High-toughness homo-polypropylene / modified barite powder composite material and preparation method thereof

Abstract

The invention provides a high-toughness homo-polypropylene / modified barite powder composite material and a preparation method thereof, and belongs to the technical field of high polymer materials. The composite material is prepared from the following raw materials in parts by weight: 80-120 parts of homo-polypropylene, 30-70 parts of co-polypropylene, 1-5 parts of an antioxidant, 1-5 parts of a stabilizer and 35-65 parts of modified barite powder. According to the prepared composite material, the adopted resin is formed by compounding the homo-polypropylene and the co-polypropylene, the characteristics of good strength of the homo-polypropylene and good toughness of the co-polypropylene are fully played, meanwhile, the composite material is relatively simple in component formula, excessive high polymer materials are not introduced, and downstream customers can conveniently select and match the components; and the method can be widely applied to various scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a high-toughness homopolypropylene / modified barite powder composite material and a preparation method thereof. Background Art

[0002] Homopolypropylene is polymerized from a single propylene monomer and does not contain ethylene monomers in its molecular chain. Homopolypropylene has the advantage of good strength and is widely used in fields such as packing belts, woven bags, toys, electrical appliances, packaging, etc. The disadvantages of homopolypropylene are poor impact resistance and toughness. By using inorganic rigid particles such as calcium carbonate, kaolin, talc powder, barium sulfate, etc., a better dispersion structure can be formed in PP to improve its toughness.

[0003] Barite is a non-metallic ore product mainly composed of barium sulfate and is the most widely distributed barium-containing mineral in nature. Barite has stable chemical properties, is insoluble in water and hydrochloric acid, has a Mohs hardness of 3 - 3.5, and a specific gravity of 4.0 - 4.6. Barite crystals often appear as thick plate-like or columnar crystals, mostly as dense massive or plate-like and granular aggregates, and are often used for toughening and modifying polypropylene due to its perfect cleavage plane.

[0004] With the development of barite ultrafine grinding and processing technology, sub-nanometer grade (D50: 1 - 2μm) barite powder has successfully achieved industrial production. To improve the compatibility between sub-nanometer grade barite powder and polypropylene and achieve good dispersion of barite powder in the PP substrate, the barite powder needs to be surface-modified. The traditional method for modifying barite powder is to perform high-speed stirring of relevant modifying aids and barite powder together. This modification process has disadvantages such as uneven coating and poor interfacial compatibility with PP, resulting in a poor toughening effect on PP.

[0005] Based on this, it is very important to provide a high-toughness homopolypropylene / modified barite powder composite material with good interfacial compatibility and dispersibility. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-toughness homopolypropylene / modified barite powder composite material and a preparation method thereof to solve the technical problems of poor compatibility and dispersibility between sub-nanometer grade barite powder and polypropylene in the prior art.

[0007] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0008] The present invention provides a high-toughness homopolypropylene / modified barite powder composite material, which is prepared from raw materials including the following parts by weight:

[0009]

[0010] Further, the grades of the homopolypropylene include PPH-T03, and the grades of the copolymer polypropylene include K9928H.

[0011] Further, the preparation method of the modified barite powder includes the following steps:

[0012] (a) Prepare an aqueous solution with a solid content of 25-35% by mixing sub-nano barite powder and water, and then add a dispersant for pre-dispersion treatment to obtain a pre-dispersed slurry;

[0013] (b) Add sodium hydroxide to the pre-dispersed slurry to adjust the pH value to 9-10, and then stir to obtain a barite slurry;

[0014] (c) Add a coupling agent to the barite slurry and continue stirring. During the stirring process, dropwise add an oxalic acid solution to adjust the pH value to 6.5-7 for reaction;

[0015] (d) After the reaction is completed, spray-dry the reacted barite slurry to obtain the modified barite powder.

