Polypropylene composite and process for its production and cable

Abstract

This application relates to the field of power cable technology, and particularly to a polypropylene composite material, its preparation method, and a cable. A polypropylene composite material comprises polypropylene resin, polystyrene resin, and a compatibilizer. The preparation method of the compatibilizer includes the following steps: esterifying aromatic diboronic acid with a polyol to generate a dioxoborane intermediate; reacting the dioxoborane intermediate with acryloyl chloride under catalytic conditions to generate a dioxoborane acrylate derivative; and subjecting the dioxoborane acrylate derivative, isotactic polypropylene resin, and styrene to a free radical polymerization reaction under free radical initiator conditions. The above compatibilizer can significantly improve the compatibility between polypropylene resin and polystyrene resin, and the polypropylene composite material exhibits good toughness and puncture resistance.

Description

Technical Field

[0001] This application relates to the field of power cable technology, and in particular to a polypropylene composite material, its preparation method, and a cable. Background Technology

[0002] Cross-linked polyethylene (XLPE) is the most commonly used insulation material in the power cable industry. It possesses excellent mechanical, electrical, and long-term aging resistance properties, and is widely used in high-voltage AC and high-voltage DC transmission. XLPE insulation is obtained by introducing a cross-linking agent into polyethylene resin. Through cross-linking, XLPE insulation exhibits high-temperature aging resistance and is suitable for long-term use at temperatures above 90°C. However, the introduction of the cross-linking agent also makes XLPE insulation unrecyclable. Furthermore, cross-linking byproducts induce space charge accumulation, significantly reducing the dielectric properties of XLPE insulation and making it prone to electrical breakdown. Therefore, it is necessary to develop an insulation material with excellent mechanical and electrical properties.

[0003] Compared to XLPE insulation materials, polypropylene materials can have high-temperature aging resistance without the introduction of crosslinking agents, thus avoiding the introduction of crosslinking agents and the harm of crosslinking by-products. However, polypropylene materials are brittle, which restricts their development in the field of insulating cable materials. Summary of the Invention

[0004] Based on this, the first aspect of this application provides a polypropylene composite material, the technical solution of which is as follows:

[0005] A polypropylene composite material comprising polypropylene resin, polystyrene resin, and a compatibilizer, wherein the compatibilizer is prepared by the following steps:

[0006] Under acidic and solvent conditions, the aromatic diboronic acid and polyol undergo an esterification reaction to generate a dioxoborane intermediate;

[0007] Under catalytic conditions, the dioxoborane intermediate and acryloyl chloride react to generate a dioxoborane acrylate derivative.

[0008] Under free radical initiator conditions, the dioxoborane acrylate derivative, polypropylene, and styrene undergo a free radical polymerization reaction.

[0009] This application has the following beneficial effects:

[0010] The polypropylene composite material of this application comprises polypropylene resin, polystyrene resin, and a compatibilizer prepared in specific steps. The polystyrene resin improves the toughness of the polypropylene material, while the compatibilizer significantly enhances the compatibility between the polypropylene resin and the polystyrene resin, reducing interfacial defects. The polypropylene composite material of this application exhibits good toughness and is less prone to failure when used as an insulating cable material. Simultaneously, the aromatic groups (e.g., phenyl, naphthyl, anthracene) contained in the compatibilizer can capture high-energy electrons, facilitating charge migration and further improving the breakdown strength and breakdown resistance of the polypropylene composite material, making it suitable for high-voltage AC and DC power transmission applications.

[0011] In the above method for preparing the compatibilizer, the aromatic diboronic acid and the polyol are first subjected to an esterification reaction to generate a dioxoborane intermediate. The dioxoborane intermediate then reacts with acryloyl chloride to generate a dioxoborane acrylate derivative. The dioxoborane acrylate derivative then undergoes a free radical polymerization reaction with polypropylene and styrene.

[0012] The aromatic diboronic acid refers to an aromatic compound containing two borate groups. These two borate groups may be arranged in the para position on the aromatic chain. Optionally, the aromatic diboronic acid includes one or more of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid, 4,4'-biphenyldiboronic acid, 4,4'-oxobis(1,4-phenylene)diboronic acid, terephthalic acid, naphthalene-1,4-diboronic acid, and anthracene-9,10-diboronic acid.

