Maleic anhydride functional modified polyolefin resin composition as well as preparation method and application thereof

Abstract

The invention discloses a maleic anhydride functional modified polyolefin resin composition as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. Comprising the following steps: mixing maleic anhydride modified polypropylene, polylactic acid and dicumyl peroxide, banburying, adding modified silicon dioxide, a synergist, epoxidized soybean oil and hydroxyl-terminated hyperbranched polyester, carrying out melt blending, and carrying out water-cooling tabletting and crushing treatment to obtain the maleic anhydride functionalized modified polyolefin resin composition. By introducing maleic anhydride modified polypropylene prepared from polypropylene, maleic anhydride and other components, the adhesive force, impact resistance and flame retardance of the polyolefin resin composition can be effectively improved; and the flame retardance, the corrosion resistance, the impact resistance and the heat resistance of the polyolefin resin composition are further improved due to the introduction of the synergist, the modified silicon dioxide and other components. Therefore, the method has a wider application prospect.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a maleic anhydride functionalized modified polyolefin resin composition, its preparation method, and its application. Background Technology

[0002] Polypropylene-based coatings are a type of coating that uses polypropylene or its modified products as the main film-forming substance. They are characterized by chemical corrosion resistance, water resistance, good insulation, and low cost, and are widely used in industrial corrosion protection, packaging, automotive parts, and home appliances. However, due to their low polarity, they have poor adhesion to metal and polar substrates.

[0003] To address the aforementioned technical problems, existing technologies propose grafting maleic anhydride onto polypropylene resin, which effectively improves the compatibility of the polypropylene resin and enhances the adhesion of polypropylene-based coatings. However, in practical applications, polypropylene-based coatings still exhibit issues such as softening and deformation at high temperatures, flammability, and the tendency to drip and spread fire during combustion. Therefore, the fire retardancy and heat resistance of existing polypropylene resin compositions still require further improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a maleic anhydride-functionalized modified polyolefin resin composition, its preparation method, and its application, thereby solving the following technical problems:

[0005] Existing polypropylene resin compositions still suffer from poor fire retardancy and heat resistance.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a maleic anhydride-functionalized modified polyolefin resin composition includes the following steps:

[0008] Maleic anhydride-modified polypropylene, polylactic acid, and dicumyl peroxide are mixed and kneaded at 155-165℃ for 5-7 minutes. Then, modified silica, synergist, epoxidized soybean oil, and hydroxyl-terminated hyperbranched polyester are added and melt-blended at 165-175℃ for 8-10 minutes. The mixture is then water-cooled, pressed into sheets, and crushed to obtain a maleic anhydride-functionalized modified polyolefin resin composition.

[0009] Preferably, the mass ratio of maleic anhydride modified polypropylene, polylactic acid, dicumyl peroxide, modified silica, synergist, epoxidized soybean oil, and hydroxyl-terminated hyperbranched polyester is 80-100:30-38:1-1.2:10-12:6-8:8-10:4-5.

[0010] Preferably, the preparation method of the maleic anhydride-modified polypropylene is as follows:

[0011] Polypropylene, maleic anhydride, and dicumyl peroxide are mixed and melt-blended using a twin-screw extruder at a zone temperature of 160-170℃, a zone temperature of 180-190℃, a zone temperature of 195-200℃, and a screw speed of 110-150 r / min. After extrusion, the mixture is water-cooled and pelletized to obtain maleic anhydride-modified polypropylene.

[0012] Preferably, the mass ratio of polypropylene, maleic anhydride, and dicumyl oxide is 95-114:5-6:1.5-1.8.

[0013] Preferably, the modified silica is prepared by the following method:

[0014] Nano-silica was added to anhydrous ethanol and ultrasonically dispersed for 20-30 minutes. Then, silane coupling agent KH-550 was added and the mixture was heated to 58-62℃ and stirred for 2-2.5 hours. Finally, the mixture was centrifuged and vacuum dried to obtain modified silica.

[0015] Preferably, the mass ratio of anhydrous ethanol, nano-silica, and silane coupling agent KH-550 is 90-100:15-17:0.7-0.9.

[0016] Preferably, the synergist is prepared by the following method:

[0017] A1: Add 3,5-diamino-1,2,4-triazole and triethylamine to tetrahydrofuran and stir at 58-62℃ for 20-30 min. Then add phenylphosphine dichloride dropwise and react at 58-60℃ for 12-13 h. After centrifugation, washing the precipitate and vacuum drying, a pale yellow solid is obtained.