[0016] Further, the particle size D50 of the sub-nano barite powder is 1-2 μm, and D97 is 3-5.5 μm;

[0017] The dispersant includes one or more of sodium polyacrylate, ethylene glycol, polyacrylic acid, polymethacrylic acid, and sodium dodecylbenzenesulfonate;

[0018] The addition amount of the dispersant is 0.5-1.5% of the mass of the sub-nano barite powder;

[0019] The coupling agent includes one or more of isopropyl trioleoyl titanate, isopropyl triisostearoyl titanate, chelate solution of bis(dioctyloxy pyrophosphate) ethylene titanate and triethanolamine, isopropyl tris(dioctylpyrophosphato) titanate, and tetra isopropyl bis(dioctyl phosphite) titanate;

[0020] The addition amount of the coupling agent is 0.5-2% of the mass of the sub-nano barite powder.

[0021] Further, in the step (a), the temperature of the pre-dispersion treatment is 60-80 °C, and the time of the pre-dispersion treatment is 10-20 min;

[0022] In the step (b), the temperature of the stirring is 70-90 °C, and the time of the stirring is 10-20 min;

[0023] In the step (c), the temperature of the reaction is 80-100 °C, and the time of the reaction is 30-60 min.

[0024] Further, in the step (d), in the spray drying process, the inlet air temperature is 170-220 °C, the outlet air temperature is 110-140 °C, and the nozzle diameter is 3-8 cm.

[0025] Further, the antioxidant includes phenolic antioxidants;

[0026] The stabilizer includes one or more of zinc stearate, calcium stearate, and calcium-zinc composite stabilizer.

[0027] The present invention also provides a method for preparing the high-toughness homopolypropylene / modified barite powder composite material, comprising the following steps:

[0028] 1) Mix homopolypropylene, copolymerized polypropylene, antioxidant, stabilizer, and modified barite powder to obtain a mixed material;

[0029] 2) Extrude and pelletize the mixed material to obtain a high-toughness homopolypropylene / modified barite powder composite material.

[0030] Further, the mixing is carried out under stirring, the stirring temperature is 100-120 °C, the stirring time is 5-20 min, and the stirring speed is 350-900 r / min.

[0031] Further, the temperature for extrusion and pelletization is as follows: the temperatures of the first to third zones are independently 220-225 °C, the temperatures of the fourth to sixth zones are independently 225-230 °C, the temperatures of the seventh to ninth zones are independently 230-235 °C, the temperature of the die head is 235 °C, the screw diameter is 30-40 mm, and the length-diameter ratio is 35-45:1.

[0032] Advantages of the present invention:

[0033] 1) The present invention prepares modified barite powder by a wet modification process. By adding a dispersing aid to prepare a barite slurry, the dispersibility of sub-nanometer barite particles is improved. In a well-dispersed state, sodium hydroxide is added to increase the -COOH groups in the liquid phase system, making it easier for the surface of barite to react with the hydrophilic groups of the coupling agent. Further, by adding oxalic acid to adjust the pH value, the reaction activity of the coupling agent can be enhanced, and at the same time, the reaction sites on the surface of barite powder can be strengthened, maximizing the modification effect of the coupling agent on barite particles, forming a strong chemical bond between the coupling agent and barite molecules, realizing "oil-loving" on the surface of barite particles, applying it to polypropylene, improving its interfacial compatibility, and enhancing toughness;

[0034] 2) The present invention fully exerts the benefit of toughening polypropylene with inorganic rigid particles. Compared with traditional polypropylene toughening and modification methods (rubber or thermoplastic elastomer toughening, ternary blending toughening), it has the advantages of simple production operation, simple process, and low production cost;

[0035] 3) The resin used in the preparation of the composite material of the present invention is a blend of homopolypropylene and copolymerized polypropylene, which gives full play to the good strength of homopolypropylene and the good toughness of copolymerized polypropylene. At the same time, the component formula of the composite material is relatively simple, without introducing too many high-molecular materials, which is convenient for downstream customers to select and match, so that it can be widely used in a variety of scenarios;

[0036] 4) For the high-toughness homopolypropylene / modified barite powder composite material prepared by the present invention, due to the good interfacial compatibility between barite particles and polypropylene, the dispersion of barite particles in polypropylene is improved, and the production of the composite material is continuous and stable, with excellent comprehensive performance. Description of the Drawings

[0037] Figure 1 SEM image of the high-toughness homopolypropylene / modified barite powder composite material prepared in Example 3;

[0038] Figure 2 SEM image of the high-toughness homopolypropylene / modified barite powder composite material prepared in Comparative Example 1;

[0039] Figure 3 SEM image of the high-toughness homopolypropylene / modified barite powder composite material prepared in Comparative Example 2;

[0040] Figure 4 SEM image of the high-toughness homopolypropylene / modified barite powder composite material prepared in Comparative Example 3. Detailed Embodiments

[0041] The present invention provides a high-toughness homopolypropylene / modified barite powder composite material, which is prepared from the following raw materials in parts by weight:

[0042]

[0043] In the present invention, by weight, the content of the homopolypropylene is preferably 85-115 parts, more preferably 90-110 parts.

