A dynamic plasticizing regulation type PVC environment-friendly stabilizer composite method

Abstract

The application discloses a dynamic plasticizing regulation type PVC environment-friendly stabilizer composite method and relates to the technical field of PVC processing aids.The dynamic plasticizing regulation type PVC environment-friendly stabilizer comprises the following raw materials in parts by weight: 20-30 parts of modified calcium stearate, 50-70 parts of modified tributyl citrate, 60-90 parts of hydrotalcite, 12-22 parts of organic tin, 18-28 parts of pentaerythritol, 16-22 parts of compound antioxidant, 4-10 parts of nano silicon dioxide, 22-32 parts of bio-based fatty acid, 2-6 parts of graphene quantum dots, 12-16 parts of methyl methacrylate-butadiene-styrene copolymer, 3-6 parts of antistatic agent, 10-14 parts of phosphorus-containing flame retardant, 4-10 parts of stearic acid and 3-7 parts of nano montmorillonite.The application modifies calcium stearate and tributyl citrate, endows the stabilizer with dynamic plasticizing regulation capability, and has multiple functions such as high-efficiency thermal stability and flame retardation.The raw materials are environment-friendly, can realize low-temperature rapid plasticizing, reduce energy consumption, and have excellent mechanical properties and strong weather resistance, are suitable for multiple scenes such as pipe materials and electronic packaging, and meet the green and intelligent development trend.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of PVC processing aids, in particular to a dynamic plasticization regulation type PVC environment-friendly stabilizer compounding method. BACKGROUND

[0002] Traditional PVC stabilizers often use compounds containing heavy metals, which have excellent thermal stability, but have health and environmental risks. With the improvement of environmental standards, such stabilizers are gradually eliminated, and alternative solutions such as calcium / zinc composite stabilizers have low thermal stability efficiency, rely on petroleum-based raw materials, and have poor compatibility with PVC recycling systems, which restricts green and circular development.

[0003] In the PVC processing process, the balance between plasticization uniformity and thermal stability is a key problem. Traditional stabilizers have insufficient response to temperature and shear rate, which easily leads to insufficient or excessive plasticization, affecting product quality. At the same time, existing methods cannot achieve nanoscale dispersion, and problems such as inorganic powder agglomeration and organic component migration further weaken the long-term performance of the product.

[0004] Modern PVC product requirements are increasingly diversified, such as the need for antistatic and flame-retardant function synergy in electronic packaging, weather resistance and slow-release properties in agricultural films, and antibacterial and halogen-free requirements in the medical field. Traditional stabilizers rely on multi-component compounding, which often causes problems such as phase separation due to poor compatibility, and some functional systems have environmental defects.

[0005] Existing stabilizer modification technologies mainly focus on single performance optimization, such as improving thermal stability at the expense of long-term performance, enhancing toughness leading to decreased heat resistance, and environmental modification facing compatibility problems of raw materials. In addition, the limitations of the process, such as insufficient shear strength of mixing equipment and poor temperature control accuracy, lead to fluctuations in stabilizer performance, making it difficult to meet the uniformity requirements of industrial production.

[0006] These problems not only limit the application of PVC materials in high-end fields, but also contradict the industry trend of green and intelligent development. How to break through the bottlenecks of traditional technology and develop new stabilizers with high efficiency, dynamic regulation, multi-functional integration, and environmental sustainability has become an important issue in the field of PVC processing. SUMMARY

[0007] In view of the deficiencies of the prior art, the application provides a dynamic plasticization regulation type PVC environment-friendly stabilizer compounding method, which solves the above problems.

[0008] To achieve the above purposes, the application is implemented through the following technical solutions:

[0009] The application discloses a dynamic plasticizing regulation type PVC environment-friendly stabilizer, which comprises the following raw materials in parts by weight: 20-30 parts of modified calcium stearate, 50-70 parts of modified tributyl citrate, 60-90 parts of hydrotalcite, 12-22 parts of organic tin, 18-28 parts of pentaerythritol, 16-22 parts of compound antioxidant, 4-10 parts of nano silicon dioxide, 22-32 parts of bio-based fatty acid, 2-6 parts of graphene quantum dots, 12-16 parts of methyl methacrylate-butadiene-styrene copolymer, 3-6 parts of antistatic agent, 10-14 parts of phosphorus-containing flame retardant, 4-10 parts of stearic acid and 3-7 parts of nano montmorillonite.

[0010] Further, the bio-based fatty acid is one of castor oil fatty acid and palm kernel oil fatty acid; the antistatic agent is one of dodecyl trimethyl ammonium chloride and octadecyl trimethyl ammonium bromide; the phosphorus-containing flame retardant is one of triphenyl phosphate and resorcinol tetraphenyl diphosphate; and the compound antioxidant is a compound of antioxidant 1010 and antioxidant 168 at a mass ratio of 1:1.

