Polypropylene composite material, preparation method thereof and cable

Abstract

The invention relates to the technical field of power cables, in particular to a polypropylene composite material, a preparation method thereof and a cable. The polypropylene composite material comprises polypropylene resin, polystyrene resin and a compatilizer, and a preparation method of the compatilizer comprises the following steps: carrying out an esterification reaction on aromatic diboric acid and polyol to generate a didioxoborane intermediate; under the condition of a catalyst, the didioxoborane intermediate and acryloyl chloride are subjected to a reaction, and a didioxoborane acrylate derivative is generated; and under the condition of a free radical initiator, carrying out free radical polymerization reaction on the didioxoborane acrylate derivative, isotactic polypropylene resin and styrene. The compatilizer can significantly improve the compatibility of polypropylene resin and polystyrene resin, and the polypropylene composite material has good toughness and breakdown resistance.

Description

Technical Field

[0001] The present application relates to the technical field of power cables, and in particular to a polypropylene composite material, a preparation method thereof, and a cable. Background Art

[0002] Cross-linked polyethylene (XLPE) is the most commonly used insulating material in the field of power cables. It has excellent mechanical, electrical and long-term aging resistance and is widely used in high-voltage AC and high-voltage DC transmission. XLPE insulating material is obtained by introducing a cross-linking agent into polyethylene resin. Through cross-linking, XLPE insulating material has high-temperature aging resistance and is suitable for long-term use conditions above 90°C, but the introduction of cross-linking agents also makes XLPE insulating material impossible to recycle. At the same time, cross-linking by-products will induce space charge accumulation, significantly reduce the dielectric properties of XLPE insulating materials, and easily lead to electrical breakdown. Therefore, it is necessary to develop an insulating material with excellent mechanical and electrical properties.

[0003] Compared with XLPE insulation materials, polypropylene materials can have high temperature aging resistance without the introduction of cross-linking agents, which can avoid the introduction of cross-linking agents and the hazards of cross-linking by-products. However, polypropylene materials are very brittle, which restricts their development in the field of insulating cable materials. Summary of the invention

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

[0005] A polypropylene composite material comprises a polypropylene resin, a polystyrene resin and a compatibilizer, wherein the preparation method of the compatibilizer comprises the following steps:

[0006] Under the conditions of an acid and a solvent, the aromatic diboronic acid and a polyol are subjected to an esterification reaction to generate a bisdioxyborane intermediate;

[0007] Under catalyst conditions, the bisdioxaborane intermediate and acryloyl chloride are reacted to generate a bisdioxaborane acrylate derivative;

[0008] Under the condition of a free radical initiator, the bis(dioxyborane) acrylate derivative, polypropylene and styrene undergo free radical polymerization.

[0009] This application has the following beneficial effects:

[0010] The polypropylene composite material of the present application comprises polypropylene resin, polystyrene resin and compatibilizer prepared by specific steps, wherein the polystyrene resin is conducive to improving the toughness of the polypropylene material, and the compatibilizer can significantly improve the compatibility of the polypropylene resin and the polystyrene resin, and reduce interface defects. The polypropylene composite material of the present application has good toughness and is not easy to fail as an insulating cable material. At the same time, the functional groups such as aromatic groups (such as phenyl, naphthyl, anthracene) contained in the compatibilizer can capture high-energy electrons, contribute to the migration of electric charges, and can further improve the breakdown strength of the polypropylene composite material, improve the breakdown resistance, and make it suitable for the field of high-voltage AC and DC power transmission.

[0011] In the preparation method of the compatibilizer, the aromatic diboric acid and polyol are first subjected to an esterification reaction to generate a bis(dioxyborane) intermediate, which is then reacted with acryloyl chloride to generate a bis(dioxyborane) acrylate derivative, which is then subjected to a free radical polymerization reaction with polypropylene and styrene.