[0044] In the present invention, the grade of the homopolypropylene is preferably PPH-T03, Sinopec Maoming Company.

[0045] In the present invention, by weight, the content of the copolymerized polypropylene is preferably 35-65 parts, more preferably 40-60 parts.

[0046] In the present invention, the grade of the copolymerized polypropylene is preferably K9928H, Zhejiang Petrochemical Co., Ltd.

[0047] In the present invention, by weight parts, the content of the antioxidant is preferably 2 to 4 parts, more preferably 3 parts.

[0048] In the present invention, the antioxidant is preferably a phenolic antioxidant.

[0049] In the present invention, by weight parts, the content of the stabilizer is preferably 2 to 4 parts, more preferably 3 parts.

[0050] In the present invention, the stabilizer includes one or more of zinc stearate, calcium stearate and calcium-zinc composite stabilizer, preferably zinc stearate or calcium stearate, more preferably zinc stearate.

[0051] In the present invention, by weight parts, the content of the modified barite powder is preferably 40 to 60 parts, more preferably 45 to 55 parts.

[0052] In the present invention, the preparation method of the modified barite powder includes the following steps:

[0053] (a) Prepare an aqueous solution with a solid content of 25 to 35% by mixing sub-nano-sized barite powder and water, and then add a dispersant for pre-dispersion treatment to obtain a pre-dispersed slurry.

[0054] (b) Add sodium hydroxide to the pre-dispersed slurry to adjust the pH value to 9 to 10, and then stir to obtain a barite slurry.

[0055] (c) Add a coupling agent to the barite slurry and continue stirring. During the stirring process, dropwise add an oxalic acid solution to adjust the pH value to 6.5 to 7 for reaction.

[0056] (d) After the reaction is completed, perform spray drying treatment on the reacted barite slurry to obtain the modified barite powder.

[0057] In the present invention, the particle size D50 of the sub-nano-sized barite powder is 1 to 2 μm, preferably 1.2 to 1.8 μm, more preferably 1.4 to 1.6 μm; D97 is 3 to 5.5 μm, preferably 3.2 to 5.2 μm, more preferably 3.5 to 5 μm.

[0058] In the present invention, the dispersant includes one or more of sodium polyacrylate, ethylene glycol, polyacrylic acid, polymethacrylic acid and sodium dodecylbenzenesulfonate, preferably one or more of sodium polyacrylate, polyacrylic acid, polymethacrylic acid and sodium dodecylbenzenesulfonate, more preferably one or more of sodium polyacrylate, polymethacrylic acid and sodium dodecylbenzenesulfonate;

[0059] The addition amount of the dispersant is 0.5-1.5% of the mass of the sub-nano barite powder, preferably 0.7-1.3%, and more preferably 0.8-1%.

[0060] In the present invention, the coupling agent includes one or more of isopropyl trioleate titanate, isopropyl triisostearoyl titanate, chelate solution of bis(dioctyloxy pyrophosphate) ethylene titanate and triethanolamine, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate, and tetra isopropyl di(dioctyl phosphite) titanate. Preferably, it is one or more of isopropyl trioleate titanate, isopropyl triisostearoyl titanate, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate, and tetra isopropyl di(dioctyl phosphite) titanate. More preferably, it is one or more of isopropyl trioleate titanate, isopropyl triisostearoyl titanate, and tetra isopropyl di(dioctyl phosphite) titanate.

[0061] The addition amount of the coupling agent is 0.5-2% of the mass of the sub-nano barite powder, preferably 0.6-1.8%, and more preferably 0.8-1.2%.

[0062] In the present invention, in the step (a), the temperature of the pre-dispersion treatment is 60-80°C, preferably 65-75°C, and more preferably 70°C; the time of the pre-dispersion treatment is 10-20 min, preferably 12-18 min, and more preferably 14-16 min.

