Process for the preparation of an antimicrobial polyurethane foam

Abstract

The application belongs to the technical field of antibacterial polyurethane and specifically relates to a preparation method of antibacterial polyurethane foam. The preparation method comprises the following steps: (1) under the condition of 25-35 DEG C, 0.5-1 parts 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 parts by weight of inorganic antibacterial filler are added into 100 parts by weight of antibacterial polyether to obtain a combined material; (2) under the condition of 25-35 DEG C, 100-110 parts by weight of polyisocyanate is added into the combined material obtained in step (1), and then stirring, foaming, curing are carried out to obtain polyurethane foam; the number average molecular weight of the antibacterial polyether is 550-650, the antibacterial polyether is prepared by reacting propylene oxide with guanidine hydrochloride, sucrose, diethylene glycol and ethylenediamine as a starting agent, and the mass fraction of propylene oxide in the antibacterial polyether is 75-80%. The foam prepared by the method has high strength and high antibacterial performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antibacterial polyurethane, and particularly relates to a preparation method of antibacterial polyurethane foam. BACKGROUND

[0002] The development of polyether polyols began in the 1930s and was initially applied in the field of non-ionic surfactants. In 1953, DuPont Company first applied polyether polyols to polyurethane soft foam; then, in 1957, Wyandotte Chemical Company of the United States industrialized polyether polyurethane foam. In the past few decades, polyether polyols have developed rapidly, and the production has increased year by year.

[0003] Polyurethane materials are subject to microbial contamination in practical applications. The polyether or polyester structural units in the macromolecular chain segments are rich in carbon elements that can be metabolized by microorganisms, and are extremely easy to become a high-quality carbon source for the growth and reproduction of microorganisms. Moreover, functional additives such as plasticizers, lignocellulose, stabilizers and colorants added to the materials will also become the target of microorganisms. These factors jointly affect the service life and application effect of polyurethane materials.

[0004] Chinese Patent CN 113045726A discloses a high-molecular antibacterial polyurethane memory foam and a preparation method thereof. By modifying isocyanate with polyguanidine prepolymer, the prepared high-molecular antibacterial polyurethane memory foam has good environmental safety and persistent antibacterial performance, effectively solving the problem of antibacterial performance decline and pollution caused by the migration of antibacterial agents in existing technology. However, the patent method is suitable for soft foam such as memory sponge, and cannot be used in hard foam such as imitation wood and board. Commonly used hard polyurethane materials in life, such as seats and handrails in public places, are often affected by bacteria and microorganisms, and the antibacterial problem of hard polyurethane materials needs to be solved urgently. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of antibacterial polyurethane foam, and the foam prepared by the method has high strength and high antibacterial performance.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] The preparation method of the antibacterial polyurethane foam comprises the following steps:

[0008] (1) Under the condition of 25-35℃, 0.5-1 parts by weight of water, 1-3 parts by weight of catalyst, 1-6 parts by weight of foam stabilizer and 0.5-1 parts by weight of inorganic antibacterial filler are added to 100 parts by weight of antibacterial polyether to obtain a combined material;

[0009] (2) adding 100-110 parts by weight of polyisocyanate into the combined material obtained in step (1) at 25-35 DEG C, stirring, foaming, and curing to obtain polyurethane foam;

[0010] The number average molecular weight of the antibacterial polyether is 550-650, and the antibacterial polyether is prepared by reacting guanidine hydrochloride, sucrose, diethylene glycol and ethylenediamine with propylene oxide, and the mass fraction of propylene oxide in the antibacterial polyether is 75-80%.

[0011] The preparation method of the antibacterial polyether comprises the following steps: adding guanidine hydrochloride, sucrose and diethylene glycol into a reaction kettle, replacing vacuum, then pumping in ethylenediamine and a catalyst, heating to 80 DEG C, introducing part of propylene oxide to initiate the reaction, continuously heating to 100-120 DEG C, introducing the remaining propylene oxide to polymerize and cure, and degassing to obtain the antibacterial polyether.

