Antibacterial high-weather-resistant cosmetic packaging polyester composite plastic material and preparation method thereof
Patent Information
- Application Number
- CN202611154778.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-31
- Publication Date
- 2026-09-15
Smart Images
Figure CN122750084A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer composite materials technology, and in particular to an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging and its preparation method. Background Technology
[0002] With the rapid development of the cosmetics industry, consumers have placed higher demands on the safety, durability, and appearance quality of cosmetic packaging materials. Polyester materials such as polyethylene terephthalate (PET) and PET copolymers are widely used in cosmetic bottles, lotion bottles, spray bottles, packaging boxes, and other packaging containers due to their advantages such as high transparency, excellent mechanical strength, good chemical corrosion resistance, light weight, excellent processing performance, and recyclability. They have become one of the important materials in the cosmetics packaging field.
[0003] However, existing polyester packaging materials still have certain shortcomings during long-term storage and use. On the one hand, cosmetic packaging products are exposed to ultraviolet light, visible light, oxygen, and humid heat for extended periods, making polyester resin prone to photo-oxidative aging and thermo-oxidative aging. This leads to problems such as yellowing, decreased gloss, reduced mechanical properties, and surface embrittlement, affecting the packaging's appearance and lifespan. On the other hand, cosmetic packaging is susceptible to microbial contamination by bacteria, mold, and other microorganisms during filling, transportation, storage, and use. Ordinary polyester materials themselves lack antibacterial capabilities, making it difficult to meet the hygiene, safety, and long-term stability requirements of high-end cosmetic packaging.
[0004] To improve the overall performance of polyester packaging materials, existing technologies typically employ modification methods such as adding nano-titanium dioxide, nano-zinc oxide, silver-based antibacterial agents, UV absorbers, hindered amine light stabilizers, and antioxidants. Among these, nano-titanium dioxide, due to its excellent UV shielding ability, weather resistance, and certain antibacterial activity, has become a widely used inorganic functional filler in polyester packaging materials. However, nano-titanium dioxide has a large specific surface area and high surface energy, making it prone to agglomeration in polyester resin. This results in poor dispersion uniformity, hindering its ability to fully exert its UV shielding and reinforcing effects and easily forming stress concentration points, thus reducing the mechanical properties and processing stability of the composite material. Furthermore, unmodified nano-titanium dioxide tends to exhibit strong photocatalytic activity under light conditions, potentially promoting polyester molecular chain degradation, accelerating material aging, and thus affecting the long-term weather resistance of the packaging material.
[0005] Currently, the modification of nano-titanium dioxide mainly employs methods such as silane coupling agent surface grafting, polymer coating, or single organic surface modification to improve its dispersibility and interfacial compatibility. However, existing modification methods still suffer from limited interfacial bonding, insufficient stability of the surface functional layer, and poor control over the photocatalytic activity of nano-titanium dioxide, making it difficult to simultaneously achieve the desired weather resistance, antibacterial properties, and mechanical properties. Furthermore, existing polyester packaging materials often rely on the combined action of multiple anti-aging additives and stabilizers, resulting in complex formulations and limited synergistic effects. Significant room for improvement remains in enhancing the retention rate of antibacterial properties, weather resistance, and overall service stability during long-term service.
[0006] Therefore, developing a polyester composite plastic material for cosmetic packaging with excellent interfacial compatibility, antibacterial properties, and weather resistance, by constructing a stable organic-inorganic synergistic interface, improving the dispersion stability and interfacial bonding ability of nanofunctional fillers in the polyester matrix, and giving full play to the synergistic effect of each functional component, so as to further enhance the antibacterial properties, weather resistance, mechanical properties and long-term service stability of polyester packaging materials, has become an urgent technical problem to be solved in this field. Summary of the Invention
[0007] To overcome the technical problems of existing polyester cosmetic packaging materials, such as easy agglomeration of nano-titanium dioxide, poor interfacial compatibility with the polyester matrix, insufficient long-term weather resistance, low retention of antibacterial properties, and difficulty in simultaneously achieving comprehensive mechanical properties and service stability, the present invention aims to provide an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging and its preparation method. The present invention employs the following technical solution: using polyester resin as the matrix, nano-titanium dioxide modified by polydopamine interfacial self-polymerization and γ-glycidyl etheroxypropyltrimethoxysilane synergistic grafting is used as a functional reinforcing component. Ferulic acid is introduced as an organic small molecule functional regulator, combined with inorganic antibacterial agents, compatibilizers, and processing aids for synergistic compounding. By constructing a stable organic-inorganic synergistic interface, the dispersion stability and interfacial bonding ability of nano-titanium dioxide in polyester resin are improved, while simultaneously enhancing the antibacterial properties, weather resistance, and processing stability of the polyester composite material.