[0018] A2: Add titanium aluminum carbide powder to deionized water and ultrasonically disperse for 30-40 minutes to obtain titanium aluminum carbide dispersion;

[0019] A3: Add a pale yellow solid to anhydrous ethanol and ultrasonically disperse for 30-40 min. Then add titanium aluminum carbide dispersion at 38-42℃ and react for 12-15 h. After centrifugation, washing the precipitate, and vacuum drying, the flame retardant is obtained.

[0020] A4: Add deionized water to anhydrous ethanol and adjust the pH to 5-5.5 with acetic acid. Then add halloysite nanotubes and perform ultrasonic dispersion for 10-20 min. Then add silane coupling agent KH-550 and reflux at 78-82℃ for 6-7 h. After centrifugation and vacuum drying, pretreated nanotubes are obtained.

[0021] A5: Add pretreated nanotubes and flame retardant to anhydrous ethanol and ultrasonically disperse for 10-20 min. Then stir and react at 58-62℃ for 4-6 h. After centrifugation and vacuum drying, the synergist is obtained.

[0022] Preferably, the mass ratio of tetrahydrofuran, 3,5-diamino-1,2,4-triazole, triethylamine, and phenylphosphine dichloride in A1 is 50-60:5-6:10-12:9.75-11.7;

[0023] The mass ratio of deionized water to titanium aluminum carbide powder in A2 is 100-120:2-3;

[0024] The mass ratio of anhydrous ethanol, pale yellow solid, and titanium aluminum carbide dispersion described in A3 is 120-150:3-4.5:102-123.

[0025] Preferably, the mass ratio of anhydrous ethanol, deionized water, halloysite nanotubes, and silane coupling agent KH-550 in A4 is 80-120:20-30:2-3:4-6;

[0026] The mass ratio of anhydrous ethanol, pretreated nanotubes, and flame retardant in A5 is 100-150:2-3:4-6.

[0027] Application of a maleic anhydride functionalized modified polyolefin resin composition, wherein the maleic anhydride functionalized modified polyolefin resin composition can be prepared into coatings for use in the fields of shipbuilding, automobiles, packaging and home appliances.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a maleic anhydride functionalized modified polyolefin resin composition, its preparation method, and its application. The invention effectively improves the adhesion, fire retardancy, and heat resistance of the polyolefin resin composition through the following method.

[0030] (1) The modified silica of this invention has a strong interaction with other components in the coating, enhancing the connection between the molecular chains of the coating, thereby improving the impact resistance and tensile strength of the coating. The modified silica can form a dense protective film on the surface of the coating. This protective film can prevent external corrosive substances such as acids, alkalis, and salts from contacting the polymer matrix inside the coating, thereby improving the corrosion resistance of the coating. The modified silica has a certain water absorption capacity, which can absorb the moisture in the coating, thereby accelerating the drying speed of the coating. During the drying process of the coating, the modified silica can adsorb moisture and make it evaporate quickly, reducing the residual time of moisture in the coating, so that the coating can form a dry paint film more quickly. The surface of the modified silica has certain active groups. These active groups can react chemically with other components in the coating and the surface of the coated object to form chemical bonds or strong intermolecular forces, thereby improving the adhesion of the coating. The rigid structure of the modified silica can restrict the movement of polymer chain segments at high temperatures, improving the heat distortion temperature and heat resistance stability of the material. Furthermore, it can reduce the debonding of fillers from the matrix at high temperatures, avoiding performance degradation caused by filler detachment. Modified silica can promote polymer charring during combustion, forming a heat-insulating and oxygen-barrier char layer, which further enhances the flame-retardant effect.

