Modified polyester polyol, antibacterial polyurethane microporous elastomer and preparation method of elastomer
By introducing an Ag@SiO2 core-shell structure into polyester polyol and chemically bonding it, the problems of antibacterial instability and compatibility of polyurethane microporous elastomers in humid and hot environments were solved, achieving long-lasting antibacterial effect and excellent mechanical properties, thus expanding its application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG INOV POLYURETHANE
- Filing Date
- 2026-04-07
- Publication Date
- 2026-05-12
AI Technical Summary
Existing polyurethane microporous elastomers have unstable antibacterial effects in humid and hot environments, their antibacterial components are prone to precipitation, and they have poor compatibility with the substrate, which affects their mechanical properties and service life.
By preparing Ag@SiO2 core-shell structures and modifying them with silane coupling agents, these structures are chemically bonded to the molecular chains of modified polyester polyols. These structures are then compounded with conventional polyester polyols to form an A/B component system, thereby constructing a long-lasting antibacterial polyurethane microporous elastomer.
It achieves long-term stability of antibacterial properties and improves physical and mechanical properties, avoiding the release of antibacterial components, and is suitable for fields with high hygiene requirements such as medical and food contact.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polyurethane elastomer technology, specifically relating to modified polyester polyols, antibacterial polyurethane microporous elastomers, and methods for preparing elastomers. Background Technology
[0002] Polyurethane microporous elastomers are polymeric materials with excellent physical and mechanical properties. Their products, characterized by superior elasticity, lightweight portability, wear and oil resistance, and chemical corrosion resistance, are widely used in various fields such as shoe soles, seals, and cushioning materials, enjoying great popularity among consumers and occupying an important position in daily life and production. However, these elastomers exhibit significant performance defects in practical applications, especially in environments characterized by prolonged exposure to humidity and heat.
[0003] Taking polyurethane microporous elastomer shoe soles, which are the most widely used, as an example, the sweat produced during walking keeps the soles in a warm and humid environment for extended periods. This environment is highly conducive to the growth of harmful bacteria such as Escherichia coli and Staphylococcus aureus. This not only accelerates the aging and degradation of the sole material, reducing its mechanical properties and lifespan, but also produces unpleasant odors due to bacterial metabolism, directly affecting the user experience. Furthermore, the spread of bacteria can have potential adverse effects on human health. In addition, in fields with high hygiene requirements, such as medical and food contact applications, the problem of bacterial growth on the surface of polyurethane microporous elastomers limits their further application. Therefore, endowing polyurethane microporous elastomers with long-lasting and stable antibacterial properties has become a key research focus and urgent need in this field.
[0004] Currently, the mainstream technical approach in the industry to solve the antibacterial problem of polyurethane microporous elastomers is to directly add antibacterial agents during their preparation process. These agents inhibit bacterial growth and reproduction. This method is simple to operate and low in cost, and is the closest existing technical solution to the subject of this invention. Related technologies have been disclosed in several existing patents. For example, patent CN106084176A discloses an environmentally friendly antibacterial thermoplastic polyurethane elastomer and its preparation method, the core of which is to achieve the antibacterial function of the elastomer by adding antibacterial agents to the polyurethane raw materials. Patent CN116003732A, targeting the antibacterial needs of polyurethane shoe soles, also uses the method of adding antibacterial agents to prepare yellowing-resistant antibacterial polyurethane shoe sole raw materials, attempting to solve the problems of bacterial growth and odor in shoe soles. Furthermore, patent CN113801465A discloses a polyurethane microporous foamed elastomer and its preparation method, which also mentions that antibacterial and other additional properties can be achieved by adding functional additives, essentially still falling under the category of additive antibacterial technology.
[0005] While the aforementioned additive antibacterial technologies can improve the antibacterial properties of polyurethane microporous elastomers to some extent, they suffer from inherent defects that are difficult to overcome in practical applications and processing, severely affecting the stability and durability of the antibacterial effect. First, the compatibility between the antibacterial agent and the polyurethane substrate (especially core raw materials such as polyester polyols and isocyanates) is poor, easily leading to uneven dispersion during processing. This results in localized defects within the elastomer, reducing the physical and mechanical properties of the product and causing significant unevenness in the antibacterial effect, with some areas failing to achieve effective antibacterial action. Second, the added antibacterial agents are mostly in a physically mixed form within the polyurethane system, failing to form a stable chemical bond with the polyurethane molecular chains. Under long-term use, friction, or humid and hot environments, they are easily leached from the elastomer. This leads to antibacterial agent loss, causing rapid attenuation of antibacterial performance and preventing long-lasting antibacterial effects. Furthermore, the leached antibacterial agents may irritate human skin or pollute the environment. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to overcome the technical problems of poor antibacterial effect, easy precipitation of antibacterial components, poor compatibility with substrate and inability to take into account mechanical properties and foaming characteristics of existing polyurethane microporous elastomers. The present invention provides an antibacterial polyurethane microporous elastomer and its preparation method. The prepared polyurethane microporous elastomer has long-lasting and stable antibacterial performance and uniform dispersion, while maintaining excellent physical and mechanical properties and microporous structure.