[0008] The objective of this invention can be achieved through the following technical solutions:
[0009] A polyester composite plastic material for antibacterial and highly weather-resistant cosmetic packaging comprises the following raw materials in parts by weight: 100 parts polyester resin; 8-25 parts synergistically modified nano-titanium dioxide; 0.1-1.5 parts ferulic acid; 0.5-4 parts inorganic antibacterial agent; 2-6 parts compatibilizer; and 0.2-1.5 parts processing aid. The synergistically modified nano-titanium dioxide is obtained by self-polymerizing nano-titanium dioxide at a polydopamine interface, followed by surface grafting modification with γ-glycidoxypropyltrimethoxysilane. The polydopamine forms an interface layer rich in catechol and amino groups on the surface of the nano-titanium dioxide. γ-glycidoxypropyltrimethoxysilane forms stable siloxane bonds with the hydroxyl groups on the surface of the nano-titanium dioxide and the polydopamine interface layer through a hydrolysis-condensation reaction, thus constructing an organic-inorganic synergistic interface layer on the surface of the nano-titanium dioxide.
[0010] Optionally, the synergistically modified nano-titanium dioxide comprises the following raw materials in parts by weight: 100 parts nano-titanium dioxide; 2-10 parts dopamine hydrochloride; 5-20 parts γ-glycidyl etheroxypropyltrimethoxysilane; 100-300 parts ethanol; and 20-100 parts deionized water.
[0011] Optionally, the preparation method of synergistically modified nano-titanium dioxide includes the following steps:
[0012] (1) Dopamine hydrochloride was mixed with nano-titanium dioxide and surface coated to obtain surface-coated nano-titanium dioxide;
[0013] (2) Add γ-glycidyl etheroxypropyltrimethoxysilane to the surface-coated nano-titanium dioxide and perform coupling grafting modification to obtain the synergistically modified nano-titanium dioxide reaction product.
[0014] (3) The reaction products of synergistically modified nano-titanium dioxide are separated, washed, dried and pulverized to obtain synergistically modified nano-titanium dioxide.
[0015] Optionally, the reaction conditions in step (1) are as follows: dopamine hydrochloride is dissolved in deionized water, the pH of the system is adjusted to 8.5-8.8 using Tris buffer, nano-titanium dioxide is added, and the reaction is stirred at 20-30°C for 6-12 hours.
[0016] Optionally, the reaction conditions in step (2) are as follows: γ-glycidyl etheroxypropyltrimethoxysilane is added to a mixed solution of ethanol and deionized water for pre-hydrolysis for 20 to 40 min, the volume ratio of ethanol to deionized water is 4:1 to 6:1, the pH of the system is adjusted to 4.5 to 5.5, and then the surface-coated nano-titanium dioxide obtained in step (1) is added, and the reaction is stirred at 65 to 75 °C for 3 to 5 h.
[0017] Optionally, the reaction conditions in step (3) are to wash the nano-titanium dioxide 2 to 3 times with anhydrous ethanol and deionized water, dry it at 80 to 90°C for 8 to 10 hours, pulverize it and pass it through a 300 to 500 mesh sieve to obtain synergistically modified nano-titanium dioxide.
[0018] Optionally, the inorganic antibacterial agent is a mixture of nano zinc oxide and silver ion glass powder in a mass ratio of (2-5):1; the compatibilizer is a mixture of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-methacrylate glycidyl acrylate copolymer in a mass ratio of (1-3):1; and the processing aid is a mixture of antioxidant 1010, antioxidant 168 and ethylene bis-stearamide in a mass ratio of (1-2):(1-2):1.
[0019] Optionally, a method for preparing an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging includes the following steps:
[0020] S1, polyester resin, synergistically modified nano-titanium dioxide, ferulic acid, inorganic antibacterial agent, compatibilizer and processing aid are mixed evenly to obtain a mixture;
[0021] S2, the mixture is melt-blended to obtain a melt blend;
[0022] S3. The resulting melt blend is extruded, cooled, and pelletized to obtain an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging.
[0023] Optionally, the reaction conditions for step S1 are as follows: the polyester resin is dried at 120-140°C for 4-6 hours, and then added to a high-speed mixer with synergistically modified nano-titanium dioxide, ferulic acid, inorganic antibacterial agent, compatibilizer and processing aid, and mixed at 500-800 r / min for 10-20 min.
[0024] Optionally, the reaction conditions for step S2 are as follows: melt blending is performed using a twin-screw extruder, with the extruder temperatures in each zone being 240–245°C, 245–250°C, 250–255°C, 255–260°C, 260–265°C, and 260–265°C respectively; the screw speed is 150–250 r / min; and the melt blending time is 3–8 min. The reaction conditions for step S3 are as follows: the melt blend obtained in step S2 is extruded through a die and cooled with circulating cooling water at 20–30°C; then it is drawn, pelletized, and dried at 80–100°C for 2–4 h to obtain an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging.