[0031] (2) In the maleic anhydride-modified polypropylene of this invention, polypropylene is a non-polar polymer with poor compatibility with polar resins and polar fillers. By grafting maleic anhydride, polar anhydride groups can be introduced, which significantly improves its interfacial affinity with polar components, reduces phase separation, improves the structural stability of the coating after film formation, reduces filler agglomeration, and makes the nanofillers uniformly distributed in the coating, thereby enhancing the mechanical properties and functionality of the coating. The anhydride groups of maleic anhydride can react chemically with other components such as epoxidized soybean oil in the coating to form chemical bonds such as ester bonds and ether bonds, which promotes the formation of cross-linked networks in the coating during the curing process, enhances the impact resistance, wear resistance and tensile strength of the coating, reduces the risk of cracking, reduces the swelling effect of solvent on the coating, and improves the resistance to corrosion by acid, alkali and salt solvents; the cross-linking reaction also enables the coating to form chemical bonds with the polar groups on the surface of the substrate, improving the adhesion of the coating. The anhydride groups of maleic anhydride-modified polypropylene can decompose into carboxylic acids during combustion, which, together with phosphorus and nitrogen compounds, catalyze the dehydration of the polypropylene matrix into carbon, blocking heat and oxygen transfer. At the same time, the anhydride groups of maleic anhydride-modified polypropylene can fix fillers such as modified silica through interfacial bonding, forming a "network skeleton" that hinders the flow of polypropylene molecular chains and significantly reduces the dripping phenomenon during combustion.

[0032] (3) The flame retardant in the synergist of this invention is composed of titanium aluminum carbide and phosphorus-nitrogen compounds. The phosphorus-containing compounds can form phosphoric acid and pyrophosphate layers during combustion, which can isolate heat and oxygen. The nitrogen-containing compounds decompose to produce inert gases, which dilute the concentration of combustible gases and promote the formation of char layers. This is an intumescent flame retardant mechanism. Titanium aluminum carbide has high thermal conductivity and high temperature resistance. It may form a ceramic layer during combustion, which can enhance the stability of the char layer, inhibit molten dripping, and further delay combustion diffusion. After pretreatment, the silane coupling agent will chemically adsorb onto the surface of the nanotubes to introduce organic groups, which can improve its compatibility with the polyolefin matrix, reduce agglomeration, and disperse it evenly in the coating. As a "nanoskeleton", the nanotubes can also bear stress transmission, improve the hardness, wear resistance, impact resistance and tensile strength of the coating, and reduce the brittleness of the coating. The titanium aluminum carbide particles in the flame retardant will form a composite reinforcing network with the nanotubes, which can further improve the overall mechanical properties of the coating, especially at high temperatures, where it may maintain structural stability. The silane coupling agent in the synergist acts on both the nanotube and flame retardant surfaces, enhancing the interfacial bonding between the filler and the matrix through chemical bonding, reducing the risk of peeling between the coating and the substrate, and improving adhesion. The silane-modified filler surface forms a hydrophobic layer, reducing the coating's sensitivity to water and solvents, improving chemical corrosion resistance, and extending its service life.

[0033] (4) The hydroxyl-terminated hyperbranched polyester of the present invention contains a large number of hydroxyl groups, which can react chemically with the anhydride groups in maleic anhydride-modified polypropylene and the epoxy groups in epoxidized soybean oil to form a covalent cross-linking network, thereby increasing the cross-linking density after the coating is cured, thus enhancing the hardness, wear resistance and tensile strength of the coating film; hydroxyl groups are polar groups, which can enhance the interfacial bonding force between the coating and the substrate through hydrogen bonding or reaction with functional groups on the surface of the substrate; the three-dimensional network structure formed after the hydroxyl-terminated groups participate in the cross-linking can hinder the penetration of solvents, water or corrosive media, and improve the chemical corrosion resistance of the coating film; the branched segments of the hyperbranched polyester can act as "flexible links", introducing a certain degree of flexibility into the cross-linking network, avoiding cracking of the purely rigid cross-linked coating film due to excessive brittleness. The molecular structure of the hydroxyl-terminated hyperbranched polyester is relatively stable and can hinder the thermal motion of polymer molecular chains to a certain extent; its chemical bonding or strong interaction with other components can enhance the overall structural stability of the system; the special molecular structure of the hydroxyl-terminated hyperbranched polyester and its interaction with other components can limit the expansion and contraction of polymer molecular chains when the temperature changes. Hydroxyl-terminated hyperbranched polyesters can promote the formation of a denser and more stable char layer, thereby improving the flame retardant properties of the material; they can also promote better dispersion of flame retardants in the polymer matrix, thereby improving the utilization rate of flame retardants.