[0013] Optionally, the polyol has ≥3 hydroxyl groups. Optionally, the polyol is preferably an alkyl polyol. The alkyl polyol refers to an alkane substituted with multiple hydroxyl groups, such as a C3-C10 alkane substituted with at least 3 hydroxyl groups. Optionally, the polyol includes one or more of 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,7-heptanetriol, 1,2,8-octanetriol, 1,2,9-nonanetriol, and 1,2,10-decanetriol.

[0014] Optionally, the molar ratio of the aromatic diboronic acid to the polyol is 1:(1.5~4). For example, the molar ratio is 1:1.5, 1:2, 1:3, or 1:4.

[0015] The above esterification reaction is carried out under acidic and solvent conditions. Optionally, the solvent includes one or more of diethyl ether, acetone, chloroform, carbon disulfide, and toluene. Optionally, the acid includes a strong acid. Optionally, the acid includes one or more of sulfuric acid and sulfurous acid. Optionally, 4000 mL to 7000 mL of solvent is added for every 2 mol of aromatic diboronic acid. Optionally, 40 mL to 60 mL of acid is added for every 2 mol of aromatic diboronic acid.

[0016] In some embodiments, the aromatic diboronic acid and polyol undergo an esterification reaction under acidic and solvent conditions, comprising the following steps:

[0017] The aromatic diboronic acid and polyol are dissolved in the solvent, the acid is added, and the mixture is stirred.

[0018] Optionally, the esterification reaction is carried out under the protection of an inert gas, including nitrogen.

[0019] Optionally, the esterification reaction temperature is 150℃~180℃. For example, the reaction temperature is 150℃, 160℃, 170℃, or 180℃. Optionally, the esterification reaction time is 10h~12h. For example, the reaction time is 10h, 11h, or 12h.

[0020] After the esterification reaction is complete, an organic solvent is added to precipitate the product. The precipitate is then removed, and the oily substance is separated to obtain a clear, transparent liquid containing the dioxoborane intermediate. Optionally, the organic solvent includes toluene.

[0021] The bis(dioxoborane) intermediate and acryloyl chloride react under catalytic conditions. The amount of acryloyl chloride can be controlled according to the amount of aromatic diboronic acid added. Optionally, the molar ratio of acryloyl chloride to aromatic diboronic acid is (0.5~2):1. For example, the molar ratios are 0.5:1, 1:1, 1.5:1, and 2:1.

[0022] Optionally, the catalyst comprises one or more of triethylamine, 4-(dimethylamino)pyridine, and triethylenediamine. Similarly, the amount of catalyst can be controlled according to the amount of aromatic diboronic acid added. Optionally, the amount of catalyst satisfies the following: for every 2 mol of aromatic diboronic acid, 0.05 mol to 0.15 mol of catalyst is added. For example, 0.05 mol, 0.10 mol, and 0.15 mol of catalyst are added accordingly.

[0023] Optionally, the reaction time is 8 to 12 hours. For example, the reaction time is 8 hours, 10 hours, or 12 hours.

[0024] The reaction between the above-described dioxoborane intermediate and acryloyl chloride can be carried out without separating the dioxoborane intermediate from the liquid containing it. After the reaction is complete, rotary evaporation and washing are performed to obtain a liquid containing the dioxoborane acrylate derivative.

[0025] A dioxoborane acrylate derivative, polypropylene, and styrene undergo free radical polymerization under free radical initiator conditions. Optionally, the number average molecular weight of the polypropylene is 10,000 g / mol to 250,000 g / mol. For example, number average molecular weights of 10,000 g / mol, 50,000 g / mol, 100,000 g / mol, 150,000 g / mol, 200,000 g / mol, and 250,000 g / mol. Optionally, the polypropylene includes isotactic polypropylene. Optionally, the isotactic index of the isotactic polypropylene is ≥95%. Optionally, the polypropylene resin includes one or more of homopolymer polypropylene and copolymer polypropylene. Optionally, the melt index of the polypropylene resin at 230°C and 2.16 kg is 0.5 g / 10 min to 10.0 g / 10 min. For example, the melt flow index is 0.5 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min, 7.0 g / 10 min, 8.6 g / 10 min, or 10.0 g / 10 min. Optionally, the mass of the polypropylene satisfies the following: 4000 g to 6000 g of polypropylene is added for every 2 mol of aromatic diboric acid. For example, 4000 g, 5000 g, or 6000 g of polypropylene is added. Optionally, the mass of the styrene satisfies the following: 10 g to 80 g of styrene is added for every 2 mol of aromatic diboric acid. For example, 10 g, 20 g, 30 g, 40 g, 50 g, 60 g, 70 g, or 80 g of styrene is added.