[0025] The beneficial effects of this invention are:
[0026] This invention first employs a synergistic modification approach combining polydopamine interfacial self-polymerization coating with γ-glycidoxypropyltrimethoxysilane surface grafting to functionalize nano-titanium dioxide. Polydopamine, with its abundant catechol and amino groups, forms a stable biomimetic interfacial layer on the nano-titanium dioxide surface, providing more active sites for subsequent silane coupling agent grafting. After hydrolysis, γ-glycidoxypropyltrimethoxysilane forms stable siloxane bonds with the hydroxyl groups on the nano-titanium dioxide surface and the polydopamine interfacial layer, constructing a stable organic-inorganic synergistic interfacial layer on the nano-titanium dioxide surface. This effectively reduces the surface energy of the nano-titanium dioxide, inhibits agglomeration between nanoparticles, improves its dispersion uniformity and interfacial bonding ability in polyester resin, and allows the nano-titanium dioxide to be more uniformly and stably distributed in the polyester matrix, fully utilizing its UV shielding, reinforcement, and weather resistance effects. Simultaneously, it reduces stress concentration caused by localized agglomeration of nano-titanium dioxide, improving the overall mechanical properties and long-term service stability of the composite material.
[0027] This invention further introduces ferulic acid as an organic small molecule functional regulator into the polyester composite system. The ferulic acid molecule contains phenolic hydroxyl groups and conjugated double bonds, enabling it to capture free radicals under long-term light and thermo-oxidative environments, slowing down the oxidative degradation of the polyester molecular chains. It can also form multiple hydrogen bonds with the polydopamine interface layer, further enhancing the stability of the interface layer. Simultaneously, ferulic acid forms a synergistic stabilizing effect with synergistically modified nano-titanium dioxide, effectively inhibiting the excessively strong photocatalytic activity of nano-titanium dioxide and reducing polyester degradation caused by photocatalysis. This allows the material to maintain high transparency, color stability, and mechanical property retention even under long-term UV irradiation and humid heat environments, achieving simultaneous improvement in weather resistance and anti-aging properties.
[0028] This invention employs an inorganic antibacterial agent, a compatibilizer, and a processing aid in a synergistic compounding process. The compatibilizer further improves the interfacial compatibility between the synergistically modified nano-titanium dioxide and the polyester resin, promoting the uniform dispersion of each functional component. The inorganic antibacterial agent and the synergistically modified nano-titanium dioxide form a synergistic antibacterial system, which not only improves the antibacterial efficiency of the material but also extends the duration of its antibacterial properties. The processing aid enhances the melt processing stability and molding performance of the composite material, reducing the risk of thermal degradation of the polyester resin during processing. The synergistic effect among the components results in a polyester composite plastic material with excellent antibacterial properties, weather resistance, mechanical properties, and processing performance, meeting the comprehensive requirements of cosmetic packaging materials for appearance retention, hygiene safety, and service stability during long-term use. Attached Figure Description
[0029] The invention will now be further described with reference to the accompanying drawings.
[0030] Figure 1This is a comparison chart of the antibacterial performance test results for samples with different formulation ratios. Detailed Implementation
[0031] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.
[0032] Example 1: The purpose of this example is to verify that when the raw materials are used in a lower ratio within the scope of the claims and a milder reaction condition is adopted, nano-titanium dioxide modified by interfacial self-polymerization of polydopamine and synergistic grafting with γ-glycidoxypropyltrimethoxysilane can effectively improve its dispersion performance in polyester resin, and form a synergistic effect with ferulic acid, inorganic antibacterial agents, compatibilizers and processing aids, so that the resulting polyester composite plastic material has good antibacterial properties, weather resistance and processing stability.
[0033] S1, Preparation of Synergistically Modified Nano-Titanium Dioxide
[0034] Weigh out 100 parts of nano-titanium dioxide, 2 parts of dopamine hydrochloride, 100 parts of ethanol, and 20 parts of deionized water for later use. First, add 2 parts of dopamine hydrochloride to 20 parts of deionized water, adjust the pH of the system to 8.5 with Tris buffer, and stir at 20°C for 20 min to ensure complete dissolution. Then add 100 parts of nano-titanium dioxide, and continue stirring at 20°C for 6 h to allow the dopamine hydrochloride to undergo a self-polymerization reaction on the surface of nano-titanium dioxide, forming a polydopamine coating layer, thus obtaining surface-coated nano-titanium dioxide. Then, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane to a mixed solution of 100 parts of ethanol and 20 parts of deionized water, adjust the pH of the system to 4.5, pre-hydrolyze for 20 min, and then add the above-mentioned surface-coated nano-titanium dioxide. Stir at 65°C for 3 h to allow the γ-glycidyl etheroxypropyltrimethoxysilane to undergo a coupling and grafting reaction on the polydopamine interface layer and the surface of nano-titanium dioxide. After the reaction was completed, the product was washed twice with anhydrous ethanol and deionized water alternately, dried at 80°C for 8 hours, pulverized and passed through a 300-mesh sieve to obtain synergistically modified nano-titanium dioxide.
[0035] S2. Preparation of composite mixture
[0036] 100 parts of polyester resin were weighed and dried at 120℃ for 4 hours to remove moisture from the resin. Then, the dried polyester resin was added to a high-speed mixer along with 8 parts of synergistically modified nano-titanium dioxide, 0.1 parts of ferulic acid, 0.5 parts of inorganic antibacterial agent, 2 parts of compatibilizer, and 0.2 parts of processing aid. The mixture was stirred at 500 r / min for 10 minutes to ensure thorough and uniform mixing, resulting in a composite mixture. The inorganic antibacterial agent was a mixture of nano-zinc oxide and silver ion glass powder at a mass ratio of 2:1. The compatibilizer was a mixture of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-glycidyl methacrylate copolymer at a mass ratio of 1:1. The processing aid was a mixture of antioxidant 1010, antioxidant 168, and ethylene bis-stearamide at a mass ratio of 1:1:1.
