Water-induced self-foaming polyhydroxy polyurethane foam as well as preparation method and application thereof

Abstract

The invention relates to water-induced self-foaming polyhydroxy polyurethane foam as well as a preparation method and application thereof.The water-induced self-foaming polyhydroxy polyurethane foam is prepared through a foaming reaction of cyclic carbonate and polyamine, the product has a good pore structure, the porosity can improve the adhesion rate of microorganisms, and the water-induced self-foaming polyhydroxy polyurethane foam has the advantages that the water-induced self-foaming polyhydroxy polyurethane foam is good in foaming effect; and the mass transfer efficiency in the reaction process can also be improved. Wide application prospects are shown in the fields of wastewater treatment, biological catalysis, environment restoration and the like. The microbial carrier can improve the reaction efficiency and stability and promote degradation of pollutants. Renewable resources are generally adopted in the synthesis process, the requirement of sustainable development is met, and environmental burden can be reduced. The non-isocyanate polyurethane is synthesized by the reaction of cyclic carbonate and amine, no isocyanate participates, and the reaction is safer, so that the non-isocyanate polyurethane is more green, environment-friendly, stable and safer than the traditional polyurethane.

Description

Technical Field

[0001] The invention relates to the technical field of polyhydroxy polyurethane foam preparation, and in particular to a water-induced self-foaming polyhydroxy polyurethane foam and a preparation method and application thereof. Background Art

[0002] Polyurethane (PU) foam is a structural component widely used in products needed in life. Its preparation usually relies on the hydrolysis process of polyols and polyisocyanates, which involves the in-situ generation of carbon dioxide (CO 2 ), thereby forming self-foaming polyurethane foam. However, with the increasingly stringent environmental protection policies, the use of isocyanate, a toxic chemical, has been increasingly restricted. Therefore, it is particularly important to find an environmentally friendly and sustainable alternative material.

[0003] As a member of the non-isocyanate polyurethane polymer family, polyhydroxy polyurethane (PHU) is regarded as a green alternative to polyurethane foam because its raw materials are derived from bio-based raw materials or gaseous waste such as carbon dioxide. 2 Self-foaming PHU is used as coatings, elastomers, hydrogels or adhesives, but these foaming agents may cause global warming, are highly flammable, or the foaming technology is difficult to transfer to industrial environments for large-scale production. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a water-induced self-foaming polyhydroxy polyurethane foam and a preparation method and application thereof, so as to solve the problems in the prior art that the foaming agent may cause global warming, is highly flammable, or the foaming technology is difficult to transfer to an industrial environment for large-scale production.

[0005] The present invention is achieved through the following technical solutions:

[0006] A water-induced self-foaming polyhydroxy polyurethane foam is prepared by foaming reaction of cyclic carbonate and polyamine.

[0007] A method for preparing a water-induced self-foaming polyhydroxy polyurethane foam comprises the following steps:

[0008] S001, raw material preparation, weighing cyclic carbonate, polyamine, stabilizer, water and catalyst according to the proportion;

[0009] S002, mixing and preheating, mixing the weighed cyclic carbonate, polyamine, stabilizer, water and catalyst in a container and then preheating at a set temperature to obtain a mixed raw material;

[0010] S003, foaming reaction, adding water to the mixed raw materials and injecting them into the mold to react under a set pressure environment;

[0011] S004, aging treatment, aging under a constant temperature and pressure environment.

[0012] It is further defined that the polyamine is a mixture of meta-xylylenediamine and tetraethylenepentamine, and the weight mixing ratio of the meta-xylylenediamine and tetraethylenepentamine is 5:1 to 8:1.

[0013] In a further embodiment, the water and the catalyst are 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0014] In a further embodiment, the stabilizer is hydrotalcite.

[0015] It is further defined that the foaming temperature in S003 is 75-85°C.

[0016] It is further defined that the method for forming the pressure environment in S003 is:

[0017] The mixed raw materials are added under normal pressure, and then the mold is closed. The gas released during the reaction of the mixed raw materials is used to naturally form a pressure environment in the closed mold.

[0018] A microbial culture medium is prepared by using the water-induced self-foaming polyhydroxy polyurethane foam prepared by the preparation method.

[0019] The beneficial effects of the present invention are:

[0020] The water-induced self-foaming polyhydroxy polyurethane foam and the preparation method and application thereof have the following advantages:

[0021] It has a good pore structure. This porosity can not only increase the attachment rate of microorganisms, but also improve their mass transfer efficiency during the reaction process.

[0022] It has shown broad application prospects in the fields of wastewater treatment, biocatalysis and environmental remediation. Microbial carriers can improve reaction efficiency and stability and promote the degradation of pollutants.

[0023] The synthesis process usually uses renewable resources, meets the requirements of sustainable development, and helps reduce the environmental burden. Non-isocyanate polyurethane is synthesized by the reaction of cyclocarbonate and amine, without the participation of isocyanate and the reaction is safer. Therefore, non-isocyanate polyurethane is greener, more environmentally friendly, stable and safer than traditional polyurethane.