[0026] Optionally, the free radical polymerization reaction is carried out in the molten state. Optionally, under free radical initiator conditions, the bis(dioxoborane) acrylate derivative, polypropylene, and styrene undergo a free radical polymerization reaction, comprising the following steps:

[0027] The polypropylene is melted, styrene is added and stirred, then dioxoborane acrylate derivative and free radical initiator are added and stirred to induce a free radical polymerization reaction.

[0028] Optionally, the melting temperature of polypropylene is 180°C to 200°C. Optionally, the mixing time for adding styrene is 1 min to 3 min. For example, 1 min, 2 min, or 3 min. Understandably, styrene is a liquid and is slowly added to the molten polypropylene.

[0029] Optionally, the free radical initiator includes an organic peroxide initiator; optionally, the organic peroxide initiator includes one or more of benzoyl peroxide, dicumyl peroxide, and bis-tert-butylperoxide. Optionally, the mass of the free radical initiator satisfies the following condition: 5g to 15g of free radical initiator is added for every 2mol of aromatic diboronic acid. For example, 5g, 10g, and 15g of free radical initiator are added accordingly.

[0030] Optionally, the temperature of the free radical polymerization reaction is 170℃~210℃. For example, the temperature of the free radical polymerization reaction is 170℃, 190℃, or 210℃. Optionally, the time of the free radical polymerization reaction is 8 min~12 min. The time of the free radical polymerization reaction is 8 min, 10 min, or 12 min.

[0031] The free radical polymerization reaction of the above-mentioned dioxoborane acrylate derivative, polypropylene, and styrene can be carried out without separating the dioxoborane acrylate derivative from the liquid containing it. After the reaction, extrusion granulation is performed. Crushing and grinding steps can be added as needed.

[0032] The compatibilizer prepared by the above method can improve the compatibility between polypropylene resin and polystyrene resin.

[0033] Optionally, the number-average molecular weight of the polypropylene is 10,000 g / mol to 250,000 g / mol. For example, the number-average molecular weight is 10,000 g / mol, 50,000 g / mol, 100,000 g / mol, 150,000 g / mol, 200,000 g / mol, or 250,000 g / mol. Optionally, the polypropylene includes isotactic polypropylene. Optionally, the isotactic index of the isotactic polypropylene is ≥95%. Optionally, the polypropylene resin includes one or more of homopolymer polypropylene and copolymer polypropylene. Optionally, the melt index of the polypropylene resin at 230°C and 2.16 kg is 0.5 g / 10 min to 10.0 g / 10 min. For example, melt flow indexes are 0.5 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 3.5 g / 10 min, 5.0 g / 10 min, 7.0 g / 10 min, 8.6 g / 10 min, and 10.0 g / 10 min. Optionally, the polystyrene resin has a melt flow index of 1.0 g / 10 min to 5.0 g / 10 min at 200°C and 5 kg. For example, melt flow indexes are 1.0 g / 10 min, 2.2 g / 10 min, 3.8 g / 10 min, 4.1 g / 10 min, and 5.0 g / 10 min.

[0034] In some embodiments, the polypropylene composite material comprises the following components in parts by weight:

[0035] 90-99 parts of polypropylene resin;

[0036] 1-9 parts of polystyrene resin;

[0037] Compatibilizer 0.5-8 parts.

[0038] Optionally, the polypropylene composite material may further include additives. Optionally, the additives include antioxidants. Optionally, the antioxidants include hindered phenolic compounds.

[0039] In some embodiments, the polypropylene composite material comprises the following components in parts by weight:

[0040] 90-99 parts of polypropylene resin;

[0041] 1-9 parts of polystyrene resin;

[0042] Compatibilizer 0.5-8 parts;

[0043] Antioxidant 0.1 to 1 part.

