A toughened modified PVC material and a method for its production

Abstract

This invention discloses a toughened modified PVC material and its preparation method, relating to the field of polymer materials technology. In preparing the toughened modified PVC material, the invention first coats the surface of potassium titanate whiskers with antimony tin oxide precipitate to obtain coated modified whiskers; reacts the coated modified whiskers with chloropropyltrimethoxysilane to obtain modified whiskers; reacts phenylphosphodichloro with dimethylaminopropylamine diisopropanol to obtain a flame-retardant chain extender; reacts 2-chloro-4,6-diamino-1,3,5-triazine with linear alkylamine to obtain a draping chain extender; reacts diisocyanate, diol, and chain extender to polymerize and obtain modified polyurethane; and then plasticizes and blends PVC resin, modified polyurethane, modified whiskers, plasticizer, heat stabilizer, and antioxidant, followed by hot pressing to obtain the toughened modified PVC material. The toughened modified PVC material prepared by this invention has the advantages of flame retardancy, antistatic properties, high toughness, and good mechanical strength.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a toughened modified PVC material and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) is one of the most widely consumed plastics globally. PVC is a durable and corrosion-resistant material widely used in construction, transportation, packaging, electrical, and healthcare fields. It is one of the earliest industrialized and most widely applied general-purpose thermoplastics in the world. However, rigid PVC, due to its high polarity and rigid molecular chains, exhibits significant brittleness and poor impact resistance; its notched impact strength at room temperature is only around 3 kJ / m². 2 -5 kJ / m 2 When the temperature drops below 0℃, its impact resistance weakens significantly, requiring toughening modification in practical applications. Furthermore, due to the unique molecular chain structure of PVC, its flowability is relatively poor compared to other general-purpose plastics, resulting in poor processing flow. To improve its processing flowability, plasticizers are usually added. However, the addition of plasticizers greatly affects the flame retardant properties of PVC, causing a significant decrease. Therefore, improving its flame retardant properties is also necessary to broaden the application range of PVC.

[0003] PVC resin materials also possess excellent electrical insulation properties, with a resistance typically as high as 10 ohms. 15 With resistance of Ω or even higher, the electrical insulation caused by high resistance makes it prone to static charge accumulation in some application scenarios, leading to adverse phenomena such as electric shock and dust attraction. In order to reduce and avoid the hazards caused by static charge accumulation, and in order to expand the application range of PVC materials, it is necessary to improve its antistatic properties. Summary of the Invention

[0004] The purpose of this invention is to provide a toughened modified PVC material and its preparation method to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A toughened modified PVC material, wherein the toughened modified PVC material is prepared by plasticizing and blending PVC resin, modified polyurethane, modified whiskers, plasticizer, heat stabilizer and antioxidant, followed by hot pressing molding.

[0007] The modified polyurethane is prepared by reacting and polymerizing diisocyanate, diol, and chain extender;

[0008] The chain extender includes flame retardant chain extender, drap chain extender, and 1,4-butanediol;

[0009] The flame retardant chain extender is prepared by reacting phenylphosphodichloro with dimethylaminopropylamine diisopropanol;

[0010] The suspension chain extender is prepared by reacting 2-chloro-4,6-diamino-1,3,5-triazine with a straight-chain alkylamine;

[0011] The modified whiskers are prepared by reacting coated modified whiskers with chloropropyltrimethoxysilane;

[0012] The modified whiskers are prepared by coating the surface of potassium titanate whiskers with antimony tin oxide precipitate.

[0013] As an optimization, the diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.

[0014] As an optimization, the diol is one or more of polytetrahydrofuran ether diol, polydimethylsiloxane diol, polycarbonate diol, polycaprolactone diol, and polyester diol.

[0015] As an optimization, the linear alkylamine is one or more of octylamine, nonylamine, decylamine, undecylamine, laurylamine, tridecylamine, and tetradecylamine.

[0016] As an optimization, the plasticizer is one or more of dioctyl phthalate and PE wax.

[0017] As an optimization, the heat stabilizer is one or more of calcium-zinc stabilizers, calcium stearate, zinc stearate, and organotin compounds.

[0018] A method for preparing toughened modified PVC material includes the following preparation steps:

[0019] (1) Disperse 2-3 parts of potassium titanate whiskers in 60-80 parts of ethanol-water mixture by mass, sonicate for 8-12 min, heat to 70-80℃, add 10-12 parts of metal mixture dropwise at 0.4-0.6 ml / min at 200-300 rpm, and maintain pH at 2-3 during the process. After the addition is completed, stir and reflux at 70-80℃, pH=2-3, 200-300 r / min for 2-3 h, filter, wash with anhydrous ethanol, vacuum dry at 70-80℃ for 10-12 h, and calcine at 500-600℃ for 2-3 h to obtain coated modified whiskers;

[0020] (2) By mass fraction, 1-1.5 parts of the coated modified whiskers are dispersed in 30-40 parts of anhydrous ethanol, sonicated for 40-60 min, stirred at 400-500 r / min for 60-80 min at room temperature, 0.8-1.2 parts of chloropropyltrimethoxysilane are added, and the mixture is stirred and refluxed at 400-500 r / min at 80-90℃ for 40-50 min. 1.5-2 parts of 1 mol / L hydrochloric acid solution are added, and the mixture is stirred and refluxed for 4-5 h. The mixture is centrifuged at 8000-10000 rpm for 12-15 min, washed 3-4 times with anhydrous ethanol, and vacuum dried at 60-70℃ for 8-10 h to obtain the modified whiskers.

[0021] (3) By mass, under an argon atmosphere, mix 5-6 parts of dimethylaminopropylamine diisopropanol, 2.45-3.15 parts of triethylamine, and 15-20 parts of toluene evenly. Stir at 200-300 r / min for 30-50 min at room temperature, heat to 75-80℃, and add 7.15-8.42 parts of 30wt% phenylphosphine dropwise at 0.3-0.5 ml / min at 300-400 r / min. After the dichlorotoluene solution was added dropwise, the mixture was stirred and refluxed at 75-80℃ and 300-400 r / min for 4-5 h, then stirred and refluxed at 95-100℃ and 300-400 r / min for 10-12 h. The mixture was then allowed to cool naturally to room temperature, filtered, and the filtrate was washed 3-4 times with pure water to remove the aqueous layer. Toluene and residual water were removed by vacuum distillation, and the mixture was dried under vacuum at 50-60℃ for 8-10 h to obtain the flame retardant chain extender.