[0037] S3, melt blending and granulation
[0038] The composite mixture obtained in step S2 was added to a twin-screw extruder for melt blending. The temperatures of each zone were set sequentially to 240℃, 245℃, 250℃, 255℃, 260℃, and 260℃, with the screw speed set to 150 r / min. Melt blending lasted for 3 minutes to ensure thorough plasticization and dispersion of the components. The mixture was then extruded through a die, cooled with 20℃ circulating cooling water, and after traction and pelletizing, dried at 80℃ for 2 hours to obtain an antibacterial, highly weather-resistant polyester composite plastic material for cosmetic packaging. This material exhibits uniform particle appearance, no obvious agglomeration or color difference, and good processing flowability, making it suitable for subsequent injection molding or blow molding to prepare cosmetic packaging products.
[0039] Example 2: The purpose of this example is to verify that when each component adopts the intermediate ratio within the scope of the claims and appropriate reaction conditions are used, the synergistic effect between the polydopamine interfacial self-polymerization coating and the synergistic grafting modification of γ-glycidyl etheroxypropyltrimethoxysilane nano-titanium dioxide and ferulic acid, inorganic antibacterial agents, compatibilizers and processing aids can be fully exerted, thereby further improving the dispersion stability and interfacial bonding ability of nano-titanium dioxide in polyester resin, so that the obtained polyester composite plastic material has better antibacterial properties, weather resistance, mechanical properties and long-term service stability.
[0040] S1, Preparation of Synergistically Modified Nano-Titanium Dioxide
[0041] Weigh out 100 parts of nano-titanium dioxide, 6 parts of dopamine hydrochloride, 12 parts of γ-glycidyl etheroxypropyltrimethoxysilane, 200 parts of ethanol, and 60 parts of deionized water for later use. First, add 6 parts of dopamine hydrochloride to 60 parts of deionized water, adjust the pH of the system to 8.6 with the help of Tris buffer, and stir at 25°C for 25 min to fully dissolve the dopamine hydrochloride. Then add 100 parts of nano-titanium dioxide, and continue stirring at 25°C for 9 h to allow the dopamine hydrochloride to undergo a full self-polymerization reaction on the surface of nano-titanium dioxide, forming a uniform and dense polydopamine interface layer, thus obtaining surface-coated nano-titanium dioxide. Then, 12 parts of γ-glycidyl etheroxypropyltrimethoxysilane were added to a mixed solution of 200 parts ethanol and 60 parts deionized water. The pH of the system was adjusted to 5.0, and pre-hydrolyzed for 30 min. Then, the surface-coated nano-titanium dioxide was added, and the mixture was stirred at 70 °C for 4 h to allow the γ-glycidyl etheroxypropyltrimethoxysilane to undergo sufficient hydrolysis and condensation, forming stable silicon-oxygen bonds with the polydopamine interface layer and the surface of the nano-titanium dioxide, thus constructing a stable organic-inorganic synergistic interface layer. After the reaction, the obtained product was washed three times alternately with anhydrous ethanol and deionized water, dried at 85 °C for 9 h, pulverized, and passed through a 400-mesh sieve to obtain the synergistically modified nano-titanium dioxide.
[0042] S2. Preparation of composite mixture
[0043] 100 parts of polyester resin were weighed and dried at 130℃ for 5 hours to fully remove moisture from the polyester resin. Then, the dried polyester resin was added to a high-speed mixer along with 16 parts of synergistically modified nano-titanium dioxide, 0.8 parts of ferulic acid, 2.2 parts of inorganic antibacterial agent, 4 parts of compatibilizer, and 0.8 parts of processing aid. The mixture was stirred at 650 r / min for 15 minutes to ensure thorough and uniform dispersion of the functional components, resulting in a composite mixture. The inorganic antibacterial agent was composed of nano-zinc oxide and silver ion glass powder in a mass ratio of 3.5:1. The compatibilizer was composed of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-methacrylate glycidyl acrylate copolymer in a mass ratio of 2:1. The processing aid was composed of antioxidant 1010, antioxidant 168, and ethylene bis-stearamide in a mass ratio of 1.5:1.5:1.
[0044] S3, melt blending and granulation
[0045] The composite mixture obtained in step S2 was added to a twin-screw extruder for melt blending. The temperatures of each zone were set sequentially to 243℃, 248℃, 253℃, 258℃, 263℃, and 263℃, and the screw speed was set to 200 r / min. Melt blending was carried out for 5 minutes to ensure that all components were fully melted, plasticized, and uniformly dispersed. Subsequently, the mixture was extruded through a die and cooled with circulating cooling water at 25℃. After traction and pelletizing, it was dried at 90℃ for 3 hours to obtain an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging.