[0044] The polypropylene resin comprises, but is not limited to, 90 parts, 92 parts, 95 parts, 97 parts, and 99 parts by weight. Preferably, it comprises 93 to 98 parts. The polystyrene resin comprises, but is not limited to, 1 part, 3 parts, 5 parts, 7 parts, and 9 parts by weight. Preferably, it comprises 2 to 7 parts. The compatibilizer comprises, but is not limited to, 0.5 parts, 1 part, 3 parts, 5 parts, and 8 parts by weight. Preferably, it comprises 1 to 5 parts. The antioxidant comprises, but is not limited to, 0.1 parts, 0.3 parts, 0.5 parts, 0.8 parts, and 1 part by weight. Preferably, it comprises 0.3 to 0.5 parts.

[0045] The second aspect of this application provides a method for preparing the above-mentioned polypropylene composite material, the technical solution of which is as follows:

[0046] A method for preparing the above-mentioned polypropylene composite material includes the following steps:

[0047] The polypropylene resin, the polystyrene resin, and the compatibilizer are melt-mixed and then granulated.

[0048] This application describes a method for preparing polypropylene materials by melt blending polypropylene resin, polystyrene resin, and a compatibilizer. The production line is mature and the cost is low.

[0049] Optionally, melt mixing and granulation can be carried out in a twin-screw extruder or a reciprocating single-screw mixer. The mixture undergoes extrusion melt treatment, filtration treatment, and granulation treatment respectively. Optionally, the screw speed for extrusion melt treatment is 200 rpm to 500 rpm, and the barrel temperature for extrusion melt treatment is 180℃ to 230℃. Optionally, the filter mesh size for filtration treatment is 60 mesh to 600 mesh. Optionally, the granulation treatment is either strand pelletizing or underwater pelletizing.

[0050] Optionally, the polypropylene composite material further includes additives, and the preparation method of the polypropylene composite material includes the following steps:

[0051] The compatibilizer and additives are mixed in a solvent and then dried to obtain a mixed powder.

[0052] The polypropylene resin, the polystyrene resin, and the mixed powder are melt-mixed and then granulated.

[0053] Optionally, the solvent for mixing the compatibilizer and the additives includes ethanol. The compatibilizer and solvent are added to the ethanol and centrifuged for 2 to 5 hours.

[0054] A third aspect of this application provides a cable comprising the aforementioned polypropylene composite material.

[0055] Alternatively, the cable can be a high-voltage AC cable or a DC transmission cable. The cable of this application possesses all the advantages of the aforementioned polypropylene composite material, which will not be elaborated here. Detailed Implementation

[0056] The present application will be further described in detail below with reference to specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0058] the term

[0059] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0060] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more or more.

[0061] In this application, "several" means at least one, such as one, two, etc., unless otherwise expressly and specifically defined.

[0062] In this application, the terms "optionally," "optionally," and "optional" refer to options that are optional, meaning they can be selected from either "with" or "without." If multiple "optional" options appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" option is independent.

[0063] In this application, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only a non-exhaustive enumeration purpose and should be understood not to constitute a closed limitation on quantity.

[0064] In this application, numerical intervals (i.e. numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the above-mentioned numerical intervals are considered continuous, and include the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical range, as well as every value between the two numerical endpoints.

[0065] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0066] In this application, room temperature refers to 10℃~40℃.

[0067] In this application, %(w / w) and wt% both represent weight percentage, %(v / v) refers to volume percentage, and %(w / v) refers to mass-volume percentage.

[0068] The following description is further illustrated with specific embodiments and comparative examples. Unless otherwise specified, the raw materials involved in the following specific embodiments and comparative examples are all commercially available. Unless otherwise specified, the instruments used are all commercially available. Unless otherwise specified, the processes involved are conventionally selected by those skilled in the art.

[0069] The polypropylene resin in the compatibilizer and polypropylene composite material is isotactic polypropylene Borclean HC312BF produced by Borouge / Borealis, with a melt index of 3.2 g / 10 min (230℃, 2.16 kg).

[0070] The polystyrene resin used was Bycolene 168N, produced by Yangzi Petrochemical-BASF Co., Ltd., with a melt index of 1.9 g / 10 min (200℃, 5 kg).

[0071] Antioxidant 300 is produced by Zibo Vanke Chemical Co., Ltd., with an ash content of less than 0.05%.