[0022] (4) Mix 2-3 parts of 2-chloro-4,6-diamino-1,3,5-triazine and 15-18 parts of dioxane by mass, heat to 80-90℃, add 10wt% dioxane solution of linear alkylamine at 0.4-0.5ml / min, with the molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to linear alkylamine being 1:(1.08-1.12), and add 5wt% sodium hydroxide solution dropwise to maintain pH 6-8. Stir and reflux at 80-90℃ and 300-400r / min for 8-9h, cool naturally to room temperature, stand for 30-40min, filter, wash alternately with pure water and acetone, and vacuum dry at 60-70℃ for 8-10h to obtain the suspension chain extender;

[0023] (5) Mix polytetrahydrofuran ether diol and polydimethylsiloxane diol at a mass ratio of 1:(0.6~0.8) and dehydrate under vacuum at 110~120℃ for 1~2h. Stop vacuuming and cool to 80~90℃ under a nitrogen atmosphere. Add hexamethylene diisocyanate and isophorone diisocyanate at a molar ratio of isocyanate group to hydroxyl group of 1:(0.55~0.6) and a molar ratio of hexamethylene diisocyanate to isophorone diisocyanate of 1:(0.25~0.3). Add catalyst at 0.005~0.006 times the mass of polytetrahydrofuran ether diol. Stir the reaction at 80~90℃ and 300~400r / min. Take a sample to confirm the reaction. After complete reaction, a flame retardant chain extender is added at a molar ratio of 1:(0.6~0.7) of the remaining isocyanate groups to hydroxyl groups. The mixture is stirred at 70~80℃ and 300~400 r / min. After sampling to confirm the complete reaction, a draping chain extender is added at a molar ratio of 1:(0.7~0.8) of the remaining isocyanate groups to hydroxyl groups. The mixture is stirred at 70~80℃ and 300~400 r / min. After sampling to confirm the complete reaction, 1,4-butanediol is added at a molar ratio of 1:(1.02~1.04) of the remaining isocyanate groups to hydroxyl groups. The mixture is stirred at 60~70℃ and 300~400 r / min. After sampling to confirm the complete reaction, the mixture is discharged to obtain the modified polyurethane.

[0024] (6) By mass, 100-120 parts of PVC resin, 10-12 parts of dioctyl phthalate, 30-35 parts of modified polyurethane, 12-16 parts of modified whiskers, 0.9-1.2 parts of dibutyltin dilaurate, 3-4 parts of calcium zinc stabilizer, 0.5-0.6 parts of antioxidant 1010, and 1-1.2 parts of PE wax are mixed evenly in a high-speed mixer, and then added to a two-roll mill and plasticized at 135-145℃ and 80-100rpm for 12-15min. The mixture is then placed in a mold and hot-pressed at 170-180℃ and 12-14MPa for 8-10min. It is then transferred to a cold press and cold-pressed at 8-10MPa for 4-5min to demold. The mixture is then allowed to stand at 60-70℃ for 18-20h to obtain toughened modified PVC material.

[0025] As an optimization, the volume ratio of anhydrous ethanol to pure water in the ethanol-water mixture in step (1) is 1:1.

[0026] As an optimization, the metal mixture in step (1) is prepared by dissolving tin chloride pentahydrate and antimony chloride in a 5 mol / L hydrochloric acid solution at a molar ratio of (6~7):1, and the content of antimony chloride in the metal mixture is 2wt%~2.5wt%.

[0027] As an optimization, the reaction process of the modified whiskers in step (2) is as follows:

[0028]

[0029] As an optimization, the reaction process of the flame retardant chain extender in step (3) is as follows:

[0030]

[0031] As an optimization, the reaction process of the suspension chain extender in step (4) is as follows:

[0032]

[0033] R = 7~13.

[0034] As an optimization, the weight-average molecular weight of the polytetrahydrofuran ether diol in step (5) is 2000.

[0035] As an optimization, the weight-average molecular weight of the polydimethylsiloxane diol in step (5) is 2000.

[0036] As an optimization, the catalyst in step (5) is dibutyltin dilaurate.

[0037] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0038] In preparing toughened modified PVC materials, this invention first coats potassium titanate whiskers with antimony tin oxide precipitate to obtain coated modified whiskers; then reacts the coated modified whiskers with chloropropyltrimethoxysilane to obtain modified whiskers; reacts phenylphosphodichloro with dimethylaminopropylamine diisopropanol to obtain a flame-retardant chain extender; reacts 2-chloro-4,6-diamino-1,3,5-triazine with linear alkylamine to obtain a draping chain extender; reacts diisocyanate, diol, and chain extender to polymerize and obtain modified polyurethane; and finally, plasticizes and blends PVC resin, modified polyurethane, modified whiskers, plasticizer, heat stabilizer, and antioxidant, followed by hot pressing to obtain the toughened modified PVC material.

[0039] First, tin-antimony oxide precipitate is coated onto the surface of potassium titanate whiskers to obtain coated modified whiskers. The surface of potassium titanate whiskers contains a large number of active hydroxyl sites, which can provide sufficient binding sites for the tin-antimony oxide precipitate coating. Tin ions and antimony ions first hydrolyze to form positively charged hydrolysis products, which are then adsorbed and precipitated on the whisker surface. During calcination, trivalent antimony ions are oxidized to pentavalent antimony ions and doped into the tin oxide lattice through pyrolysis and solid solution reactions, thus forming tin-antimony oxide precipitate coated onto the surface of potassium titanate whiskers. Potassium titanate whiskers have good mechanical strength. After the surface is coated with tin-antimony oxide, the good electrical conductivity of tin-antimony oxide further enhances the mechanical strength of the potassium titanate whiskers. The surface of the whiskers is transformed into a conductive surface, improving the conductivity of potassium titanate whiskers. At the same time, antimony tin oxide has a promoting effect on flame retardant elements such as phosphorus, nitrogen, and silicon. In the presence of flame retardant elements, it can effectively synergistically promote their better flame retardant effect. Modified whiskers are prepared by reacting the coated and modified whiskers with chloropropyltrimethoxysilane. Although potassium titanate whiskers have been coated and modified with antimony tin oxide, their surface energy is still high, and there is a risk of agglomeration and poor dispersion. Therefore, silane coupling agents with chlorine atoms are used to modify them, which improves the dispersibility of the modified whiskers and their compatibility with the polymer matrix, while introducing reactive groups with chlorine atoms on the surface of the modified whiskers.

[0040] Secondly, a flame-retardant chain extender is prepared by reacting phenylphosphine dichloride with dimethylaminopropylamine diisopropanol. The two phosphoryl chloride groups on the phenylphosphine dichloride react with one hydroxyl group on each of the two dimethylaminopropylamine diisopropanol groups, thereby forming a flame-retardant chain extender with phosphorus, two tertiary amine groups, and two alcohol hydroxyl groups. The two alcohol hydroxyl groups serve as reaction sites to participate in the subsequent polymerization reaction of modified polyurethane. The phosphorus element is introduced into the chain segment as a flame-retardant element, which has good flame-retardant properties and can effectively improve the decrease in flame-retardant properties caused by the addition of plasticizers to polyvinyl chloride resin. The two tertiary amine groups have the potential to undergo quaternization reaction with chlorine atoms. A hanging chain extender was prepared by reacting 2-chloro-4,6-diamino-1,3,5-triazine with a straight-chain alkylamine. The last chlorine atom on the 2-chloro-4,6-diamino-1,3,5-triazine exhibits good reactivity under appropriate reaction conditions and can react with the primary amine group on the straight-chain alkylamine, thereby introducing a long carbon chain onto the 2-chloro-4,6-diamino-1,3,5-triazine. The two amino groups in the hanging chain extender are used in the subsequent polymerization synthesis of modified polyurethane. Simultaneously, the long carbon chain introduced in the hanging chain extender can serve as a hanging chain segment after being introduced into the polyvinyl chloride matrix. Long carbon chains exhibit excellent compatibility with PVC segments. Furthermore, the introduction of long carbon chains as overhanging segments effectively improves the damping properties of the matrix, enhances its energy dissipation capacity, and assists other materials in absorbing impact energy, synergistically improving the toughness of the PVC matrix. However, the long carbon chains used as overhanging segments should not be too long, otherwise it will excessively hinder the movement of molecular chain segments, making processing difficult. The prepared overhanging chain extender is based on triazine groups and contains a large amount of nitrogen. Combined with flame-retardant elements such as phosphorus and silicon, as well as the promoting effect of tin oxide and antimony oxide, it can exert a good flame-retardant effect.

