Preparation method of antibacterial polyurethane foam

Abstract

The invention belongs to the technical field of antibacterial polyurethane, and particularly relates to a preparation method of antibacterial polyurethane foam. The preparation method comprises the following steps: (1) adding 0.5-1 part by weight of water, 1-3 parts by weight of a catalyst, 1-6 parts by weight of a foam stabilizer and 0.5-1 part by weight of an inorganic antibacterial filler into 100 parts by weight of antibacterial polyether under the condition of 25-35 DEG C to obtain a combined material; (2) adding 100-110 parts by weight of polyisocyanate into the combined material obtained in the step (1) under the condition of 25-35 DEG C, stirring, foaming and curing to obtain polyurethane foam; the number-average molecular weight of the antibacterial polyether is 550-650, guanidine hydrochloride, cane sugar, diethylene glycol and ethidene diamine are used as initiators and react with epoxypropane to prepare the antibacterial polyether, and the mass fraction of epoxypropane in the antibacterial polyether is 75-80%. The foam prepared by the method is high in strength and high in antibacterial property.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial polyurethane technology, and specifically relates to a method for preparing antibacterial polyurethane foam. Background Technology

[0002] The development of polyether polyols began in the 1930s, initially applied to the field of nonionic surfactants. In 1953, DuPont first applied polyether polyols to polyurethane flexible foam; subsequently, WayneDort Chemicals in the United States industrialized polyether-based polyurethane foam in 1957. Over the decades, polyether polyols have developed rapidly, with production increasing year by year.

[0003] Polyurethane materials face the problem of microbial contamination in practical applications. The polyether or polyester structural units in their macromolecular chains, rich in carbon elements that can be metabolized and utilized by microorganisms, easily become a high-quality carbon source for microbial growth and reproduction. Furthermore, functional additives such as plasticizers, lignocellulose, stabilizers, and colorants added to the materials also become targets for microbial attack. These factors combined severely affect the service life and application performance of polyurethane materials.

[0004] Chinese patent CN 113045726A discloses a polymeric antibacterial polyurethane memory foam and its preparation method. By modifying isocyanate with polyguanidine prepolymer, the prepared polymeric antibacterial polyurethane memory foam is environmentally friendly and safe, and possesses long-lasting antibacterial properties. This effectively solves the problem of decreased antibacterial performance and pollution caused by the migration of antibacterial agents in existing technologies using externally blended antibacterial polyurethane. However, this patented method is suitable for soft foams such as memory foam and cannot be used in rigid foams such as wood-look boards. Rigid polyurethane materials commonly used in daily life, such as seats and handrails in public places, are often affected by bacteria and microorganisms, and the antibacterial problem of rigid polyurethane materials urgently needs to be solved. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing antibacterial polyurethane foam, which produces foam with high strength and high antibacterial properties.

[0006] The objective of this invention is achieved through the following technical solution: The method for preparing the antibacterial polyurethane foam includes the following steps: (1) Under the condition of 25-35℃, add 0.5-1 parts of water, 1-3 parts of catalyst, 1-6 parts of foam stabilizer and 0.5-1 parts of inorganic antibacterial filler to 100 parts by weight of antibacterial polyether to obtain the composite material. (2) At 25-35℃, 100-110 parts by weight of polyisocyanate are added to the composite material obtained in step (1), stirred and foamed, and then cured to obtain polyurethane foam. The antibacterial polyether has a number average molecular weight of 550-650 and is prepared by reacting guanidine hydrochloride, sucrose, diethylene glycol and ethylenediamine as initiators with propylene oxide, wherein propylene oxide accounts for 75-80% of the mass fraction of the antibacterial polyether.

[0007] The method for preparing the antibacterial polyether is as follows: Guanidine hydrochloride, sucrose, and diethylene glycol are added to a reaction vessel, and after displacement and vacuuming, ethylenediamine and catalyst are introduced. The temperature is raised to 80°C, and a portion of propylene oxide is introduced to initiate the reaction. The temperature is then raised to 100-120°C, and the remaining propylene oxide is introduced for polymerization and ripening. After degassing, the antibacterial polyether is obtained.