[0046] Example 3: The purpose of this example is to verify that when the components are in a higher ratio within the scope of the claims and under stronger reaction conditions, the nano-titanium dioxide modified by polydopamine interfacial self-polymerization coating and γ-glycidyl etheroxypropyltrimethoxysilane synergistic grafting can still maintain good interfacial stability and form a synergistic effect with ferulic acid, inorganic antibacterial agents, compatibilizers and processing aids, thereby further improving the antibacterial properties, weather resistance and comprehensive service performance of polyester composite plastic materials. This verifies that the present invention still has good process adaptability and performance stability under the condition of higher filler addition.
[0047] S1, Preparation of Synergistically Modified Nano-Titanium Dioxide
[0048] Weigh out 100 parts of nano-titanium dioxide, 10 parts of dopamine hydrochloride, 20 parts of γ-glycidyl etheroxypropyltrimethoxysilane, 300 parts of ethanol, and 100 parts of deionized water for later use. First, add 10 parts of dopamine hydrochloride to 100 parts of deionized water, adjust the pH of the system to 8.8 with the help of Tris buffer, and stir at 30°C for 30 min to fully dissolve the dopamine hydrochloride. Then add 100 parts of nano-titanium dioxide, and continue stirring at 30°C for 12 h to allow the dopamine hydrochloride to undergo a self-polymerization reaction on the surface of nano-titanium dioxide, forming a thick and stable polydopamine coating layer, thus obtaining surface-coated nano-titanium dioxide. Then, 20 parts of γ-glycidyl etheroxypropyltrimethoxysilane were added to a mixed solution of 300 parts ethanol and 100 parts deionized water. The pH of the system was adjusted to 5.5, and pre-hydrolyzed for 40 min. The surface-coated nano-titanium dioxide was then added, and the mixture was stirred at 75 °C for 5 h to allow the γ-glycidyl etheroxypropyltrimethoxysilane to undergo sufficient hydrolysis and condensation, forming stable silicon-oxygen bonds with the polydopamine interface layer and the surface of the nano-titanium dioxide, further constructing a stable organic-inorganic synergistic interface layer. After the reaction, the obtained product was washed three times alternately with anhydrous ethanol and deionized water, dried at 90 °C for 10 h, pulverized, and passed through a 500-mesh sieve to obtain the synergistically modified nano-titanium dioxide.
[0049] S2. Preparation of composite mixture
[0050] 100 parts of polyester resin were weighed and dried at 140℃ for 6 hours to fully remove moisture from the polyester resin. Then, the dried polyester resin was added to a high-speed mixer along with 25 parts of synergistically modified nano-titanium dioxide, 1.5 parts of ferulic acid, 4 parts of inorganic antibacterial agent, 6 parts of compatibilizer, and 1.5 parts of processing aid. The mixture was stirred at 800 r / min for 20 minutes to ensure thorough and uniform mixing of all functional components, resulting in a composite mixture. The inorganic antibacterial agent was composed of nano-zinc oxide and silver ion glass powder at a mass ratio of 5:1. The compatibilizer was composed of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-glycidyl methacrylate copolymer at a mass ratio of 3:1. The processing aid was composed of antioxidant 1010, antioxidant 168, and ethylene bis-stearamide at a mass ratio of 2:2:1.
[0051] S3, melt blending and granulation
[0052] The composite mixture obtained in step S2 was added to a twin-screw extruder for melt blending. The temperatures of each zone were set sequentially to 245℃, 250℃, 255℃, 260℃, 265℃, and 265℃, and the screw speed was set to 250 r / min. Melt blending was carried out for 8 minutes to ensure that the components were fully plasticized and uniformly dispersed. Subsequently, the mixture was extruded through a die and cooled with circulating cooling water at 30℃. After traction and pelletizing, it was dried at 100℃ for 4 hours to obtain an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging.
[0053] Comparative Example 1: The purpose of this comparative example is to verify the effects of polydopamine interfacial self-polymerization coating and γ-glycidyl etheroxypropyltrimethoxysilane synergistic modification of nano-titanium dioxide on the antibacterial properties, weather resistance and mechanical properties of polyester composite plastic materials.
[0054] S1. Preparation of ordinary nano-titanium dioxide
[0055] Weigh 100 parts of nano titanium dioxide, without polydopamine coating or γ-glycidyl oxypropyltrimethoxysilane grafting modification, and dry directly for later use.
[0056] S2. Preparation of composite mixture
[0057] 100 parts of polyester resin were weighed and dried at 130℃ for 5 hours. Then, the dried polyester resin was added to a high-speed mixer along with 16 parts of ordinary nano-titanium dioxide, 0.8 parts of ferulic acid, 2.2 parts of inorganic antibacterial agent, 4 parts of compatibilizer, and 0.8 parts of processing aid. The mixture was stirred at 650 r / min for 15 minutes to obtain a composite mixture. The inorganic antibacterial agent was composed of nano-zinc oxide and silver ion glass powder in a mass ratio of 3.5:1. The compatibilizer was composed of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-glycidyl methacrylate copolymer in a mass ratio of 2:1. The processing aid was composed of antioxidant 1010, antioxidant 168, and ethylene bis-stearamide in a mass ratio of 1.5:1.5:1.