[0041] Finally, the modified polyurethane was prepared by reacting and polymerizing diisocyanate, diol, and chain extender. The flame retardant chain extender and the drap chain extender were introduced into the modified polyurethane segments by reacting with the isocyanate groups. Tertiary amine side chains, drap chains, and flame retardant elements such as phosphorus and nitrogen were also introduced into the modified polyurethane segments. In the synthesis of the modified polyurethane, polydimethylsiloxane diol was also introduced into the modified polyurethane segments as a diol. The siloxane segments in polydimethylsiloxane diol have good flexibility, which can effectively improve the elastic properties of the modified polyurethane. In addition, it also contains a large amount of flame retardant element silicon, which can work synergistically with other flame retardant elements to effectively improve the flame retardant properties of the matrix. Toughened modified PVC material is prepared by plasticizing and blending PVC resin, modified polyurethane, modified whiskers, plasticizer, heat stabilizer, and antioxidant, followed by hot pressing. During the plasticizing, blending, and hot pressing process, the tertiary amine side chains on the modified polyurethane segments and the chlorine atoms introduced onto the surface of the modified whiskers can be linked and cross-linked through a quaternization reaction. This forms a three-dimensional interpenetrating network structure in the PVC matrix, with the modified whiskers as the skeleton and the modified polyurethane as the flexible network, providing excellent toughening modification. The modified whiskers, acting as the skeleton, act as stress concentration bodies, inducing a large number of crazing in the surrounding matrix and forcing the matrix to undergo plastic deformation, thereby absorbing a large amount of impact energy. The flexible network... Modified polyurethane connects modified whiskers together through a quaternization reaction, and the modified polyurethane also has dangling chains, which effectively improves the damping performance of the matrix, enhances the matrix's ability to dissipate impact energy, and, in conjunction with the energy absorption capacity of the modified whiskers, effectively improves the toughness of the PVC matrix while avoiding a decrease in mechanical strength, thus expanding its application range. Furthermore, the tin-antimony oxide coating on the surface of the modified whiskers has good electrical conductivity, and the modified polyurethane is connected to the modified whiskers through the quaternization reaction. The quaternary ammonium cations formed by the quaternization reaction act as network conductors, forming a complete conductive network along the three-dimensional interpenetrating network, effectively reducing the resistance of the matrix and improving its antistatic properties. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] The raw material information used in all the following examples and comparative examples is as follows:

[0044] Potassium titanate whiskers: average diameter 0.4 μm, average length 9 μm, purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd.

[0045] Ethanol-water mixture: The volume ratio of anhydrous ethanol to pure water is 1:1;

[0046] Metal mixture: Prepared by dissolving tin chloride pentahydrate and antimony chloride in a 5 mol / L hydrochloric acid solution at a molar ratio of 6.5:1, with the antimony chloride content in the metal mixture being 2.25 wt%.

[0047] Polytetrahydrofuran ether diol: weight average molecular weight is 2000;

[0048] Polydimethylsiloxane diol: weight average molecular weight is 2000;

[0049] Catalyst: Dibutyltin dilaurate;

[0050] PVC resin: Model TG-1000, purchased from Tosoh (Guangzhou) Chemical Co., Ltd.;

[0051] Calcium-zinc stabilizer: model wwp-b, purchased from Guangdong Weilinna New Material Technology Co., Ltd.;

[0052] PE wax: Model CERALENE 691, purchased from Foshan Weng Kai'er Trading Co., Ltd. Example 1:

[0053] A method for preparing a toughened modified PVC material, the method comprising the following steps:

[0054] (1) By mass fraction, 2 parts of potassium titanate whiskers were dispersed in 60 parts of ethanol-water mixture, ultrasonically dispersed for 8 min, heated to 70°C, and 10 parts of metal mixture were added dropwise at 0.4 ml / min at 200 rpm, while maintaining pH 2. After the addition was completed, the mixture was stirred and refluxed at 70°C, pH=2, and 200 r / min for 3 h. The mixture was filtered, washed with anhydrous ethanol, vacuum dried at 70°C for 12 h, and calcined at 500°C for 3 h to obtain coated modified whiskers.

[0055] (2) By mass fraction, 1 part of the coated modified whiskers was dispersed in 30 parts of anhydrous ethanol, sonicated for 40 min, stirred at 400 r / min for 80 min at room temperature, 0.8 parts of chloropropyltrimethoxysilane was added, and the mixture was stirred and refluxed at 400 r / min at 80 °C for 50 min, 1.5 parts of 1 mol / L hydrochloric acid solution was added, and the mixture was stirred and refluxed for 5 h, centrifuged at 8000 rpm for 15 min, washed 3 times with anhydrous ethanol, and vacuum dried at 60 °C for 10 h to obtain the modified whiskers;

[0056] (3) By mass fraction, under an argon atmosphere, 5 parts of dimethylaminopropylamine diisopropanol, 2.45 parts of triethylamine and 15 parts of toluene were mixed evenly, stirred at 200 r / min for 50 min at room temperature, heated to 75°C, and 7.15 parts of 30wt% phenylphosphodichlorotoluene solution were added dropwise at 0.3 ml / min at 300 r / min. After the addition was completed, the mixture was stirred and refluxed at 75°C at 300 r / min for 5 h, and then stirred and refluxed at 95°C at 300 r / min for 12 h. The mixture was naturally cooled to room temperature, filtered, and the filtrate was washed three times with pure water to remove the water layer. Toluene and residual water were removed by vacuum distillation, and the mixture was dried under vacuum at 50°C for 10 h to obtain the flame retardant chain extender.

[0057] (4) By mass fraction, 2 parts of 2-chloro-4,6-diamino-1,3,5-triazine and 15 parts of dioxane were mixed evenly, heated to 80°C, and 10 wt% dioxane solution of octylamine was added dropwise at 0.4 ml / min, with the molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to octylamine being 1:1.08. During this process, 5 wt% sodium hydroxide solution was added dropwise to maintain the pH at 6. The mixture was stirred and refluxed at 300 r / min at 80°C for 9 h, cooled naturally to room temperature, allowed to stand for 30 min, filtered, washed alternately with pure water and acetone, and dried under vacuum at 60°C for 10 h to obtain the suspension chain extender.

[0058] (5) Polytetrahydrofuran ether diol and polydimethylsiloxane diol were mixed at a mass ratio of 1:0.6 and then vacuum-dehydrated at 110°C for 2 hours. After vacuuming was stopped, the mixture was cooled to 80°C under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate were added at a molar ratio of 1:0.55 (isocyanate group to hydroxyl group) and a molar ratio of 1:0.25 (hexamethylene diisocyanate to isophorone diisocyanate). 0.005 times the mass of the catalyst was added to the mixture. The mixture was stirred at 300 r / min at 80°C, and samples were taken to confirm the reaction. After complete reaction, a flame retardant chain extender was added at a molar ratio of 1:0.6 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 70°C and 300 r / min. After sampling to confirm the complete reaction, a draping chain extender was added at a molar ratio of 1:0.8 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 70°C and 300 r / min. After sampling to confirm the complete reaction, 1,4-butanediol was added at a molar ratio of 1:1.02 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 60°C and 300 r / min. After sampling to confirm the complete reaction, the mixture was discharged to obtain the modified polyurethane.