[0034] Therefore, the maleic anhydride functionalized modified polyolefin resin composition prepared by this invention has excellent adhesion, flame retardancy, corrosion resistance, impact resistance and heat resistance, as well as a wider range of application prospects. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Unless otherwise specified, the following information pertains to some of the raw materials used in the following embodiments and comparative examples of this invention:

[0037] Nano-silica was purchased from Zhejiang Manli Nanotechnology Co., Ltd., item number: ML-SiO2; polypropylene was purchased from Wuhan Jiyesheng Chemical Co., Ltd., item number: A00813; titanium aluminum carbide powder was purchased from Shanghai Baoyang Baoxin Biotechnology Co., Ltd., item number: BX0614; halloysite nanotubes were purchased from Guangdong Jina New Materials Technology Co., Ltd., item number: JN-1; polylactic acid was purchased from Hubei Xinhongli Chemical Co., Ltd., item number: XHL3570; hydroxyl-terminated hyperbranched polyester was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., item number: PA98433.

[0038] Example 1: A method for preparing a maleic anhydride functionalized modified polyolefin resin composition is as follows:

[0039] S1: 15g of nano-silica was added to 90g of anhydrous ethanol and ultrasonically dispersed at 450W and 35kHz for 20min. Then, 0.7g of silane coupling agent KH-550 was added and the temperature was raised to 58℃. After stirring and reacting at 58℃ for 2h, the mixture was centrifuged and vacuum dried at 78℃ for 12h to obtain modified silica.

[0040] S2: 95g polypropylene, 5g maleic anhydride, and 1.5g dicumyl peroxide were mixed and melt-blended using a twin-screw extruder at a zone temperature of 160℃ in zone 1, 180℃ in zone 2, 195℃ in zone 3, and a screw speed of 110r / min. After extrusion, the mixture was cooled with water and pelletized to obtain maleic anhydride modified polypropylene.

[0041] S3: Add 5g of 3,5-diamino-1,2,4-triazole and 10g of triethylamine to 50g of tetrahydrofuran and stir at 58℃ for 20min. Then add 9.75g of phenylphosphine dichloride dropwise at 0.5g / min and react at 58℃ for 12h. After centrifugation, wash the precipitate 5 times with deionized water and then vacuum dry at 58℃ for 12h to obtain a pale yellow solid.

[0042] S4: Add 2g of titanium aluminum carbide powder to 100mL of deionized water and perform ultrasonic dispersion at 350W and 30kHz for 30min to obtain titanium aluminum carbide dispersion.

[0043] S5: Add 3g of pale yellow solid to 120g of anhydrous ethanol and disperse it by ultrasonication for 30min. Then add 102g of titanium aluminum carbide dispersion at 38℃ and react for 12h. Then centrifuge and wash the precipitate three times with anhydrous ethanol, then wash it three times with deionized water and then vacuum dry it at 58℃ for 12h to obtain the flame retardant.

[0044] S6: Add 20g of deionized water to 80g of anhydrous ethanol and adjust the pH to 5 with acetic acid. Then add 2g of halloysite nanotubes and perform ultrasonic dispersion for 10min. Then add 4g of silane coupling agent KH-550 and reflux at 78℃ for 6h. After centrifugation and vacuum drying, pretreated nanotubes are obtained.

[0045] S7: Add 2g of pretreated nanotubes and 4g of flame retardant to 100g of anhydrous ethanol and ultrasonically disperse for 10min. Then stir and react at 58℃ for 4h, then centrifuge and vacuum dry at 78℃ for 24h to obtain the synergist.

[0046] S8: Mix 80g of maleic anhydride-modified polypropylene, 30g of polylactic acid, and 1g of dicumyl peroxide and knead at 155°C for 5 minutes. Then add 10g of modified silica, 6g of synergist, 8g of epoxidized soybean oil, and 4g of hydroxyl-terminated hyperbranched polyester and melt-blend at 165°C for 8 minutes. After water-cooling, pressing, and crushing, a maleic anhydride functionalized modified polyolefin resin composition is obtained.

[0047] Example 2: A method for preparing a maleic anhydride functionalized modified polyolefin resin composition is as follows:

[0048] S1: 16g of nano-silica was added to 95g of anhydrous ethanol and ultrasonically dispersed at 480W and 38kHz for 25min. Then, 0.8g of silane coupling agent KH-550 was added and the temperature was raised to 60℃. After stirring and reacting at 60℃ for 2-2.3h, the mixture was centrifuged and vacuum dried at 80℃ for 13h to obtain modified silica.

