A kind of intercalation modified hydrotalcite-based high-efficiency thermal stabilizer for PVC and its preparation method

Abstract

The application belongs to the field of high polymer materials, and discloses a kind of intercalation modified hydrotalcite-based PVC high-efficiency heat stabilizer and its preparation method, high-efficiency heat stabilizer includes the following weight parts raw materials: modified hydrotalcite 90~110 parts, zirconium-based porphyrin MOF 25~40 parts, modified boron nitride nanosheet 15~30 parts, calcium stearate 15~25 parts, zinc stearate 8~15 parts, stearyl benzoyl methane 5~10 parts and pentaerythritol stearate 5~10 parts;The application is compounded by modified hydrotalcite, two-dimensional zirconium-based MOF and modified boron nitride nanosheet, and is used synergistically with conventional auxiliary stabilizer, and a high-efficiency stabilizing system is constructed, which is four-in-one of chemical absorption, free radical capture, physical barrier and interface strengthening, the heat stabilizer shows excellent comprehensive performance when applied to PVC processing.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an intercalated modified hydrotalcite-based PVC high-efficiency heat stabilizer and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) is a general-purpose thermoplastic widely used in pipes, profiles, cable materials, packaging materials, and building decoration. However, the unstable structures such as tertiary chlorine and allyl chloride in the PVC molecular chain make it highly susceptible to thermal degradation at processing temperatures (approximately 180-200°C). This degradation primarily manifests as a dehydrochlorination reaction, generating conjugated polyene sequences, leading to discoloration, decreased mechanical properties, and in severe cases, complete carbonization. To inhibit the thermal degradation of PVC, heat stabilizers must be added during processing. Traditional heat stabilizers mainly include lead salts, organotin compounds, metal soaps, and organic auxiliary stabilizers. With increasingly stringent global environmental regulations (such as RoHS and REACH) and the advancement of lead-free trends, the use of lead salt stabilizers has been gradually restricted. While organotin compounds offer excellent performance, they are biotoxic and expensive. Therefore, non-toxic and environmentally friendly heat stabilizers, represented by calcium-zinc systems, have become a hot research topic in the industry. Hydrotalcite (layered bimetallic hydroxides, LDHs) has become an indispensable functional component in calcium-zinc systems due to its unique layered structure and the exchangeability of anions between layers. It can exert a thermal stabilizing effect through mechanisms such as absorbing hydrogen chloride, substituting unstable chlorine atoms, and physical barrier.

[0003] Although hydrotalcite-based heat stabilizers have seen some industrial applications, current technology still has many shortcomings. Firstly, the interlayer anions in conventional hydrotalcites are mostly carbonate or simple organic acid anions (such as stearate and maleate), resulting in limited functionality. They can only absorb hydrogen chloride through ion exchange, lacking the ability to capture free radicals and metal ions (especially Zn). 2+The strong chelating ability of hydrotalcite leads to frequent zinc burning and insufficient long-term thermal stability. Secondly, existing hydrotalcite modification methods mostly employ single anionic intercalation or simple physical blending strategies, lacking chemical bonds between components and resulting in limited synergistic efficiency, making it difficult to simultaneously meet multiple requirements such as acid absorption, chelation, free radical capture, and UV aging resistance. Thirdly, hydrotalcite and commonly used inorganic fillers (such as boron nitride) exhibit poor dispersibility in the PVC matrix, easily agglomerating, which not only weakens their physical barrier and thermal conductivity but also leads to a decline in the mechanical properties of the composite material due to weak interfacial bonding. Fourthly, existing technologies pay little attention to the photo-oxidative degradation of PVC; most heat stabilizers are designed only for thermal degradation and lack effective means to inhibit the free radical chain reaction induced by UV light, resulting in poor weather resistance of outdoor products. Therefore, developing an environmentally friendly PVC heat stabilizer that combines high-efficiency acid absorption, strong metal chelation, free radical capture, excellent dispersibility and photostability, and synergistic effects between components has significant industrial value and market prospects. Summary of the Invention

[0004] To address the shortcomings mentioned in the background art, the present invention aims to provide an intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC and its preparation method. The present invention constructs a highly efficient stabilizing system integrating chemical absorption, free radical capture, physical barrier, and interface reinforcement by compounding modified hydrotalcite, two-dimensional zirconium-based MOF, and modified boron nitride nanosheets, and using them in conjunction with conventional auxiliary stabilizers. This heat stabilizer exhibits excellent comprehensive performance when applied to PVC processing.

[0005] The objective of this invention can be achieved through the following technical solutions: A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 90-110 parts modified hydrotalcite, 25-40 parts zirconium-based porphyrin MOF, 15-30 parts modified boron nitride nanosheets, 15-25 parts calcium stearate, 8-15 parts zinc stearate, 5-10 parts stearoylbenzoylmethane, and 5-10 parts pentaerythritol stearate; The modified hydrotalcite is a phytic acid-mercaptobenzothiazole hybrid anion co-intercalation modified magnesium aluminum lanthanum hydrotalcite; the zirconium-based porphyrin MOF is a two-dimensional MOF nanosheet prepared by solvothermal method from zirconium tetrachloride and tetra(4-carboxyphenyl)porphyrin; the modified boron nitride nanosheet is a boron nitride nanosheet grafted with hyperbranched polyamide-amine after surface hydroxylation treatment.

[0006] Preferably, the preparation method of the modified hydrotalcite includes the following steps: (1) Magnesium nitrate, aluminum nitrate and lanthanum nitrate are dissolved in deionized water and stirred until completely dissolved to obtain a mixed salt solution; phytic acid aqueous solution and mercaptobenzothiazole are added to deionized water and stirred until completely dissolved, and then NaOH is slowly added to adjust the pH to 12 to obtain an intercalation solution; (2) Under nitrogen protection, the mixed salt solution and intercalation solution are slowly dripped into the reactor while stirring vigorously to maintain the reaction temperature at 90°C. After the dripping is completed, stirring and aging continue for 1.5 to 2.5 hours. (3) Transfer the reaction slurry to a hydrothermal reactor, seal it and crystallize it at 110°C for 10-14 hours. After cooling naturally to room temperature, centrifuge and wash it repeatedly with deionized water until the pH of the filtrate is neutral. After vacuum drying, grind it through a 200-mesh sieve to obtain modified hydrotalcite.

