Soybean-based epoxy chloropropane adhesive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of material synthesis and material modification, in particular to a soybean-based epichlorohydrin adhesive as well as a preparation method and application thereof. The soybean-based epichlorohydrin adhesive is prepared from the following raw materials in parts by mass: 8 to 12 parts of soybean protein isolate, 0.05 to 0.3 part of cysteine, 8 to 12 parts of epichlorohydrin and 1 to 3 parts of microcrystalline cellulose. The proportional relation between the mass part and the volume part is g: mL. According to the environment-friendly soybean-based epoxy chloropropane adhesive and the preparation method thereof, cysteine is added to modify soybean protein, and then epoxy chloropropane is added to crosslink protein molecules, so that the environment-friendly soybean-based epoxy chloropropane adhesive with high bonding strength and good water resistance is prepared. The adhesive can be used for manufacturing plywood and joint plates in the market, and has the advantages of low cost, higher reaction activity, environment friendliness and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of material synthesis and material modification, and in particular to a soybean-based epichlorohydrin adhesive and a preparation method and application thereof. Background Art

[0002] Artificial boards are boards made by adding chemical adhesives to the scraps produced by wood processing in the field of wood processing. There are a large number of artificial boards in my country, and the demand is also relatively high. At present, the wood adhesives used in artificial boards are mainly formaldehyde-based resin adhesives. Formaldehyde is a harmful substance and is very harmful to the human body. With the development of science and technology and the progress of society, consumers pay more and more attention to the quality of products in daily life, and more and more toxic and harmful substances are banned or restricted from use in daily life. Therefore, environmentally friendly adhesives have become a future development trend. It is particularly important to develop new green and environmentally friendly formaldehyde-free wood adhesives. In recent years, people's interest in bioadhesives including soy-based adhesives has increased rapidly. Soy protein-based adhesives refer to natural adhesives with protein substances as the main raw materials. They are rich in raw materials, simple in production process, high in reaction activity, not easy to degumming, and fast in growth. The preparation of environmentally friendly and harmless soy protein-based adhesives to replace toxic and harmful formaldehyde-based resin adhesives is the current pursuit of scientists. However, soy protein-based adhesives have disadvantages such as low bonding strength, poor water resistance, and poor mildew resistance. They cannot be used in large quantities and cannot meet industrial application standards well.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a soybean-based-epichlorohydrin adhesive and a preparation method and application thereof.

[0005] Specifically, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a soybean-based-epichlorohydrin adhesive, which is prepared from raw materials in the following dosage ratios: 8-12 parts by mass of soy protein isolate, 0.05-0.3 parts by mass of cysteine, 8-12 parts by volume of epichlorohydrin, and 1-3 parts by mass of microcrystalline cellulose; the ratio of the parts by mass to the parts by volume is g:mL.

[0006] Preferably, it is prepared from raw materials in the following dosage ratios: 10±1 parts by mass of isolated soy protein, 0.2±0.1 parts by mass of cysteine, 10±1 parts by volume of epichlorohydrin, and 2±1 parts by mass of microcrystalline cellulose.

[0007] Preferably, the raw materials for its preparation also include: a KOH solution with a mass fraction of 10±2% and a HCl solution with a volume fraction of 10±2%.

[0008] The present invention modifies soybean protein by adding cysteine, and then cross-links the protein molecules by adding epichlorohydrin, so as to prepare a green and environmentally friendly soybean-based-epichlorohydrin adhesive with high bonding strength and good water resistance. The adhesive has the advantages of being green, environmentally friendly and pollution-free, and has great benefits for environmental protection.

[0009] In a second aspect, the present invention provides a method for preparing the soy-based-epichlorohydrin adhesive, which comprises the following steps: (1) reacting soy protein and cysteine ​​in a deionized water dispersion system to obtain a reaction product; and (2) reacting the reaction product in a deionized water dispersion system with epichlorohydrin and microcrystalline cellulose in sequence.

[0010] Preferably, the reaction in step (1) comprises: dispersing soybean protein in deionized water, adding cysteine, stirring and reacting at 30-70° C. for 1-3 hours; adjusting the pH value of the reaction system to 7-10, and standing the reaction for 0.5-2 hours; continuing to adjust the pH value of the reaction system to 4-5, centrifuging to obtain a precipitate; and drying and grinding the precipitate to obtain a powder.

[0011] More preferably, the reaction in step (1) comprises: dispersing soy protein in deionized water, adding cysteine, stirring and reacting at 30-60° C. for 1-2 hours; adjusting the pH value of the reaction system to 8-10, and standing the reaction for 1-2 hours; continuing to adjust the pH value of the reaction system to 4-5, centrifuging to obtain a precipitate; and drying and grinding the precipitate to obtain a powder.

[0012] Preferably, the reaction in step (2) comprises: redissolving the powder in deionized water, adjusting the pH value of the dispersed system after redissolution to 6.5-7.5, adding epichlorohydrin, and stirring at 35-45°C; adding microcrystalline cellulose, and continuing stirring at 35-45°C.