[0012] The aromatic diboronic acid refers to an aromatic compound containing two boronic acid groups. The two boronic acid groups can 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'-diboric acid, 4,4'-biphenyl diboric acid, 4,4'-oxybis(1,4-phenylene) diboric acid, terephthalene diboric acid, naphthalene-1,4-diboric acid and anthracene-9,10-diboric acid.

[0013] Optionally, the number of hydroxyl groups of the polyol is ≥3. 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-octantriol, 1,2,9-nonanetriol and 1,2,10-decanetriol.

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

[0015] The above esterification reaction is carried out under the conditions of an acid and a solvent. Optionally, the solvent includes one or more of 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, 4000mL~7000mL of solvent is added for every 2mol of aromatic diboric acid. Optionally, 40mL~60mL of acid is added for every 2mol of aromatic diboric acid.

[0016] In some embodiments, the aromatic diboronic acid and the polyol are subjected to an esterification reaction under the conditions of an acid and a solvent, comprising the following steps:

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

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

[0019] Optionally, the reaction temperature of the esterification reaction is 150° C. to 180° C. For example, the reaction temperature is 150° C., 160° C., 170° C., 180° C. Optionally, the reaction time of the esterification reaction is 10 h to 12 h. For example, the reaction time is 10 h, 11 h, 12 h.

[0020] After the esterification reaction is completed, an organic solvent is added for precipitation, the precipitate is removed, and the oily substance is separated to obtain a clear and transparent liquid containing the bisdioxaborane intermediate. Optionally, the organic solvent includes toluene.

[0021] The bisdioxaborane intermediate and acryloyl chloride react under catalyst conditions. The amount of acryloyl chloride can be controlled according to the amount of aromatic diboric acid added. Optionally, the molar ratio of acryloyl chloride to the aromatic diboric acid is (0.5-2):1. For example, the molar ratio is 0.5:1, 1:1, 1.5:1, 2:1.

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

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

[0024] The reaction of the bisdioxyborane intermediate and acryloyl chloride can be carried out without separating the bisdioxyborane intermediate from the liquid containing the bisdioxyborane intermediate. After the reaction is completed, rotary evaporation and washing are performed to obtain a liquid containing the bisdioxyborane acrylate derivative.

[0025] A free radical polymerization reaction is carried out between the bis(dioxyborane) acrylate derivative, polypropylene and styrene under the condition of a free radical initiator. Optionally, the number average molecular weight of the polypropylene is 10000 g / mol to 250000 g / mol. For example, the number average molecular weight is 10000 g / mol, 50000 g / mol, 100000 g / mol, 150000 g / mol, 200000 g / mol, 250000 g / mol. Optionally, the polypropylene includes isotactic polypropylene. Optionally, the isotactic index of isotactic polypropylene is ≥95%. Optionally, the polypropylene resin includes one or more of homopolypropylene and copolymer polypropylene. Optionally, the polypropylene resin has a melt index of 0.5 g / 10 min to 10.0 g / 10 min at 230° C. and 2.16 kg. For example, the melt index is 0.5g / 10min, 1.0g / 10min, 2.0g / 10min, 3.5g / 10min, 5.0g / 10min, 7.0g / 10min, 8.6g / 10min, 10.0g / 10min. Optionally, the mass of the polypropylene satisfies: 4000g~6000g of polypropylene is added for every 2mol of aromatic diboric acid. For example, 4000g, 5000g, 6000g of polypropylene is added. Optionally, the mass of the styrene satisfies: 10g~80g of styrene is added for every 2mol of aromatic diboric acid. For example, 10g, 20g, 30g, 40g, 50g, 60g, 70g, 80g of styrene is added.

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

[0027] The polypropylene is melted, styrene is added and stirred and mixed, and then a bis(dioxyborane) acrylate derivative and a free radical initiator are added and stirred and mixed to cause a free radical polymerization reaction.