[0011] Further, the modified calcium stearate is prepared according to the following steps:

[0012] A1, calcium stearate is added into an ethanol-water mixed solution, and a gamma-aminopropyl triethoxysilane coupling agent is added at the same time, and ultrasonic dispersion is carried out for 40 min, then the dispersion liquid is transferred into a high-pressure reaction kettle, and stirring reaction is carried out for 3 h; after the reaction is completed, the reaction kettle is cooled to room temperature, centrifugal separation is carried out for 10 min, the precipitate is washed with ethanol, and vacuum drying is carried out at 60 DEG C for 12 h, so as to obtain surface-modified nano calcium stearate;

[0013] A2, the surface-modified nano calcium stearate is added into a zinc nitrate solution, after being uniformly stirred, a sodium hydroxide solution is slowly added dropwise, the pH is adjusted to 10, and stirring reaction is carried out at 50 DEG C for 4 h; after the reaction is completed, filtration is carried out, the precipitate is washed with deionized water until neutral, and vacuum drying is carried out at 80 DEG C for 2 h, and then calcination is carried out at 400 DEG C for 3 h, so as to obtain calcium stearate loaded with zinc oxide;

[0014] A3, the calcium stearate loaded with zinc oxide is added into a dimethylbenzene solution, maleic anhydride and dibenzoyl peroxide are added, stirring reaction is carried out at 110 DEG C for 5 h under the protection of nitrogen; after the reaction is completed, the product is washed with acetone, and vacuum drying is carried out for 8 h, so as to obtain functionalized composite modified calcium stearate.

[0015] Further, in the step A1, the amount ratio of calcium stearate, the ethanol-water mixed solution and the gamma-aminopropyl triethoxysilane coupling agent is 25 g:300 mL:5 mL; in the ethanol-water mixed solution, the volume ratio of ethanol to water is 7:3; the reaction kettle reaction conditions are 120 DEG C, 1.5 MPa, and the stirring speed is 400 r / min; the centrifugal speed is 8000 r / min; and the precipitate is washed with ethanol for 3 times.

[0016] Further, in the A2 step, the amount ratio of the surface-modified nano calcium stearate and zinc nitrate solution is 25 g:150 mL; the concentration of the zinc nitrate solution is 0.5 mol / L; the mass fraction of the sodium hydroxide solution is 20%; the stirring speed is 400 r / min; in the A3 step, the amount ratio of the xylene solution, maleic anhydride and dibenzoyl peroxide is 200 mL:8 g:0.5 g; the stirring speed is 300 r / min; and the vacuum drying condition is 60℃ and-0.09 MPa.

[0017] Through ultrasonic dispersion and γ-aminopropyl triethoxysilane coupling agent treatment, the calcium stearate particles are dispersed to the nanoscale, and meanwhile the silane coupling agent forms Si-O-Ca bonds by hydrolysis and is coated on the surface of the calcium stearate.

[0018] The amino group of the coupling agent faces outward, and the particles are endowed with organic affinity, thereby solving the compatibility problem of the inorganic powder and the PVC matrix.

[0019] The zinc nitrate reacts with sodium hydroxide to generate zinc hydroxide precipitate, which is loaded on the surface of the calcium stearate by chemical bonding and is converted into zinc oxide by calcination. The ZnO acts as a metal oxide stabilizer, inhibits the degradation of PVC by neutralizing HCl and capturing free radicals such as Cl, and forms a Ca-Zn synergistic stabilizing system with the calcium stearate.

[0020] The maleic anhydride is grafted with the hydroxyl group on the surface of the calcium stearate through a grafting reaction of a free radical initiator dibenzoyl peroxide, and carboxylic acid groups and double bonds are introduced. The carboxylic acid groups form hydrogen bonds with the polar groups -Cl of the PVC molecular chain, thereby enhancing the interfacial bonding force; and the double bonds can crosslink with antioxidants, plasticizers and the like, thereby improving the overall compatibility.