[0063] In the present invention, in the step (b), the temperature of the stirring is 70-90°C, preferably 75-85°C, and more preferably 80°C; the time of the stirring is 10-20 min, preferably 12-18 min, and more preferably 14-16 min.

[0064] In the present invention, in the step (c), the temperature of the reaction is 80-100°C, preferably 85-95°C, and more preferably 90°C; the time of the reaction is 30-60 min, preferably 35-55 min, and more preferably 40-50 min.

[0065] In the present invention, in the step (d), in the spray drying treatment, the inlet air temperature is 170-220°C, preferably 175-215°C, and more preferably 180-210°C; the outlet air temperature is 110-140°C, preferably 115-135°C, and more preferably 120-130°C; the nozzle diameter is 3-8 cm, preferably 4-7 cm, and more preferably 5-6 cm.

[0066] The present invention also provides a preparation method of the high-toughness homopolypropylene / modified barite powder composite material as described above, including the following steps:

[0067] 1) Mix homopolypropylene, copolymerized polypropylene, antioxidant, stabilizer and modified barite powder to obtain a mixed material;

[0068] 2) Extrude and pelletize the mixed material to obtain a high-toughness homopolypropylene / modified barite powder composite material.

[0069] In the present invention, the mixing is carried out under stirring. The temperature of stirring is 100 - 120 °C, preferably 105 - 115 °C, and more preferably 110 °C; the time of stirring is 5 - 20 min, preferably 8 - 15 min, and more preferably 10 min; the speed of stirring is 350 - 900 r / min, preferably 400 - 850 r / min, and more preferably 450 - 800 r / min.

[0070] In the present invention, the temperature for extrusion granulation is as follows: the temperatures of the first to the third zones are independently 220 - 225 °C, the temperatures of the fourth to the sixth zones are independently 225 - 230 °C, the temperatures of the seventh to the ninth zones are independently 230 - 235 °C, the temperature of the die head is 220 - 250 °C, the screw diameter is 30 - 40 mm, and the length-diameter ratio is 35 - 45:1;

[0071] Preferably, the temperature for extrusion granulation is as follows: the temperatures of the first to the third zones are independently 221 - 224 °C, the temperatures of the fourth to the sixth zones are independently 226 - 229 °C, the temperatures of the seventh to the ninth zones are independently 231 - 234 °C, the temperature of the die head is 230 - 240 °C, the screw diameter is 32 - 38 mm, and the length-diameter ratio is 37 - 43:1;

[0072] More preferably, the temperature for extrusion granulation is as follows: the temperatures of the first to the third zones are independently 222 - 223 °C, the temperatures of the fourth to the sixth zones are independently 227 - 228 °C, the temperatures of the seventh to the ninth zones are independently 232 - 233 °C, the temperature of the die head is 235 °C, the screw diameter is 34 - 36 mm, and the length-diameter ratio is 40:1.

[0073] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0074] The antioxidant model adopted in the present invention is antioxidant 1010, BASF (China) Co., Ltd.; the model of zinc stearate is AV320, Dongguan Hanwei Technology Co., Ltd.;

[0075] The twin-screw extruder adopted in the present invention is the SHJ-36 twin-screw extruder of Nanjing Hongjiayuan Machinery Technology Co., Ltd.

[0076] Example 1

[0077] 6 kg of sub-nano barite powder (D50 is 1.7 μm, D97 is 5.3 μm) was formulated with 14 kg of water into an aqueous solution with a solid content of 30%. Subsequently, 24 g of sodium polyacrylate and 24 g of ethylene glycol were added, and pre-dispersion treatment was carried out at 70 °C for 15 min to obtain a pre-dispersed slurry; sodium hydroxide was added to the pre-dispersed slurry to adjust the pH value to 9.5, and then stirred at 80 °C for 15 min to obtain a barite slurry; 72 g of isopropyltris(dioctylpyrophosphato)titanate coupling agent was added to the barite slurry and stirred continuously. During the stirring process, an oxalic acid solution was added dropwise to adjust the pH value to 6.5, and then reacted at a reaction temperature of 90 °C for 45 min; after the reaction, the reacted barite slurry was spray-dried using a spray dryer with a nozzle diameter of 5 cm, the inlet air temperature was 200 °C, and the outlet air temperature was 130 °C to obtain modified barite powder;