[0028] Optionally, the melting temperature of polypropylene is 180° C. to 200° C. Optionally, the time for adding styrene and stirring and mixing is 1 min to 3 min. For example, 1 min, 2 min, 3 min. It can be understood that 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, diisopropylbenzene peroxide and di-tert-butyl peroxyisopropylbenzene. Optionally, the mass of the free radical initiator satisfies: 5g to 15g of free radical initiator is added for every 2mol of aromatic diboric acid. For example, 5g, 10g, or 15g of free radical initiator is added accordingly.

[0030] Optionally, the temperature of the free radical polymerization reaction is 170° C. to 210° C. For example, the temperature of the free radical polymerization reaction is 170° C., 190° C., or 210° C. Optionally, the time of the free radical polymerization reaction is 8 min to 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 bis(dioxyborane) acrylate derivative, polypropylene and styrene can be carried out without separating the bis(dioxyborane) acrylate derivative from the liquid containing the bis(dioxyborane) acrylate derivative. After the reaction is completed, extrusion granulation is performed. Crushing and grinding steps can be performed as needed.

[0032] The compatibilizer prepared in the above manner can improve the compatibility of polypropylene resin and polystyrene resin.

[0033] Optionally, the number average molecular weight of the polypropylene is 10000 g / mol to 250000 g / mol. For example, the number average molecular weight is 10000 g / mol, 50000 g / mol, 100000 g / mol, 150000 g / mol, 200000 g / mol, 250000 g / mol. Optionally, the polypropylene includes isotactic polypropylene. Optionally, the isotactic index of isotactic polypropylene is ≥95%. Optionally, the polypropylene resin includes one or more of homopolymer polypropylene and copolymer polypropylene. Optionally, the polypropylene resin has a melt index of 0.5 g / 10min to 10.0 g / 10min at 230°C and 2.16 kg. For example, the melt 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, 10.0 g / 10 min. Optionally, the melt index of the polystyrene resin is 1.0 g / 10 min to 5.0 g / 10 min under the conditions of 200° C. and 5 kg. For example, the melt index is 1.0 g / 10 min, 2.2 g / 10 min, 3.8 g / 10 min, 4.1 g / 10 min, 5.0 g / 10 min.

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

[0035] Polypropylene resin 90-99 parts;

[0036] 1-9 parts of polystyrene resin;

[0037] Compatibilizer 0.5~8 parts.

[0038] Optionally, the polypropylene composite material may further include an auxiliary agent. Optionally, the auxiliary agent includes an antioxidant. Optionally, the antioxidant includes a hindered phenol compound.

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

[0040] Polypropylene resin 90-99 parts;

[0041] 1-9 parts of polystyrene resin;

[0042] Compatibilizer 0.5~8 parts;

[0043] Antioxidant 0.1~1 part.

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

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

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

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

[0048] The present application prepares the polypropylene material by melt blending the polypropylene resin, the polystyrene resin and the compatibilizer, and 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 mixed material is subjected to extrusion melting treatment, filtration treatment and granulation treatment respectively. Optionally, the screw speed of the extrusion melting treatment is 200rpm~500rpm, and the barrel temperature of the extrusion melting treatment is 180℃~230℃. Optionally, the filter mesh number of the filtration treatment is 60 mesh~600 mesh. Optionally, the granulation treatment is strand pelletizing or underwater pelletizing.

[0050] Optionally, the polypropylene composite material further comprises an auxiliary agent, and the preparation method of the polypropylene composite material comprises the following steps:

[0051] Mixing the compatibilizer and the auxiliary agent in a solvent, and drying 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 auxiliary agent includes ethanol. The compatibilizer and the solvent are added to the ethanol and centrifuged for 2 h to 5 h.

[0054] A third aspect of the present application provides a cable, which includes the above-mentioned polypropylene composite material.

[0055] Optionally, the cable may be a high voltage AC cable or a DC transmission cable. The cable of the present application has all the advantages of the above-mentioned polypropylene composite material, which will not be described in detail here. DETAILED DESCRIPTION

[0056] The present application will be further described in detail below in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0058] the term

[0059] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0060] In the present application, "plurality", "multiple", "multiple times", "plurality", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0061] In the present application, “several” means at least one, such as one, two, etc., unless otherwise clearly defined.