[0021] Further, the modified citric acid tributyl ester is prepared according to the following steps:

[0022] B1, citric acid tributyl ester is added to a reaction kettle, phosphotungstic acid is added, and hydrogen peroxide solution is slowly added at 45℃, after the addition is completed, the temperature is raised to 65℃ and stirred for 5h; after the reaction is completed, the product is washed with saturated brine, the organic phase is separated, vacuum dried for 4h, and the epoxidized modified citric acid tributyl ester is obtained;

[0023] B2, the epoxidized citric acid tributyl ester is mixed with sodium alginate, stirred uniformly to form an oil-water emulsion, then poly N-isopropyl acrylamide solution and calcium chloride solution are added, and stirred at 45℃ for 4h; after the reaction is completed, centrifugal separation is performed, the precipitate is washed with deionized water, and then dried for 10h to obtain the microcapsule-smart material composite modified citric acid tributyl ester;

[0024] B3, the microcapsule-smart material composite tributyl citrate is added to dichloromethane solution, 2-carboxyethyl phenyl phosphinic acid and dibutyl tin dilaurate catalyst are added, and reaction is carried out at 75 DEG C under nitrogen protection for 7h; after reaction is completed, filtration is carried out, the precipitate is washed with deionized water, and drying is carried out for 8h, to obtain modified tributyl citrate with functions of flame retardation, temperature-sensitive regulation and stabilization.

[0025] Further, in the B1 step, the amount ratio of tributyl citrate, phosphotungstic acid and hydrogen peroxide solution is 60g:0.8g:35mL; the mass fraction of hydrogen peroxide solution is 35%; the hydrogen peroxide solution dropwise adding time is controlled in 2h; the stirring speed is 300r / min; and the vacuum drying condition is 60 DEG C, 3kPa.

[0026] Further, in the B2 step, the amount ratio of sodium alginate, poly-N-isopropyl acrylamide solution and calcium chloride solution is 20g:12mL:15mL; the mass fraction of sodium alginate is 3%, the mass fraction of poly-N-isopropyl acrylamide solution is 15%, and the concentration of calcium chloride solution is 0.2mol / L; the stirring speed is 400r / min; the centrifugal speed is 10000r / min, and the centrifugal time is 10min each time; the drying temperature is 40 DEG C; in the B3 step, the amount ratio of dichloromethane solution, 2-carboxyethyl phenyl phosphinic acid and dibutyl tin dilaurate is 250mL:10g:0.6g; and the drying temperature is 50 DEG C.

[0027] The hydrogen peroxide is epoxidized to the double bond of tributyl citrate under the catalysis of phosphotungstic acid, to generate an epoxy group. The epoxy group can react with HCl generated by PVC degradation, to consume the corrosive gas, and to enhance the interface interaction with inorganic fillers such as calcium stearate and hydrotalcite through the polar group.

[0028] The epoxidized tributyl citrate as an oil phase is emulsified with sodium alginate through high-speed shearing to form an oil-water emulsion, and the oil phase is encapsulated by sodium alginate microcapsules after crosslinking with calcium chloride. The poly-N-isopropyl acrylamide is introduced as a temperature-sensitive material, and the low critical solution temperature of the poly-N-isopropyl acrylamide makes the microcapsules release plasticizers at high temperature in PVC processing, and keeps the structure stable at low temperature.

[0029] The 2-carboxyethyl phenyl phosphinic acid is grafted to the hydroxyl group of tributyl citrate through dibutyl tin dilaurate catalysis, to introduce phosphorus-carbon bond and carboxylic acid group. The phosphorus-containing group forms a phosphoric acid / pyrophosphoric acid covering layer during combustion, to block heat and oxygen, and to release non-combustible gas to dilute oxygen in the flame area.

[0030] A dynamic plasticizing regulation type PVC environment-friendly stabilizer composite method, specifically comprising the following steps:

[0031] S1, start the high-speed mixer, open the stirring, and add 20-30 parts of modified calcium stearate, 60-90 parts of hydrotalcite, 12-22 parts of organic tin, 4-10 parts of nano silicon dioxide, 3-7 parts of nano montmorillonite, keep the stirring speed for 5 min, realize the uniform dispersion and preliminary compounding of inorganic powder through mechanical force, and avoid agglomeration;

[0032] S2, increase the stirring speed, and add 50-70 parts of modified tributyl citrate, 18-28 parts of pentaerythritol, 22-32 parts of bio-based fatty acid, 12-16 parts of methyl methacrylate-butadiene-styrene copolymer, and 4-10 parts of stearic acid, and stir for 8 min, so that the organic components form core-shell structure composite particles with inorganic powder through physical coating effect;

[0033] S3, increase the stirring speed again, and add 16-22 parts of compounded antioxidant, 2-6 parts of graphene quantum dots, 3-6 parts of antistatic agent, and 10-14 parts of phosphorus-containing flame retardant, keep the stirring speed for 7 min, and the shear force strengthens the uniform dispersion of functional additives in the composite system, and the multi-component synergistic compounding process is completed;

[0034] S4, the mixture is transferred to a double screw extruder, the temperature and screw speed of each section of the double screw extruder are set, the components are fully combined at the molecular level through the effects of melt blending and dynamic shear compounding in the extruder, the extrudate is extruded through a circular die, immediately enters a cooling water tank, and the material is solidified and cut into particles to obtain a multifunctional composite stabilizer product with a core-shell structure.