[0049] S2: 100g polypropylene, 5.5g maleic anhydride and 1.7g dicumyl peroxide were mixed and melt-blended using a twin-screw extruder at a zone temperature of 165℃ in zone 1, 185℃ in zone 2 and 198℃ in zone 3 and a screw speed of 130r / min. After extrusion, the mixture was cooled with water and pelletized to obtain maleic anhydride modified polypropylene.

[0050] S3: Add 5.5g of 3,5-diamino-1,2,4-triazole and 11g of triethylamine to 55g of tetrahydrofuran and stir at 60℃ for 25min. Then add 10.7g of phenylphosphine dichloride dropwise at 0.6g / min and react at 59℃ for 12.5h. After centrifugation, wash the precipitate 6 times with deionized water and then dry it under vacuum at 59℃ for 13h to obtain a pale yellow solid.

[0051] S4: Add 2.5g of titanium aluminum carbide powder to 110mL of deionized water and perform ultrasonic dispersion at 380W power and 33kHz for 35min to obtain titanium aluminum carbide dispersion.

[0052] S5: Add 3.75g of pale yellow solid to 135g of anhydrous ethanol and disperse it by ultrasonication for 35min. Then add 113g of titanium aluminum carbide dispersion at 40℃ and react for 14h. Then centrifuge and wash the precipitate 4 times with anhydrous ethanol, then wash it 4 times with deionized water and then vacuum dry it at 60℃ for 14h to obtain the flame retardant.

[0053] S6: Add 25g of deionized water to 100g of anhydrous ethanol and adjust the pH to 5.2 with acetic acid. Then add 2.5g of halloysite nanotubes and perform ultrasonic dispersion for 15min. Then add 5g of silane coupling agent KH-550 and reflux at 80℃ for 8h. After centrifugation and vacuum drying, pretreated nanotubes are obtained.

[0054] S7: Add 2.5g of pretreated nanotubes and 5g of flame retardant to 125g of anhydrous ethanol and ultrasonically disperse for 15min. Then stir and react at 60℃ for 5h, then centrifuge and vacuum dry at 80℃ for 24.5h to obtain the synergist.

[0055] S8: Mix 90g of maleic anhydride-modified polypropylene, 34g of polylactic acid, and 1.1g of dicumyl peroxide and knead at 160℃ for 6 minutes. Then add 11g of modified silica, 7g of synergist, 9g of epoxidized soybean oil, and 4.5g of hydroxyl-terminated hyperbranched polyester and melt-blend at 170℃ for 9 minutes. After water-cooling, pressing, and crushing, a maleic anhydride functionalized modified polyolefin resin composition is obtained.

[0056] Example 3: A method for preparing a maleic anhydride functionalized modified polyolefin resin composition is as follows:

[0057] S1: 17g of nano-silica was added to 100g of anhydrous ethanol and ultrasonically dispersed at 500W and 40kHz for 30min. Then, 0.9g of silane coupling agent 550 was added and the temperature was raised to 62℃. After stirring at 62℃ for 2.5h, the mixture was centrifuged and vacuum dried at 82℃ for 15h to obtain modified silica.

[0058] S2: 114g of polypropylene, 6g of maleic anhydride, and 1.8g of dicumyl peroxide were mixed and melt-blended using a twin-screw extruder at a zone temperature of 170℃ in zone 1, 190℃ in zone 2, 200℃ in zone 3, and a screw speed of 150r / min. After extrusion, the mixture was cooled with water and pelletized to obtain maleic anhydride-modified polypropylene.

[0059] S3: Add 6g of 3,5-diamino-1,2,4-triazole and 12g of triethylamine to 60g of tetrahydrofuran and stir at 62℃ for 30min. Then add 11.7g of phenylphosphine dichloride dropwise at 0.7g / min and react at 60℃ for 13h. After centrifugation, wash the precipitate 7 times with deionized water and then vacuum dry at 60℃ for 15h to obtain a pale yellow solid.

[0060] S4: Add 3g of titanium aluminum carbide powder to 120mL of deionized water and perform ultrasonic dispersion at 400W power and 35kHz frequency for 40min to obtain titanium aluminum carbide dispersion.