[0024] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a micrograph of the product of the control group;

[0026] Figure 2 This is a micrograph of the product from the experimental group;

[0027] Figure 3 This is the product picture of the comparison group;

[0028] Figure 4 This is the product picture of the experimental group;

[0029] Figure 5 For dilution 10-7, refer to the colony map of sample 1 on the plate;

[0030] Figure 6 For dilution 10-6, refer to the colony map of sample 1 on the plate;

[0031] Figure 7 For the dilution of 10-7, refer to the colony map of sample 2 on the plate;

[0032] Figure 8 For the dilution of 10-6, refer to the second and sample 2 plate colony images; DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0036] In the above description of the present invention, it should be noted that the terms "one side", "the other side", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In addition, the term "same" does not mean that the parts must be absolutely the same, but slight differences are allowed. The term "vertical" only means that the positional relationship between the parts is more vertical than "parallel", and does not mean that the structure must be completely vertical, but can be slightly tilted.

[0038] The invention provides a technical solution: a water-induced self-foaming polyhydroxy polyurethane foam, which is prepared by foaming reaction of cyclic carbonate and polyamine.

[0039] A method for preparing a water-induced self-foaming polyhydroxy polyurethane foam comprises the following steps:

[0040] S001, raw material preparation, weighing cyclic carbonate, polyamine, stabilizer, water and catalyst according to the proportion;

[0041] S002, mixing and preheating, mixing the weighed cyclic carbonate, polyamine, stabilizer, water and catalyst in a container and then preheating at a set temperature to obtain a mixed raw material;

[0042] S003, foaming reaction, adding water to the mixed raw materials and injecting them into the mold to react under a set pressure environment;

[0043] S004, aging treatment, aging under a constant temperature and pressure environment.

[0044] The polyamine is a mixture of meta-xylylenediamine and tetraethylenepentamine, and the weight mixing ratio of the meta-xylylenediamine and tetraethylenepentamine is 5:1 to 8:1.

[0045] The water and the catalyst are 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0046] The stabilizer is hydrotalcite.

[0047] The foaming temperature in S003 is 75-85°C.

[0048] The method for forming the pressure environment in S003 is:

[0049] The mixed raw materials are added under normal pressure, and then the mold is closed. The gas released during the reaction of the mixed raw materials is used to naturally form a pressure environment in the closed mold.

[0050] The specific preparation method is:

[0051] The process of preparing water-induced self-foaming polyhydroxy polyurethane foam uses a stirrer, an intelligent constant temperature water-oil bath magnetic stirrer, a polytetrafluoroethylene closed mold and other instruments, as well as trimethylolpropane tricarbonate (TMPTC), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), meta-phenylenediamine (XDA), tetraethylenepentamine (TEPA), hydrotalcite, water and glycerol.

[0052] Select appropriate cyclic carbonates (such as ethylene carbonate, etc.) and polyamines (such as m-xylene diamine, etc.) as raw materials, and prepare a certain amount of water and a catalyst (such as 1,8-diazabicyclo[5.4.0]undec-7-ene, DBU).

[0053] The raw materials are mixed evenly in a certain proportion and preheated at a certain temperature to promote the hydrolysis and copolymerization reactions.

[0054] Add an appropriate amount of water to the preheated mixture and perform a foaming reaction at a certain temperature and pressure. During this process, the cyclic carbonate will hydrolyze and release CO 2 , forming bubbles, and at the same time undergoing polymerization reaction with polyamine to form polyhydroxy polyurethane foam.

[0055] After the foaming reaction is completed, the foam is aged at an appropriate temperature for a period of time to consolidate its structure. The foam is then taken out for necessary post-processing operations such as cutting and trimming.

[0056] Among them, the weight ratio of various raw materials is shown in the following table:

[0057]

[0058] Experimental verification

[0059] Experimental group preparation:

[0060] Add the mixed raw materials into a beaker and stir evenly under a stirrer. Put it into an 80℃ electric blast drying oven for foaming for eight hours. The foam produced by open mold foaming does not have a good shape, the foaming volume is low, and the foam is not dense enough. Preliminary analysis shows that the evaporation of water in the open mold foaming and the electric blast drying oven during the foaming process cannot provide uniform temperature control for the foaming mold, and the escape of gas during the foaming process causes the polymer to be unable to solidify, resulting in foam collapse.

[0061] Preparation of the control group:

[0062] The difference between the preparation of the control group and the experimental group is that the polyamine in the control group is meta-phenylenediamine.