[0007] Preferably, the molar ratio of magnesium nitrate, aluminum nitrate, lanthanum nitrate, phytic acid and mercaptobenzothiazole is 2~4:0.6~1.0:0.1~0.3:0.4~0.5:0.2~0.4.

[0008] Preferably, the preparation method of the zirconium-based porphyrin MOF includes the following steps: A. Dissolve citric acid in N,N-dimethylformamide to obtain solution A, and dissolve tetrakis(4-carboxyphenyl)porphyrin in N,N-dimethylformamide to obtain solution B. Mix the two solutions, add benzoic acid, and continue stirring for 8-12 minutes. B. Transfer the mixture to a high-pressure reactor, heat it to 120°C at a rate of 5°C / min, and react at a constant temperature for 22-26 hours. After the reaction is complete, allow it to cool naturally to room temperature. C. Collect the product by centrifugation, wash it three times with N,N-dimethylformamide, then exchange it with acetone twice for 1 hour each time, and finally vacuum dry it to obtain a two-dimensional sheet MOF. Then place the dried MOF in a vacuum desiccator and activate it at 150°C for 6-10 hours to obtain a zirconium-based porphyrin MOF.

[0009] Preferably, the molar ratio of citric acid chloride to tetra(4-carboxyphenyl)porphyrin is 3~5:1.

[0010] Preferably, the method for preparing the modified boron nitride nanosheets includes the following steps: a. Weigh h-boron nitride powder, disperse it in a mixture of concentrated sulfuric acid and concentrated nitric acid, ultrasonically disperse it for 20-40 min, reflux and stir it in an oil bath at 80℃ for 4-8 h, cool it, dilute it with deionized water, centrifuge it, wash it with deionized water until the pH of the filtrate is neutral, and vacuum dry it to obtain hydroxylated boron nitride. b. A GO product containing amide bonds and terminal amine groups was prepared by reacting succinic anhydride with diethylenetriamine. Then, methyl acrylate and DETA were added for chain extension to obtain a terminal amine hyperbranched polymer with a molecular weight of 3000~5000 Da. Finally, the terminal amine hyperbranched polymer was reacted with succinic anhydride to obtain a carboxyl-terminated hyperbranched polyamide-amine. c. Hydroxylated boron nitride was ultrasonically dispersed in N,N-dimethylacetamide to form a stable dispersion. Terminal carboxyl hyperbranched polyamide-amine and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was stirred at 80°C for 8-12 h under nitrogen protection. After the reaction was completed, the mixture was centrifuged, washed three times alternately with N,N-dimethylacetamide and methanol, vacuum dried, ground and sieved to obtain modified boron nitride nanosheets.

[0011] Preferably, the preparation of terminal carboxyl hyperbranched polyamide-amine in step b specifically includes the following steps: b1. Succinic anhydride was dissolved in N,N-dimethylacetamide, and diethylenetriamine was slowly added dropwise under an ice-water bath. After the addition was completed, the temperature was raised to 40°C and the reaction was carried out for 3-5 hours to obtain the GO product containing amide bonds and terminal amine groups. b2. Add methyl acrylate to the G0 reaction solution and react at 60°C for 4-8 hours to carry out Michael addition. Then add DETA and continue to react at 60°C for 4-8 hours to obtain the terminal amine hyperbranched polymer G1. b3. Repeat the operation in b2, continue to add methyl acrylate to the reaction solution, react at 60°C for 4~8h to carry out Michael addition, then add DETA, continue to react at 60°C for 4~8h to obtain the terminal amine hyperbranched polymer G2. b4. Dissolve the amine-terminated hyperbranched polymer G2 in N,N-dimethylacetamide, add succinic anhydride and triethylamine, react at 60°C for 6-10 h, precipitate with ethanol after the reaction, filter, and dry under vacuum to obtain carboxyl-terminated hyperbranched polyamide-amine.

[0012] Preferably, the molar ratio of succinic anhydride to diethylenetriamine is 1:2; The molar ratio of the GO product, methyl acrylate, and DETA is 1:4:4; The molar ratio of the terminal amine hyperbranched polymer G1, methyl acrylate, and DETA is 1:8:8; The molar ratio of the terminal amine hyperbranched polymer G2 to succinic anhydride is 1:16.

[0013] Preferably, the mass ratio of the hydroxylated boron nitride, the carboxyl-terminated hyperbranched polyamide-amine, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1:2:1.

[0014] A method for preparing an intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC includes the following steps: S1. First, add modified hydrotalcite, zirconium-based porphyrin MOF and modified boron nitride nanosheets into a drum ball mill and ball mill at 150 rpm for 20-40 min under a nitrogen atmosphere to obtain mixed powder raw materials; S2. Then add the premixed powder raw materials, calcium stearate, zinc stearate, stearoyl benzoylmethane and pentaerythritol stearate to a high-speed mixer and mix at 800~1000 rpm for 10~15 min. Pass through a 100-mesh sieve to obtain the intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC.