[0008] in: The mass fraction of guanidine hydrochloride in the antimicrobial polyether is 3.4-5%, and the mass fraction of ethylenediamine in the antimicrobial polyether is 2.1-3.1%.

[0009] The sucrose accounts for 9-13.5% of the mass of the antimicrobial polyether, and the diethylene glycol accounts for 4-5.8% of the mass of the antimicrobial polyether.

[0010] The aforementioned extraction of ethylenediamine and catalyst, wherein the catalyst is trimethylamine.

[0011] The polymerization and maturation process is carried out at a temperature of 100-120℃ for 2-5 hours.

[0012] In step (1), the catalyst is one or a mixture of two of triethylenediamine and N,N-dimethylcyclohexylamine.

[0013] In step (1), the foam stabilizer is one of L580 and L590.

[0014] In step (1), the inorganic antibacterial filler is one or a mixture of two of ZnO and SiO2.

[0015] In step (2), the polyisocyanate is PM200.

[0016] In step (2), the curing temperature is 25°C and the time is 24 hours.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In the raw material system of the antibacterial polyether of the present invention, the high-functionality raw material sucrose can play a key role in high strength support, while the ethylenediamine polyether modified with guanidine hydrochloride can endow the material with excellent antibacterial properties. The two work together to provide support for the antibacterial properties of the polyether polyol.

[0018] (2) By introducing inorganic antibacterial fillers during the formulation stage of polyether, the present invention significantly improves the antibacterial properties of polyurethane foam without affecting its mechanical strength.

[0019] (3) The preparation process of the present invention is simple and easy to implement, and the operation process is concise, which lays the foundation for its promotion and application in many fields and has broad market prospects and practical value. Detailed Implementation

[0020] The present invention will be further described below with reference to the embodiments and comparative examples. Unless otherwise specified, the raw materials used in the embodiments and comparative examples are all conventional commercial raw materials, and the process methods used are all conventional methods in the art unless otherwise specified. The parts involved in the raw materials in the embodiments and comparative examples are all parts by mass.

[0021] The raw materials used in the examples and comparative examples are described below: Triethylenediamine was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. N,N-Dimethylcyclohexylamine was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. ZnO was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. SiO2 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. L580, purchased from Momentive Corporation, USA; L590, purchased from Momentive Corporation, USA; PM200 was purchased from Wanhua Chemical Group Co., Ltd.

[0022] Antibacterial test: The bactericidal effect of polyurethane foam against Escherichia coli was tested using the colony counting method. A 25mm × 25mm × 1mm polyurethane foam sample was placed in 50mL of a solution containing 1×10⁻⁶ bacteria. 5 The bacterial suspension was prepared in CFU / mL. After shaking and incubating for 120 min in a constant temperature shaker at 37℃, the suspension was diluted 10 times. 100 μL of each of the control and experimental groups was then spread on agar plates for bacterial counting.

[0023] The formula for calculating the antibacterial rate is as follows: Antibacterial rate (%) = (1 - number of colonies in the experimental group / number of colonies in the control group) × 100%.

[0024] Example 1 Preparation of antibacterial polyethers: 95.5g of guanidine hydrochloride, 369g of sucrose, and 160g of diethylene glycol were added to a reaction vessel. After pressure testing for 20 minutes, nitrogen was replaced three times, and the pressure was evacuated to -0.99MPa. 60g of ethylenediamine and 5g of trimethylamine catalyst were then introduced. After heating to 80℃, 524g of propylene oxide was pre-dropped to initiate polymerization. After 1 hour of curing, the temperature was raised to 110℃, 1545g of propylene oxide was added, and the mixture was kept at this temperature for 2 hours. After degassing, guanidine-containing ethylenediamine polyether polyol was obtained.