[0035] Further, in the S1 step, the stirring speed is 300-400 r / min;In the S2 step, the stirring speed is 500-600 r / min;In the S3 step, the stirring speed is 700-800 r / min;In the S4 step, the temperature of the first zone is 125-135 DEG C, the temperature of the second zone is 145-155 DEG C, the temperature of the third zone is 165-175 DEG C, the temperature of the fourth zone is 185-195 DEG C, the temperature of the fifth zone is 205-215 DEG C, the die temperature is 195-205 DEG C, and the screw speed is controlled at 200-300 r / min;The cooling water tank temperature is 5-10 DEG C.

[0036] The application provides a dynamic plasticization regulation type PVC environment-friendly stabilizer compounding method, which has the following beneficial effects:

[0037] 1、The present application significantly improves the comprehensive performance of PVC stabilizer by multi-step modification and multi-component formula design of calcium stearate, tributyl citrate and other raw materials. After nanocrystallization, loading of zinc oxide and functional composite modification of calcium stearate, the thermal stability is greatly enhanced, effectively inhibiting the degradation and yellowing of PVC during processing; after epoxidation, microcapsule composite and flame retardant modification of tributyl citrate, it has dynamic plasticizing control, temperature response and flame retardant functions. With the synergistic effect of various additives, PVC products have excellent thermal stability, mechanical properties and long-term weather resistance, which can meet the needs of complex processing procedures such as extrusion and injection molding, and expand the application field of PVC materials.

[0038] 2、The stabilizer of the present application has precise dynamic plasticizing control ability, can adjust the flowability and plasticizing efficiency of PVC melt in real time according to processing temperature and shear rate, avoid over-plasticizing or insufficient plasticizing problem, improve production efficiency and product qualification rate. At the same time, the stabilizer gives PVC products excellent antistatic, flame retardant and chemical corrosion resistance, which can reduce the safety hazards caused by static accumulation in electronic packaging, building pipes and other application scenarios, improve the service life of products in complex environment, reduce product loss and replacement cost caused by insufficient performance.

[0039] 3、Through raw material modification and method optimization, the present application effectively controls the production cost while improving the performance of PVC stabilizer. On the one hand, some traditional additives are replaced by environmentally friendly and relatively low-cost raw materials such as bio-based fatty acids and nanomontmorillonite; on the other hand, the unique composite method simplifies the production process, reduces energy consumption and raw material waste. Compared with traditional PVC stabilizer, the unit production cost of the product of the present application is reduced by about 15%-20%, and the performance is improved by more than 30%, so that the downstream enterprises can significantly reduce the production cost on the premise of ensuring product quality, enhance the market competitiveness, and improve the economic benefit.

[0040] 4、The present application strictly follows the concept of environmental protection, and the stabilizer does not contain heavy metals such as lead and cadmium, and harmful substances such as phthalate esters, which meets the strict environmental protection standards at home and abroad. At the same time, the use of a large amount of bio-based raw materials and the introduction of degradable components reduce the dependence on petrochemical resources and reduce the pollution to the environment after the product is discarded. Compared with traditional PVC products, the PVC material of the present application can be gradually degraded in the natural environment after being discarded, effectively reducing the "white pollution", providing technical support for the green transformation of the plastic industry, and having important significance for realizing the coordinated development of economic development and ecological protection. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0042] Embodiment 1, preparation of dynamic plasticization regulation type PVC environment-friendly stabilizer, the specific steps are as follows:

[0043] S1, start the high-speed mixer, set the initial rotation speed to 300 r / min, add 20 parts of modified calcium stearate, 60 parts of hydrotalcite, 12 parts of organic tin, 4 parts of nano silicon dioxide, and 3 parts of nano montmorillonite in turn, keep stirring at the rotation speed for 5 min, realize uniform dispersion and preliminary compounding of inorganic powder through mechanical force action, and avoid agglomeration;

[0044] S2, increase the rotation speed to 500 r / min, add 50 parts of modified tributyl citrate, 18 parts of pentaerythritol, 22 parts of castor oil fatty acid, 12 parts of methyl methacrylate-butadiene-styrene copolymer, and 4 parts of stearic acid in turn, stir for 8 min, and make the organic components form core-shell structure composite particles with the inorganic powder through physical coating action;

[0045] S3, increase the rotation speed to 700 r / min, add 16 parts of compounded antioxidant, 2 parts of graphene quantum dots, 3 parts of dodecyl trimethyl ammonium chloride, and 10 parts of triphenyl phosphate in turn, keep stirring at the rotation speed for 7 min, uniformly disperse the functional additives in the composite system through shear force, and complete the multi-component synergistic compounding process;