[0015] The beneficial effects of this invention are: This invention constructs a highly efficient stabilizing system integrating chemical absorption, free radical capture, physical barrier, and interfacial reinforcement by compounding modified hydrotalcite, two-dimensional zirconium-based MOF, and modified boron nitride nanosheets, and using them synergistically with conventional auxiliary stabilizers. This heat stabilizer exhibits excellent comprehensive performance when applied to PVC processing. The heat stabilizer of this invention significantly prolongs the Congo red thermal stability time of PVC samples at high temperatures, greatly delays the initial coloring time during static thermal aging, effectively suppresses zinc burning, and demonstrates significantly better long-term heat aging resistance than traditional calcium-zinc systems and single modified hydrotalcite systems. This system significantly prolongs the dynamic thermal stability time of PVC while reducing the equilibrium torque, shortening the plasticizing time, improving processing fluidity, and exhibiting a wider safe processing window. This system shifts the initial decomposition temperature and maximum weight loss rate temperature of PVC towards higher temperatures, significantly increases the thermal degradation activation energy, and significantly increases the char residue, indicating a fundamental improvement in the thermal stability of the PVC molecular chain. This system can simultaneously improve the tensile strength, elongation at break, and impact toughness of PVC products, and improve the interfacial bonding between inorganic fillers and the resin matrix. In terms of photoaging performance, the system of this invention endows PVC products with excellent resistance to ultraviolet aging, with small color difference changes and low carbonyl index increase after long-term accelerated aging, and significantly enhanced weather resistance.

[0016] This invention relates to a modified hydrotalcite using phytic acid and mercaptobenzothiazole hybrid anion-intercalated magnesium aluminum lanthanum hydrotalcite. The phytic acid molecule contains six phosphate groups, each capable of neutralizing HCl, resulting in a significantly higher acid absorption capacity than traditional carbonate-intercalated hydrotalcite. During the thermal degradation of PVC, the interlayer phytate ions continuously absorb HCl through ion exchange, effectively inhibiting the autocatalytic effect of HCl and slowing down the degradation process. The six phosphate groups of phytic acid can provide multiple oxygen coordinating atoms, which can interact with Zn in the system. 2+ Ca 2+ The formation of stable multidentate chelate rings by metal ions significantly delays the formation and accumulation of ZnCl2, thereby inhibiting the "zinc burning" phenomenon. This chelating ability is not possessed by single carboxylate intercalated hydrotalcites in existing technologies. The thiol group in mercaptobenzothiazole can undergo nucleophilic addition with the conjugated polyene chain formed by PVC deHClation, interrupting the elongation of the polyene sequence and thus inhibiting yellowing of the product. Simultaneously, the nitrogen and sulfur atoms on the thiazole ring possess certain free radical scavenging and metal coordination capabilities, complementing the acid absorption and chelating functions of phytic acid. The La in the hydrotalcite layer...3+ With a vacant 4f electron orbital, it can coordinate with the unstable allyl chloride on the PVC molecular chain, inhibiting the initial deHCl reaction. Meanwhile, La... 3+ A larger ionic radius can increase the interlayer spacing of hydrotalcite, providing sufficient intercalation space for the two larger organic anions, phytate and mercaptobenzothiazoline, thus ensuring the stability of co-intercalation.

[0017] This invention relates to a zirconium-based porphyrin MOF, a two-dimensional MOF nanosheet prepared from zirconium tetrachloride and tetra(4-carboxyphenyl)porphyrin via a solvothermal method. The porphyrin ligand possesses a large conjugated system with 18π electrons, enabling it to efficiently capture alkyl and peroxy radicals generated by the thermal and photodegradation of PVC, thus disrupting chain degradation propagation. This function is extremely rare in existing PVC heat stabilizers, filling a gap in the free radical capture capabilities of traditional hydrotalcite systems. 4+ The nodes possess strong Lewis acidity, enabling them to coordinate with unstable allyl chloride atoms on the PVC molecular chain, inducing their substitution and delaying the deHCl reaction at its source, thus achieving passivation of unstable chlorine atoms. Zirconium-based porphyrin MOFs have ultra-high specific surface area and a regular mesoporous structure, allowing for the physical adsorption of HCl and small volatile molecules. This forms a complementary mechanism with the chemical absorption of component A, providing rapid capture and long-term absorption, thereby improving overall acid adsorption efficiency. The π→π* transition of the porphyrin macrocycle can absorb ultraviolet light and convert it into heat energy, reducing the generation of photo-initiated free radicals and significantly improving the weather resistance and anti-yellowing ability of PVC products under outdoor conditions.

[0018] This invention modifies boron nitride nanosheets by chemically grafting carboxyl-terminated hyperbranched polyamide-amine onto the surface of boron nitride nanosheets. The three-dimensional spherical hyperbranched structure of the carboxyl-terminated hyperbranched polyamide-amine contains a large number of polar carboxyl-terminated groups, which can be adsorbed onto the surfaces of boron nitride and hydrotalcite, effectively preventing the agglomeration of inorganic fillers through steric hindrance. Compared with the simple physical blending or silane coupling agent modification in the prior art, this chemical grafting method has more durable dispersion stability and stronger interfacial forces. The carboxyl groups of the carboxyl-terminated hyperbranched polyamide-amine form chemical bonds or hydrogen bonds with the hydroxyl groups on the surface of boron nitride, while the long chains and amide groups at the other end have good compatibility with the PVC matrix, constructing molecular bridges between inorganic fillers and organic resins, strengthening interfacial bonding, and thus significantly improving the mechanical properties of PVC composites. The large number of amide groups and carboxyl-terminated groups in the hyperbranched polymer can react with HCl, participating in the acid absorption process as an auxiliary heat stabilizer; at the same time, the carboxyl groups affect Zn... 2+Metal ions possess coordination ability, forming a multidentate chelate network with phytic acid in component A, further enhancing the inhibitory effect on zinc calcination. Boron nitride nanosheets exhibit extremely high thermal conductivity and excellent sheet-like physical barrier properties. After uniform dispersion in a PVC matrix, they can rapidly disperse local hot spots, preventing heat concentration from triggering degradation; simultaneously, their layered structure can form a physical barrier, delaying the diffusion of HCl and oxygen, synergistically improving thermal stability.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0020] 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.