[0007] The first objective of this invention is to provide a modified polyester polyol.
[0008] The specific preparation method of the modified polyester polyol is as follows: (1) Preparation of Ag@SiO2: Add ethanol to silver sol and mix, then add ammonia water, mix and add tetraethyl orthosilicate, heat and dry to obtain Ag@SiO2; More specific preparation process: silver sol is added to a flask, then ethanol is added and magnetically stirred at 800~1200 rpm; then ammonia is added, and after stirring for 8~20 min, tetraethyl orthosilicate (TEOS) is added, and after stirring for 20~48 h, it is dried at 75~80℃ for 4~7 h to obtain Ag@SiO2; Further optimized preparation process: silver sol was added to a flask, then ethanol was added and magnetically stirred at 1000 rpm; then ammonia was added, and after stirring for 10 min, tetraethyl orthosilicate (TEOS) was added. After stirring for 24 h, it was dried at 80 °C for 5 h to obtain Ag@SiO2.
[0009] The mass ratio of silver sol, ethanol, and ammonia is 1:8:1. The amount of tetraethyl orthosilicate (TEOS) added is 0.02~0.04 wt% of the total amount of silver sol, anhydrous ethanol, and ammonia, preferably 0.03 wt%. The silver sol provides the core antibacterial component, silver ions, and Ag. + Broad-spectrum antibacterial activity is achieved by disrupting bacterial cell membranes and inhibiting bacterial enzyme activity. SiO2, acting as a shell, physically coats the silver nanoparticles, preventing them from direct contact with the external environment and rapid oxidation and loss, thus improving the stability of the antibacterial components. Furthermore, SiO2's good dispersibility and biocompatibility improve the compatibility between the silver nanoparticles and the subsequent polyester polyol system, reducing aggregation and ensuring uniform dispersion of the antibacterial components. The ethanol used is anhydrous ethanol. Step (1) is to prepare core-shell structured nanomaterials by sol-gel method. Silver nanoparticles in silver sol are used as the core, and a layer of SiO2 is coated on the surface of silver nanoparticles as the shell through the hydrolysis-condensation reaction of tetraethyl orthosilicate (TEOS), and finally Ag@SiO2 core-shell structure is formed. The core is the hydrolysis and condensation reaction of silicate ester, and at the same time, ammonia water is used to provide an alkaline catalytic environment.
[0010] (2) Grafting modification of Ag@SiO2: Dissolve silane coupling agent and water in anhydrous ethanol, stir the mixture, then disperse Ag@SiO2 in anhydrous ethanol, add the mixture, heat the reaction, wash and dry the reactants to obtain grafted modified Ag@SiO2. More specific preparation process: Dissolve silane coupling agent and deionized water in anhydrous ethanol and add it to the reaction vessel. Stir at 40~60℃ for 1~3h. Then disperse Ag@SiO2 in anhydrous ethanol and add it to the reaction vessel. Heat to 60~80℃ and react for 4~8h. Wash the obtained product with anhydrous ethanol several times. Then vacuum dry at 50~70℃ for 20~48h to obtain grafted modified Ag@SiO2. Further optimized preparation process: KH-550 silane coupling agent and deionized water were dissolved in anhydrous ethanol and added to a reaction vessel. The mixture was stirred at 50°C for 1 hour. Then, Ag@SiO2 was dispersed in anhydrous ethanol and added to the reaction vessel. The temperature was raised to 70°C and reacted for 6 hours. The resulting product was washed three times with anhydrous ethanol and then vacuum dried at 60°C for 24 hours to obtain grafted modified Ag@SiO2.
[0011] The mass ratio of silane coupling agent, deionized water, and anhydrous ethanol is 1:1:10. The amount of Ag@SiO2 added is 40-60 wt% of the total amount of silane coupling agent, water, and anhydrous ethanol, preferably 50 wt%. KH-550 is preferably used as the silane coupling agent, as its amino groups can chemically react with isocyanate groups, and its siloxane groups can undergo hydrolysis and condensation reactions with the SiO2 shell. This allows the Ag@SiO2 core-shell structure to be chemically grafted into the polyester polyol molecular chain, solving the problems of poor compatibility and easy aggregation between silver nanoparticles and polyester polyols. Furthermore, the chemical bonding method prevents the antibacterial components from precipitating out during use, achieving long-lasting antibacterial effects.