[0072] Preparation of compatibilizer-1#:

[0073] S1. 924 g of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid (2 mol) and 456 g of 1,2,6-hexanetriol (3.4 mol) were added to 5000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added to precipitate the product. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -1#.

[0074] S2. Mix the liquid-1# containing the dioxoborane intermediate described in step S1, 145g of acryloyl chloride (1.59mol), and 10g of triethylamine (0.1mol), and react for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, the reaction solution yields liquid-1# containing the dioxoborane acrylate derivative;

[0075] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 15g of styrene to the mixer and stir for 2 minutes. Then add the liquid-1# containing dioxoborane acrylate derivatives described in step S2 and 7.5g of benzoyl peroxide. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the product. After cooling, crushing, and grinding, compatibilizer-1# is obtained.

[0076] Preparation of compatibilizer-2#:

[0077] S1. 924 g of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid (2 mol) and 670 g of 1,2,6-hexanetriol (5 mol) were added to 6000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added for precipitation. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -2#.

[0078] S2. Mix the liquid-2# containing the dioxoborane intermediate described in step S1, 227 g of acryloyl chloride (2.49 mol), and 10 g of triethylamine (0.1 mol), and react for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, the reaction solution yields liquid-2# containing the dioxoborane acrylate derivative;

[0079] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 50g of styrene to the mixer and stir for 2 minutes. Then add the liquid-2# containing didioxoborane acrylate derivatives mentioned in step S2 and 10g of di-tert-butylperoxyisopropylbenzene. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the mixture. After cooling, crushing, and grinding, compatibilizer-2# is obtained.

[0080] Preparation of compatibilizer-3#:

[0081] S1. 924 g of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid (2 mol) and 938 g of 1,2,6-hexanetriol (7 mol) were added to 6000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added for precipitation. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -3#.

[0082] S2. Mix the liquid-3# containing the dioxoborane intermediate described in step S1, 272g of acryloyl chloride (2.99mol), and 10g of triethylamine (0.1mol), and react for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, the reaction solution yields liquid-3# containing the dioxoborane acrylate derivative.

[0083] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 75g of styrene to the mixer and stir for 2 minutes. Then add the liquid-3# containing dioxoborane acrylate derivatives mentioned in step S2 and 15g of dicumyl peroxide. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the product. After cooling, crushing and grinding, compatibilizer-3# is obtained.

[0084] Preparation of compatibilizer-4#:

[0085] S1. 484 g of 4,4'-biphenyl diboronic acid (2 mol) and 810 g of 1,2,8-octanediol (5 mol) were added to 6000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added to precipitate the product. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -4#.

[0086] S2. The liquid-4# containing the dioxoborane intermediate described in step S1, 227 g of acryloyl chloride (2.49 mol), and 9.7 g of 4-(dimethylamino)pyridine (0.08 mol) were mixed and reacted for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, liquid-4# containing the dioxoborane acrylate derivative was obtained.

[0087] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 50g of styrene to the mixer and stir for 2 minutes. Then add the liquid-4# containing didioxoborane acrylate derivatives mentioned in step S2 and 10g of di-tert-butylperoxyisopropylbenzene. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the mixture. After cooling, crushing, and grinding, compatibilizer-4# is obtained.

[0088] Preparation of compatibilizer-5#:

[0089] S1. 484 g of 4,4'-biphenyl diboronic acid (2 mol) and 950 g of 1,2,10-decanetriol (5 mol) were added to 6000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added to precipitate the product. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -5#.

[0090] S2. The liquid-5# containing the dioxoborane intermediate described in step S1, 227g of acryloyl chloride (2.49mol), and 11g of triethylenediamine (0.1mol) are mixed and reacted for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, liquid-5# containing the dioxoborane acrylate derivative is obtained.

[0091] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 50g of styrene to the mixer and stir for 2 minutes. Then add the liquid-5# containing didioxoborane acrylate derivatives mentioned in step S2 and 10g of di-tert-butylperoxyisopropylbenzene. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the product. After cooling, crushing, and grinding, compatibilizer-5# is obtained.