[0078] 10 kg of homopolypropylene PPH-T03, 5 kg of copolymerized polypropylene K9928H, 200 g of antioxidant 1010, 200 g of zinc stearate AV320, and 5 kg of modified barite powder were mixed. The mixing was carried out with stirring, the stirring temperature was 105 °C, the stirring time was 10 min, the stirring speed was 600 r / min. After stirring evenly, the material was discharged and cooled to obtain a mixed material;

[0079] The mixed material was poured into the barrel of a twin-screw extruder, and extrusion granulation was carried out using a horizontal twin-screw extruder. The screw diameter was 35.5 mm, the length-diameter ratio was 40:1, the temperature of the first to the third zones was 220 °C, the temperature of the fourth to the sixth zones was 225 °C, the temperature of the seventh to the ninth zones was 230 °C, and the die head temperature was 235 °C. After water-cooling and strand pelletization, a high-toughness homopolypropylene / modified barite powder composite material was obtained.

[0080] Example 2

[0081] Compared with Example 1, the difference is only that in Example 2, the D50 of the sub-nano barite powder is 1.3 μm and the D97 is 3.7 μm.

[0082] Example 3

[0083] Compared with Example 2, the difference is only that in Example 3, the dispersant is a chelate solution of 36 g of isopropyltris(dioctylpyrophosphato)titanate coupling agent, 36 g of bis(dioctyloxyphosphato)ethylene titanate, and triethanolamine.

[0084] Comparative Example 1

[0085] Compared with Example 3, the difference is that in the comparative example, the particle size of the sub-nano barite powder is D50: 3.9 μm, D97: 16.68 μm.

[0086] Comparative Example 2

[0087] 10 kg of homopolypropylene PPH-T03, 5 kg of copolymerized polypropylene K9928H, 200 g of antioxidant 1010, 200 g of zinc stearate AV320, and 5 kg of untreated barite powder (D50: 1.3 μm, D97: 3.7 μm) were mixed. The mixing was carried out with stirring at a temperature of 105°C, for a time of 10 min, at a speed of 600 r / min. After stirring evenly, the mixture was discharged and cooled to obtain a mixed material;

[0088] The mixed material was poured into the barrel of a twin-screw extruder and extruded into pellets using a horizontal twin-screw extruder. The screw diameter was 35.5 mm, the length-diameter ratio was 40:1, the temperature from zone 1 to zone 3 was 220°C, the temperature from zone 4 to zone 6 was 225°C, the temperature from zone 7 to zone 9 was 230°C, and the die head temperature was 235°C. After water-cooling and strand pelletization, a homopolypropylene / modified barite powder composite material was obtained.

[0089] Comparative Example 3

[0090] 10 kg of homopolypropylene PPH-T03, 5 kg of copolymerized polypropylene K9928H, 200 g of antioxidant 1010, 200 g of zinc stearate AV320, and 5 kg of modified ultrafine precipitated barium sulfate produced by Andeli were mixed. The mixing was carried out with stirring at a temperature of 105°C, for a time of 10 min, at a speed of 600 r / min. After stirring evenly, the mixture was discharged and cooled to obtain a mixed material;

[0091] The mixed material was poured into the barrel of a twin-screw extruder and extruded into pellets using a horizontal twin-screw extruder. The screw diameter was 35.5 mm, the length-diameter ratio was 40:1, the temperature from zone 1 to zone 3 was 220°C, the temperature from zone 4 to zone 6 was 225°C, the temperature from zone 7 to zone 9 was 230°C, and the die head temperature was 235°C. After water-cooling and strand pelletization, a homopolypropylene / modified barite powder composite material was obtained.