[0062] In this application, "optionally", "optional" and "optional" refer to optional, that is, to any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

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

[0064] In the present application, when referring to a numerical interval (i.e., a numerical range), unless otherwise specified, the optional numerical distribution within the above numerical interval is deemed to be continuous and includes the two numerical endpoints of the numerical range (i.e., the minimum value and the maximum value), and every numerical value between the two numerical endpoints.

[0065] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0066] In this application, room temperature refers to 10°C to 40°C.

[0067] In the present 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 is further described in conjunction with specific embodiments and comparative examples. The raw materials involved in the following specific embodiments and comparative examples, unless otherwise specified, can all be commercially available, the instruments used, unless otherwise specified, can all be commercially available, and the processes involved, unless otherwise specified, are all routinely 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° C., 2.16 kg);

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

[0071] The antioxidant 300 is produced by Zibo Vanke Chemical Co., Ltd., and the ash content is less than 0.05%.

[0072] Preparation of compatibilizer-1#:

[0073] S1. Add 924g 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboric acid (2mol) and 456g 1,2,6-hexanetriol (3.4mol) to 5000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stock water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering and removing the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate-1#;

[0074] S2. Mix the liquid-1# containing the bisdioxyborane 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 bisdioxyborane acrylate derivative. After rotary evaporation and washing, the reaction liquid is obtained to obtain a liquid-1# containing a bisdioxyborane acrylate derivative;

[0075] S3. Add 5000g of polypropylene resin into an internal mixer and melt it at 190°C. Slowly add 15g of styrene into the internal mixer and stir and mix for 2 minutes. Then add the liquid-1# containing the bis(dioxyborane) acrylate derivative 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 completed, extrude and granulate, cool, crush and grind to obtain compatibilizer-1#.

[0076] Preparation of compatibilizer-2#:

[0077] S1. Add 924g 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboric acid (2mol) and 670g 1,2,6-hexanetriol (5mol) to 6000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stock water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering to remove the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate-2#;

[0078] S2. Mix the liquid-2# containing the bisdioxyborane 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 bisdioxyborane acrylate derivative. After rotary evaporation and washing, the reaction liquid is obtained to obtain a liquid-2# containing a bisdioxyborane acrylate derivative;

[0079] S3. Add 5000g of polypropylene resin into an internal mixer and melt it at 190°C. Slowly add 50g of styrene into the internal mixer and stir and mix for 2 minutes. Then add the liquid-2# containing the bis(dioxyborane) acrylate derivative described in step S2 and 10g of di-tert-butyl peroxyisopropylbenzene, stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is completed, extrude and granulate, cool, crush and grind to obtain compatibilizer-2#.

[0080] Preparation of compatibilizer-3#:

[0081] S1. Add 924g 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboric acid (2mol) and 938g 1,2,6-hexanetriol (7mol) to 6000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stoke water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering and removing the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate - 3#;

[0082] S2, mixing the liquid-3# containing the bisdioxyborane intermediate described in step S1, 272g of acryloyl chloride (2.99mol) and 10g of triethylamine (0.1mol), and reacting for 10 hours to generate a bisdioxyborane acrylate derivative. After rotary evaporation and washing, the reaction liquid is obtained to obtain a liquid-3# containing a bisdioxyborane acrylate derivative;

[0083] S3, adding 5000g of polypropylene resin into an internal mixer and melting it at 190°C, slowly adding 75g of styrene into the internal mixer and stirring and mixing for 2min, then adding the liquid-3# containing the bis(dioxyborane) acrylate derivative described in step S2 and 15g of diisopropylbenzene peroxide, stirring and mixing for 10 minutes, allowing free radical polymerization to occur, and after the reaction is completed, extruding and granulating, cooling, crushing and grinding to obtain compatibilizer-3#.