[0046] S4, transfer the mixed materials to a double screw extruder, set the temperature of each section of the double screw extruder as follows: 125 DEG C for the first section, 145 DEG C for the second section, 165 DEG C for the third section, 185 DEG C for the fourth section, 205 DEG C for the fifth section, the die temperature is 195 DEG C, and the screw rotation speed is controlled at 200 r / min, the materials realize sufficient combination at the molecular level through the effects of melt blending and dynamic shear compounding in the extruder, the extrudate is extruded through a circular die, immediately enters a 5 DEG C cooling water tank, the material is solidified and then granulated, and a multifunctional composite stabilizer product with core-shell structure is prepared.

[0047] Embodiment 2, preparation of dynamic plasticization regulation type PVC environment-friendly stabilizer, the specific steps are as follows:

[0048] S1, start the high-speed mixer, set the initial rotation speed to 400 r / min, add 30 parts of modified calcium stearate, 90 parts of hydrotalcite, 22 parts of organic tin, 10 parts of nano silicon dioxide, and 7 parts of nano montmorillonite in turn, keep stirring at the rotation speed for 5 min, realize uniform dispersion and preliminary compounding of inorganic powder through mechanical force action, and avoid agglomeration;

[0049] S2, the rotating speed is increased to 600 r / min, 70 parts of modified tributyl citrate, 28 parts of pentaerythritol, 32 parts of palm kernel oil fatty acid, 16 parts of methyl methacrylate-butadiene-styrene copolymer, and 10 parts of stearic acid are sequentially added, and stirring is performed for 8 min, so that the organic components form core-shell structure composite particles with the inorganic powder through physical coating;

[0050] S3, the rotating speed is increased to 800 r / min, 22 parts of a compounded antioxidant, 6 parts of graphene quantum dots, 6 parts of octadecyl trimethyl ammonium bromide, and 14 parts of resorcinol tetraphenyl diphosphate are sequentially added, stirring is performed at the rotating speed for 7 min, the uniform dispersion of the functional additives in the composite system is strengthened through shear force, and a multi-component synergistic compounding process is completed;

[0051] S4, the mixture is transferred to a twin-screw extruder, the temperature of each section of the twin-screw extruder is set as follows: 135 DEG C in the first section, 155 DEG C in the second section, 175 DEG C in the third section, 195 DEG C in the fourth section, 215 DEG C in the fifth section, the temperature of the die is 205 DEG C, the rotating speed of the screw is controlled at 300 r / min, the components are fully combined at the molecular level through the effects of melt blending and dynamic shear compounding in the extruder, the extrudate is extruded through a circular die and immediately enters a 10 DEG C cooling water tank, the material is solidified and then pelletized, and a multifunctional composite stabilizer product with a core-shell structure is prepared.

[0052] Example 3, a dynamic plasticization regulation type PVC environment-friendly stabilizer is prepared, and the specific steps are as follows:

[0053] S1, a high-speed mixer is started, the initial rotating speed is set to 350 r / min, 25 parts of modified calcium stearate, 75 parts of hydrotalcite, 17 parts of organotin, 7 parts of nano silicon dioxide, and 5 parts of nano montmorillonite are sequentially added, stirring is performed at the rotating speed for 5 min, the uniform dispersion and preliminary compounding of the inorganic powder are realized through mechanical force, and agglomeration is avoided;

[0054] S2, the rotating speed is increased to 550 r / min, 60 parts of modified tributyl citrate, 23 parts of pentaerythritol, 27 parts of palm kernel oil fatty acid, 14 parts of methyl methacrylate-butadiene-styrene copolymer, and 7 parts of stearic acid are sequentially added, and stirring is performed for 8 min, so that the organic components form core-shell structure composite particles with the inorganic powder through physical coating;

[0055] S3, the rotating speed is increased to 750 r / min, 19 parts of a compounded antioxidant, 4 parts of graphene quantum dots, 4 parts of octadecyl trimethyl ammonium bromide, and 12 parts of resorcinol tetraphenyl diphosphate are sequentially added, stirring is performed at the rotating speed for 7 min, the uniform dispersion of the functional additives in the composite system is strengthened through shear force, and a multi-component synergistic compounding process is completed;

[0056] S4, the mixture is transferred to a twin-screw extruder, and the temperature of each section of the twin-screw extruder is set as follows: 130 DEG C for the first section, 150 DEG C for the second section, 170 DEG C for the third section, 190 DEG C for the fourth section, 210 DEG C for the fifth section, and 200 DEG C for the die head; the screw rotation speed is controlled at 250 r / min; the material is subjected to the combined action of melt blending and dynamic shearing in the extruder, so that the components are fully combined at the molecular level; the extrudate is extruded through a circular die head and immediately enters a 7 DEG C cooling water tank; the material is cut into particles after solidification, and a multifunctional composite stabilizer product with core-shell structure is prepared.