[0092] Preparation of compatibilizer-6#:

[0093] S1. 432 g of naphthalene-1,4-diboronic acid (2 mol) and 810 g of 1,2,8-octanediol (5 mol) were added to 6000 mL of acetone, mixed, heated, and dissolved. 50 mL of sulfurous acid was added to obtain a reaction mixture. The reaction mixture was placed in a Dean-Stocker water separator and heated under nitrogen protection at 170 °C under reflux for 12 hours to induce esterification and generate a dioxoborane intermediate. The reaction solution was cooled to room temperature and 5000 mL of toluene was added to precipitate the product. After filtering to remove the precipitate, an oily substance was separated from the filtrate using a Soxhlet extractor to obtain a clear and transparent liquid containing the dioxoborane intermediate -6#.

[0094] S2. The liquid-6# containing the dioxoborane intermediate described in step S1, 227 g of acryloyl chloride (2.49 mol), and 14 g of triethylenediamine (0.13 mol) were mixed and reacted for 10 hours to generate a dioxoborane acrylate derivative. After rotary evaporation and washing, the reaction solution yielded liquid-6# containing the dioxoborane acrylate derivative.

[0095] S3. Add 5000g of polypropylene resin to a mixer and melt it at 190℃. Slowly add 50g of styrene to the mixer and stir for 2 minutes. Then add the liquid-6# containing didioxoborane acrylate derivatives described in step S2 and 10g of di-tert-butylperoxyisopropylbenzene. Stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is complete, extrude and granulate the product. After cooling, crushing, and grinding, compatibilizer-6# is obtained.

[0096] Preparation of compatibilizer A

[0097] The preparation methods of compatibilizer A and compatibilizer-3# are basically the same, the main difference being that step S2 is omitted and step S3 is as follows: 5000g of polypropylene resin is added to a mixer and melted at 190℃. 75g of styrene is slowly added to the mixer and stirred for 2 minutes. Then, liquid-3# containing dioxoborane intermediate as described in step S1 and 15g of dicumyl peroxide are added and stirred for 10 minutes to undergo free radical polymerization. After the reaction is completed, the mixture is extruded and granulated, cooled, crushed, and ground to obtain compatibilizer A.

[0098] Preparation of compatibilizer B

[0099] The preparation methods of compatibilizer B and compatibilizer-3# are basically the same, with the main difference being that steps S1 and S2 are omitted, and step S3 is as follows: 5000g of polypropylene resin is added to a mixer and melted at 190℃, followed by the addition of 924g of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid and 15g of dicumyl peroxide. The mixture is stirred and mixed for 10 minutes to induce a free radical polymerization reaction. After the reaction is completed, the mixture is extruded and granulated, then cooled, crushed, and ground to obtain compatibilizer B.

[0100] Preparation of compatibilizer C

[0101] The preparation methods of compatibilizer C and compatibilizer-3# are basically the same, with the main difference being: Step S3 is as follows: 5000g of polypropylene resin is added to a mixer and melted at 190°C. Then, liquid-3# containing dioxoborane acrylate derivatives as described in step S2 and 15g of dicumyl peroxide are added. The mixture is stirred and mixed for 10 minutes to induce a free radical polymerization reaction. After the reaction is completed, the mixture is extruded and granulated, cooled, crushed, and ground to obtain compatibilizer C.

[0102] Preparation of compatibilizer D

[0103] 5000g of polypropylene resin was added to a mixer and melted at 190℃. 75g of styrene was slowly added to the mixer and stirred for 2 minutes. Then 15g of dicumyl peroxide was added and stirred for 10 minutes to induce free radical polymerization. After the reaction was completed, the mixture was extruded and granulated. After cooling, crushing and grinding, compatibilizer A was obtained.

[0104] Preparation of compatibilizer E

[0105] 5000g of polypropylene resin was added to a mixer and melted at 190℃. 75g of styrene was slowly added to the mixer and stirred for 2 minutes, then stirred for another 10 minutes. The mixture was then extruded and granulated, cooled, crushed, and ground to obtain compatibilizer E.

[0106] Comparative Example 1

[0107] This comparative example provides a polypropylene composite material and its preparation method, the steps of which are as follows:

[0108] S1. Prepare polypropylene resin, polystyrene resin and antioxidant 300 according to the weight parts shown in Table 1 using two loss-in-weight scales.

[0109] S2. Polypropylene resin, polystyrene resin and antioxidant 300 are mixed and then melt-mixed, filtered and granulated by a twin-screw extruder to obtain a polypropylene composite material. The barrel temperature is 210℃, the screw speed is 400rpm and the filter mesh is 500 mesh.