[0084] Preparation of compatibilizer-4#:

[0085] S1. Add 484g 4,4'-biphenyldiboronic acid (2mol) and 810g 1,2,8-octantriol (5mol) to 6000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stoke water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering and removing the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate - 4#;

[0086] S2. Mix the liquid-4# containing the bisdioxyborane intermediate described in step S1, 227 g of acryloyl chloride (2.49 mol) and 9.7 g of 4-(dimethylamino)pyridine (0.08 mol), and react for 10 hours to generate a bisdioxyborane acrylate derivative. After rotary evaporation and washing, the reaction liquid is obtained to obtain a liquid-4# containing a bisdioxyborane acrylate derivative;

[0087] S3. Add 5000g of polypropylene resin into an internal mixer and melt it at 190°C. Slowly add 50g of styrene into the internal mixer and stir and mix for 2 minutes. Then add the liquid-4# containing the bis(dioxyborane) acrylate derivative described in step S2 and 10g of di-tert-butyl peroxyisopropylbenzene, stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is completed, extrude and granulate, cool, crush and grind to obtain compatibilizer-4#.

[0088] Preparation of compatibilizer-5#:

[0089] S1. Add 484g 4,4'-biphenyldiboronic acid (2mol) and 950g 1,2,10-decanetriol (5mol) to 6000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stoke water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering and removing the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate - 5#;

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

[0091] S3. Add 5000g of polypropylene resin into an internal mixer and melt it at 190°C. Slowly add 50g of styrene into the internal mixer and stir and mix for 2 minutes. Then add the liquid-5# containing the bis(dioxyborane) acrylate derivative described in step S2 and 10g of di-tert-butyl peroxyisopropylbenzene, stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is completed, extrude and granulate, cool, crush and grind to obtain compatibilizer-5#.

[0092] Preparation of compatibilizer-6#:

[0093] S1. Add 432g naphthalene-1,4-diboric acid (2mol) and 810g 1,2,8-octantriol (5mol) to 6000mL acetone, mix and heat to dissolve, add 50mL sulfurous acid to obtain a reaction mixture. Place the reaction mixture in a Dean-Stoke water separator, heat and reflux at 170°C for 12 hours under nitrogen protection, and an esterification reaction occurs to generate a bis(dioxyborane) intermediate. Cool the reaction solution to room temperature and add 5000mL toluene for precipitation. After filtering and removing the precipitate, use a Soxhlet extractor to separate the oil from the filtrate to obtain a clear and transparent liquid containing a bis(dioxyborane) intermediate-6#;

[0094] S2. Mix the liquid-6# containing the bisdioxyborane intermediate described in step S1, 227 g of acryloyl chloride (2.49 mol) and 14 g of triethylenediamine (0.13 mol), and react for 10 hours to generate a bisdioxyborane acrylate derivative. After rotary evaporation and washing, the reaction liquid is obtained to obtain a liquid-6# containing a bisdioxyborane acrylate derivative;

[0095] S3. Add 5000g of polypropylene resin into an internal mixer and melt it at 190°C. Slowly add 50g of styrene into the internal mixer and stir and mix for 2 minutes. Then add the liquid-6# containing the bis(dioxyborane) acrylate derivative described in step S2 and 10g of di-tert-butyl peroxyisopropylbenzene, stir and mix for 10 minutes to allow free radical polymerization to occur. After the reaction is completed, extrude and granulate, cool, crush and grind to obtain compatibilizer-6#.

[0096] Preparation of compatibilizer A

[0097] The preparation methods of compatibilizer A and compatibilizer-3# are basically the same, with the main difference being that there is no step S2, and step S3 is: 5000g of polypropylene resin is added to an internal mixer and melted at 190°C, 75g of styrene is slowly added to the internal mixer and stirred for 2 minutes, then the liquid-3# containing the bis(dioxaborane) intermediate described in step S1 and 15g of diisopropylbenzene peroxide are added, stirred for 10 minutes, a free radical polymerization reaction occurs, and after the reaction is completed, extrusion granulation is performed, and the compatibilizer A is obtained after cooling, crushing and grinding.