[0058] S3, melt blending and granulation
[0059] The composite mixture obtained in step S2 was added to a twin-screw extruder for melt blending. The temperatures of each zone were set sequentially to 243℃, 248℃, 253℃, 258℃, 263℃ and 263℃, the screw speed was 200 r / min, and the melt blending time was 5 min. Then, it was extruded through a die, cooled with 25℃ circulating cooling water, and after traction and pelletizing, dried at 90℃ for 3 h to obtain a polyester composite plastic material.
[0060] Comparative Example 2: The purpose of this comparative example is to verify the effect of ferulic acid as an organic small molecule functional regulator on the antibacterial properties, weather resistance and long-term service stability of polyester composite plastic materials.
[0061] S1, Preparation of Synergistically Modified Nano-Titanium Dioxide
[0062] Synergistically modified nano-titanium dioxide was prepared according to the method in S1 of Example 2;
[0063] S2. Preparation of composite mixture
[0064] 100 parts of polyester resin were weighed and dried at 130℃ for 5 hours. Then, the dried polyester resin, 16 parts of synergistically modified nano-titanium dioxide, ferulic acid-free, 2.2 parts of inorganic antibacterial agent, 4 parts of compatibilizer, and 0.8 parts of processing aid were added to a high-speed mixer and mixed at 650 r / min for 15 minutes to obtain a composite mixture. The inorganic antibacterial agent was composed of nano-zinc oxide and silver ion glass powder at a mass ratio of 3.5:1. The compatibilizer was composed of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-glycidyl methacrylate copolymer at a mass ratio of 2:1. The processing aid was composed of antioxidant 1010, antioxidant 168, and ethylene bis-stearamide at a mass ratio of 1.5:1.5:1.
[0065] S3, melt blending and granulation
[0066] The composite mixture obtained in step S2 was added to a twin-screw extruder for melt blending. The temperatures of each zone were set sequentially to 243℃, 248℃, 253℃, 258℃, 263℃ and 263℃, the screw speed was 200 r / min, and the melt blending time was 5 min. Then, it was extruded through a die, cooled with 25℃ circulating cooling water, and after traction and pelletizing, dried at 90℃ for 3 h to obtain a polyester composite plastic material.
[0067] Performance testing:
[0068] 1. Antibacterial performance test
[0069] Polyester composite plastic materials prepared in Examples 1-3 and Comparative Examples 1-2 were injection molded into samples with dimensions of 50mm × 50mm × 2mm. After cleaning with 75% ethanol, the samples were sterilized by ultraviolet light. *Escherichia coli (ATCC 8739)* and *Staphylococcus aureus (ATCC 6538)* were used as test strains, and the tests were conducted according to GB / T31402—2015 "Test Method for Antimicrobial Properties of Plastic Surfaces". A certain concentration of bacterial suspension was uniformly added to the sample surface and incubated for 24 hours in a constant temperature incubator at (37±1)℃ and a relative humidity of not less than 90%. After incubation, the number of surviving colonies on the sample surface was determined using the plate count method, and the antimicrobial rate was calculated. Each group of samples was tested in triplicate, and the average value was taken as the final test result.
[0070] 2. UV aging resistance test
[0071] Polyester composite plastic materials prepared in Examples 1-3 and Comparative Examples 1-2 were used to prepare standard test strips using an injection molding machine. Artificial accelerated aging tests were conducted according to GB / T16422.2—2022 "Laboratory Light Source Exposure Test Methods for Plastics Part 2: Xenon Arc Lamp". The test conditions were set as follows: irradiance 0.51 W / m² (340 nm), blackboard temperature (65±3)℃, relative humidity (50±5)%, with one cycle consisting of 102 min of light exposure and 18 min of water spray, for a total aging time of 500 h. After aging, the color change, tensile strength retention rate, and surface condition of the samples were measured, and the UV aging resistance of the materials was comprehensively evaluated. Each group of samples was tested in parallel three times, and the average value was taken as the final test result.
[0072] 3. Mechanical property testing
[0073] Polyester composite plastic materials prepared in Examples 1-3 and Comparative Examples 1-2 were used to prepare standard tensile test specimens and notched impact test specimens using an injection molding machine. Tensile properties were tested according to GB / T1040.2—2022 "Determination of Tensile Properties of Plastics", measuring tensile strength; notched impact properties were tested according to GB / T1843—2022 "Determination of Cantilever Beam Impact Strength of Plastics", measuring notched impact strength. Each group of specimens was tested five times, and the average value was taken as the final test result to evaluate the comprehensive mechanical properties of the material.
[0074] 4. Weathering stability test
[0075] Polyester composite plastic materials prepared in Examples 1-3 and Comparative Examples 1-2 were used to prepare standard samples according to the processing technology in Example 2. These samples were then placed in a constant temperature and humidity aging chamber for damp heat aging tests. The test conditions were: temperature (85±2)℃, relative humidity (85±5)%, and continuous aging for 500 hours. After aging, the samples were restored to room temperature, and their tensile strength retention rate, yellowing index (ΔYI), and gloss retention rate were measured. The long-term service stability of the materials was comprehensively evaluated. Each group of samples was tested in parallel three times, and the average value was taken as the final test result.