[0059] (6) By mass, 100 parts of PVC resin, 10 parts of dioctyl phthalate, 30 parts of modified polyurethane, 12 parts of modified whiskers, 0.9 parts of dibutyltin dilaurate, 3 parts of calcium zinc stabilizer, 0.5 parts of antioxidant 1010 and 1 part of PE wax are mixed evenly in a high-speed mixer, and then added to a two-roll mill and plasticized at 135°C and 80 rpm for 15 min. The mixture is then placed in a mold and hot-pressed at 170°C and 12 MPa for 10 min. It is then transferred to a cold press and cold-pressed at 8 MPa for 5 min to demold. The mixture is then allowed to stand at 60°C for 20 h to obtain toughened modified PVC material. Example 2:

[0060] A method for preparing a toughened modified PVC material, the method comprising the following steps:

[0061] (1) By mass fraction, 2.5 parts of potassium titanate whiskers were dispersed in 70 parts of ethanol-water mixture, ultrasonically dispersed for 10 min, heated to 75°C, and 11 parts of metal mixture were added dropwise at 0.5 ml / min at 250 rpm, while maintaining pH at 2.5. After the addition was completed, the mixture was stirred and refluxed at 75°C, pH=2.5, and 250 r / min for 2.5 h. The mixture was filtered, washed with anhydrous ethanol, vacuum dried at 75°C for 11 h, and calcined at 550°C for 2.5 h to obtain coated modified whiskers.

[0062] (2) By mass fraction, 1.2 parts of the coated modified whiskers were dispersed in 35 parts of anhydrous ethanol, sonicated for 50 min, stirred at 450 r / min for 70 min at room temperature, 1 part of chloropropyltrimethoxysilane was added, and the mixture was stirred and refluxed at 450 r / min at 85 °C for 45 min. 1.8 parts of 1 mol / L hydrochloric acid solution were added, and the mixture was stirred and refluxed for 4.5 h. The mixture was centrifuged at 9000 rpm for 13 min, washed 3 times with anhydrous ethanol, and dried under vacuum at 65 °C for 9 h to obtain the modified whiskers.

[0063] (3) By mass fraction, under an argon atmosphere, 5.5 parts of dimethylaminopropylamine diisopropanol, 2.79 parts of triethylamine and 18 parts of toluene were mixed evenly, stirred at 250 r / min for 40 min at room temperature, heated to 80 °C, and 7.8 parts of 30 wt% phenylphosphodichlorotoluene solution were added dropwise at 0.4 ml / min at 350 r / min. After the addition was completed, the mixture was stirred and refluxed at 350 r / min at 80 °C for 4.5 h, and then stirred and refluxed at 350 r / min at 98 °C for 11 h. The mixture was naturally cooled to room temperature, filtered, and the filtrate was washed three times with pure water to remove the water layer. The toluene and residual water were removed by vacuum distillation, and the mixture was dried under vacuum at 55 °C for 9 h to obtain the flame retardant chain extender.

[0064] (4) By mass fraction, 2.5 parts of 2-chloro-4,6-diamino-1,3,5-triazine and 16.5 parts of dioxane were mixed evenly, heated to 85°C, and 10 wt% dioxane solution of decylamine was added dropwise at 0.45 ml / min, with a molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to decylamine of 1:1.1. During this process, 5 wt% sodium hydroxide solution was added dropwise to maintain pH 7. The mixture was stirred and refluxed at 350 r / min at 85°C for 8.5 h, cooled naturally to room temperature, allowed to stand for 35 min, filtered, washed alternately with pure water and acetone, and dried under vacuum at 65°C for 9 h to obtain the suspension chain extender;

[0065] (5) Polytetrahydrofuran ether diol and polydimethylsiloxane diol were mixed at a mass ratio of 1:0.7 and then vacuum-dehydrated at 115°C for 1.5 h. After vacuuming was stopped, the mixture was cooled to 85°C under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate were added at a molar ratio of 1:0.58 (isocyanate group to hydroxyl group) and a molar ratio of 1:0.28 (hexamethylene diisocyanate to isophorone diisocyanate). 0.0055 times the mass of the catalyst was added to the mixture. The mixture was stirred at 350 r / min at 85°C, and samples were taken to confirm the reaction. After complete reaction, a flame retardant chain extender was added at a molar ratio of 1:0.65 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 75°C and 350 r / min. After sampling to confirm the complete reaction, a draping chain extender was added at a molar ratio of 1:0.75 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 75°C and 350 r / min. After sampling to confirm the complete reaction, 1,4-butanediol was added at a molar ratio of 1:1.03 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 65°C and 350 r / min. After sampling to confirm the complete reaction, the mixture was discharged to obtain the modified polyurethane.

[0066] (6) By mass, 110 parts of PVC resin, 11 parts of dioctyl phthalate, 32 parts of modified polyurethane, 14 parts of modified whiskers, 1.05 parts of dibutyltin dilaurate, 3.5 parts of calcium zinc stabilizer, 0.55 parts of antioxidant 1010 and 1.1 parts of PE wax are mixed evenly in a high-speed mixer, and then added to a two-roll mill and plasticized at 140°C and 90 rpm for 13 min. The mixture is then placed in a mold and hot-pressed at 175°C and 13 MPa for 9 min. It is then transferred to a cold press and cold-pressed at 9 MPa for 4.5 min to demold. The mixture is then allowed to stand at 65°C for 19 h to obtain toughened modified PVC material. Example 3:

[0067] A method for preparing a toughened modified PVC material, the method comprising the following steps:

[0068] (1) By mass fraction, 3 parts of potassium titanate whiskers were dispersed in 80 parts of ethanol-water mixture, ultrasonically dispersed for 12 min, heated to 80°C, and 12 parts of metal mixture were added dropwise at 0.6 ml / min at 300 rpm, while maintaining pH 3. After the addition was completed, the mixture was stirred and refluxed at 80°C, pH=3, and 300 r / min for 2 h. The mixture was filtered, washed with anhydrous ethanol, vacuum dried at 80°C for 10 h, and calcined at 600°C for 2 h to obtain coated modified whiskers.

[0069] (2) By mass fraction, 1.5 parts of the coated modified whiskers were dispersed in 40 parts of anhydrous ethanol, sonicated for 60 min, stirred at 500 r / min for 60 min at room temperature, 1.2 parts of chloropropyltrimethoxysilane were added, and the mixture was stirred and refluxed at 500 r / min at 90 °C for 40 min. 2 parts of 1 mol / L hydrochloric acid solution were added, and the mixture was stirred and refluxed for 4 h. The mixture was centrifuged at 10000 rpm for 12 min, washed 4 times with anhydrous ethanol, and dried under vacuum at 70 °C for 8 h to obtain the modified whiskers.

[0070] (3) By mass fraction, under an argon atmosphere, 6 parts of dimethylaminopropylamine diisopropanol, 3.15 parts of triethylamine and 20 parts of toluene were mixed evenly, stirred at 300 r / min for 30 min at room temperature, heated to 80 °C, and 8.42 parts of 30 wt% phenylphosphodichlorotoluene solution were added dropwise at 0.5 ml / min at 400 r / min. After the addition was completed, the mixture was stirred and refluxed at 400 r / min at 80 °C for 4 h, and then stirred and refluxed at 400 r / min at 100 °C for 10 h. The mixture was naturally cooled to room temperature, filtered, and the filtrate was washed 4 times with pure water to remove the water layer. The toluene and residual water were removed by vacuum distillation, and the mixture was dried under vacuum at 60 °C for 8 h to obtain the flame retardant chain extender.