[0021] Example 1

[0022] A modified hydrotalcite, wherein the modified hydrotalcite is a phytic acid-mercaptobenzothiazole hybrid anion co-intercalated modified magnesium aluminum lanthanum hydrotalcite, is prepared by the following steps: (1) 38.46 g magnesium nitrate, 15.01 g aluminum nitrate and 4.33 g lanthanum nitrate were dissolved in 400 mL deionized water and stirred until completely dissolved to obtain a mixed salt solution. 90 mL 50 wt% phytic acid aqueous solution and 7.53 g mercaptobenzothiazole were added to 400 mL deionized water and stirred until completely dissolved. Then NaOH was slowly added to adjust the pH to 12 to obtain the intercalation solution. (2) Under nitrogen protection, the mixed salt solution and intercalation solution are slowly dripped into the reactor while stirring vigorously to maintain the reaction temperature at 90°C. After the dripping is completed, stirring and aging continue for 2 hours. (3) The reaction slurry was transferred to a hydrothermal reactor, sealed and crystallized at 110°C for 12 hours. After cooling naturally to room temperature, it was separated by centrifugation and repeatedly washed with deionized water until the pH of the filtrate was neutral. After vacuum drying, it was ground through a 200-mesh sieve to obtain modified hydrotalcite.

[0023] Example 2

[0024] A zirconium-based porphyrin MOF, wherein the zirconium-based porphyrin MOF is a two-dimensional MOF nanosheet prepared by a solvothermal method from zirconium tetrachloride and tetrakis(4-carboxyphenyl)porphyrin, the preparation method comprising the following steps: A. Dissolve 11.65g ZrCl4 in 150mL N,N-dimethylformamide to obtain solution A. Dissolve 9.89g tetrakis(4-carboxyphenyl)porphyrin in 100mL N,N-dimethylformamide to obtain solution B. Mix the two solutions, add 183.2g benzoic acid, and continue stirring for 10min. B. Transfer the mixture to a high-pressure reactor, heat it to 120°C at a rate of 5°C / min, and maintain the temperature for 24 hours. After the reaction is complete, allow it to cool naturally to room temperature. C. The product was collected by centrifugation and washed three times with N,N-dimethylformamide to remove unreacted tetrakis(4-carboxyphenyl)porphyrin and benzoic acid. Then, it was solvent-exchanged twice with acetone for 1 hour each time. Finally, it was vacuum dried for 12 hours to obtain a two-dimensional sheet-like MOF. The dried MOF was then placed in a vacuum desiccator and activated at 150°C for 8 hours to remove residual solvent in the pores, thus obtaining a zirconium-based porphyrin MOF.

[0025] Example 3

[0026] A modified boron nitride nanosheet, wherein the modified boron nitride nanosheet is prepared by grafting hyperbranched polyamide-amine onto boron nitride nanosheets after surface hydroxylation treatment, and the preparation method includes the following steps: a. Weigh 3 g of h-boron nitride powder, disperse it in a mixture of 150 mL concentrated sulfuric acid and 50 mL concentrated nitric acid, sonicate for 30 min, reflux and stir in an oil bath at 80 °C for 6 h, cool, dilute with deionized water, centrifuge, wash with deionized water until the pH of the filtrate is neutral, and vacuum dry to obtain hydroxylated boron nitride. b1. Dissolve 5.0 g of succinic anhydride in 50 mL of N,N-dimethylacetamide, and slowly add 10.32 g of diethylenetriamine dropwise under an ice-water bath. After the addition is complete, heat to 40 °C and react for 4 h to obtain the G0 product containing amide bonds and terminal amine groups. b2. Add 17.22 g of methyl acrylate to the G0 reaction solution, react at 60 °C for 6 h to carry out Michael addition, then add 41.27 g of DETA, and continue to react at 60 °C for 6 h to obtain the terminal amine hyperbranched polymer G1. b3. Add 34.44 g of methyl acrylate to the reaction solution and react at 60°C for 6 h to carry out Michael addition. Then add 82.54 g of DETA and continue to react at 60°C for 6 h to obtain the terminal amine hyperbranched polymer G2. b4. Dissolve the amine-terminated hyperbranched polymer G2 in N,N-dimethylacetamide, add 20.01 g of succinic anhydride and 1 mL of triethylamine, react at 60 °C for 10 h, precipitate with ethanol after the reaction, filter, and dry under vacuum to obtain carboxyl-terminated hyperbranched polyamide-amine. c. Take 1.0 g of hydroxylated boron nitride and ultrasonically disperse it in 50 mL of N,N-dimethylacetamide to form a stable dispersion. Add 2.0 g of terminal carboxyl hyperbranched polyamide-amine and 1.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Stir and react at 80 °C for 10 h under nitrogen protection. After the reaction is completed, centrifuge and wash three times alternately with N,N-dimethylacetamide and methanol. After vacuum drying, grind and sieve to obtain modified boron nitride nanosheets.

[0027] Example 4

[0028] A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 90 parts modified hydrotalcite, 25 parts zirconium-based porphyrin MOF, 15 parts modified boron nitride nanosheets, 15 parts calcium stearate, 8 parts zinc stearate, 5 parts stearoylbenzoylmethane, and 5 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, the zirconium-based porphyrin MOF is prepared in Example 2, and the modified boron nitride nanosheets are prepared in Example 3.

[0029] The preparation method of the above-mentioned intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC includes the following steps: S1. First, add modified hydrotalcite, zirconium-based porphyrin MOF and modified boron nitride nanosheets into a drum ball mill and ball mill at 150 rpm for 20 min under a nitrogen atmosphere to obtain mixed powder raw materials; S2. Then add the premixed powder raw materials, calcium stearate, zinc stearate, stearoyl benzoylmethane and pentaerythritol stearate to a high-speed mixer, mix at 800 rpm for 10 minutes, and pass through a 100-mesh sieve to obtain the intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC.