[0057] Example 4, preparation of modified calcium stearate, the specific steps are as follows:

[0058] A1, 25g calcium stearate is added to 300mL ethanol-water mixed solution, the volume ratio of ethanol to water is 7:3, 5mL γ-aminopropyl triethoxysilane coupling agent is added at the same time, ultrasonic dispersion is carried out for 40min, then the dispersion liquid is transferred to a high-pressure reaction kettle, and reaction is carried out at 120 DEG C, 1.5MPa for 3h; after the reaction is completed, it is cooled to room temperature, centrifugal separation is carried out at 8000r / min for 10min, the precipitate is washed with ethanol for 3 times, and vacuum drying is carried out at 60 DEG C for 12h, to obtain surface-modified nano calcium stearate;

[0059] A2, the surface-modified nano calcium stearate is added to 150mL zinc nitrate solution with a concentration of 0.5mol / L, after stirring uniformly, 20% sodium hydroxide solution is slowly added dropwise, the pH is adjusted to 9-10, and reaction is carried out at 50 DEG C for 4h; after the reaction is completed, filtration is carried out, the precipitate is washed with deionized water until neutral, and vacuum drying is carried out at 80 DEG C for 2h, then calcination is carried out at 400 DEG C for 3h, to obtain calcium stearate loaded with zinc oxide;

[0060] A3, the calcium stearate loaded with zinc oxide is added to 200mL dimethylbenzene solution, 8g maleic anhydride and 0.5g dibenzoyl peroxide are added, stirring is carried out at 300r / min under the protection of nitrogen at 110 DEG C, and reaction is carried out for 5h; after the reaction is completed, the product is washed with acetone, and vacuum drying is carried out at 60 DEG C, -0.09MPa for 8h, to obtain functionalized composite modified calcium stearate.

[0061] Example 5, preparation of modified tributyl citrate, the specific steps are as follows:

[0062] B1, 60g tributyl citrate is added to a reaction kettle, 0.8g tungstophosphoric acid is added, 35mL hydrogen peroxide solution with a mass fraction of 35% is slowly added dropwise at 45 DEG C, the dropwise adding time is controlled at 2h, after the dropwise adding is completed, the temperature is increased to 65 DEG C, and stirring is carried out at 300r / min for 5h; after the reaction is completed, the product is washed with saturated brine, the organic phase is separated, and vacuum drying is carried out at 60 DEG C, 3kPa for 4h, to obtain epoxidized modified tributyl citrate;

[0063] B2, the epoxidized tributyl citrate was mixed with 20 g of 3% by mass sodium alginate, stirred to form an oil-water emulsion, then 12 mL of 15% by mass poly-N-isopropyl acrylamide solution and 15 mL of 0.2 mol / L calcium chloride solution were added, and the reaction was stirred at 400 r / min for 4 h at 45°C; after the reaction was completed, the product was centrifuged at 10,000 r / min for 10 min, the precipitate was washed with deionized water, and dried at 40°C for 10 h to obtain microcapsule-smart material composite modified tributyl citrate;

[0064] B3, the microcapsule-smart material composite tributyl citrate was added to 250 mL of dichloromethane solution, 10 g of 2-carboxyethyl phenyl phosphinic acid and 0.6 g of dibutyltin dilaurate catalyst were added, and the reaction was carried out at 75°C under nitrogen protection for 7 h; after the reaction was completed, the precipitate was filtered, washed with deionized water, and dried at 50°C for 8 h to obtain modified tributyl citrate with flame retardation, temperature-sensitive regulation and stabilization functions.

[0065] Comparative Example 1, a dynamic plasticization regulation type PVC environmental protection stabilizer was prepared, and the specific steps were as follows:

[0066] The remaining steps were unchanged, only the modified calcium stearate of Example 2 was replaced with untreated calcium stearate to prepare a dynamic plasticization regulation type PVC environmental protection stabilizer.

[0067] Comparative Example 2, a dynamic plasticization regulation type PVC environmental protection stabilizer was prepared, and the specific steps were as follows:

[0068] The remaining steps were unchanged, only the modified tributyl citrate of Example 2 was replaced with untreated tributyl citrate to prepare a dynamic plasticization regulation type PVC environmental protection stabilizer.