[0071] (4) By mass fraction, 3 parts of 2-chloro-4,6-diamino-1,3,5-triazine and 18 parts of dioxane were mixed evenly, heated to 90°C, and 10 wt% dioxane solution of laurylamine was added dropwise at 0.5 ml / min, with the molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to laurylamine being 1:1.12. During this process, 5 wt% sodium hydroxide solution was added dropwise to maintain the pH at 8. The mixture was stirred and refluxed at 400 r / min at 90°C for 8 h, cooled naturally to room temperature, allowed to stand for 40 min, filtered, washed alternately with pure water and acetone, and dried under vacuum at 70°C for 8 h to obtain the suspension chain extender;

[0072] (5) Polytetrahydrofuran ether diol and polydimethylsiloxane diol were mixed at a mass ratio of 1:0.8 and then vacuum-dehydrated at 120°C for 1 hour. After vacuuming was stopped, the mixture was cooled to 90°C under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate were added at a molar ratio of 1:0.6 for isocyanate groups and 1:0.3 for isophorone diisocyanate. 0.006 times the mass of the catalyst was added to the mixture. The mixture was stirred at 400 r / min at 90°C. Samples were taken to confirm the completion of the reaction. Afterwards, a flame retardant chain extender was added at a molar ratio of 1:0.7 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 80°C and 400 r / min. After sampling to confirm the complete reaction, a draping chain extender was added at a molar ratio of 1:0.7 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 80°C and 400 r / min. After sampling to confirm the complete reaction, 1,4-butanediol was added at a molar ratio of 1:1.04 of the remaining isocyanate groups to hydroxyl groups. The mixture was stirred at 70°C and 400 r / min. After sampling to confirm the complete reaction, the mixture was discharged to obtain the modified polyurethane.

[0073] (6) By mass, 120 parts of PVC resin, 12 parts of dioctyl phthalate, 35 parts of modified polyurethane, 16 parts of modified whiskers, 1.2 parts of dibutyltin dilaurate, 4 parts of calcium zinc stabilizer, 0.6 parts of antioxidant 1010 and 1.2 parts of PE wax are mixed evenly in a high-speed mixer, and then added to a two-roll mill and plasticized at 145°C and 100 rpm for 12 min. The mixture is then placed in a mold and hot-pressed at 180°C and 14 MPa for 8 min. It is then transferred to a cold press and cold-pressed at 10 MPa for 4 min to demold. The mixture is then allowed to stand at 70°C for 18 h to obtain toughened modified PVC material.

[0074] Comparative Example 1:

[0075] The preparation method of the toughened modified PVC material in Comparative Example 1 differs from that in Example 2 in that step (1) is omitted, and step (2) is modified as follows: 1.2 parts by mass of potassium titanate whiskers are dispersed in 35 parts of anhydrous ethanol, sonicated for 50 min, stirred at 450 r / min for 70 min at room temperature, 1 part of chloropropyltrimethoxysilane is added, and the mixture is stirred and refluxed at 450 r / min at 85 °C for 45 min. 1.8 parts of 1 mol / L hydrochloric acid solution are added, and the mixture is stirred and refluxed for another 4.5 h. The mixture is centrifuged at 9000 rpm for 13 min, washed three times with anhydrous ethanol, and vacuum dried at 65 °C for 9 h to obtain the modified whiskers. The remaining steps are the same as in Example 2.

[0076] Comparative Example 2:

[0077] The preparation method of the toughened modified PVC material in Comparative Example 2 differs from that in Example 2 in that step (2) is omitted, and step (6) is modified as follows: 110 parts by mass of PVC resin, 11 parts by mass of dioctyl phthalate, 32 parts by mass of modified polyurethane, 14 parts by mass of coated modified whiskers, 1.05 parts by mass of dibutyltin dilaurate, 3.5 parts by mass of calcium-zinc stabilizer, 0.55 parts by mass of antioxidant 1010, and 1.1 parts by mass of PE wax are mixed evenly in a high-speed mixer, then added to a two-roll mill and plasticized at 140°C and 90 rpm for 13 min. The mixture is then placed in a mold and hot-pressed at 175°C and 13 MPa for 9 min, then transferred to a cold press and cold-pressed at 9 MPa for 4.5 min to demold. The mixture is then allowed to stand at 65°C for 19 h to obtain the toughened modified PVC material. The remaining steps are the same as in Example 2.

[0078] Comparative Example 3:

[0079] The preparation method of the toughened modified PVC material in Comparative Example 3 differs from that in Example 2 in that steps (1) and (2) are omitted, and step (6) is modified as follows: 110 parts by mass of PVC resin, 11 parts by mass of dioctyl phthalate, 32 parts by mass of modified polyurethane, 1.05 parts by mass of dibutyltin dilaurate, 3.5 parts by mass of calcium-zinc stabilizer, 0.55 parts by mass of antioxidant 1010, and 1.1 parts by mass of PE wax are mixed evenly in a high-speed mixer, then added to a two-roll mill and plasticized at 140°C and 90 rpm for 13 min. The mixture is then placed in a mold and hot-pressed at 175°C and 13 MPa for 9 min, then transferred to a cold press and cold-pressed at 9 MPa for 4.5 min to demold. The mixture is then allowed to stand at 65°C for 19 h to obtain the toughened modified PVC material. The remaining steps are the same as in Example 2.

[0080] Comparative Example 4:

[0081] The preparation method of the toughened modified PVC material in Comparative Example 4 differs from that in Example 2 in that step (3) is omitted, and step (5) is modified as follows: polytetrahydrofuran ether diol and polydimethylsiloxane diol are mixed at a mass ratio of 1:0.7 and then vacuum dehydrated at 115°C for 1.5 h. After stopping the vacuuming, the temperature is lowered to 85°C under a nitrogen atmosphere, and hexamethylene diisocyanate and isophorone diisocyanate are added at a molar ratio of isocyanate group to hydroxyl group of 1:0.58. The molar ratio of hexamethylene diisocyanate to isophorone diisocyanate is 1:0. 28. Add catalyst at 0.0055 times the mass of polytetrahydrofuran ether diol, and stir at 85°C and 350 rpm. After confirming complete reaction by sampling, add a suspension chain extender at a molar ratio of 1:0.2625 of the remaining isocyanate groups to hydroxyl groups, and stir at 75°C and 350 rpm. After confirming complete reaction by sampling, add 1,4-butanediol at a molar ratio of 1:1.03 of the remaining isocyanate groups to hydroxyl groups, and stir at 65°C and 350 rpm. After confirming complete reaction by sampling, discharge the product to obtain modified polyurethane. The remaining steps are the same as in Example 2.