[0098] Preparation of compatibilizer B

[0099] The preparation method of compatibilizer B is basically the same as that of compatibilizer-3#, the main difference being that there are no steps S1 and S2, and step S3 is: 5000g of polypropylene resin is added to an internal mixer and melted at 190°C, followed by adding 924g of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl-3,3'-diboric acid and 15g of diisopropylbenzene peroxide, stirring and mixing for 10 minutes to allow free radical polymerization to occur, extruding and granulating after the reaction, cooling, crushing and grinding 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 that step S3 is: adding 5000g of polypropylene resin into an internal mixer and melting it at 190°C, then adding the liquid-3# containing the bis(dioxyborane) acrylate derivative described in step S2 and 15g of diisopropylbenzene peroxide, stirring and mixing for 10 minutes to allow free radical polymerization to occur, extruding and granulating after the reaction, cooling, crushing and grinding to obtain compatibilizer C.

[0102] Preparation of compatibilizer D

[0103] 5000g of polypropylene resin was added into an internal mixer and melted at 190°C. 75g of styrene was slowly added into the internal mixer and stirred for 2 minutes. Then 15g of diisopropylbenzene peroxide was added and stirred for 10 minutes to allow free radical polymerization to occur. 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] 5000 g of polypropylene resin was added to an internal mixer and melted at 190° C. 75 g of styrene was slowly added to the internal mixer and stirred for 2 minutes, then stirred for 10 minutes, extruded into granules, cooled, crushed and ground to obtain compatibilizer E.

[0106] Comparative Example 1

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

[0108] S1. Prepare polypropylene resin, polystyrene resin and 300 antioxidants by weight as shown in Table 1 using two loss-in-weight scales.

[0109] S2. The polypropylene resin, polystyrene resin and antioxidant 300 are mixed and then melt-kneaded in a twin-screw extruder, filtered through a filter and granulated by water drawing to obtain a polypropylene composite material, wherein the barrel temperature is 210° C., the screw speed is 400 rpm, and the filter mesh number 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 preparation method thereof, the steps 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 by weighing on two loss-in-weight scales according to the weight parts shown in Table 1.

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

[0114] S3. The polypropylene resin, polystyrene resin and mixed powder are mixed and then melt-kneaded in a twin-screw extruder, filtered through a filter and granulated by water drawing to obtain a polypropylene composite material, wherein the barrel temperature is 210° C., the screw speed is 400 rpm, and the filter mesh number is 500 mesh.

[0115] Table 1

[0116]

[0117] Note: “-” means not added.

[0118] The polypropylene composite materials of the above embodiments and comparative examples were tested as follows. 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 can be seen that in Comparative Example 1, no compatibilizer was added, the interface compatibility between the polypropylene resin and the polystyrene resin was poor, the toughness of the polypropylene composite material was poor, and the breakdown strength was low.

[0126] Compared with Comparative Example 1, Comparative Examples 1-6 respectively added compatibilizer A, compatibilizer B, compatibilizer C, compatibilizer D and compatibilizer E, but the compatibilizer had no obvious effect on improving the toughness, tensile strength and breakdown strength of the polypropylene composite material.

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

[0128] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A polypropylene composite material, characterized in that: The invention comprises a polypropylene resin, a polystyrene resin and a compatibilizer, and the preparation method of the compatibilizer comprises the following steps: Under the conditions of an acid and a solvent, the aromatic diboronic acid and a polyol are subjected to an esterification reaction to generate a bisdioxyborane intermediate; Under catalyst conditions, the bisdioxaborane intermediate and acryloyl chloride are reacted to generate a bisdioxaborane acrylate derivative; Under the condition of a free radical initiator, the bis(dioxyborane) acrylate derivative, polypropylene and styrene undergo free radical polymerization.

