composite material particles. The mechanical mixing and extrusion conditions include: rotor speed of 2000~4500rpm, feed rate of 0.3~3kg / h, and barrel temperature of 200~250℃. Low hydrogen permeability polyolefin composite material is obtained by pressing polyolefin composite particles through a flat vulcanizing machine. The conditions of the flat vulcanizing machine include: temperature of 180~220℃, pressure of 10~20 MPa, and time of 5~20 min. The nucleating agent is barium sulfate and calcium carbonate, and the compatibilizer is maleic anhydride. Based on the mass parts of the raw materials, the ultra-high molecular weight polyethylene modified composite material is 10-50 parts by weight, the high-density polyethylene is 50-90 parts by weight, the nucleating agent content is 0.003-1 parts by weight, and the compatibilizer content is 0.4-2 parts by weight. The weight-average molecular weight of the high-density polyethylene is 120,000 to 300,000.

2. The preparation method according to claim 1, characterized in that: Based on the mass fractions of raw materials, petroleum resin comprises 9-13 parts and xylene comprises 87-96 parts.

3. The preparation method according to claim 1 or 2, characterized in that: The oxidant is an oxygen-ozone mixture, wherein the O3 volume concentration is 2%.

4. The preparation method according to claim 3, characterized in that: The oxidation reaction is carried out at a temperature of 3-8°C for a time of 20-50 minutes.

5. The preparation method according to claim 4, characterized in that: The hydrothermal reaction is carried out at a temperature of 70-90°C for 1-3 hours.

6. The preparation method according to claim 1, characterized in that: The process involves blending and melting ultra-high molecular weight polyethylene (UHMWPE) and modified petroleum resin, wherein the UHMWPE has a weight-average molecular weight of 3-9 million and the modified petroleum resin has a weight-average molecular weight of 1000-2500. The blending and melting process is carried out in the mixing chamber of a Hacker rheometer 300P, wherein the rotor speed is 50-70 rpm, the temperature is 150-170°C, and the time is 7-15 min.

7. The low-hydrogen-permeable polyolefin composite material prepared by any of the preparation methods described in claims 1 to 6.

8. The application of the low hydrogen permeability polyolefin composite material according to claim 7 in the preparation of hydrogen storage containers.

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