[0063] The results are as follows Figures 1 to 8 As shown:

[0064] The product made by the control group uses a single-component water-induced self-blowing PHU foam. The PHU network cannot capture carbon dioxide gas well, resulting in low-quality foam, foam rupture, collapse, unstable pore size, and a rough foam surface, which makes it easy for microorganisms to adsorb on the surface and reproduce. The pore diameter is 70μm to 1.2mm, and the pore size is unstable;

[0065] The product made by the experimental group uses multi-component water-induced self-blowing PHU foam. Different PHU networks can better capture carbon dioxide gas and make the cross-linking system more stable, thereby increasing the foam density, reducing the foam size, and generally improving the foam uniformity, making the pore surface smoother, microorganisms are not easy to adsorb on its surface, and are more likely to reproduce in the pores, which is better used in water eutrophication. The pore diameter is generally 160±100μm, the minimum pore diameter is 17.3μm, the pore size is relatively stable, and its porous structure can provide sufficient oxygen and nutrients, thereby increasing the activity and metabolic rate of microorganisms.

[0066] Comparison results

[0067] The control group used single-component water-induced self-blowing PHU foam, which was harder, unstable in shape, and not easy for microorganisms to survive;

[0068] The experimental group used multi-component water-induced self-blowing PHU foam, which was softer, more stable in morphology, dense in pores, and had better biocompatibility, and could adsorb more microorganisms. At the same time, PHU was more hydrophilic than traditional PU (due to the presence of pending hydroxyl groups) and absorbed low levels of air moisture, which led to strong water plasticization of the polymer matrix.

[0069] A microbial culture medium is prepared by using the water-induced self-foaming polyhydroxy polyurethane foam prepared by the preparation method.

[0070] Experimental verification

[0071] The commercial Bacillus mixed bacteria were cultured in LB liquid medium for bacterial culture. Two groups were cultured separately, and a certain amount of water was used to dissolve them directly. Then, after 2 days of shaking culture at 30 degrees, a small amount of bacterial suspension was extracted and numbered as reference 1 and reference 2. Then, the non-isocyanate polyurethane foam was placed in the two groups of culture medium and continued to be cultured for 24 hours. After the Bacillus was adsorbed, a small amount of bacterial suspension was drawn and numbered as sample 1 and sample 2. A certain amount of bacterial suspension reference 1 and reference 2 were taken respectively, and sample 1 and sample 2 were gradiently diluted, and then 100 μl of the dilution was evenly coated on the plate culture medium, and three plates were coated for each dilution. The coated plates were placed under appropriate conditions and cultured for 24 hours.

[0072] Reference 1 is shown in the following table:

[0073]

[0074] Sample 1 is shown in the following table:

[0075]

[0076] Reference 2 is shown in the following table:

[0077]

[0078]

[0079] Sample 2 is shown in the following table:

[0080]

[0081] Comparison results

[0082] like Figure 5-8 As shown, by comparing the total number of bacteria in reference 1 and sample 1, the average adsorption rate of sample 1 is 31.94%, and by comparing the total number of bacteria in reference 2 and sample 2, the average adsorption rate of sample 2 is 55.65%. According to the experimental results, it is proved that the water-induced self-foaming polyhydroxy polyurethane foam has a certain adsorption capacity for mixed Bacillus, and the comprehensive experimental average adsorption rate is 43.79%. The foam material can effectively adsorb about half of the mixed Bacillus from the liquid phase, showing its potential in environmental remediation applications. At the same time, the adsorbed microorganisms can be effectively retained in the foam, which can be used to enhance the removal rate of organic matter in sewage and improve the treatment effect. In the future, it can be attempted to adsorb a variety of different microorganisms to study their ability in eutrophication of water bodies and treatment of invasive aquatic species.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A water-induced self-foaming polyhydroxy polyurethane foam, characterized in that: The polyol is prepared by foaming reaction of cyclic carbonate and polyamine.

2. A method for preparing the water-induced self-foaming polyhydroxy polyurethane foam as claimed in claim 1, characterized in that: The steps include: S001, raw material preparation, weighing cyclic carbonate, polyamine, stabilizer, water and catalyst according to the proportion; S002, mixing and preheating, mixing the weighed cyclic carbonate, polyamine, stabilizer, water and catalyst in a container and then preheating at a set temperature to obtain a mixed raw material; S003, foaming reaction, adding water to the mixed raw materials and injecting them into the mold to react under a set pressure environment; S004, aging treatment, aging under a constant temperature and pressure environment.

3. The preparation method according to claim 2, characterized in that: The polyamine is a mixture of meta-xylylenediamine and tetraethylenepentamine, and the weight mixing ratio of the meta-xylylenediamine and tetraethylenepentamine is 5:1 to 8:

1.

4. The preparation method according to claim 2, characterized in that: The water and the catalyst are 1,8-diazabicyclo[5.4.0]undec-7-ene.

5. The preparation method according to claim 2, characterized in that: The stabilizer is hydrotalcite.

6. The preparation method according to claim 2, characterized in that: The foaming temperature in S003 is 75-85°C.

7. The preparation method according to claim 2, characterized in that: The method for forming the pressure environment in S003 is: The mixed raw materials are added under normal pressure, and then the mold is closed. The gas released during the reaction of the mixed raw materials is used to naturally form a pressure environment in the closed mold.

8. Use of the water-induced self-foaming polyhydroxy polyurethane foam prepared by the preparation method according to any one of claims 2 to 7 in a microbial culture medium.

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