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'-diboric acid, 4,4'-biphenyl diboric acid, 4,4'-oxybis(1,4-phenylene) diboric acid, terephthalene diboric acid, naphthalene-1,4-diboric acid and anthracene-9,10-diboric acid; 2) The number of hydroxyl groups of the polyol is ≥3; Optionally, the polyol is preferably an alkyl polyol; 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-octantriol, 1,2,9-nonanetriol and 1,2,10-decanetriol; 3) The molar ratio of the aromatic diboric acid to the polyol is 1:(1.5-4).

3. 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 ether, acetone, chloroform, carbon disulfide and toluene; 2) The quality of the solvent satisfies: 4000 mL to 7000 mL of solvent is added for every 2 mol of aromatic diboric acid; 3) The acid agent includes one or more of sulfuric acid and sulfurous acid; 4) The mass of the acid agent satisfies: 40 mL to 60 mL of the acid agent is added for every 2 mol of aromatic diboric acid; 5) The reaction temperature of the esterification reaction is 150°C to 180°C; 6) The reaction time of the esterification reaction is 10h~12h.

4. The polypropylene composite material according to claim 1, characterized in that: Includes at least one of the following features: 1) The molar ratio of the acryloyl chloride to the aromatic diboric acid is (0.5-2):1; 2) The catalyst includes one or more of triethylamine, 4-(dimethylamino)pyridine and triethylenediamine; 3) The amount of the catalyst is such that 0.05 mol to 0.15 mol of the catalyst is added for every 2 mol of aromatic diboric acid; 4) The reaction time is 8h~12h.

5. 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 10000 g / mol to 250000 g / mol; 2) The polypropylene includes isotactic polypropylene; optionally, the isotactic index of the isotactic polypropylene is ≥95%; 3) The polypropylene includes one or more of homopolypropylene and copolymer polypropylene; 4) The polypropylene has a melt index of 0.5 g / 10 min to 10.0 g / 10 min at 230° C. and 2.16 kg; 5) The mass of the polypropylene satisfies: 4000 g to 6000 g of polypropylene is added for every 2 mol of aromatic diboric acid; 6) The mass of the styrene satisfies: 10 g to 80 g of styrene is added for every 2 mol of aromatic diboric acid; 7) The free radical polymerization reaction is carried out in a molten state; 8) The free radical initiator includes an organic peroxide initiator; optionally, the organic peroxide initiator includes one or more of benzoyl peroxide, diisopropylbenzene peroxide and di-tert-butyl peroxyisopropylbenzene; 9) The mass of the free radical initiator satisfies: 5 g to 15 g of free radical initiator is added for every 2 mol of aromatic diboric acid; 10) The temperature of the free radical polymerization reaction is 170°C to 210°C; 11) The free radical polymerization reaction time is 8 min to 12 min.

6. The polypropylene composite material according to any one of claims 1 to 5, 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; optionally, the isotactic index of the isotactic polypropylene is ≥95%; 3) The polypropylene resin includes one or more of homopolypropylene and copolymer polypropylene; 4) The polypropylene resin has a melt index of 0.5 g / 10 min to 10.0 g / 10 min at 230° C. and 2.16 kg; 5) The polystyrene resin has a melt index of 1.0 g / 10 min to 5.0 g / 10 min at 200° C. and 5 kg.

7. The polypropylene composite material according to any one of claims 1 to 5, characterized in that The weight portion of the polypropylene resin is 90-99 parts, preferably 93-98 parts; the weight portion of the polystyrene resin is 1-9 parts, preferably 2-7 parts; the weight portion of the compatibilizer is 0.5-8 parts, preferably 1-5 parts.

8. The polypropylene composite material according to claim 7, characterized in that: The invention also comprises an auxiliary agent, wherein the auxiliary agent comprises an antioxidant; optionally, the antioxidant comprises a hindered phenol compound; optionally, the weight portion of the antioxidant is 0.1 to 1 part; preferably 0.3 to 0.5 part.

9. A method for preparing the polypropylene composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polypropylene resin, the polystyrene resin and the compatibilizer are melt-mixed and then granulated.

10. A cable, characterized in that: The polypropylene composite material comprises the polypropylene composite material according to any one of claims 1 to 8.

Images