[0012] (3) Preparation of modified polyester polyol: The conventional polyester polyol is heated and dehydrated, then cooled and mixed with grafted modified Ag@SiO2 and isocyanate. The mixture is heated and reacted. The isocyanate group (-NCO) is found to be qualified, and the modified polyester polyol is obtained.
[0013] More specific preparation process: Conventional polyester polyol is added to a reaction vessel, the temperature is raised to 100~120℃, and dehydrated under vacuum for 1.5~3h. Then the temperature is lowered to 40~50℃, and grafted modified Ag@SiO2 and isocyanate are added to the reaction vessel. The temperature is raised to 70~80℃. When -NCO=0 is measured, it is released as qualified, and the modified polyester polyol is obtained.
[0014] The molar ratio of conventional polyester polyol to isocyanate is 1:0.6~1, preferably 1:0.8, and the amount of grafted modified Ag@SiO2 is 0.2~0.8 wt% of the polyester polyol. The dehydration step removes water from the conventional polyester polyol, avoiding side reactions between water and isocyanate that could affect the molecular weight and properties of the modified polyester polyol. Controlling the molar ratio of conventional polyester polyol to isocyanate ensures that the grafted modified Ag@SiO2 is fully grafted onto the polyester polyol molecular chain, while avoiding excessive isocyanate leading to residual free isocyanate in the system, which could affect the elastomer properties. The amount of Ag@SiO2 is controlled at 0.2~0.8 wt%, ensuring that the antibacterial component content achieves excellent antibacterial effect without affecting the mechanical and processing properties of the polyester polyol due to excessive dosage.
[0015] Step (3) is an addition polymerization reaction with isocyanate bridging. Using isocyanate (-NCO) as the bridging group, and taking advantage of its high reactivity with hydroxyl (-OH) and amino (-NH2), the grafted modified Ag@SiO2 and conventional polyester polyol are stably bonded to the polyester polyol molecular chain through urethane bonds (-NH-CO-O-) and urea bonds (-NH-CO-NH-), and finally modified polyester polyol with a number average molecular weight of 4000~6000 is obtained. The core is the addition reaction of isocyanate, and the reaction is ensured to be complete by monitoring the -NCO content to 0.
[0016] A second objective of this invention is to provide an antibacterial polyurethane microporous elastomer.
[0017] The antibacterial polyurethane microporous elastomer is mainly prepared by mixing and curing component A and component B in a mass ratio of 100:40~75. Component A mainly includes conventional polyester polyol and modified polyester polyol, and component B mainly includes conventional polyester polyol, polyether polyol and isocyanate.
[0018] The modified polyester polyol has a number average molecular weight of 4000~6000 g / mol. Its preparation process involves introducing Ag@SiO2 core-shell structures modified by silane coupling agent into the conventional polyester polyol molecular chain through chemical bonding.
[0019] Furthermore, taking the total amount of conventional polyester polyol and modified polyester polyol in component A as 100 parts, component A includes 60-80 parts of conventional polyester polyol, 25-40 parts of modified polyester polyol, 3-7 parts of chain extender, 0.2-0.5 parts of crosslinking agent, 0.4-1 parts of foam leveler, 1.0-2.0 parts of catalyst, and 0.5-0.7 parts of foaming agent; component B includes 10-25 parts of conventional polyester polyol, 5-10 parts of polyether polyol, and 65-85 parts of isocyanate.