[0092] The homopolypropylene / modified barite powder composite materials prepared in Example 3 and Comparative Examples 1 to 3 were scanned, and the test results are as Figures 1 to 4 shown. From Figures 1 to 4It can be seen that in Example 3, barite particles form continuous dispersion in the PP substrate, and the particle size is relatively uniform; in Comparative Example 1, the dispersion continuity is poor, and there are larger particles; in Comparative Example 2, there are larger particles in the region, and the dispersion continuity is poor, which has a great relationship with the unmodified surface treatment of the added barite powder; Comparative Example 3 is a composite material prepared by using modified precipitated barium sulfate, where the particles are concentrated at certain points, and the particle dispersion is relatively continuous, but there are large aggregates. Based on the comprehensive SEM test results, it can be found that the composite material prepared by the present invention has better dispersibility, which is also consistent with the test results of the impact strength.

[0093] Comparative Example 4

[0094] Mix 10 kg of homopolypropylene PPH-T03, 5 kg of copolymer polypropylene K9928H, 200 g of antioxidant 1010, and 200 g of zinc stearate AV320. The mixing is carried out during stirring. The stirring temperature is 105 °C, the stirring time is 10 min, and the stirring speed is 600 r / min. After stirring evenly, the material is discharged and cooled to obtain a mixed material.

[0095] Pour the mixed material into the barrel of a twin-screw extruder and perform extrusion granulation using a horizontal twin-screw extruder. The screw diameter is 35.5 mm, the length-diameter ratio is 40:1, the temperature from zone 1 to zone 3 is 220 °C, the temperature from zone 4 to zone 6 is 225 °C, the temperature from zone 7 to zone 9 is 230 °C, and the die head temperature is 235 °C. After water cooling and strand cutting, a homopolypropylene / modified barite powder composite material is obtained.

[0096] Put the composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 into an injection molding machine. The temperature of the injection molding machine is set at 220 °C, and injection molding is performed on the composite materials to make standard specimens for relevant performance tests. The test methods are as follows:

[0097] Tensile property: Test according to GB / T528-2009 using a Chengde Jinjian UTM-1422 type electronic universal testing machine.

[0098] Impact resistance property: Test according to GB / T1843-2008 using a Chengde Jinjian XJUD-5.5 type electronic cantilever beam impact testing machine.

[0099] Particle dispersibility test: Analyze the morphology of the cross-section of the specimen after impact using a Phenom Pharos G2 field emission scanning electron microscope from Phenom Company, take pictures at a magnification of 3000 times, and observe its dispersibility. The test results are shown in Table 1.

[0100] Table 1 Performance test results of the composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4

[0101] Tensile strength (MPa) <![CDATA[Impact strength (KJ / m 2 )]]> Example 1 14.28 13.34 Example 2 14.40 13.69 Example 3 14.58 13.95 Comparative Example 1 14.04 9.13 Comparative Example 2 13.88 7.79 Comparative Example 3 14.24 12.32 Comparative Example 4 25.16 7.27

[0102] As can be seen from Table 1, the tensile strength of the PP / modified barite composite prepared by the present invention is improved compared with Comparative Examples 1-4; among them, Example 3 reaches the maximum value. This shows that the modified barite powder prepared by the present invention has good effects. This is because the titanate coupling agent contains a titanate group and an organic group, which can simultaneously undergo chemical reactions or physical adsorption with the surface of the inorganic filler and the organic matrix (PP), making the inorganic-organic interface have strong interaction forces, thereby effectively improving the tensile strength of the composite material.

[0103] As can be seen from Table 1, the impact strength of the PP / modified barite composite prepared by the present invention is improved compared with Comparative Examples 1-4; among them, Example 3 reaches the maximum value. At the same time, compared with the pure resin system, the impact strength is greatly improved after adding barite. Comparing Example 3 with Comparative Examples 1-4, the impact strength is increased by 50.9% compared with Comparative Example 1; the impact strength is increased by 79% compared with Comparative Example 2; the impact strength is increased by 13.2% compared with Comparative Example 3; the impact strength is increased by 91.9% compared with Comparative Example 4. This is because the sub-nanometer-sized modified barite particles with small particle sizes are more evenly dispersed in the PP matrix, the interfacial bonding force is enhanced, and the smaller barite particles can effectively disperse the external force and slow down the local stress concentration, thereby improving the impact strength of the composite material; the higher the impact strength, the better the toughness of the material. The test results of the impact strength show that the composite material prepared by the present invention has high toughness.