[0025] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 0.5 parts by weight of water, 1 part by weight of triethylenediamine catalyst, 1 part by weight of foam stabilizer L580, and 0.5 parts by weight of inorganic antibacterial filler ZnO are added to 100 parts by weight of antibacterial polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 100 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0026] Example 2 Preparation of antibacterial polyethers: 119.5g of guanidine hydrochloride, 369g of sucrose, and 160g of diethylene glycol were added to a reaction vessel. After pressure testing for 20 minutes, nitrogen was replaced three times. The pressure was then evacuated to -0.99MPa, and 75g of ethylenediamine and 5g of trimethylamine catalyst were introduced. The temperature was raised to 80℃, and 557g of propylene oxide was pre-dropped to initiate polymerization. After the addition was completed and the mixture was matured for 1 hour, the temperature was raised to 110℃, 1774g of propylene oxide was added, and the mixture was kept at this temperature for 3 hours. After degassing, guanidine-containing ethylenediamine polyether polyol was obtained.

[0027] Antibacterial polyurethane foam material was prepared using the following method: (1) At 30°C, 0.7 parts by weight of water, 2 parts by weight of catalyst N,N-dimethylcyclohexylamine, 3 parts by weight of foam stabilizer L590 and 1 part by weight of inorganic antibacterial filler SiO2 are added to 100 parts by weight of antibacterial polyether and mixed thoroughly to obtain the composite material. (2) At 30°C, 100 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0028] Example 3 Preparation of antibacterial polyethers: 143g of guanidine hydrochloride, 369g of sucrose, and 160g of diethylene glycol were added to a reaction vessel. After pressure testing for 20 minutes, nitrogen was replaced three times. The pressure was then evacuated to -0.99MPa, and 90g of ethylenediamine and 5g of trimethylamine catalyst were introduced. The temperature was raised to 80℃, and 617g of propylene oxide was pre-dropped to initiate polymerization. After the addition was completed and the mixture was matured for 1 hour, the temperature was raised to 120℃, 1978g of propylene oxide was added, and the mixture was kept at this temperature for 5 hours. After degassing, guanidine-containing ethylenediamine polyether polyol was obtained.

[0029] Antibacterial polyurethane foam material was prepared using the following method: (1) At 35°C, 0.9 parts by weight of water, 3 parts by weight of triethylenediamine catalyst, 5 parts by weight of foam stabilizer L580 and 0.7 parts by weight of inorganic antibacterial filler ZnO were added to 100 parts by weight of antibacterial polyether and mixed thoroughly to obtain the composite material. (2) At 35°C, 105 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0030] Example 4 Preparation of antibacterial polyethers: 194g of guanidine hydrochloride, 369g of sucrose, and 160g of diethylene glycol were added to a reaction vessel. After pressure testing for 20 minutes, nitrogen was replaced three times. The vessel was then evacuated to -0.99MPa, and 120g of ethylenediamine and 5g of trimethylamine catalyst were introduced. The temperature was raised to 80℃, and 785g of propylene oxide was pre-dropped to initiate polymerization. After the addition was completed and the vessel was matured for 1 hour, the temperature was raised to 110℃, 2355g of propylene oxide was added, and the vessel was kept at this temperature for 3 hours. After degassing, guanidine-containing ethylenediamine polyether polyol was obtained.

[0031] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 1 part by weight of water, 2 parts by weight of catalyst N,N-dimethylcyclohexylamine, 6 parts by weight of foam stabilizer L580 and 0.6 parts by weight of inorganic antibacterial filler ZnO were added to 100 parts by weight of antibacterial polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 110 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0032] Comparative Example 1 Preparation of polyethers: While ensuring that the functionality, hydroxyl value and viscosity of the polyether are consistent with those in the examples, 369g of sucrose and 160g of diethylene glycol were added to the reactor. After pressure testing for 20 minutes, nitrogen was replaced three times. The reactor was then evacuated to -0.99MPa, and 85g of ethylenediamine and 5g of trimethylamine catalyst were introduced. After heating to 80°C, 472g of propylene oxide was pre-dropped to initiate polymerization. After 1 hour of curing, the temperature was raised to 110°C, 1224g of propylene oxide was added, and the reactor was kept at this temperature for 3 hours. After degassing, guanidine-free polyether polyol was obtained.