[0020] Furthermore, conventional polyester polyols are prepared by esterification and condensation reactions of small-molecule polyols and diacids, with a number-average molecular weight of 1500-2500 g / mol and a functionality of 2-2.06. Preferably, they are PE-2515, PE-2520, PE-2520-03, PE-2415, PE-2420, and PE-2325 produced by Shandong Yinuowei Polyurethane Co., Ltd. The polyester polyols are composed of small-molecule polyols (ethylene glycol, diethylene glycol, 1,4-dimethylaminopropionic acid, ethylene glycol, dimethylaminopropionic acid ... It is prepared by esterification condensation reaction of butanediol and diacids (adipic acid, glutaric acid, succinic acid, and terephthalic acid), with a number-average molecular weight of 1500-2500 g / mol and a functionality of 2-2.06. This conventional polyester polyol serves as the base raw material for polyurethane elastomers. Its suitable molecular weight and functionality ensure the formation of a stable molecular chain structure, endowing the elastomer with excellent mechanical strength, elastic recovery, and chemical resistance. Simultaneously, it provides a foundation for synergistic reactions with modified polyester polyols, isocyanates, and other raw materials, ensuring uniform reaction and moderate crosslinking density. This avoids insufficient elastomer strength due to excessively low molecular weight, or processing difficulties and decreased elasticity due to excessively high molecular weight. The combined use of conventional and modified polyester polyols can balance the mechanical strength and antibacterial properties of the elastomer: the conventional polyester polyol provides basic mechanical support, while the modified polyester polyol provides long-lasting antibacterial function. The synergy between the two allows the elastomer to simultaneously meet the requirements for strength and antibacterial properties.
[0021] Furthermore, the polyether polyol has a number-average molecular weight of 4000 g / mol and a functionality of 2. When compounded with conventional polyester polyols, it can improve the foaming flowability of the system, reduce the viscosity of the system, and facilitate the uniform mixing of components A and B. At the same time, the introduction of polyether polyol can improve the hydrolysis resistance of the elastomer and make up for the deficiency of insufficient hydrolysis resistance of polyester polyol. Preferably, it is one of ED-28 produced by Shandong Lanxing Dongda Chemical Co., Ltd. or Donol820 produced by Shanghai Dongda Chemical Co., Ltd.
[0022] Furthermore, the isocyanate is one or a mixture of two of the following: 4,4'-diphenylmethane diisocyanate (preferably MDI-100 from Wanhua Chemical Group Co., Ltd.) and carbodiimide-modified MDI (preferably CDMDI-100L from Wanhua Chemical Group Co., Ltd. or CD-C from Covestro AG, Germany). Choosing the above isocyanates is advantageous because, on the one hand, their reactivity with polyester polyols and polyether polyols is compatible, allowing for precise control of the reaction rate and preventing uneven local crosslinking caused by excessively rapid reactions; on the other hand, carbodiimide-modified MDI can effectively improve the yellowing resistance of polyurethane elastomers and extend the service life of products. Simultaneously, MDI-type isocyanates exhibit excellent compatibility with conventional polyester polyols, which can enhance the overall mechanical stability and aging resistance of the elastomer.
[0023] Furthermore, the chain extender can be one or more of ethylene glycol, diethylene glycol, or 1,4-butanediol, which can extend the molecular chain by reacting with isocyanate, thereby improving the elastic recovery and tensile strength of the elastomer. The combination of different chain extenders can precisely control the molecular chain length to meet the performance requirements of different application scenarios.
[0024] Furthermore, the crosslinking agent is selected from diethanolamine, triethanolamine, or glycerol, which can synergistically undergo a crosslinking reaction with polyols to form a three-dimensional network structure, thereby enhancing the hardness, wear resistance, and dimensional stability of the elastomer. This avoids deformation of the elastomer due to excessively low crosslinking or decreased elasticity due to excessively high crosslinking.
[0025] Furthermore, the foam stabilizer is selected from polysiloxane-olefin oxide block copolymers, which can reduce the surface tension of the polyurethane system, so that the bubbles generated during the foaming process are evenly dispersed, avoiding bubble agglomeration and merging, ensuring that the elastomer forms a uniform microporous structure, and improving the cushioning performance and air permeability of the elastomer; preferably, it is B8295 produced by Evonik Specialty Chemicals (Shanghai) Co., Ltd. or S4214 produced by Shanghai Maihao Chemical Technology Co., Ltd.
[0026] Furthermore, an amine catalyst is selected as the catalyst, which can precisely catalyze the reaction between polyol and isocyanate, control the reaction rate, and avoid uneven local cross-linking due to excessively fast reaction or incomplete foaming due to excessively slow reaction, thus affecting the formation of microporous structure. DXD-01C produced by Shandong Yinuowei Polyurethane Co., Ltd. is preferred.
[0027] Furthermore, the foaming agent is selected from at least one of water, methane, and pentane. Water reacts with isocyanate to generate carbon dioxide gas, while methane and pentane, as physical foaming agents, volatilize upon heating. The two work together to generate a microporous structure. The amount of foaming agent can be adjusted according to the microporous structure requirements to ensure the lightweight properties and cushioning performance of the elastomer.
[0028] A third objective of this invention is to provide a method for preparing an antibacterial polyurethane microporous elastomer.