[0030] Example 5

[0031] A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 110 parts modified hydrotalcite, 40 parts zirconium-based porphyrin MOF, 30 parts modified boron nitride nanosheets, 25 parts calcium stearate, 15 parts zinc stearate, 10 parts stearoylbenzoylmethane, and 10 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, the zirconium-based porphyrin MOF is prepared in Example 2, and the modified boron nitride nanosheets are prepared in Example 3.

[0032] The preparation method of the above-mentioned intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC includes the following steps: S1. First, add modified hydrotalcite, zirconium-based porphyrin MOF and modified boron nitride nanosheets into a drum ball mill and ball mill at 150 rpm for 40 min under a nitrogen atmosphere to obtain mixed powder raw materials; S2. Then add the premixed powder raw materials, calcium stearate, zinc stearate, stearoyl benzoylmethane and pentaerythritol stearate to a high-speed mixer, mix at 1000 rpm for 15 minutes, and pass through a 100-mesh sieve to obtain the intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC.

[0033] Example 6

[0034] A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 100 parts modified hydrotalcite, 32.5 parts zirconium-based porphyrin MOF, 22.5 parts modified boron nitride nanosheets, 20 parts calcium stearate, 12 parts zinc stearate, 7.5 parts stearoylbenzoylmethane, and 7.5 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, the zirconium-based porphyrin MOF is prepared in Example 2, and the modified boron nitride nanosheets are prepared in Example 3.

[0035] The preparation method of the above-mentioned intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC includes the following steps: S1. First, add modified hydrotalcite, zirconium-based porphyrin MOF and modified boron nitride nanosheets into a drum ball mill and ball mill at 150 rpm for 30 min under a nitrogen atmosphere to obtain mixed powder raw materials; S2. Then add the premixed powder raw materials, calcium stearate, zinc stearate, stearoyl benzoylmethane and pentaerythritol stearate to a high-speed mixer, mix at 900 rpm for 12 minutes, and pass through a 100-mesh sieve to obtain an intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC.

[0036] Comparative Example 1 A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 100 parts magnesium aluminum lanthanum hydrotalcite, 32.5 parts zirconium-based porphyrin MOF, 22.5 parts modified boron nitride nanosheets, 20 parts calcium stearate, 12 parts zinc stearate, 7.5 parts stearoylbenzoylmethane, and 7.5 parts pentaerythritol stearate; wherein the zirconium-based porphyrin MOF is prepared in Example 2, and the modified boron nitride nanosheets are prepared in Example 3.

[0037] The preparation method of the magnesium aluminum lanthanum hydrotalcite includes the following steps: 19.23 g magnesium nitrate, 7.5 g aluminum nitrate, and 2.16 g lanthanum nitrate were dissolved in 400 mL of deionized water to obtain a mixed solution. Na₂CO₃ and NaOH were dissolved in 400 mL of deionized water to obtain an alkaline solution. The mixed salt solution and the alkaline solution were added dropwise to a reactor in parallel stream. The pH was controlled at 10 ± 0.1, and the reaction was stirred at 90 °C for 4 h. The product was transferred to a hydrothermal reactor and crystallized at 110 °C for 12 h. After centrifugation and washing until pH=7, the product was dried at 80 °C for 12 h, ground, and sieved to obtain magnesium aluminum lanthanum hydrotalcite.

[0038] The preparation method of the above-mentioned intercalated modified hydrotalcite-based PVC high-efficiency heat stabilizer is the same as that in Example 6, except that in step S1, the modified hydrotalcite is replaced with an equal amount of unmodified magnesium aluminum lanthanum hydrotalcite.

[0039] Comparative Example 2 A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 100 parts modified hydrotalcite, 22.5 parts modified boron nitride nanosheets, 20 parts calcium stearate, 12 parts zinc stearate, 7.5 parts stearoylbenzoylmethane, and 7.5 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, and the modified boron nitride nanosheets are prepared in Example 3.

[0040] The preparation method of the above-mentioned intercalated modified hydrotalcite-based PVC high-efficiency heat stabilizer is the same as that in Example 6, except that zirconium-based porphyrin MOF is not added in step S1.

[0041] Comparative Example 3 A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 100 parts modified hydrotalcite, 32.5 parts zirconium-based porphyrin MOF, 22.5 parts nano-nitride sheets, 20 parts calcium stearate, 12 parts zinc stearate, 7.5 parts stearoylbenzoylmethane, and 7.5 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, and the zirconium-based porphyrin MOF is prepared in Example 2.

[0042] The preparation method of the above-mentioned intercalated modified hydrotalcite-based PVC high-efficiency heat stabilizer is the same as that in Example 6, except that in step S1, the modified boron nitride nanosheets are replaced with an equal amount of unmodified nano-boron nitride.

[0043] Performance testing A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC comprises the following raw materials in parts by weight: 100 parts modified hydrotalcite, 32.5 parts zirconium-based porphyrin MOF, 22.5 parts boron nitride nanosheets, 20 parts calcium stearate, 12 parts zinc stearate, 7.5 parts stearoylbenzoylmethane, and 7.5 parts pentaerythritol stearate; wherein the modified hydrotalcite is prepared in Example 1, and the zirconium-based porphyrin MOF is prepared in Example 2.

[0044] The preparation method of the above-mentioned intercalated modified hydrotalcite-based PVC high-efficiency heat stabilizer is the same as that in Example 6, except that in step S1, the modified boron nitride nanosheets are replaced with an equal amount of unmodified boron nitride nanosheets.