[0033] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 0.5 parts by weight of water, 2 parts by weight of triethylenediamine catalyst, and 3 parts by weight of foam stabilizer L580 are added to 100 parts by weight of polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 100 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0034] Comparative Example 2 Preparation of polyethers: While ensuring that the functionality, hydroxyl value and viscosity of the polyether are consistent with those in the examples, 71g of guanidine hydrochloride, 369g of sucrose and 160g of diethylene glycol were added to the reactor. After pressure testing for 20 minutes, nitrogen purging was completed three times, and the pressure was evacuated to -0.99MPa. 5g of trimethylamine catalyst was then introduced. After heating to 80°C, 426g of propylene oxide was pre-dropped to initiate polymerization. After 1 hour of curing after the addition was completed, the temperature was raised to 110°C, 1021g of propylene oxide was added, and the mixture was kept at this temperature for 3 hours. After degassing, guanidine-containing, ethylenediamine-free polyether polyol was obtained.

[0035] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 0.5 parts by weight of water, 2 parts by weight of triethylenediamine catalyst, and 3 parts by weight of foam stabilizer L580 are added to 100 parts by weight of polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 110 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0036] Comparative Example 3 The guanidinium diamine polyether prepared in Example 1 was used.

[0037] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 0.5 parts by weight of water, 2 parts by weight of triethylenediamine catalyst, and 3 parts by weight of foam stabilizer L580 are added to 100 parts by weight of polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 100 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0038] Comparative Example 4 Preparation of antibacterial polyethers: While ensuring that the functionality, hydroxyl value and viscosity of the polyether are consistent with those in the examples, 125g of guanidine hydrochloride, 369g of sucrose and 160g of diethylene glycol were added to the reactor. After pressurizing and leak testing for 20 minutes, three nitrogen purgings were completed. The pressure was then evacuated to -0.99MPa, and 130g of ethylenediamine and 5g of trimethylamine catalyst were introduced. After heating to 80°C, 768g of propylene oxide was pre-dropped to initiate polymerization. After the addition was completed, the mixture was aged for 1 hour. Then, the temperature was raised to 110°C, 2020g of propylene oxide was added, and the mixture was kept at this temperature for 3 hours. After degassing, guanidine-containing ethylenediamine polyether polyol was obtained.

[0039] Antibacterial polyurethane foam material was prepared using the following method: (1) At 25°C, 0.5 parts by weight of water, 2 parts by weight of triethylenediamine catalyst, 3 parts by weight of foam stabilizer L580 and 0.5 parts by weight of inorganic antibacterial filler ZnO are added to 100 parts by weight of polyether and mixed thoroughly to obtain the composite material. (2) At 25°C, 100 parts by weight of PM200 were added to the composite material obtained in step (1), stirred and foamed, and cured at 25°C for 24 hours to obtain polyurethane foam.

[0040] The performance indicators and raw material contents of the polyether products prepared in the examples and comparative examples are shown in Table 1.

[0041] The performance indicators and inorganic antibacterial filler dosage of the polyurethane foam products prepared in the examples and comparative examples are shown in Table 2.

[0042] Table 1 Performance indicators and raw material content of polyether products prepared in the examples and comparative examples

[0043] Table 2 Performance indicators and inorganic antibacterial filler dosage of polyurethane foam products prepared in the examples and comparative examples

[0044] As can be seen from Table 1, after the formulation design was completed, the viscosity of the guanidine-containing antibacterial polyether with different contents was 13400±1000mPa·s, and the hydroxyl value was 420±2mgKOH / g.