[0061] S5: Add 4.5g of pale yellow solid to 150g of anhydrous ethanol and disperse it by ultrasonication for 40min. Then add 123g of titanium aluminum carbide dispersion at 42℃ and react for 15h. Then centrifuge and wash the precipitate 5 times with anhydrous ethanol, then wash it 5 times with deionized water and then vacuum dry it at 62℃ for 15h to obtain the flame retardant.

[0062] S6: Add 30g of deionized water to 120g of anhydrous ethanol and adjust the pH to 5.5 with acetic acid. Then add 3g of halloysite nanotubes and perform ultrasonic dispersion for 20min. Then add 6g of silane coupling agent KH-550 and reflux at 82℃ for 7h. After centrifugation and vacuum drying, pretreated nanotubes are obtained.

[0063] S7: Add 3g of pretreated nanotubes and 6g of flame retardant to 150g of anhydrous ethanol and ultrasonically disperse for 20min. Then stir and react at 62℃ for 6h, then centrifuge and vacuum dry at 82℃ for 25h to obtain the synergist.

[0064] S8: Mix 100g of maleic anhydride-modified polypropylene, 38g of polylactic acid, and 1.2g of dicumyl peroxide and knead at 165°C for 7 minutes. Then add 12g of modified silica, 8g of synergist, 10g of epoxidized soybean oil, and 5g of hydroxyl-terminated hyperbranched polyester and melt-blend at 175°C for 10 minutes. After water-cooling, pressing, and crushing, a maleic anhydride functionalized modified polyolefin resin composition is obtained.

[0065] Comparative Example 1:

[0066] Compared with Example 1, this comparative example only replaces the "modified silica" added during the S8 preparation process with "nano silica". All other steps and parameters are the same, and will not be repeated in this comparative example. The final result is a maleic anhydride functionalized modified polyolefin resin composition.

[0067] Comparative Example 2:

[0068] Compared with Example 1, this comparative example only did not add "modified silica" in the S8 preparation process. All other steps and parameters were the same, and will not be repeated here. The final result was a maleic anhydride functionalized modified polyolefin resin composition.

[0069] Comparative Example 3:

[0070] Compared with Example 1, this comparative example only replaces "maleic anhydride-modified polypropylene" added during the S8 preparation process with "polypropylene". All other steps and parameters are the same, and will not be repeated in this comparative example. The final result is a maleic anhydride functionalized modified polyolefin resin composition.

[0071] Comparative Example 4:

[0072] Compared with Example 1, this comparative example only replaces the "synergist" added during the S8 preparation process with a "flame retardant". All other steps and parameters are the same, and will not be repeated here. The final result is a maleic anhydride functionalized modified polyolefin resin composition.

[0073] Comparative Example 5:

[0074] This comparative example differs from Example 1 only in that no flame retardant was added during the S7 preparation process; all other steps and parameters are the same. This comparative example will not be repeated here. The final result is a maleic anhydride functionalized modified polyolefin resin composition.

[0075] Comparative Example 6:

[0076] Compared with Example 1, this comparative example only did not add a "synergist" in the preparation process of S8. All other steps and parameters were the same, and will not be repeated here. The final result was a maleic anhydride functionalized modified polyolefin resin composition.

[0077] Comparative Example 7:

[0078] Compared with Example 1, this comparative example only did not add "terminated hydroxyl hyperbranched polyester" in the preparation process of S8. All other steps and parameters were the same, and will not be repeated here. The final result was a maleic anhydride functionalized modified polyolefin resin composition.

[0079] Performance testing:

[0080] 45g xylene and 30g butyl acetate were mixed evenly, and then 25g of the maleic anhydride functionalized modified polyolefin resin composition prepared in this invention was added and ball-milled for 1 hour to disperse it. Then, it was stirred at 800r / min for 30min and sprayed onto the surface of a substrate (50mm×120mm×3mm aluminum plate). When the spray thickness reached 5mm, the spraying was stopped and the sample was placed at 25℃ for 20min to dry. Finally, it was baked at 80℃ for 30min to obtain the test sample.

[0081] Adhesion determination:

[0082] Referring to GB / T9286-2021 "Cross-cut test of paints and varnishes", the coating adhesion grades of the test samples made of maleic anhydride functionalized modified polyolefin resin compositions prepared in Examples 1-3 and Comparative Examples 1-7 of this invention were determined (divided into grades 0-5, with grade 0 being the strongest adhesion and grade 5 being the weakest adhesion). The test results are shown in Table 1.