[0082] Comparative Example 5:

[0083] The preparation method of the toughened modified PVC material in Comparative Example 5 differs from that in Example 2 in that step (4) is omitted, and step (5) is modified as follows: polytetrahydrofuran ether diol and polydimethylsiloxane diol are mixed at a mass ratio of 1:0.7 and then vacuum-dehydrated at 115°C for 1.5 h. After stopping the vacuuming, the mixture is cooled to 85°C under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate are added at a molar ratio of isocyanate group to hydroxyl group of 1:0.58 and a molar ratio of hexamethylene diisocyanate to isophorone diisocyanate of 1:0.28. A catalyst with a mass of 0.0055 times that of polytetrahydrofuran ether diol is added, and the mixture is heated at 85°C and 350 r / After stirring the reaction for 350 rpm for 1 minute and taking a sample to confirm the complete reaction, a flame retardant chain extender was added at a molar ratio of 1:0.65 of the remaining isocyanate groups to hydroxyl groups. The reaction was then stirred at 75°C and 350 rpm for 1 minute. After taking a sample to confirm the complete reaction, 2,4-diamino-6-n-butylamino-1,3,5-triazine was added at a molar ratio of 1:0.75 of the remaining isocyanate groups to hydroxyl groups. The reaction was then stirred at 75°C and 350 rpm for 1 minute. After taking a sample to confirm the complete reaction, 1,4-butanediol was added at a molar ratio of 1:1.03 of the remaining isocyanate groups to hydroxyl groups. The reaction was then stirred at 65°C and 350 rpm for 1 minute. After taking a sample to confirm the complete reaction, the product was discharged to obtain the modified polyurethane. The remaining steps were the same as in Example 2.

[0084] Comparative Example 6:

[0085] The difference between the preparation method of the toughened modified PVC material in Comparative Example 6 and Example 2 lies in step (4). Step (4) is modified as follows: 2.5 parts by mass of 2-chloro-4,6-diamino-1,3,5-triazine and 16.5 parts of dioxane are mixed evenly, heated to 85°C, and 10 wt% dioxane solution of octadecylamine is added dropwise at 0.45 ml / min, with a molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to octadecylamine of 1:1.1. During this process, 5 wt% sodium hydroxide solution is added dropwise to maintain the pH at 7. The mixture is stirred and refluxed at 350 r / min at 85°C for 12 h, naturally cooled to room temperature, allowed to stand for 35 min, filtered, washed alternately with pure water and acetone, and vacuum dried at 65°C for 9 h to obtain the suspension chain extender. The remaining steps are the same as in Example 2.

[0086] Comparative Example 7:

[0087] The preparation method of the toughened modified PVC material in Comparative Example 7 differs from that in Example 2 in that step (4) is omitted, and step (5) is modified as follows: polytetrahydrofuran ether diol and polydimethylsiloxane diol are mixed at a mass ratio of 1:0.7 and then vacuum-dehydrated at 115°C for 1.5 h. After stopping the vacuuming, the temperature is lowered to 85°C under a nitrogen atmosphere, and hexamethylene diisocyanate and isophorone diisocyanate are added at a molar ratio of isocyanate group to hydroxyl group of 1:0.58. The molar ratio of hexamethylene diisocyanate to isophorone diisocyanate is 1:0. 0.28. Add catalyst at 0.0055 times the mass of polytetrahydrofuran ether diol, and stir at 85°C and 350 rpm. After confirming complete reaction by sampling, add flame retardant chain extender at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1:0.65, and stir at 75°C and 350 rpm. After confirming complete reaction by sampling, add 1,4-butanediol at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1:1.03, and stir at 65°C and 350 rpm. After confirming complete reaction by sampling, discharge the product to obtain modified polyurethane. The remaining steps are the same as in Example 2.

[0088] Comparative Example 8:

[0089] The difference between the preparation method of the toughened modified PVC material in Comparative Example 8 and Example 2 lies in the difference in step (5). Step (5) is modified as follows: Polytetrahydrofuran ether diol is dehydrated under vacuum at 115°C for 1.5 h. After vacuuming is stopped, the temperature is lowered to 85°C under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate are added at a molar ratio of 1:0.58 (hexamethylene diisocyanate to isophorone diisocyanate molar ratio of 1:0.28). A catalyst with a mass of 0.0055 times that of polytetrahydrofuran ether diol is added. The mixture is then heated at 85°C and 350 r / min. After stirring and confirming complete reaction by sampling, a flame retardant chain extender was added at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1:0.65. The reaction was stirred at 75°C and 350 rpm. After confirming complete reaction by sampling, a draping chain extender was added at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1:0.75. The reaction was stirred at 75°C and 350 rpm. After confirming complete reaction by sampling, 1,4-butanediol was added at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1:1.03. The reaction was stirred at 65°C and 350 rpm. After confirming complete reaction by sampling, the product was discharged to obtain the modified polyurethane. The remaining steps were the same as in Example 2.

[0090] Comparative Example 9:

[0091] The preparation method of the toughened modified PVC material in Comparative Example 9 differs from that in Example 2 in that steps (3), (4), and (5) are omitted, and step (6) is modified as follows: 110 parts by mass of PVC resin, 11 parts by mass of dioctyl phthalate, 14 parts by mass of modified whiskers, 1.05 parts by mass of dibutyltin dilaurate, 3.5 parts by mass of calcium-zinc stabilizer, 0.55 parts by mass of antioxidant 1010, and 1.1 parts by mass of PE wax are mixed evenly in a high-speed mixer, then added to a two-roll mill and plasticized at 140°C and 90 rpm for 13 min. The mixture is then placed in a mold and hot-pressed at 175°C and 13 MPa for 9 min, then transferred to a cold press and cold-pressed at 9 MPa for 4.5 min to demold. The mixture is then allowed to stand at 65°C for 19 h to obtain the toughened modified PVC material. The remaining steps are the same as in Example 2.

[0092] Test Example 1:

[0093] Mechanical property testing: The tensile strength and impact strength of the prepared toughened modified PVC material are tested to evaluate its mechanical strength and toughness. The specific test methods are as follows:

[0094] Tensile strength: The tensile strength of the toughened modified PVC material prepared according to GB / T 1040.2-2022 was tested. The specimen shape was 1B, the thickness was 4 mm, the test speed was 20 mm / min, and each group of specimens was tested in parallel 5 times. The average value was recorded.

[0095] Impact strength: The notched impact strength of the toughened modified PVC material prepared was tested in accordance with GB / T 1043.1-2008 using a dynamic impact analyzer. The notch shape of the sample was C-type. The test was conducted at room temperature. Each group of samples was tested in parallel 5 times, and the average value was recorded.

[0096] The results are shown in Table 1.

[0097] Table 1

[0098]

[0099] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-9 in Table 1 reveals that the toughened modified PVC material prepared by this invention possesses good mechanical strength and toughness.

[0100] The data comparison in the table shows that the modification of coated whiskers with chloropropyltrimethoxysilane successfully improved their dispersibility and compatibility in the PVC matrix material. At the same time, chlorine atom reactive groups were introduced into the surface of the modified whiskers, allowing them to undergo quaternization reaction with the tertiary amine side chains on the modified polyurethane, thereby forming a three-dimensional interpenetrating network structure. The formation of this structure combines the hard toughening effect of the modified whiskers with the soft toughening effect of the modified polyurethane, and the energy absorption capacity combined with the energy dissipation capacity. The two work synergistically to effectively improve the toughness of the PVC material. Furthermore, the interpenetrating network structure also improves the tensile strength of the PVC material, avoiding the negative effect of low strength caused by traditional toughening.

[0101] By comparing the data in the table, the data in Comparative Example 3 shows that the addition of modified whiskers, as a stress concentrate, induces a large number of silver streaks in the surrounding matrix when subjected to external impact, and forces the matrix to undergo plastic deformation, thereby absorbing a large amount of impact energy and effectively improving the toughness and tensile strength of PVC materials.