[0045] As shown in Table 2, the four examples demonstrate that the antibacterial polyurethane foam prepared by the combined polyether containing guanidine ethylenediamine polyether and inorganic fillers exhibits high hardness and an antibacterial rate greater than 99%. A comparison between Comparative Example 1 and Example 1 shows that foam prepared using only ethylenediamine, sucrose, and diethylene glycol as initiators has almost no antibacterial properties. Comparisons between Example 1 and Comparative Example 2 show that the polyurethane foam prepared by the synergistic effect of guanidine hydrochloride and ethylenediamine has better antibacterial properties than polyurethane foam containing only guanidine hydrochloride. A comparison between Example 1 and Comparative Example 3 shows that the addition of inorganic antibacterial fillers can improve the antibacterial rate to some extent. A comparison between Comparative Example 4 and Example 1 shows that excessively high ethylenediamine content leads to a decrease in the synergistic antibacterial effect.

[0046] The high-strength antibacterial polyurethane foam prepared by this invention has excellent antibacterial properties, with an inhibition rate of over 99% against Escherichia coli, and also has excellent foam strength and hardness.

Claims

1. A method for preparing antibacterial polyurethane foam, characterized in that: Includes the following steps: (1) Under the condition of 25-35℃, add 0.5-1 parts of water, 1-3 parts of catalyst, 1-6 parts of foam stabilizer and 0.5-1 parts of inorganic antibacterial filler to 100 parts by weight of antibacterial polyether to obtain the composite material. (2) At 25-35℃, 100-110 parts by weight of polyisocyanate are added to the composite material obtained in step (1), stirred and foamed, and then cured to obtain polyurethane foam. The antibacterial polyether has a number average molecular weight of 550-650 and is prepared by reacting guanidine hydrochloride, sucrose, diethylene glycol and ethylenediamine as initiators with propylene oxide, wherein propylene oxide accounts for 75-80% of the mass fraction of the antibacterial polyether.

2. The method for preparing antibacterial polyurethane foam according to claim 1, characterized in that: The method for preparing the antibacterial polyether is as follows: Guanidine hydrochloride, sucrose, and diethylene glycol are added to a reaction vessel, and after displacement and vacuuming, ethylenediamine and catalyst are introduced, the temperature is raised, and a portion of propylene oxide is introduced to initiate the reaction. The temperature is further raised, and the remaining propylene oxide is introduced for polymerization and ripening. After degassing, the antibacterial polyether is obtained.

3. The method for preparing antibacterial polyurethane foam according to claim 1 or 2, characterized in that: The mass fraction of guanidine hydrochloride in the antimicrobial polyether is 3.4-5%, and the mass fraction of ethylenediamine in the antimicrobial polyether is 2.1-3.1%.

4. The method for preparing antibacterial polyurethane foam according to claim 1 or 2, characterized in that: The sucrose accounts for 9-13.5% of the mass of the antimicrobial polyether, and the diethylene glycol accounts for 4-5.8% of the mass of the antimicrobial polyether.

5. The method for preparing antibacterial polyurethane foam according to claim 2, characterized in that: The aforementioned extraction of ethylenediamine and catalyst, wherein the catalyst is trimethylamine.

6. The method for preparing antibacterial polyurethane foam according to claim 2, characterized in that: The polymerization and maturation process is carried out at a temperature of 100-120℃ for 2-5 hours.

7. The method for preparing antibacterial polyurethane foam according to claim 1, characterized in that: In step (1), the catalyst is one or a mixture of two of triethylenediamine and N,N-dimethylcyclohexylamine.

8. The method for preparing antibacterial polyurethane foam according to claim 1, characterized in that: In step (1), the foam stabilizer is one of L580 and L590.

9. The method for preparing antibacterial polyurethane foam according to claim 1, characterized in that: In step (1), the inorganic antibacterial filler is one or a mixture of two of ZnO and SiO2.

10. The method for preparing antibacterial polyurethane foam according to claim 1, characterized in that: In step (2), the polyisocyanate is PM200.

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