[0083] Determination of limiting oxygen index:

[0084] Referring to GB / T 2406.2-2009 "Determination of Combustion Behavior by Oxygen Index Method for Plastics - Part 2: Room Temperature Test", the surface coating of the test specimen was made into a long strip specimen (80mm long × 10mm wide × 1.5mm thick). Then, the limiting oxygen index (%) of the coating of the test specimen made of maleic anhydride functionalized modified polyolefin resin composition prepared in Examples 1-3 and Comparative Examples 1-7 was determined using a JF-5 intelligent oxygen index meter (JYW-74, Modis Combustion Technology Co., Ltd.). The test results are shown in Table 1.

[0085] Determination of flame retardancy:

[0086] Referring to the UL94 standard, the surface coating of the test specimen was made into a long strip specimen (120 mm long × 10 mm wide × 1.5 mm thick). Vertical burning tests were conducted on the coatings of the test specimens made of maleic anhydride functionalized modified polyolefin resin compositions prepared in Examples 1-3 and Comparative Examples 1-7. The test results are shown in Table 1.

[0087] Corrosion resistance testing:

[0088] Referring to the GB / T10125-2021 standard "Artificial Atmosphere Corrosion Test - Salt Spray Test", the test samples were sealed with epoxy putty and then placed in a salt spray test chamber (JAY-1127, Zhuhai Jiayi Testing Equipment Co., Ltd.). A 24-hour salt spray and 24-hour drying cycle test was conducted at 35℃ using a 5% sodium chloride solution with a pH of 6.5-7.2. Samples were taken and observed every 48 hours, and the test duration for the appearance of red rust on each sample was recorded. The neutral salt spray test ended when the last sample showed red rust. The corrosion resistance (h) of the test samples made from the maleic anhydride functionalized modified polyolefin resin compositions prepared in Examples 1-3 and Comparative Examples 1-7 of this invention was determined according to the above method. The test results are shown in Table 1.

[0089] Impact resistance testing:

[0090] Referring to GB / T 20624.2-2006 "Paints and varnishes - Rapid impact (impact resistance) test, Part 2: Drop hammer test (small area punch)", the impact resistance (kg·cm) of the test specimens made of maleic anhydride functionalized modified polyolefin resin compositions prepared in Examples 1-3 and Comparative Examples 1-7 of this invention was measured using a paint film impact tester (TCJ-II, Shanghai Leao Test Instrument Co., Ltd.) with a 1kg hammer. The test results are shown in Table 1.

[0091] Determination of heat resistance:

[0092] Referring to the test standard GB / T 1735-2009 "Determination of Heat Resistance of Paints and Varnishes", the test samples were tested to determine whether defects such as blistering, cracking, and discoloration occurred after heat treatment at 200℃ for 100 hours. The heat resistance of test samples made from the maleic anhydride functionalized modified polyolefin resin compositions prepared in Examples 1-3 and Comparative Examples 1-7 of this invention was determined according to the above method. The test results are shown in Table 1.

[0093] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-9

[0094] project Adhesion / Grade Limiting oxygen index / % Flame retardancy rating Corrosion resistance / h Impact resistance / kg·cm Heat resistance Example 1 0 33.2 VO 1392 50 No defects Example 2 0 33.3 VO 1392 50 No defects Example 3 0 33.1 VO 1392 50 No defects Comparative Example 1 0 31.9 VO 1248 50 No defects Comparative Example 2 1 29.2 V-1 1008 45 cracking Comparative Example 3 0 28.8 V-1 1104 40 cracking Comparative Example 4 0 29.5 VO 1344 45 No defects Comparative Example 5 0 23.1 V-1 1344 45 foaming Comparative Example 6 1 20.3 V-2 1296 40 foaming Comparative Example 7 0 29.0 V-1 1296 40 foaming

[0095] Data Analysis:

[0096] As can be seen from Table 1, the maleic anhydride functionalized modified polyolefin resin composition prepared in the embodiments of the present invention has excellent adhesion, flame retardancy, corrosion resistance, impact resistance and heat resistance.