[0110] Examples 1-10 and Comparative Examples 2-6

[0111] Examples 1-10 and Comparative Examples 2-6 provide a polypropylene composite material and a method for preparing the same, the steps of which are as follows:

[0112] S1. Prepare polypropylene resin, polystyrene resin, compatibilizers (compatibilizer-1#, compatibilizer-2#, compatibilizer-3#, compatibilizer-4#, compatibilizer-5#, compatibilizer-6#, compatibilizer A, compatibilizer B, compatibilizer C, compatibilizer D, compatibilizer E) and antioxidant 300 according to the weight parts shown in Table 1 using two loss-in-weight scales.

[0113] S2. Add compatibilizer and antioxidant 300 to ethanol, centrifuge and stir at room temperature for 3 hours, then dry to obtain mixed powder.

[0114] S3. Polypropylene resin, polystyrene resin and mixed powder are mixed and then melt-mixed, filtered and granulated by a twin-screw extruder to obtain a polypropylene composite material. The barrel temperature is 210℃, the screw speed is 400rpm and the filter mesh is 500 mesh.

[0115] Table 1

[0116]

[0117] Note: "-" indicates that it has not been added.

[0118] The polypropylene composite materials of the above embodiments and comparative examples were tested as follows, and the test results are shown in Table 2:

[0119] 1. Notched impact strength, refer to ISO 180.

[0120] 2. Tensile strength, refer to ISO 527.

[0121] 3. Elongation at break, refer to ISO 527.

[0122] 4. DC breakdown strength, refer to GB / T 1408.2-2006.

[0123] Table 2

[0124]

[0125] It is evident that in Comparative Example 1, without the addition of a compatibilizer, the interfacial compatibility between polypropylene resin and polystyrene resin was poor, resulting in poor toughness and low breakdown strength of the polypropylene composite material.

[0126] Compared to Comparative Example 1, Comparative Examples 1-6, which included compatibilizers A, B, C, D, and E respectively, showed no significant improvement in the toughness, tensile strength, and puncture strength of the polypropylene composites.

[0127] Compared to Comparative Example 1, Compatibilizers 1#, 2#, 3#, 4#, 5#, and 6# were added to Examples 1-10, respectively. The toughness, tensile strength, and breakdown strength of the polypropylene composite material were significantly improved, indicating that Compatibilizers 1#, 2#, 3#, 4#, 5#, and 6# improved the compatibility between polypropylene resin and polystyrene resin, and can prepare polypropylene composite insulation materials for cables that simultaneously meet the requirements of electrical strength and toughness.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A polypropylene composite material, characterized in that, The mixture comprises polypropylene resin, polystyrene resin, and a compatibilizer, wherein the polypropylene resin comprises 90-99 parts by weight, the polystyrene resin comprises 1-9 parts by weight, and the compatibilizer comprises 0.5-8 parts by weight. The preparation method of the compatibilizer includes the following steps: Under acidic and solvent conditions, aromatic diboronic acid and polyol undergo an esterification reaction to generate a dioxoborane intermediate, wherein the molar ratio of aromatic diboronic acid to polyol is 1:(1.5~4). Under catalytic conditions, the dioxoborane intermediate and acryloyl chloride react to generate a dioxoborane acrylate derivative, wherein the molar ratio of acryloyl chloride to aromatic diboronic acid is (0.5~2):1; Under free radical initiator conditions, the dioxoborane acrylate derivative, polypropylene, and styrene undergo a free radical polymerization reaction, wherein the mass of the polypropylene satisfies the following: for every 2 mol of aromatic diboronic acid, 4000 g to 6000 g of polypropylene is added, and the mass of the styrene satisfies the following: for every 2 mol of aromatic diboronic acid, 10 g to 80 g of styrene is added.

2. The polypropylene composite material according to claim 1, characterized in that, Includes at least one of the following features: 1) The aromatic diboronic acid includes one or more of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboronic acid, 4,4'-biphenyldiboronic acid, 4,4'-oxobis(1,4-phenylene)diboronic acid, terephthalic acid, naphthalene-1,4-diboronic acid and anthracene-9,10-diboronic acid; 2) The number of hydroxyl groups in the polyol is ≥3.

3. The polypropylene composite material according to claim 1, characterized in that, The polyol is selected from alkyl polyols.