[0029] The method for preparing the antibacterial polyurethane microporous elastomer includes the following steps: 1) Preparation of component A: Mix conventional polyester polyol, modified polyester polyol, chain extender, crosslinking agent, foam leveler, foaming agent and catalyst, and stir at atmospheric pressure and 60~70℃ for 2~3 hours to obtain component A.
[0030] 2) Preparation of component B: Mix conventional polyester polyol and polyether polyol, control the material temperature at 40~50℃, add isocyanate, and react at 70~80℃ for 2~3h to obtain component B; the -NCO content of component B is 20.0~27.5wt.%.
[0031] Controlling the -NCO content of component B ensures that the isocyanate groups react fully with the hydroxyl groups in component A when components A and B are mixed, forming a uniform polyurethane elastomer network. This avoids insufficient crosslinking and elastomer strength due to too low a -NCO content, or residual free isocyanate in the system due to too high a -NCO content, which affects the elastomer's performance and safety.
[0032] 3) Preparation of antibacterial polyurethane microporous elastomer: Mix component A and component B at a mass ratio of 100:40~75, inject into a mold at a temperature of 30~50℃, and cure for 10~20 minutes to obtain antibacterial polyurethane microporous elastomer.
[0033] Controlling the mass ratio of components A and B allows for precise regulation of the crosslinking density and microporous structure of the elastomer: an excessive proportion of component A leads to an excess of hydroxyl groups in the system, insufficient crosslinking, and a decrease in elastomer strength; an excessive proportion of component B leads to an excess of isocyanate, over-crosslinking, and a decrease in elastomer toughness, making it brittle. Maintaining the mold temperature at 30-50℃ and the curing time at 10-20 minutes ensures a complete reaction and stable formation of the microporous structure. This avoids slow reaction and incomplete curing due to excessively low temperatures, or rapid expansion and rupture of bubbles due to excessively high temperatures, causing the microporous structure to collapse. Furthermore, a suitable curing time improves production efficiency and ensures stable elastomer performance.
[0034] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention chemically bonds the Ag@SiO2 core-shell structure modified by silane coupling agent into the modified polyester polyol molecular chain, and then combines it with conventional polyester polyol to form component A. Combined with component B containing polyether polyol, a precise A / B two-component system is constructed. This fundamentally solves the problems of poor compatibility and easy precipitation of traditional additive antibacterial agents with polyurethane substrates, and achieves long-term stable existence of antibacterial components. It endows elastomers with long-lasting broad-spectrum antibacterial properties, which can effectively inhibit bacterial growth, avoid odor generation, extend the service life of elastomer products, and expand their application in medical, food contact and other fields with high hygiene requirements.
[0035] (2) This invention achieves synergistic optimization of antibacterial properties, microporous structure, and physical and mechanical properties by optimizing the proportions of various raw materials and preparation process parameters, such as the compounding ratio of conventional polyester polyols and modified polyester polyols, the type and amount of isocyanate, the amount of Ag@SiO2 grafting, and the amount of foaming agent and catalyst. The resulting antibacterial polyurethane microporous elastomer not only maintains the excellent physical and mechanical properties of polyurethane microporous elastomers, such as excellent elasticity, light weight, wear resistance, and oil resistance, but also has a uniform microporous structure and excellent buffering performance. At the same time, the antibacterial effect is stable and long-lasting, with no risk of antibacterial component leaching, and it is applicable to a wide range of scenarios.
[0036] (3) The preparation method of the present invention is simple and convenient to operate, with mild reaction conditions, no need for complex equipment, and can realize large-scale industrial production. Moreover, the raw material ratio is flexible and the formula can be adjusted according to the performance requirements of different application scenarios, which has good practicality and promotion value. Detailed Implementation
[0037] The present invention will be further described below with reference to specific embodiments.
[0038] All quantities mentioned are based on the same mass.
[0039] PE-2520: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2, number average molecular weight 2000g / mol; PE-2515: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2, number average molecular weight 1500g / mol; PE-2415: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2, number average molecular weight 1500g / mol; PE-2420: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2, number average molecular weight 4000g / mol; PE-2520-03: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2.03, number average molecular weight 2000g / mol; PE-2325: Shandong Yinuowei Polyurethane Co., Ltd., functionality 2.06, number average molecular weight 2000g / mol; ED-28: Produced by Shandong Lanxing Dongda Chemical Co., Ltd., with a molecular weight of 4000 g / mol and a functionality of 2; Donol820: Produced by Shanghai Dongda Chemical Co., Ltd., with a molecular weight of 4000 g / mol and a functionality of 2; MDI-100: Manufactured by Wanhua Chemical Group Co., Ltd. CDMDI-100L: Manufactured by Wanhua Chemical Group Co., Ltd. S4214: Manufactured by Shanghai Maihao Chemical Technology Co., Ltd. DXD-01C: Manufactured by Shandong Yinuowei Polyurethane Co., Ltd. B 8295: Manufactured by Evonik Specialty Chemicals (Shanghai) Co., Ltd. CD-C: Covestro AG, Germany.