[0097] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for preparing a maleic anhydride-functionalized modified polyolefin resin composition, characterized in that, Includes the following steps: Maleic anhydride-modified polypropylene, polylactic acid, and dicumyl peroxide are mixed and kneaded at 155-165℃ for 5-7 minutes. Then, modified silica, synergist, epoxidized soybean oil, and hydroxyl-terminated hyperbranched polyester are added and melt-blended at 165-175℃ for 8-10 minutes. The mixture is then water-cooled, pressed into sheets, and crushed to obtain a maleic anhydride-functionalized modified polyolefin resin composition.

2. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 1, characterized in that, The mass ratio of maleic anhydride-modified polypropylene, polylactic acid, dicumyl peroxide, modified silica, synergist, epoxidized soybean oil, and hydroxyl-terminated hyperbranched polyester is 80-100:30-38:1-1.2:10-12:6-8:8-10:4-5.

3. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 1, characterized in that, The preparation method of the maleic anhydride modified polypropylene is as follows: Polypropylene, maleic anhydride, and dicumyl peroxide were mixed and melt-blended using a twin-screw extruder. After extrusion, the mixture was cooled with water and pelletized to obtain maleic anhydride-modified polypropylene.

4. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 3, characterized in that, The mass ratio of polypropylene, maleic anhydride, and diisopropylbenzene oxide is 95-114:5-6:1.5-1.

8.

5. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 1, characterized in that, The modified silica is prepared as follows: Nano-silica was added to anhydrous ethanol and ultrasonically dispersed for 20-30 minutes. Then, silane coupling agent KH-550 was added and the mixture was heated to 58-62℃ and stirred for 2-2.5 hours. Finally, the mixture was centrifuged and vacuum dried to obtain modified silica.

6. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 5, characterized in that, The mass ratio of anhydrous ethanol, nano-silica, and silane coupling agent KH-550 is 90-100:15-17:0.7-0.

9.

7. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 1, characterized in that, The preparation method of the synergist is as follows: A1: Add 3,5-diamino-1,2,4-triazole and triethylamine to tetrahydrofuran and stir at 58-62℃ for 20-30 min. Then add phenylphosphine dichloride dropwise and react at 58-60℃ for 12-13 h. After centrifugation, washing the precipitate and vacuum drying, a pale yellow solid is obtained. A2: Add titanium aluminum carbide powder to deionized water and ultrasonically disperse for 30-40 minutes to obtain titanium aluminum carbide dispersion; A3: Add a pale yellow solid to anhydrous ethanol and ultrasonically disperse for 30-40 min. Then add titanium aluminum carbide dispersion at 38-42℃ and react for 12-15 h. After centrifugation, washing the precipitate, and vacuum drying, the flame retardant is obtained. A4: Add deionized water to anhydrous ethanol and adjust the pH to 5-5.

5. Then add halloysite nanotubes and perform ultrasonic dispersion for 10-20 min. Then add silane coupling agent KH-550 and reflux at 78-82℃ for 6-7 h. After centrifugation and vacuum drying, pretreated nanotubes are obtained. A5: Add pretreated nanotubes and flame retardant to anhydrous ethanol and ultrasonically disperse for 10-20 min. Then stir and react at 58-62℃ for 4-6 h. After centrifugation and vacuum drying, the synergist is obtained.

8. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 7, characterized in that, The mass ratio of tetrahydrofuran, 3,5-diamino-1,2,4-triazole, triethylamine, and phenylphosphine dichloride in A1 is 50-60:5-6:10-12:9.75-11.

7. The mass ratio of deionized water to titanium aluminum carbide powder in A2 is 100-120:2-3; The mass ratio of anhydrous ethanol, pale yellow solid, and titanium aluminum carbide dispersion described in A3 is 120-150:3-4.5:102-123.

9. The method for preparing the maleic anhydride functionalized modified polyolefin resin composition according to claim 7, characterized in that, The mass ratio of anhydrous ethanol, deionized water, halloysite nanotubes, and silane coupling agent KH-550 in A4 is 80-120: 20-30: 2-3: 4-6; The mass ratio of anhydrous ethanol, pretreated nanotubes, and flame retardant in A5 is 100-150:2-3:4-6.

10. The application of a maleic anhydride functionalized modified polyolefin resin composition according to any one of claims 1-9, characterized in that, The maleic anhydride functionalized modified polyolefin resin composition can be prepared into coatings for use in shipbuilding, automotive, packaging, and home appliance industries.