[0104] As can be seen from the above examples, the present invention provides a high-toughness homopolypropylene / modified barite powder composite material and a preparation method thereof, which are prepared from the following raw materials in parts by weight: 80-120 parts of homopolypropylene, 30-70 parts of copolymerized polypropylene, 1-5 parts of antioxidant, 1-5 parts of stabilizer, and 35-65 parts of modified barite powder. The resin used in the composite material prepared by the present invention is a compound of homopolypropylene and copolymerized polypropylene, which gives full play to the characteristics of good strength of homopolypropylene and good toughness of copolymerized polypropylene. At the same time, the component formula of the composite material is relatively simple, and not too many polymer materials are introduced, which is convenient for downstream customers to select and match, so that it can be widely used in a variety of scenarios.

[0105] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high-toughness homopolymer polypropylene / modified barite powder composite material, characterized in that: The method is prepared by including the following raw materials in parts by weight:

2. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 1, characterized in that: The grades of the homopolypropylene include PPH-T03, and the grades of the copolymer polypropylene include K9928H.

3. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 2, characterized in that: The preparation method of the modified barite powder comprises the following steps: (a) preparing a sub-nanometer barite powder and water into an aqueous solution with a solid content of 25 to 35%, and then adding a dispersant for pre-dispersion treatment to obtain a pre-dispersion slurry; (b) adding sodium hydroxide to the pre-dispersed slurry to adjust the pH value to 9-10, followed by stirring to obtain a barite slurry; (c) adding a coupling agent to the barite slurry and continuing to stir, and during the stirring process, dropping an oxalic acid solution to adjust the pH value to 6.5 to 7 for reaction; (d) After the reaction is completed, the barite slurry after the reaction is spray-dried to obtain modified barite powder.

4. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 3, characterized in that: The sub-nano barite powder has a particle size D50 of 1 to 2 μm and a D97 of 3 to 5.5 μm; The dispersant includes one or more of sodium polyacrylate, ethylene glycol, polyacrylic acid, polymethacrylic acid and sodium dodecylbenzene sulfonate; The amount of the dispersant added is 0.5-1.5% of the mass of the sub-nanometer barite powder; The coupling agent includes one or more of trioleyl isopropyl titanate, triisostearoyl isopropyl titanate, a chelate solution of bis(dioctyl pyrophosphate)ethylene titanate and triethanolamine, isopropyl tri(dioctyl pyrophosphate) titanate and tetraisopropyl di(dioctyl phosphite) titanate; The added amount of the coupling agent is 0.5-2% of the mass of the sub-nanometer barite powder.

5. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 3 or 4, characterized in that: In the step (a), the pre-dispersion treatment temperature is 60 to 80° C., and the pre-dispersion treatment time is 10 to 20 minutes; In the step (b), the stirring temperature is 70 to 90° C. and the stirring time is 10 to 20 min; In the step (c), the reaction temperature is 80-100° C. and the reaction time is 30-60 min.

6. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 5, characterized in that: In the step (d), during the spray drying process, the air inlet temperature is 170-220° C., the air outlet temperature is 110-140° C., and the nozzle diameter is 3-8 cm.

7. The high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 1, characterized in that: The antioxidant includes a phenolic antioxidant; The stabilizer includes one or more of zinc stearate, calcium stearate and calcium-zinc composite stabilizer.

8. A method for preparing the high-toughness homopolymer polypropylene / modified barite powder composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) mixing homopolypropylene, copolymer polypropylene, an antioxidant, a stabilizer and modified barite powder to obtain a mixed material; 2) Extruding and granulating the mixture to obtain a high-toughness homopolymer polypropylene / modified barite powder composite material.

9. The method for preparing the high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 8, characterized in that: The mixing is carried out under stirring, the stirring temperature is 100-120° C., the stirring time is 5-20 min, and the stirring speed is 350-900 r / min.

10. The method for preparing the high-toughness homopolymer polypropylene / modified barite powder composite material according to claim 9, characterized in that: The temperature of the extrusion granulation is: the temperature of zones 1 to 3 is independently 220-225°C, the temperature of zones 4 to 6 is independently 225-230°C, the temperature of zones 7 to 9 is independently 230-235°C, the temperature of the die head is 235°C, the screw diameter is 30-40mm, and the aspect ratio is 35-45:1.

Images