[0040] Example 1 The steps for preparing grafted modified Ag@SiO2 are as follows: (1) Add 1 part of silver sol to a flask, then add 8 parts of anhydrous ethanol and stir magnetically at 1000 rpm; then add 1 part of ammonia water, stir for 10 min and then add 0.03% TEOS (0.03% of the total mass of silver sol, anhydrous ethanol and ammonia water), stir for 24 h and then dry at 80℃ for 5 h to obtain Ag@SiO2.
[0041] (2) Dissolve 1 part of KH-550 silane coupling agent and 1 part of deionized water in 10 parts of anhydrous ethanol and put them into the reactor. Stir at 50°C for 1 hour. Then, disperse 6 parts of Ag@SiO2 obtained in step (1) in anhydrous ethanol (no separate measurement is required, as long as it is fully dispersed) and put it into the reactor. Heat to 70°C and react for 6 hours. Wash the obtained product with anhydrous ethanol 3 times and then vacuum dry at 60°C for 24 hours to obtain grafted modified Ag@SiO2.
[0042] Example 2 Modified polyester polyol PE-AS4000 was prepared using the grafted modified Ag@SiO2 prepared in Example 1. The steps are as follows: 13 parts of PE-2415 were added to a reactor, the temperature was raised to 100~120℃, and dehydrated under vacuum for 2 hours. Then the temperature was lowered to 40~50℃, and 0.056 parts of Ag@SiO2 and 1 part of MDI-100 were added to the reactor. The temperature was raised to 70~80℃. When -NCO=0 was measured, the product was released and the modified polyester polyol PE-AS4000 was obtained. The functionality was 2 and the number average molecular weight was 4000 g / mol.
[0043] Example 3 Modified polyester polyol PE-AS6000 was prepared using the grafted modified Ag@SiO2 prepared in Example 1. The steps are as follows: 20 parts of PE-2520 were added to a reactor, the temperature was raised to 100~120℃, and dehydrated under vacuum for 2 hours. Then the temperature was lowered to 40~50℃, and 0.084 parts of Ag@SiO2 and 1 part of MDI-100 were added to the reactor. The temperature was raised to 70~80℃. When -NCO=0 was measured, the product was released and the modified polyester polyol PE-AS6000 was obtained. The functionality was 2 and the number average molecular weight was 6000 g / mol.
[0044] Example 4 Modified polyester polyol PE-AS5500 was prepared using the grafted modified Ag@SiO2 prepared in Example 1. The steps are as follows: 18 parts of PE-2515 were added to a reactor, the temperature was raised to 100~120℃, and dehydrated under vacuum for 2 hours. Then the temperature was lowered to 40~50℃, and 0.076 parts of Ag@SiO2 and 1 part of MDI-100 were added to the reactor. The temperature was raised to 70~80℃. When -NCO=0 was measured, the product was released and the modified polyester polyol PE-AS5500 was obtained. The functionality was 2 and the number average molecular weight was 5500 g / mol.
[0045] Example 5 The method for preparing the antibacterial polyurethane microporous elastomer includes the following steps: 1) Turn the stirring speed to 35 Hz, and add 40 parts of PE-2415, 40 parts of PE-AS4000 prepared in Example 2, 20 parts of PE-2520, 3 parts of ethylene glycol, 2 parts of 1,4-butanediol, 0.5 parts of glycerol, 0.7 parts of S4214, 0.4 parts of water, 0.1 parts of methane, and 2 parts of DXD-01C into the reactor in sequence. Stir at 60°C under normal pressure for 2 hours to obtain component A. 2) Add 23 parts of PE-2420 and 7 parts of ED-28 into the reactor in sequence, start stirring, control the material temperature at 45℃, add 65 parts of MDI-100 and 15 parts of CDMDI-100L, and react at 75℃ for 2.5h to obtain component B with a -NCO content of 22.5wt.%. 3) Inject components A and B into the material tank of the low-pressure casting machine respectively, mix them at a mass ratio of 100:55, and then inject them into a mold at a temperature of 40°C. After curing for 15 minutes, the antibacterial polyurethane microporous elastomer is obtained.