[0069] Performance test

[0070]

[0071]

[0072] The performance test results showed that the thermal stability time of Examples 1-3 was 42-45 min, which was significantly higher than 25 min of Comparative Example 1 and 28 min of Comparative Example 2; the plasticization peak torque was 26-28 N·m, which was lower than 33-35 N·m of the comparative examples; the tensile strength was 45-48 MPa, and the elongation at break was 350%-380%, which were all better than 32-35 MPa and 220%-250% of the comparative examples; the flame retardant grade reached UL94 V-0, while Comparative Example 1 was V-2 and Comparative Example 2 was HB; the surface resistance was ≤8.5× Ω, meets the antistatic requirement, the comparative example does not meet the requirement; the retention rate of elongation at break is 88%-92% after ultraviolet aging for 500h, which is much higher than 65%-70% of the comparative example, indicating that the stabilizer of the application is significantly better than the unmodified system in thermal stability, plasticizing performance, mechanical strength, flame retardant antistatic and weather resistance, and has significant performance advantages.

[0073] The above is only an example and description of the application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as the modifications or supplements do not deviate from the application or exceed the scope defined by the present claims, which shall belong to the protection scope of the application.

Claims

1. A dynamic plasticizing-regulating environmentally friendly PVC stabilizer, characterized in that: It contains the following raw materials in parts by weight: 20-30 parts modified calcium stearate, 50-70 parts modified tributyl citrate, 60-90 parts hydrotalcite, 12-22 parts organotin, 18-28 parts pentaerythritol, 16-22 parts compound antioxidant, 4-10 parts nano silica, 22-32 parts bio-based fatty acids, 2-6 parts graphene quantum dots, 12-16 parts methyl methacrylate-butadiene-styrene copolymer, 3-6 parts antistatic agent, 10-14 parts phosphorus-containing flame retardant, 4-10 parts stearic acid, and 3-7 parts nano montmorillonite. The modified calcium stearate is prepared using the following specific steps: A1. Calcium stearate was added to an ethanol-water mixture, along with γ-aminopropyltriethoxysilane coupling agent. The mixture was ultrasonically dispersed for 40 min, and then the dispersion was transferred to a high-pressure reactor and stirred for 3 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged for 10 min, the precipitate was washed with ethanol, and then vacuum dried at 60 °C for 12 h to obtain surface-modified nano-calcium stearate. A2. Add the surface-modified nano-calcium stearate to the zinc nitrate solution, stir evenly, slowly add sodium hydroxide solution, adjust the pH to 10, and stir the reaction at 50℃ for 4h. After the reaction is completed, filter, wash the precipitate with deionized water until neutral, and vacuum dry at 80℃ for 2h. Then calcine at 400℃ for 3h to obtain zinc oxide-loaded calcium stearate. A3. Add zinc oxide-loaded calcium stearate to xylene solution, add maleic anhydride and benzoyl peroxide, and stir the reaction at 110°C for 5 h under nitrogen protection. After the reaction is completed, wash the product with acetone and vacuum dry for 8 h to obtain functionalized composite modified calcium stearate. The modified tributyl citrate is prepared using the following specific steps: B1. Add tributyl citrate to a reaction vessel, then add phosphotungstic acid, and slowly add hydrogen peroxide solution at 45°C. After the addition is complete, raise the temperature to 65°C and stir the reaction for 5 hours. After the reaction is complete, wash the product with saturated brine, separate the organic phase, and vacuum dry for 4 hours to obtain epoxidized tributyl citrate. B2. Epoxidized tributyl citrate was mixed with sodium alginate and stirred evenly to form an oil-water emulsion. Then, poly(N-isopropylacrylamide) solution and calcium chloride solution were added and stirred at 45°C for 4 hours. After the reaction was completed, the mixture was centrifuged, the precipitate was washed with deionized water and dried for 10 hours to obtain microcapsule-smart material composite modified tributyl citrate. B3. Add the microcapsule-smart material composite tributyl citrate to a dichloromethane solution, add 2-carboxyethylphenylphosphonic acid and dibutyltin dilaurate catalysts, and react at 75°C under nitrogen protection for 7 hours. After the reaction is complete, filter, wash the precipitate with deionized water, and dry for 8 hours to obtain modified tributyl citrate with flame retardant, temperature-sensitive regulation and stabilizing functions.

2. The dynamic plasticization-regulating environmentally friendly PVC stabilizer according to claim 1, characterized in that: The bio-based fatty acid is one of castor oil fatty acid and palm kernel oil fatty acid; the antistatic agent is one of dodecyltrimethylammonium chloride and octadecyltrimethylammonium bromide; the phosphorus-containing flame retardant is one of triphenyl phosphate and resorcinol tetraphenyl diphosphate; the compound antioxidant is antioxidant 1010 and antioxidant 168 compounded in a mass ratio of 1:

1.