[0012] Among them:

[0013] The mass fraction of guanidine hydrochloride in the antibacterial polyether is 3.4-5%, and the mass fraction of ethylenediamine in the antibacterial polyether is 2.1-3.1%.

[0014] The mass fraction of sucrose in the antibacterial polyether is 9-13.5%, and the mass fraction of diethylene glycol in the antibacterial polyether is 4-5.8%.

[0015] The pumping in ethylenediamine and the catalyst is that the catalyst is trimethylamine.

[0016] The polymerization and curing is that the curing temperature is 100-120 DEG C, and the time is 2-5 h.

[0017] In step (1), the catalyst is a mixture of one or both of triethylenediamine and N,N-dimethylcyclohexylamine.

[0018] In step (1), the foam stabilizer is one of L580 and L590.

[0019] In step (1), the inorganic antibacterial filler is a mixture of one or both of ZnO and SiO2.

[0020] In step (2), the polyisocyanate is PM200.

[0021] In step (2), the curing temperature is 25 DEG C, and the time is 24 h.

[0022] Compared with the prior art, the beneficial effects of the present application are as follows:

[0023] (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.

[0024] (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.

[0025] (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

[0026] 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.

[0027] The raw materials used in the examples and comparative examples are described below:

[0028] Triethylenediamine was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0029] N,N-Dimethylcyclohexylamine was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0030] ZnO was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0031] SiO2 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0032] L580, purchased from Momentive Corporation, USA;

[0033] L590, purchased from Momentive Corporation, USA;

[0034] PM200 was purchased from Wanhua Chemical Group Co., Ltd.

[0035] 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 bacterial suspensions was then spread on agar plates for bacterial counting.

[0036] The formula for calculating the antibacterial rate is as follows:

[0037] Antibacterial rate (%) = (1 - number of colonies in the experimental group / number of colonies in the control group) × 100%.

[0038] Example 1

[0039] Preparation of antibacterial polyethers:

[0040] 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.

[0041] Antibacterial polyurethane foam material was prepared using the following method:

[0042] (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.

[0043] (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.

[0044] Example 2

[0045] Preparation of antibacterial polyethers:

[0046] 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.

[0047] Antibacterial polyurethane foam material was prepared using the following method:

[0048] (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.

[0049] (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.

[0050] Example 3

[0051] Preparation of antibacterial polyethers:

[0052] 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.

[0053] Antibacterial polyurethane foam material was prepared using the following method:

[0054] (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.

[0055] (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.

[0056] Example 4

[0057] Preparation of antibacterial polyethers:

[0058] 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.

[0059] Antibacterial polyurethane foam material was prepared using the following method:

[0060] (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.

[0061] (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.

[0062] Comparative Example 1

[0063] Preparation of polyethers:

[0064] 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.

[0065] Antibacterial polyurethane foam material was prepared using the following method:

[0066] (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.

[0067] (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.

[0068] Comparative Example 2

[0069] Preparation of polyethers:

[0070] 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.

[0071] Antibacterial polyurethane foam material was prepared using the following method:

[0072] (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.

[0073] (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.

[0074] Comparative Example 3

[0075] The guanidinium diamine polyether prepared in Example 1 was used.

[0076] Antibacterial polyurethane foam material was prepared using the following method:

[0077] (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.

[0078] (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.

[0079] Comparative Example 4

[0080] Preparation of antibacterial polyethers:

[0081] 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.

[0082] Antibacterial polyurethane foam material was prepared using the following method:

[0083] (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.

[0084] (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.

[0085] The performance indicators and raw material contents of the polyether products prepared in the examples and comparative examples are shown in Table 1.

[0086] 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.

[0087] Table 1 Performance indicators and raw material content of polyether products prepared in the examples and comparative examples

[0088]

[0089] Table 2 Performance indicators and inorganic antibacterial filler dosage of polyurethane foam products prepared in the examples and comparative examples

[0090]

[0091] 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.

[0092] 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.

[0093] 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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