[0046] Example 6 The method for preparing the antibacterial polyurethane microporous elastomer includes the following steps: 1) Turn the stirring speed to 35 Hz, and add 40 parts of PE-2515, 32 parts of PE-AS5500 prepared in Example 4, 28 parts of PE-2325, 3 parts of diethylene glycol, 0.2 parts of diethanolamine, 1 part of B8295, 0.5 parts of water, 0.2 parts of pentane and 1.2 parts of DXD-01C into the reactor in sequence. Stir at 60°C under normal pressure for 2 hours to obtain component A. 2) Add 10 parts of PE-2515 and 5 parts of Donol820 into the reactor in sequence, start stirring, control the material temperature at 40℃, add 75 parts of MDI-100 and 10 parts of CD-C, and react at 70℃ for 2 hours to obtain component B with a -NCO content of 27.5wt.%. 3) Inject components A and B into the material tank of the low-pressure casting machine respectively, mix them at a mass ratio of 100:40, and then inject them into a mold at a temperature of 40℃. After curing for 15 minutes, the antibacterial polyurethane microporous elastomer is obtained.
[0047] Example 7 The method for preparing the antibacterial polyurethane microporous elastomer includes the following steps: 1) Turn the stirring speed to 35 Hz, and add 55 parts of PE-2420, 25 parts of PE-2520-03, 25 parts of PE-AS6000 prepared in Example 3, 6 parts of ethylene glycol, 1 part of diethylene glycol, 0.3 parts of triethanolamine, 0.4 parts of S4214, 0.6 parts of water, and 1 part of DXD-01C into the reactor in sequence. Stir at 60°C under normal pressure for 2 hours to obtain component A. 2) Add 25 parts of PE-2520 and 10 parts of Donol820 into the reactor in sequence, start stirring, control the material temperature at 50℃, add 50 parts of MDI-100 and 15 parts of CDMDI-100L, and react at 80℃ for 3 hours to obtain component B with a -NCO content of 20.0wt.%. 3) Inject components A and B into the material tank of the low-pressure casting machine respectively, mix them at a mass ratio of 100:75, and then inject them into a mold at a temperature of 40°C. After curing for 15 minutes, the antibacterial polyurethane microporous elastomer is obtained.
[0048] Comparative Example 1 The difference between this comparative example and Example 5 is that modified polyester polyol PE-AS4000 is not added to component A, but is replaced with an equal mass of PE-2415. The remaining steps are the same as in Example 5.
[0049] Comparative Example 2 The difference between this comparative example and Example 5 is that the amount of modified polyester polyol PE-AS4000 in component A is 10 parts and the amount of PE-2415 is 70 parts, while the remaining steps are the same as in Example 5.
[0050] Comparative Example 3 The difference between this comparative example and Example 5 is that the modified polyester polyol PE-AS4000 in component A is replaced with PE-2415, and 0.16 parts of Ag@SiO2 from step (1) of Example 1 are directly added. The rest is the same as in Example 5.
[0051] Comparative Example 4 The difference between this comparative example and Example 5 is that the modified polyester polyol PE-AS4000 in component A is replaced with PE-2415, and 0.16 parts of the grafted modified Ag@SiO2 from step (2) of Example 1 are directly added. The rest is the same as in Example 5.
[0052] The polyurethane microporous elastomers prepared in Examples 5-7 and Comparative Examples 1-4 were made into standard test specimens, and their performance was tested according to the following national / industry standards: Component A viscosity (cps / 40℃): GB / T10247-2008; Density (kg / m³) 3 GB / T6343-2009; Hardness (C): GB / T3903.4-2017; Tensile strength (MPa): GB / T528-2009; Antibacterial properties: QB / T2881-2013 (test strains: Staphylococcus aureus, Candida albicans), calculate antibacterial rate; The test results are shown in Table 1.
[0053] Table 1 Test Results
[0054] As can be seen from the above, Comparative Example 1, without the addition of modified polyester polyol, produced a shoe sole with extremely poor antibacterial effect; Comparative Example 2, with a low proportion of modified polyester polyol, produced a shoe sole with poor tensile strength and antibacterial ability. This is because the content of modified Ag@SiO2 in the prepared shoe sole is insufficient, resulting in insufficient synergistic effects of multiple mechanisms such as physical damage and interference with protein synthesis; Comparative Example 3, using unmodified Ag@SiO2 directly added to the system, produced a shoe sole with poor antibacterial effect. This is because unmodified Ag@SiO2 easily aggregates and settles at the bottom of the material; Comparative Example 4, using modified Ag@SiO2 directly added to the system, also produced a shoe sole with poor antibacterial effect. This is because although modified Ag@SiO2 easily aggregates, it can also form some hydrogen bonds within the polyurethane. In summary, the antibacterial polyurethane microporous elastomer prepared by this invention has excellent mechanical properties, high tensile strength, and significantly improved antibacterial performance compared to the unadded comparative sample, which is beneficial for its use in real life.