3. The dynamic plasticization-regulating environmentally friendly PVC stabilizer according to claim 1, characterized in that: In step A1, the ratio of calcium stearate, ethanol-water mixture, and γ-aminopropyltriethoxysilane coupling agent is 25g:300mL:5mL; in the ethanol-water mixture, the volume ratio of ethanol to water is 7:3; the reaction conditions in the reactor are 120℃, 1.5MPa, stirring speed of 400r / min, centrifugation speed of 8000r / min; and the precipitate is washed three times with ethanol.

4. The dynamic plasticization-regulating environmentally friendly PVC stabilizer according to claim 1, characterized in that: In step A2, the ratio of surface-modified nano-calcium stearate to zinc nitrate solution is 25g:150mL; the concentration of zinc nitrate solution is 0.5mol / L; the mass fraction of sodium hydroxide solution is 20%; and the stirring speed is 400r / min. In step A3, the ratio of xylene solution, maleic anhydride, and benzoyl peroxide is 200mL:8g:0.5g; the stirring speed is 300r / min; and the vacuum drying conditions are 60℃ and -0.09MPa.

5. The dynamic plasticization-regulating environmentally friendly PVC stabilizer according to claim 1, characterized in that: In step B1, the ratio of tributyl citrate, phosphotungstic acid, and hydrogen peroxide solution is 60g:0.8g:35mL; the mass fraction of hydrogen peroxide solution is 35%; the hydrogen peroxide solution is added over a period of 2 hours; the stirring speed is 300r / min; and the vacuum drying conditions are 60℃ and 3kPa.

6. The dynamic plasticizing regulating type environmentally friendly PVC stabilizer according to claim 1, characterized in that: In step B2, the ratio of sodium alginate, poly(N-isopropylacrylamide) solution, and calcium chloride solution is 20g:12mL:15mL; the mass fraction of sodium alginate is 3%, the mass fraction of poly(N-isopropylacrylamide) solution is 15%, and the concentration of calcium chloride solution is 0.2mol / L; the stirring speed is 400r / min; the centrifugation speed is 10000r / min, and the centrifugation time is 10min per cycle; the drying temperature is 40℃. In step B3, the ratio of dichloromethane solution, 2-carboxyethylphenylphosphonic acid, and dibutyltin dilaurate is 250mL:10g:0.6g; the drying temperature is 50℃.

7. The composite method of a dynamic plasticizing-regulating environmentally friendly PVC stabilizer according to claim 1, characterized in that: Specifically, it includes the following steps: S1. Start the high-speed mixer and turn on the stirring. Add 20-30 parts of modified calcium stearate, 60-90 parts of hydrotalcite, 12-22 parts of organotin, 4-10 parts of nano silica, and 3-7 parts of nano montmorillonite in sequence. Maintain the stirring speed for 5 minutes to achieve uniform dispersion and preliminary compounding of inorganic powders through mechanical force and avoid agglomeration. S2. Increase the stirring speed and add 50-70 parts of modified tributyl citrate, 18-28 parts of pentaerythritol, 22-32 parts of bio-based fatty acids, 12-16 parts of methyl methacrylate-butadiene-styrene copolymer, and 4-10 parts of stearic acid in sequence. Stir for 8 minutes to allow the organic components to form core-shell structured composite particles with the inorganic powder through physical coating. S3. Increase the stirring speed again, and add 16-22 parts of compound antioxidant, 2-6 parts of graphene quantum dots, 3-6 parts of antistatic agent, and 10-14 parts of phosphorus-containing flame retardant in sequence. Maintain the stirring speed for 7 minutes to enhance the uniform dispersion of functional additives in the composite system through shear force, and complete the multi-component synergistic compounding process. S4. Transfer the mixture to a twin-screw extruder, set the temperature and screw speed of each section of the twin-screw extruder, and the material is fully combined at the molecular level through melt blending and dynamic shearing in the extruder. The extrudate is extruded through a circular die and immediately enters the cooling water tank. After the material solidifies, it is pelletized to obtain a multifunctional composite stabilizer product with a core-shell structure.

8. The composite method of a dynamic plasticizing-regulating environmentally friendly PVC stabilizer according to claim 7, characterized in that: In step S1, the stirring speed is 300-400 r / min; in step S2, the stirring speed is 500-600 r / min; in step S3, the stirring speed is 700-800 r / min; in step S4, the temperatures are set as follows: Zone 1: 125-135℃; Zone 2: 145-155℃; Zone 3: 165-175℃; Zone 4: 185-195℃; Zone 5: 205-215℃; Die head temperature: 195-205℃; Screw speed: 200-300 r / min; Cooling water tank temperature: 5-10℃.

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