[0102] By comparing the data in the table, the data in Comparative Example 4 shows that the introduction of the flame retardant chain extender into the modified polyurethane chain introduces tertiary amine side chains onto the modified polyurethane, allowing them to undergo quaternization reactions with the chlorine atoms on the modified whiskers, thereby forming a three-dimensional interpenetrating network structure. The formation of this structure combines the hard toughening effect of the modified whiskers with the soft toughening effect of the modified polyurethane, and the energy absorption capacity combined with the energy dissipation capacity. The two work synergistically to effectively improve the toughness of PVC materials. Furthermore, the interpenetrating network structure also improves the tensile strength of PVC materials, avoiding the negative effects of traditional toughening methods that result in low strength.

[0103] By comparing the data in the table, the data from Comparative Examples 5 to 7 show that the introduction of the dangling chain extender introduces dangling chains into the modified polyurethane. The dangling chains improve the damping of PVC materials by hindering and slowing down the movement of molecular chain segments, thereby improving the ability to dissipate impact energy and thus improving the toughness of PVC materials. At the same time, the results of Comparative Examples 5 and 6 also show that the length of the dangling chains should be within a reasonable range to achieve better results; they should not be too long or too short.

[0104] By comparing the data in the table, the data in Comparative Example 8 shows that the addition of polydimethylsiloxane diol introduces siloxane segments into the modified polyurethane chain. The siloxane segments have good flexibility and can improve the soft toughening effect of the modified polyurethane.

[0105] By comparing the data in the table, the data in Comparative Example 9 shows that the siloxane segments, tertiary amine side chains, and dangling chains contained in the modified polyurethane all have different toughening abilities. At the same time, as an elastomer, the polyurethane segments themselves also have a good toughening effect on PVC materials. The synergistic effect of multiple toughening elements effectively improves the tensile strength and toughness of PVC materials.

[0106] Test Example 2:

[0107] Flame retardant and antistatic performance tests: The limiting oxygen index, UL 94 flammability rating, and surface resistivity of the prepared toughened modified PVC material were tested to evaluate its flame retardant effect and antistatic performance. The specific test methods are as follows:

[0108] Limiting oxygen index test: The limiting oxygen index of the toughened modified PVC materials prepared in the examples and comparative examples was tested using an oxygen index instrument according to GB / T 2406.1-2008. The sample size was 150mm×10mm×3mm. Five samples were tested in each group and the average value was recorded.

[0109] Vertical burning test: The test was conducted using a vertical-horizontal burning tester according to ASTM D3801-2010. Five samples were tested in each group, and the average value was recorded.

[0110] Antistatic properties: The surface resistivity of the toughened modified PVC material was tested according to GB / T 31838.3-2019 standard. The test was conducted using a ZC90G model high resistance insulation tester. The sample size was 100mm×100mm×4mm. The sample was pretreated for 96h at 23℃ and 50% relative humidity. A voltage of 100V was applied to the electrode device for measuring flat plate samples. After electrolysis for 1min, the surface resistance was measured. The surface resistivity was calculated according to the formula in the standard. Each group of samples was tested in parallel 5 times, and the average value was recorded.

[0111] The results are shown in Table 2.

[0112] Table 2

[0113]

[0114] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-9 in Table 2 reveals that the toughened modified PVC material prepared by this invention has good flame retardant and antistatic properties.

[0115] By comparing the data in the table, the data in Comparative Example 1 shows that the deposition and coating of antimony tin oxide on the surface of potassium titanate whiskers introduces a conductive antimony tin oxide layer on its surface. Furthermore, antimony tin oxide is also a good flame retardant promoter, which can effectively promote the flame retardant elements phosphorus, nitrogen, silicon, and chlorine to exert better flame retardant effects, thereby significantly improving the flame retardant effect and antistatic properties of PVC materials.

[0116] By comparing the data in the table, the data in Comparative Example 2 shows that the chlorine atoms introduced on the surface of the coated and modified whiskers can undergo a quaternization reaction with the tertiary amine side chains in the modified polyurethane, thereby forming a quaternary ammonium cation structure. This structure, together with the tin-antimony oxide layer on the surface of the coated and modified whiskers, forms a complete conductive network, thus effectively improving the antistatic properties of the PVC material.

[0117] By comparing the data in the table, the data in Comparative Example 3 shows that the addition of modified whiskers introduces conductive tin-antimony oxide and chlorine atoms that can form quaternary ammonium cation structures. The combination of the two constructs a complete conductive network, thereby effectively improving the antistatic properties of PVC materials.

[0118] By comparing the data in the table, the data in Comparative Example 4 shows that the addition of the flame retardant chain extender introduces the flame retardant element phosphorus into the modified polyurethane chain segment. Phosphorus has a good flame retardant effect. Under the catalysis of antimony tin oxide and with the synergy of nitrogen, silicon and chlorine flame retardant elements, it effectively offsets the reduction in flame retardancy caused by the addition of a large amount of plasticizer. At the same time, the tertiary amine side chain on the flame retardant chain extender can also form quaternary ammonium cations with the chlorine atoms on the surface of the modified whiskers through quaternization reaction, thereby constructing a complete conductive network and further improving the antistatic properties of PVC materials.

[0119] By comparing the data in the table, the data in Comparative Example 7 shows that the triazine ring structure on the drap chain extender contains a large amount of flame-retardant element nitrogen, which works synergistically with other flame-retardant elements to further improve the flame-retardant performance of PVC materials.

[0120] By comparing the data in the table, the data in Comparative Example 8 shows that the addition of polydimethylsiloxane diol introduces the flame-retardant element silicon into the modified polyurethane chain segment. In conjunction with other flame-retardant elements, it can exert a good flame-retardant effect and effectively improve the flame-retardant performance of PVC materials.

[0121] By comparing the data in the table, the data in Comparative Example 9 shows that the modified polyurethane contains a large amount of flame-retardant elements phosphorus, nitrogen, and silicon. These flame-retardant elements exert good flame-retardant properties under the catalytic action of antimony tin oxide, thereby effectively improving the flame-retardant effect of PVC materials. At the same time, the tertiary amine side chains on the modified polyurethane react with chlorine atoms on the surface of the modified whiskers to form quaternary ammonium cations, thereby constructing a complete conductive network and further improving the antistatic properties of PVC materials.

[0122] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A toughened modified PVC material, characterized in that, The toughened modified PVC material is prepared by hot pressing and blending 100-120 parts of PVC resin, 10-12 parts of dioctyl phthalate, 30-35 parts of modified polyurethane, 12-16 parts of modified whiskers, 0.9-1.2 parts of dibutyltin dilaurate, 3-4 parts of calcium-zinc stabilizer, 0.5-0.6 parts of antioxidant 1010, and 1-1.2 parts of PE wax. The modified polyurethane is prepared by reacting and polymerizing diisocyanate, diol, and chain extender; The diol is a mixture of polytetrahydrofuran ether diol and polydimethylsiloxane diol in a mass ratio of 1:(0.6~0.8); The chain extender includes flame retardant chain extender, drap chain extender, and 1,4-butanediol; The flame retardant chain extender is prepared by reacting phenylphosphodichloro with dimethylaminopropylamine diisopropanol; The suspension chain extender is prepared by reacting 2-chloro-4,6-diamino-1,3,5-triazine with a straight-chain alkylamine; The linear alkylamine is one or more selected from octylamine, nonylamine, decylamine, undecylamine, laurylamine, tridecylamine, and tetradecylamine; The modified whiskers are prepared by reacting coated modified whiskers with chloropropyltrimethoxysilane; The modified whiskers are prepared by coating the surface of potassium titanate whiskers with antimony tin oxide precipitate.