4. The polypropylene composite material according to claim 1, characterized in that, The polyols include one or more of 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,7-heptanetriol, 1,2,8-octanetriol, 1,2,9-nonanetriol, and 1,2,10-decanetriol.

5. The polypropylene composite material according to claim 1, characterized in that, Includes at least one of the following features: 1) The solvent includes one or more of diethyl ether, acetone, chloroform, carbon disulfide, and toluene; 2) The mass of the solvent must meet the following requirement: 4000 mL to 7000 mL of solvent should be added for every 2 mol of aromatic diboronic acid; 3) The acid agent includes one or more of sulfuric acid and sulfurous acid; 4) The mass of the acid agent must meet the following requirement: 40 mL to 60 mL of acid agent should be added for every 2 mol of aromatic diboric acid; 5) The reaction temperature for the esterification reaction is 150℃~180℃; 6) The reaction time for the esterification reaction is 10h~12h.

6. The polypropylene composite material according to claim 1, characterized in that, Includes at least one of the following features: 1) The catalyst comprises one or more of triethylamine, 4-(dimethylamino)pyridine, and triethylenediamine; 2) The amount of the catalyst is such that for every 2 mol of aromatic diboronic acid, 0.05 mol to 0.15 mol of catalyst is added; 3) The reaction time is 8h~12h.

7. The polypropylene composite material according to claim 1, characterized in that, Includes at least one of the following features: 1) The number average molecular weight of the polypropylene is 10,000 g / mol to 250,000 g / mol; 2) The polypropylene includes isotactic polypropylene; 3) The polypropylene includes one or more of homopolymer polypropylene and copolymer polypropylene; 4) The melt index of the polypropylene is 0.5 g / 10 min to 10.0 g / 10 min at 230℃ and 2.16 kg. 5) The free radical polymerization reaction is carried out in the molten state; 6) The free radical initiator includes organic peroxide initiators; 7) The mass of the free radical initiator satisfies the following requirement: 5g~15g of free radical initiator should be added for every 2mol of aromatic diboronic acid; 8) The temperature of the free radical polymerization reaction is 170℃~210℃; 9) The free radical polymerization reaction takes 8 min to 12 min.

8. The polypropylene composite material according to claim 7, characterized in that, Includes at least one of the following features: 1) The isotactic index of the isotactic polypropylene is ≥95%; 2) The organic peroxide initiator includes one or more of benzoyl peroxide, dicumyl peroxide and bis-tert-butylperoxyisopropylbenzene.

9. The polypropylene composite material according to any one of claims 1 to 8, characterized in that, Includes at least one of the following features: 1) The number average molecular weight of the polypropylene resin is 10000 g / mol to 250000 g / mol; 2) The polypropylene resin includes isotactic polypropylene; 3) The polypropylene resin includes one or more of homopolymer polypropylene and copolymer polypropylene; 4) The melt flow index of the polypropylene resin at 230℃ and 2.16 kg is 0.5 g / 10 min to 10.0 g / 10 min; 5) The polystyrene resin has a melt index of 1.0 g / 10 min to 5.0 g / 10 min at 200℃ and 5 kg.

10. The polypropylene composite material according to claim 9, characterized in that, The isotactic polypropylene has an isotactic index of ≥95%.

11. The polypropylene composite material according to any one of claims 1 to 8 and 10, characterized in that, The polypropylene resin is in the amount of 93-98 parts by weight; the polystyrene resin is in the amount of 2-7 parts by weight; and the compatibilizer is in the amount of 1-5 parts by weight.

12. The polypropylene composite material according to claim 11, characterized in that, It also contains additives, including antioxidants.

13. The polypropylene composite material according to claim 12, characterized in that, The antioxidants include hindered phenolic compounds.

14. The polypropylene composite material according to claim 13, characterized in that, The antioxidant is present in a weight ratio of 0.1 to 1 part.

15. The polypropylene composite material according to claim 14, characterized in that, The antioxidant is present in an amount of 0.3 to 0.5 parts by weight.

16. A method for preparing a polypropylene composite material according to any one of claims 1 to 15, characterized in that, Includes the following steps: The polypropylene resin, the polystyrene resin, and the compatibilizer are melt-mixed and then granulated.

17. A cable, characterized in that, The polypropylene composite material included in any one of claims 1 to 15.

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