[0045] Performance testing The high-efficiency heat stabilizer prepared in Example 6 and Comparative Examples 1-3 of this invention was used to prepare PVC samples. The basic formulation of the PVC samples was: 100 parts of PVC resin, 4 parts of the high-efficiency heat stabilizer of this invention, 10 parts of calcium carbonate filler, 0.6 parts of stearic acid lubricant, and 2 parts of acrylate processing aid ACR. Then, the following performance tests were conducted respectively: I. Static thermal stability test (1) Stability time of Congo red fever Referring to GB / T 2917.1-2002, the oil bath temperature was set to (180±1)℃. A moistened Congo red test paper was attached to the test tube 2 cm above the sample. The time when the test paper began to turn blue was recorded, which is the thermal stability time. (2) Static oven thermal aging According to GB / T 7141-2008, place the double-roll pressed PVC sheet (1mm thick) in a constant temperature oven at (180±2)℃, and take it out every 10 minutes to record the color change until the material is completely carbonized and turns black. The results are shown in Table 1 below.

[0046]

[0047] As can be seen from the data in Table 1, Comparative Example 2 has the shortest thermal stability time, proving that the zirconium-based porphyrin MOF has an irreplaceable key function, namely the physisorption of HCl by the porphyrin structure and the Lewis acid Zr. 4+ The passivation of the C-Cl bond plays a dual role in the stabilizer system, absorbing HCl and capturing free radicals. In Comparative Example 1, the unmodified hydrotalcite relies solely on CO3... 2- The hydrotalcite, which exchanges and absorbs HCl, exhibits a single function and a short stabilization time, confirming that the acid absorption capacity and functional diversity of the intercalated modified hydrotalcite are significantly improved. Comparative Example 3, due to the lack of modified boron nitride nanosheets, has poor uniform dispersion, preventing boron nitride from fully exerting its physical barrier effect. However, it still retains some thermal conductivity and weak barrier properties, resulting in a thermal stabilization time slightly higher than Comparative Example 1 but significantly lower than Example 6. Example 6 achieves a thermal stabilization time of 86 min, indicating that the acid absorption, capture, and barrier network synergistically constructed by the three sets of modified additives is highly effective in significantly delaying HCl release.

[0048] The static oven aging test results further verified the functional differences of each component. Comparative Example 2, lacking the zirconium-based porphyrin MOF to capture free radicals, showed a significant deepening of color (yellowish-brown) within 15 minutes and was the first to exhibit zinc burning, confirming the indispensable pioneering role of the zirconium-based porphyrin MOF in inhibiting free radical chain degradation. Comparative Example 1 showed a slightly slower coloring rate than Comparative Example 2, but due to the absence of modified hydrotalcite, its acid absorption capacity rapidly declined, and localized zinc burning black spots appeared after approximately 45 minutes. This indicates that the role of modified hydrotalcite in long-term stability was fully confirmed, and that simple CO3... 2- Intercalation cannot meet the long-term acid absorption requirements. The coloring speed of Comparative Example 3 was significantly slower than that of Comparative Examples 1 and 2, indicating that the zirconium-based porphyrin MOF and modified hydrotalcite had played a major stabilizing role. However, there was still a significant gap compared to Example 6. This is because the interfacial compatibility between the unmodified boron nitride and the PVC matrix was poor, leading to easy agglomeration of boron nitride and insufficient utilization of its thermal conductivity and barrier properties, thereby reducing the overall stabilization efficiency of the system. The initial color change time of Example 6 was significantly better than that of the three control groups, and no zinc burn spots appeared until 90 min. The complete blackening time reached 120 min, confirming that the multi-level stabilizing network constructed by the three components played an effective protective role at each stage.

[0049] II. Dynamic Thermal Stability Test Referring to the ASTM D2538 standard, a torque rheometer was used to simulate the actual PVC processing process. In a closed processing chamber, the PVC mixture was melted and mixed by controlling the temperature and rotor speed, and the torque change curve over time was recorded. The results are shown in Table 2 below.

[0050]

[0051] As shown in Table 2, Example 6 exhibited the shortest plasticizing time and the lowest equilibrium torque, indicating that the modified boron nitride nanosheets not only promoted the uniform dispersion of inorganic fillers in the PVC matrix but also reduced the frictional resistance between molecular chains, improving processing fluidity. Comparative Example 3, lacking graft modification, showed poor interfacial compatibility between boron nitride and the PVC matrix, leading to easy agglomeration and a significantly prolonged plasticizing time, increased equilibrium torque, and larger torque fluctuations. Comparative Example 2 lacked the free radical scavenging function of the zirconium-based porphyrin MOF, resulting in rapid free radical chain degradation under dynamic shear conditions and a drastically shortened dynamic thermal stability time. Comparative Example 1 also lacked a key stabilizing component, and its dynamic thermal stability time was significantly lower than that of Example 6. Example 6 exhibited the longest dynamic thermal stability time, confirming that the three modified additives could synergistically maintain long-term stability under dynamic processing conditions.

[0052] III. Thermal Decomposition Kinetics Analysis Thermogravimetric analysis (TGA) was used to measure the thermal degradation at three heating rates of 10℃ / min, 15℃ / min, and 20℃ / min under a nitrogen atmosphere. The thermogravimetric curves were recorded, and the activation energy E of thermal degradation was calculated using the Kissinger method and the Flynn-Wall-Ozawa method. a The data were processed and calculated in accordance with GB / T 33047.2-2021 "Thermogravimetric Analysis (TG) of Plastic Polymers - Part 2: Determination of Activation Energy"; the results are shown in Table 3 below.