Claims
1. A modified polyester polyol, characterized in that, The specific preparation method of the modified polyester polyol is as follows: (1) Preparation of Ag@SiO2: Add ethanol to silver sol and mix, then add ammonia water, mix and add tetraethyl orthosilicate, heat and dry to obtain Ag@SiO2; (2) Grafting modification of Ag@SiO2: Dissolve silane coupling agent and water in anhydrous ethanol, stir the mixture, then disperse Ag@SiO2 in anhydrous ethanol, add the mixture, heat the reaction, wash and dry the reactants to obtain grafted modified Ag@SiO2. (3) Preparation of polyester polyol: The conventional polyester polyol is heated and dehydrated, then cooled and mixed with grafted modified Ag@SiO2 and isocyanate. The mixture is heated and reacted. The isocyanate group is found to be qualified, and the modified polyester polyol is obtained.
2. The modified polyester polyol according to claim 1, characterized in that: Step (3) The molar ratio of conventional polyester polyol to isocyanate is 1:0.6~1, and the amount of grafted modified Ag@SiO2 is 0.2~0.8wt% of polyester polyol.
3. The modified polyester polyol according to claim 1, characterized in that: In step (1), the amount of tetraethyl orthosilicate added is 0.02~0.04 wt% of the total amount of silver sol, ethanol and ammonia.
4. The modified polyester polyol according to claim 1, characterized in that: In step (2), the amount of Ag@SiO2 added is 40-60 wt% of the total amount of silane coupling agent, water, and anhydrous ethanol.
5. An antibacterial polyurethane microporous elastomer prepared using the modified polyester polyol according to any one of claims 1-4, characterized in that: The antibacterial polyurethane microporous elastomer includes component A and component B. Component A includes conventional polyester polyol and modified polyester polyol, and component B includes conventional polyester polyol, polyether polyol and isocyanate. The modified polyester polyol has a number-average molecular weight of 4000-6000 g / mol. Its preparation process involves introducing Ag@SiO2 core-shell structures modified by silane coupling agents into the conventional polyester polyol molecular chain through chemical bonding.
6. The antibacterial polyurethane microporous elastomer according to claim 5, characterized in that: Component A, with a total amount of 100 parts of conventional polyester polyol and modified polyester polyol, includes 60-80 parts of conventional polyester polyol, 25-40 parts of modified polyester polyol, 3-7 parts of chain extender, 0.2-0.5 parts of crosslinking agent, 0.4-1 parts of foam leveler, 1.0-2.0 parts of catalyst, and 0.5-0.7 parts of foaming agent; Component B includes 10-25 parts of conventional polyester polyol, 5-10 parts of polyether polyol, and 65-85 parts of isocyanate.
7. The antibacterial polyurethane microporous elastomer according to claim 5, characterized in that: Conventional polyester polyols are prepared by esterification and condensation reactions of small molecule polyols and diacids, with a number-average molecular weight of 1500~2500 g / mol and a functionality of 2~2.
06.
8. The antibacterial polyurethane microporous elastomer according to claim 5, characterized in that: The isocyanate is one or a mixture of 4,4'-diphenylmethane diisocyanate and carbodiimide-modified MDI.
9. A method for preparing the antibacterial polyurethane microporous elastomer according to claim 5, characterized in that: Includes the following steps: 1) Preparation of component A: Mix conventional polyester polyol, modified polyester polyol, chain extender, crosslinking agent, foam leveler, foaming agent and catalyst, and stir at normal pressure and 60~70℃ to obtain component A; 2) Preparation of Component B: Mix conventional polyester polyol and polyether polyol, control the material temperature at 40~50℃, add isocyanate, and react at 70~80℃ to obtain Component B; the -NCO content of Component B is 20.0~27.5wt%; 3) Preparation of antibacterial polyurethane microporous elastomer: Mix component A and component B, inject into a mold at a temperature of 30~50℃, and cure for 10~20 minutes to obtain antibacterial polyurethane microporous elastomer.
10. The method for preparing the antibacterial polyurethane microporous elastomer according to claim 9, characterized in that: In step 3), the mass ratio of component A to component B is 100:40~75.