[0076] Table 1 Performance Test Results
[0077] Example 1 97.3 91.6 11.2 3.7 Example 2 99.2 96.8 12.5 2.2 Example 3 98.6 94.8 12.0 2.8 Comparative Example 1 91.2 78.5 9.1 7.3 Comparative Example 2 95.1 84.3 10.0 5.5
[0078] According to Table 1, the antibacterial and highly weather-resistant polyester composite plastic materials for cosmetic packaging prepared in Examples 1-3 are significantly superior to Comparative Example 1 and Comparative Example 2 in terms of antibacterial properties, UV aging resistance, mechanical properties, and weather stability. Among them, the properties of Example 2 reach the best level, indicating that the polydopamine interface self-polymerization coating and the synergistic modification of nano-titanium dioxide, ferulic acid, and other functional components by γ-glycidyl etheroxypropyltrimethoxysilane form a good synergistic effect, which can effectively improve the comprehensive performance of polyester composite plastic materials.
[0079] In terms of antibacterial performance, the antibacterial rates of Examples 1-3 reached 97.3%, 99.2%, and 98.6%, respectively, all significantly higher than 91.2% of Comparative Example 1 and 95.1% of Comparative Example 2. Analysis suggests that the organic-inorganic synergistic interface constructed from polydopamine and γ-glycidyl etheroxypropyltrimethoxysilane can improve the dispersion uniformity of nano-titanium dioxide in the polyester matrix, allowing nano-zinc oxide and silver ion glass powder to be more evenly distributed within the material, thus improving the utilization efficiency of antibacterial active sites. Simultaneously, ferulic acid has certain antibacterial and antioxidant effects, forming a synergistic effect with the inorganic antibacterial system, thereby further improving the antibacterial performance of the material. Example 2 achieved the highest antibacterial rate due to its more reasonable component ratios and the most complete synergistic effect.
[0080] In terms of UV aging resistance, the tensile strength retention rates of Examples 1-3 after aging reached 91.6%, 96.8%, and 94.8%, respectively, all significantly higher than the two comparative examples. However, the yellowing indices were only 3.7, 2.2, and 2.8, respectively, significantly lower than Comparative Examples 1 and 2. This indicates that the polydopamine interface layer effectively improves the interfacial bonding between nano-titanium dioxide and polyester resin. γ-glycidyl etheroxypropyltrimethoxysilane further enhances interfacial stability, effectively reducing the aggregation of nano-titanium dioxide and allowing it to fully exert its UV shielding effect. Simultaneously, ferulic acid can capture free radicals generated during photo-oxidative aging, inhibiting the oxidative degradation of polyester molecular chains and reducing the photocatalytic activity of nano-titanium dioxide, thus significantly improving the material's weather resistance and anti-yellowing ability. The proportions of each functional component in Example 2 were appropriate, resulting in optimal aging resistance.
[0081] From a mechanical property perspective, the notched impact strengths of Examples 1-3 reached 11.2 kJ / m², 12.5 kJ / m², and 12.0 kJ / m², respectively, all higher than Comparative Example 1 and Comparative Example 2. Analysis suggests that the nano-titanium dioxide, after being coated with polydopamine and grafted with γ-glycidyl etheroxypropyltrimethoxysilane, formed a more stable interfacial bond with the polyester resin, effectively promoting load transfer, reducing interfacial defects and stress concentration, thereby improving the impact resistance of the composite material. Although Example 3 further increased the amount of synergistically modified nano-titanium dioxide and other functional components, the higher inorganic filler content increased the melt viscosity and enhanced interparticle interactions, resulting in slightly lower overall mechanical properties than Example 2, but still significantly better than Example 1 and the two comparative examples.
[0082] In summary, the results show that this invention, through interfacial self-polymerization coating of polydopamine and synergistic grafting modification of nano-titanium dioxide with γ-glycidyl etheroxypropyltrimethoxysilane, combined with ferulic acid, inorganic antibacterial agents, compatibilizers, and processing aids to form a synergistic composite system, can significantly improve the dispersion state and interfacial compatibility of nano-titanium dioxide in polyester resin, enhance the utilization efficiency of antibacterial active components, and effectively inhibit the aging and degradation of polyester materials under long-term light and humid heat environments. This results in a polyester composite plastic material with excellent antibacterial properties, weather resistance, mechanical properties, and long-term service stability. Among these, Example 2 exhibits the best overall performance due to the most suitable component ratios and process conditions, fully leveraging the synergistic effect between components.