[0053]

[0054] As can be seen from the data in Table 3, the initial decomposition temperature T in Example 6 is... 5% Compared with Comparative Example 1, the temperature increased by 19℃, and compared with Comparative Example 2, the temperature increased by 31℃. The maximum decomposition rate temperature T max The temperature reached 307℃, 35℃ higher than Comparative Example 2; the char residue was 11.3%, nearly three times higher than Comparative Example 2. This indicates that the stability of the PVC molecular chain in Example 6 was significantly improved at high temperatures, and the synergistic effect of the three modified components formed a denser thermal degradation barrier. Comparative Example 2 had the lowest activation energy, indicating that the lack of zirconium-based porphyrin MOF resulted in a lack of effective free radical capture mechanism in the system, making chain degradation reactions more likely to occur. This also explains why Comparative Example 2 performed the worst in all tests. The Tf of Comparative Example 3... 5% T max Both the residual carbon content and the yield were higher than those of Comparative Examples 1 and 2, but still somewhat lower than those of Example 6. This indicates that the grafted modified layer plays an irreplaceable role in enhancing interfacial bonding and promoting uniform dispersion. Even if unmodified boron nitride is present, uneven dispersion will lead to accelerated local thermal degradation. The degradation activation energy of ordinary unmodified PVC is usually in the range of 100~120 kJ / mol, while the result of 167 kJ / mol in Example 6 is close to the level of some high-performance engineering plastics, proving that the stabilizer system has a very significant effect on improving the thermal stability of PVC.

[0055] IV. Mechanical Property Testing (1) Tensile properties Tensile strength and elongation at break were determined in accordance with GB / T 1040.2-2022. The specimens were type I dumbbell specimens with a gauge length of 50 mm and a width of 10.0 mm (neck) to 20.0 mm (end). An electronic universal testing machine was used with a tensile rate of 50 mm / min and a room temperature of 23℃. (2) Impact strength Notched impact performance was tested according to GB / T1843-2008. A simply supported beam impact testing machine was used. The specimen was placed on the impact frame, and a pendulum impacted the specimen. The notched impact strength (kJ / m) was recorded.2 The results are shown in Table 4 below.

[0056]

[0057] As shown in Table 4, the tensile strength and elongation at break of Example 6 were significantly higher than those of the three control groups. Comparative Example 3, due to the tendency of unmodified boron nitride to agglomerate, formed stress concentration points in the PVC matrix, resulting in the lowest tensile strength and elongation at break. This demonstrates the crucial role of hyperbranched polyamide-amine graft modification in the modified boron nitride nanosheets in the uniform dispersion and interfacial strengthening of the inorganic filler. Comparative Example 2, while lacking zirconium-based porphyrin MOF, still retained modified hydrotalcite and modified boron nitride nanosheets, showing improved mechanical properties compared to Comparative Examples 1 and 3. This indicates that modified hydrotalcite and modified boron nitride nanosheets still have a toughening effect on the PVC matrix, but the absence of zirconium-based porphyrin MOF is insufficient to achieve the superior performance of Example 6.

[0058] The notched impact strength of the simply supported beam in Example 6 was significantly better than that of Comparative Examples 1-3. Comparative Example 3 exhibited the lowest impact strength due to brittle fracture caused by the agglomeration of unmodified boron nitride. The impact strength of Comparative Example 2 was slightly higher than that of Comparative Example 1, indicating that the uniform dispersion of modified hydrotalcite and modified boron nitride had a certain toughening effect on the PVC matrix. The absence of the zirconium-based porphyrin MOF did not significantly affect the impact performance, as the MOF's main contribution is thermal stability rather than mechanical reinforcement. Example 6 demonstrated superior overall mechanical properties; the hyperbranched polymer grafting modification and the uniformly dispersed interface were key to achieving the reinforcing and toughening effects.

[0059] V. Photoaging Performance Test Accelerated aging tests were conducted using fluorescent ultraviolet lamps according to GB / T 16422.3, employing UVA-340 lamps with an irradiance of 0.89 W·m. -2 ·nm -1 @340 nm, 8 h of light exposure (60℃) → 4 h of condensation (50℃) cycle, total aging time 1500 h; color difference ΔE was measured using a colorimeter (refer to ASTM D2244), carbonyl index was measured by FTIR at 1720 cm⁻¹. -1 carbonyl peak and internal standard peak (e.g., 2920 cm⁻¹) -1 The absorbance ratio of the methylene peak was used to evaluate the degree of photo-oxidative degradation; the results are shown in Table 5 below.

[0060]

[0061] As shown in Table 5, Example 6 exhibits a color difference ΔE of only 8.2 and a carbonyl index of 0.21 after 1500 h of accelerated aging, significantly superior to Comparative Examples 1-3. Comparative Example 2 has the highest carbonyl index (0.58) and a color difference of 24.3, demonstrating that the 18π-electron conjugated macrocyclic structure of the porphyrin ligand in the zirconium-based porphyrin MOF possesses strong absorption and energy transfer capabilities for ultraviolet light. In Comparative Example 3, the unmodified boron nitride lacks ultraviolet absorption and energy transfer capabilities, resulting in photoaging performance lower than Example 6. Although Comparative Example 1 shows CO3 in the interlayer of the hydrotalcite... 2- It has weak absorption of ultraviolet light, but the effect is limited, and the overall photoaging performance is far inferior to that of Example 6, which contains zirconium-based porphyrin MOF.

[0062] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC, characterized in that, The raw materials include the following parts by weight: 90-110 parts of modified hydrotalcite, 25-40 parts of zirconium-based porphyrin MOF, 15-30 parts of modified boron nitride nanosheets, 15-25 parts of calcium stearate, 8-15 parts of zinc stearate, 5-10 parts of stearoylbenzoylmethane, and 5-10 parts of pentaerythritol stearate; The modified hydrotalcite is a phytic acid-mercaptobenzothiazole hybrid anion co-intercalation modified magnesium aluminum lanthanum hydrotalcite; the zirconium-based porphyrin MOF is a two-dimensional MOF nanosheet prepared by solvothermal method from zirconium tetrachloride and tetra(4-carboxyphenyl)porphyrin; the modified boron nitride nanosheet is a boron nitride nanosheet grafted with hyperbranched polyamide-amine after surface hydroxylation treatment.

2. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 1, characterized in that, The preparation method of the modified hydrotalcite includes the following steps: (1) Magnesium nitrate, aluminum nitrate and lanthanum nitrate are dissolved in deionized water and stirred until completely dissolved to obtain a mixed salt solution; phytic acid aqueous solution and mercaptobenzothiazole are added to deionized water and stirred until completely dissolved, and then NaOH is slowly added to adjust the pH to 12 to obtain an intercalation solution; (2) Under nitrogen protection, the mixed salt solution and intercalation solution are slowly dripped into the reactor while stirring vigorously to maintain the reaction temperature at 90°C. After the dripping is completed, stirring and aging continue for 1.5 to 2.5 hours. (3) Transfer the reaction slurry to a hydrothermal reactor, seal it and crystallize it at 110°C for 10-14 hours. After cooling naturally to room temperature, centrifuge and wash it repeatedly with deionized water until the pH of the filtrate is neutral. After vacuum drying, grind it through a 200-mesh sieve to obtain modified hydrotalcite.

3. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 2, characterized in that, The molar ratio of magnesium nitrate, aluminum nitrate, lanthanum nitrate, phytic acid, and mercaptobenzothiazole is 2~4:0.6~1.0:0.1~0.3:0.4~0.5:0.2~0.

4.

4. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 1, characterized in that, The preparation method of the zirconium-based porphyrin MOF includes the following steps: A. Dissolve citric acid in N,N-dimethylformamide to obtain solution A, and dissolve tetrakis(4-carboxyphenyl)porphyrin in N,N-dimethylformamide to obtain solution B. Mix the two solutions, add benzoic acid, and continue stirring for 8-12 minutes. B. Transfer the mixture to a high-pressure reactor, heat it to 120°C at a rate of 5°C / min, and maintain the temperature for 22-26 hours. After the reaction is complete, allow it to cool naturally to room temperature. C. Collect the product by centrifugation, wash it three times with N,N-dimethylformamide, then exchange it with acetone twice for 1 hour each time, and finally vacuum dry it to obtain a two-dimensional sheet MOF. Then place the dried MOF in a vacuum desiccator and activate it at 150°C for 6-10 hours to obtain a zirconium-based porphyrin MOF.

5. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 4, characterized in that, The molar ratio of citric acid chloride to tetra(4-carboxyphenyl)porphyrin is 3~5:

1.

6. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 1, characterized in that, The method for preparing the modified boron nitride nanosheets includes the following steps: a. Weigh h-boron nitride powder, disperse it in a mixture of concentrated sulfuric acid and concentrated nitric acid, ultrasonically disperse it for 20-40 min, reflux and stir it in an oil bath at 80℃ for 4-8 h, cool it, dilute it with deionized water, centrifuge it, wash it with deionized water until the pH of the filtrate is neutral, and vacuum dry it to obtain hydroxylated boron nitride. b. A GO product containing amide bonds and terminal amine groups was prepared by reacting succinic anhydride with diethylenetriamine. Then, methyl acrylate and DETA were added for chain extension to obtain a terminal amine hyperbranched polymer with a molecular weight of 3000~5000 Da. Finally, the terminal amine hyperbranched polymer was reacted with succinic anhydride to obtain a carboxyl-terminated hyperbranched polyamide-amine. c. Hydroxylated boron nitride was ultrasonically dispersed in N,N-dimethylacetamide to form a stable dispersion. Carboxyl-terminated hyperbranched polyamide-amine and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was stirred at 80°C for 8-12 hours under nitrogen protection. After the reaction was completed, the mixture was centrifuged, washed three times alternately with N,N-dimethylacetamide and methanol, dried under vacuum, ground and sieved to obtain modified boron nitride nanosheets.

7. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 6, characterized in that, The preparation of terminal carboxyl hyperbranched polyamide-amine in step b specifically includes the following steps: b1. Succinic anhydride was dissolved in N,N-dimethylacetamide, and diethylenetriamine was slowly added dropwise under an ice-water bath. After the addition was completed, the temperature was raised to 40°C and the reaction was carried out for 3-5 hours to obtain the GO product containing amide bonds and terminal amine groups. b2. Add methyl acrylate to the G0 reaction solution and react at 60°C for 4-8 hours to carry out Michael addition. Then add DETA and continue to react at 60°C for 4-8 hours to obtain the terminal amine hyperbranched polymer G1. b3. Repeat the operation in b2, continue to add methyl acrylate to the reaction solution, react at 60°C for 4~8h to carry out Michael addition, then add DETA, continue to react at 60°C for 4~8h to obtain the terminal amine hyperbranched polymer G2. b4. Dissolve the amine-terminated hyperbranched polymer G2 in N,N-dimethylacetamide, add succinic anhydride and triethylamine, react at 60°C for 6-10 h, precipitate with ethanol after the reaction, filter, and dry under vacuum to obtain carboxyl-terminated hyperbranched polyamide-amine.

8. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 7, characterized in that, The molar ratio of succinic anhydride and diethylenetriamine is 1:2; The molar ratio of the GO product, methyl acrylate, and DETA is 1:4:4; The molar ratio of the terminal amine hyperbranched polymer G1, methyl acrylate, and DETA is 1:8:8; The molar ratio of the terminal amine hyperbranched polymer G2 to succinic anhydride is 1:

16.

9. The high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC according to claim 6, characterized in that, The mass ratio of the hydroxylated boron nitride, the carboxyl-terminated hyperbranched polyamide-amine, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1:2:

1.

10. A method for preparing a high-efficiency heat stabilizer for intercalated modified hydrotalcite-based PVC as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. First, add modified hydrotalcite, zirconium-based porphyrin MOF and modified boron nitride nanosheets into a drum ball mill and ball mill at 150 rpm for 20-40 min under a nitrogen atmosphere to obtain mixed powder raw materials; S2. Then add the premixed powder raw materials, calcium stearate, zinc stearate, stearoyl benzoylmethane and pentaerythritol stearate to a high-speed mixer and mix at 800~1000 rpm for 10~15 min. Pass through a 100-mesh sieve to obtain the intercalated modified hydrotalcite-based high-efficiency heat stabilizer for PVC.

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