2. The toughened modified PVC material according to claim 1, characterized in that, The diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.

3. A method for preparing the toughened modified PVC material according to claim 1, characterized in that, The preparation steps include the following: (1) Disperse potassium titanate whiskers in an ethanol-water mixture, sonicate, add metal mixture dropwise, maintain pH, stir and reflux reaction, filter, wash, dry, calcine to obtain coated modified whiskers; (2) The coated modified whiskers were dispersed in anhydrous ethanol, sonicated, stirred at room temperature, chloropropyltrimethoxysilane was added, and the mixture was stirred and refluxed. Hydrochloric acid solution was added, and the mixture was stirred and refluxed again. The mixture was centrifuged, washed, and dried to obtain the modified whiskers. (3) Under an argon atmosphere, dimethylaminopropylamine diisopropanol, triethylamine and toluene are mixed evenly, stirred at room temperature, and phenylphosphodichlorotoluene solution is added dropwise. After the addition is completed, the mixture is stirred and refluxed, cooled, filtered, washed, distilled under reduced pressure, and dried to obtain a flame retardant chain extender. (4) Mix 2-chloro-4,6-diamino-1,3,5-triazine and dioxane evenly, add dioxane solution of straight-chain alkylamine dropwise, add sodium hydroxide solution dropwise to maintain pH, stir and reflux reaction, cool, stand, filter, wash, dry, and obtain suspension chain extender; (5) After mixing polytetrahydrofuran ether diol and polydimethylsiloxane diol, dehydrate them, add hexamethylene diisocyanate and isophorone diisocyanate under a nitrogen atmosphere, add a catalyst, stir and react, add a flame retardant chain extender, stir and react, add a draping chain extender, stir and react, add 1,4-butanediol, stir and react to obtain modified polyurethane; (6) Mix PVC resin, dioctyl phthalate, modified polyurethane, modified whiskers, dibutyltin dilaurate, calcium zinc stabilizer, antioxidant 1010 and PE wax evenly, add to a two-roll mill for plasticizing, put into a mold for hot pressing, transfer to a cold press for cold pressing and demolding, let stand, and obtain toughened modified PVC material.

4. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The coated modified whiskers in step (1) are prepared by dispersing 2-3 parts of potassium titanate whiskers in 60-80 parts of an ethanol-water mixture by mass, ultrasonically dispersing for 8-12 minutes, heating to 70-80°C, and adding 10-12 parts of a metal mixture dropwise at 0.4-0.6 ml / min, maintaining the pH at 2-3. After the addition is complete, the mixture is stirred and refluxed at 70-80°C and pH=2-3 for 2-3 hours, filtered, washed, vacuum dried for 10-12 hours, and calcined at 500-600°C for 2-3 hours. The metal mixture is prepared by dissolving tin chloride pentahydrate and antimony chloride in a 5 mol / L hydrochloric acid solution at a molar ratio of (6~7):

1. The content of antimony chloride in the metal mixture is 2wt%~2.5wt%.

5. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The modified whiskers described in step (2) are prepared by dispersing 1-1.5 parts of coated modified whiskers in 30-40 parts of anhydrous ethanol by mass, sonicating for 40-60 min, stirring at room temperature for 60-80 min, adding 0.8-1.2 parts of chloropropyltrimethoxysilane, stirring and refluxing at 80-90℃ for 40-50 min, adding 1.5-2 parts of 1mol / L hydrochloric acid solution, continuing to stir and reflux for 4-5 h, centrifuging for 12-15 min, washing by centrifugation, and vacuum drying for 8-10 h.

6. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The flame retardant chain extender described in step (3) is prepared by mixing 5-6 parts of dimethylaminopropylamine diisopropanol, 2.45-3.15 parts of triethylamine, and 15-20 parts of toluene in an argon atmosphere, stirring at room temperature for 30-50 minutes, heating to 75-80°C, and adding 7.15-8.42 parts of 30wt% phenylphosphodichlorotoluene solution dropwise at 0.3-0.5 ml / min. After the addition is complete, the mixture is stirred and refluxed at 75-80°C for 4-5 hours, and then stirred and refluxed at 95-100°C for 10-12 hours. The mixture is then naturally cooled to room temperature, filtered, and the filtrate is washed with pure water, distilled under reduced pressure, and dried under vacuum for 8-10 hours.

7. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The suspension chain extender described in step (4) is prepared by mixing 2-3 parts of 2-chloro-4,6-diamino-1,3,5-triazine and 15-18 parts of dioxane by mass, heating to 80-90°C, and adding 10wt% dioxane solution of linear alkylamine at a rate of 0.4-0.5 ml / min. The addition is carried out at a molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to linear alkylamine of 1:(1.08-1.12). During the addition, 5wt% sodium hydroxide solution is added dropwise to maintain the pH at 6-8. The mixture is stirred and refluxed at 80-90°C for 8-9 hours, then naturally cooled to room temperature, allowed to stand for 30-40 minutes, filtered, washed, and vacuum dried for 8-10 hours.

8. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The modified polyurethane in step (5) is prepared by mixing polytetrahydrofuran ether diol and polydimethylsiloxane diol at a mass ratio of 1:(0.6~0.8), then vacuum dehydrating at 110~120℃ for 1~2 hours. After stopping the vacuuming, the mixture is cooled to 80~90℃ under a nitrogen atmosphere. Hexamethylene diisocyanate and isophorone diisocyanate are added at a molar ratio of isocyanate groups to hydroxyl groups of 1:(0.55~0.6), with the molar ratio of hexamethylene diisocyanate to isophorone diisocyanate being 1:(0.25~0.3). The amount of polytetrahydrofuran ether diol added is... The catalyst was added at 0.005 to 0.006 times the volume, and the reaction was stirred at 80 to 90°C until complete. A flame retardant chain extender was added at a molar ratio of 1:(0.6 to 0.7) of the remaining isocyanate groups to hydroxyl groups, and the reaction was stirred at 70 to 80°C until complete. A draping chain extender was added at a molar ratio of 1:(0.7 to 0.8) of the remaining isocyanate groups to amino groups, and the reaction was stirred at 70 to 80°C until complete. 1,4-Butanediol was added at a molar ratio of 1:(1.02 to 1.04) of the remaining isocyanate groups to hydroxyl groups, and the reaction was stirred at 60 to 70°C until complete. The product was then discharged.

9. The method for preparing a toughened modified PVC material according to claim 3, characterized in that, The toughened modified PVC material described in step (6) is prepared by mixing 100-120 parts of PVC resin, 10-12 parts of dioctyl phthalate, 30-35 parts of modified polyurethane, 12-16 parts of modified whiskers, 0.9-1.2 parts of dibutyltin dilaurate, 3-4 parts of calcium-zinc stabilizer, 0.5-0.6 parts of antioxidant 1010, and 1-1.2 parts of PE wax in a high-speed mixer. Then, the mixture is added to a two-roll mill and plasticized at 135-145°C and 80-100 rpm for 12-15 minutes. The mixture is then placed in a mold and hot-pressed at 170-180°C and 12-14 MPa for 8-10 minutes. After hot pressing, the mixture is transferred to a cold press and cold-pressed at 8-10 MPa for 4-5 minutes to demold. Finally, the mixture is allowed to stand at 60-70°C for 18-20 hours.

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