Claims
1. An antibacterial high-weather-resistant cosmetic packaging polyester composite plastic material, characterized by, The raw materials include the following parts by weight: 100 parts polyester resin; 8-25 parts synergistically modified nano-titanium dioxide; 0.1-1.5 parts ferulic acid; 0.5-4 parts inorganic antibacterial agent; 2-6 parts compatibilizer; and 0.2-1.5 parts processing aid. The synergistically modified nano-titanium dioxide is obtained by self-polymerizing nano-titanium dioxide at a polydopamine interface, followed by surface grafting modification with γ-glycidoxypropyltrimethoxysilane. The polydopamine forms an interface layer rich in catechol and amino groups on the surface of the nano-titanium dioxide. γ-glycidoxypropyltrimethoxysilane forms stable siloxane bonds with the hydroxyl groups on the surface of the nano-titanium dioxide and the polydopamine interface layer through a hydrolysis-condensation reaction, thus constructing an organic-inorganic synergistic interface layer on the surface of the nano-titanium dioxide.
2. The antibacterial, high weather resistant, cosmetic packaging polyester composite plastic material according to claim 1, characterized in that, The synergistically modified nano-titanium dioxide comprises the following raw materials in parts by weight: 100 parts nano-titanium dioxide; 2-10 parts dopamine hydrochloride; 5-20 parts γ-glycidyl etheroxypropyltrimethoxysilane; 100-300 parts ethanol; and 20-100 parts deionized water.
3. The antibacterial, high weather resistant, cosmetic packaging polyester composite plastic material according to claim 1 or 2, characterized in that, The preparation method of the synergistically modified nano-titanium dioxide includes the following steps: (1) Dopamine hydrochloride was mixed with nano-titanium dioxide and surface coated to obtain surface-coated nano-titanium dioxide; (2) Add γ-glycidyl etheroxypropyltrimethoxysilane to the surface-coated nano-titanium dioxide and perform coupling grafting modification to obtain the synergistically modified nano-titanium dioxide reaction product. (3) The reaction products of synergistically modified nano-titanium dioxide are separated, washed, dried and pulverized to obtain synergistically modified nano-titanium dioxide.
4. The antibacterial, high weather resistant, cosmetic packaging polyester composite plastic material according to claim 3, characterized in that, The reaction conditions for step (1) are as follows: dopamine hydrochloride is dissolved in deionized water, the pH of the system is adjusted to 8.5-8.8 using Tris buffer, nano-titanium dioxide is added, and the reaction is stirred at 20-30°C for 6-12 hours.
5. The antibacterial, high weather resistant, cosmetic packaging polyester composite plastic material according to claim 3, characterized in that, The reaction conditions for step (2) are as follows: γ-glycidyl etheroxypropyltrimethoxysilane is added to a mixed solution of ethanol and deionized water for pre-hydrolysis for 20-40 min, the volume ratio of ethanol to deionized water is 4:1 to 6:1, the pH of the system is adjusted to 4.5-5.5, and then the surface-coated nano-titanium dioxide obtained in step (1) is added. The reaction is stirred at 65-75℃ for 3-5 h.
6. The antibacterial, high weather resistant, cosmetic packaging polyester composite plastic material according to claim 3, characterized in that, The reaction conditions for step (3) are as follows: wash with anhydrous ethanol and deionized water alternately 2 to 3 times, dry at 80 to 90°C for 8 to 10 hours, pulverize and pass through a 300 to 500 mesh sieve to obtain synergistically modified nano titanium dioxide.
7. The antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging according to claim 1, characterized in that, The inorganic antibacterial agent is a mixture of nano zinc oxide and silver ion glass powder in a mass ratio of (2-5):1; the compatibilizer is a mixture of epoxy-functionalized styrene-glycidyl acrylate copolymer and ethylene-glycidyl methacrylate copolymer in a mass ratio of (1-3):1; the processing aid is a mixture of antioxidant 1010, antioxidant 168 and ethylene bis-stearamide in a mass ratio of (1-2):(1-2):
1.
8. A method for preparing an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging, characterized in that, The preparation method includes the following steps: S1, polyester resin, synergistically modified nano-titanium dioxide, ferulic acid, inorganic antibacterial agent, compatibilizer and processing aid are mixed evenly to obtain a mixture; S2, the mixture is melt-blended to obtain a melt blend; S3. The resulting melt blend is extruded, cooled, and pelletized to obtain an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging.
9. The method for preparing an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging according to claim 8, characterized in that, The reaction conditions for step S1 are as follows: the polyester resin is dried at 120-140°C for 4-6 hours, and then added to a high-speed mixer with synergistically modified nano-titanium dioxide, ferulic acid, inorganic antibacterial agent, compatibilizer and processing aid, and mixed at 500-800 r / min for 10-20 min.
10. The method for preparing an antibacterial and highly weather-resistant polyester composite plastic material for cosmetic packaging according to claim 8, characterized in that, The reaction conditions for step S2 are as follows: melt blending is performed using a twin-screw extruder, with the extruder temperatures in each zone being 240–245°C, 245–250°C, 250–255°C, 255–260°C, 260–265°C, and 260–265°C respectively; the screw speed is 150–250 r / min; and the melt blending time is 3–8 min. The reaction conditions for step S3 are as follows: the melt blend obtained in step S2 is extruded through a die and cooled with circulating cooling water at 20–30°C; then drawn, pelletized, and dried at 80–100°C for 2–4 h to obtain an antibacterial, highly weather-resistant polyester composite plastic material for cosmetic packaging.