[0013] Further preferably, the method of the present invention comprises the following steps: dispersing soybean protein in deionized water, adding cysteine, stirring and reacting at 40-50°C for 1-2h; adjusting the pH value of the reaction system to 8-9 using a KOH solution with a mass fraction of 10±2%, and standing for reaction for 1-2h; adjusting the pH value of the reaction system to 4-5 using a HCl solution with a volume fraction of 10±2%, and centrifuging at 7200±1000rpm to obtain a precipitate; drying the precipitate at 70±5°C for 1±0.5h, grinding to obtain a powder; redissolving the powder in deionized water, adjusting the pH value of the dispersed system after redissolution to 6.5-7.5, adding epichlorohydrin, and stirring at 35-45°C; adding microcrystalline cellulose, and continuing to stir at 35-45°C.

[0014] Optionally, after preparing the soy-based-epichlorohydrin adhesive, the present invention adds an antibacterial agent to the soy-based-epichlorohydrin adhesive, thereby effectively enhancing the storage time of the soy-based-epichlorohydrin adhesive and improving product stability.

[0015] The raw material cost adopted by the present invention is low, the material is rich, the production process is relatively simple, the reaction activity is relatively high, it is not easy to debond, and the growth speed is relatively fast. It can be mass-produced and processed into plywood and joint boards and put on the market.

[0016] In a third aspect, the present invention provides the use of the soy-based-epichlorohydrin adhesive or the preparation method in the production of artificial boards.

[0017] Beneficial effects: The present invention provides a soybean-based-epichlorohydrin adhesive and a preparation method and application thereof. The soybean-based-epichlorohydrin adhesive is prepared from raw materials including the following usage ratios: 8-12 parts by mass of soy protein isolate, 0.05-0.3 parts by mass of cysteine, 8-12 parts by volume of epichlorohydrin, and 1-3 parts by mass of microcrystalline cellulose; the ratio of the parts by mass to the parts by volume is g:mL. The present invention modifies soybean protein by adding cysteine, and then cross-links the protein molecules by adding epichlorohydrin, thereby preparing a green and environmentally friendly soybean-based-epichlorohydrin adhesive with high bonding strength and good water resistance, which can be used for the manufacture of plywood and seam boards on the market, and has the advantages of low cost, high reaction activity, and green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be described below.

[0019] Figure 1 The maximum tensile force variation diagram of the soy-based-epichlorohydrin adhesive prepared in different embodiments (Note: in order to reduce experimental errors, the maximum tensile forces obtained in the examples and comparisons of the present invention are the average values ​​of three groups of each example or comparative example).

[0020] Figure 2 This is the infrared spectrum of soybean-based adhesive.

[0021] Figure 3 This is a photo of a soybean-based adhesive sample under an optical microscope showing the formation of a double cross-linked network after the addition of epichlorohydrin, which explains the bonding reinforcement mechanism of the adhesive. DETAILED DESCRIPTION

[0022] The present invention provides a soybean-based-epichlorohydrin adhesive and a preparation method and application thereof. The soybean-based-epichlorohydrin adhesive is prepared from the following raw materials: soybean protein isolate, KOH solution, HCL solution, cysteine, epichlorohydrin, and microcrystalline cellulose. At the same time, the present invention optimizes the process in terms of the amount of cysteine ​​and microcrystalline cellulose, reaction temperature, reaction time, and control of pH in the reaction. The present invention utilizes the cross-linking reaction of epoxide and soybean protein isolate, and the modification of cysteine ​​and soybean protein isolate to prepare a soybean protein adhesive with strong water resistance and bonding strength. The process of the present invention is formaldehyde-free and belongs to a green and environmentally friendly wood adhesive. The selected material soybean has low cost, high protein content, and is easy to process. The present invention can be used in the manufacture of plywood and joint boards, and plays a lot of roles in people's lives.

[0023] As a very specific embodiment, the present invention provides a soybean-based epichlorohydrin adhesive, which is prepared from the following raw materials: 10g of soy protein isolate, a KOH solution with a mass fraction of 10%, a HCL solution with a volume fraction of 10%, 0.05-0.3g of cysteine, 10ml of epichlorohydrin, and 1-3g of microcrystalline cellulose.

[0024] The present invention also provides a method for preparing the above-mentioned soy-based-epichlorohydrin adhesive, comprising the following steps: 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0025] 2) Take out the beaker and add 0.2g of cysteine, then add magnetite, and stir in a water bath at 30-70℃ under a magnetic stirrer for 1-3h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 7-10, and let it react for 0.5-2h.

[0026] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0027] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 1-3 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. 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.

[0029] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0032] Example 1

[0033] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0034] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 50℃ water bath under a magnetic stirrer for 1h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0035] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0036] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0037] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0038] Example 2

[0039] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0040] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0041] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0042] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0043] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0044] Example 3

[0045] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0046] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 2h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0047] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0048] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0049] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0050] Example 4

[0051] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0052] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0053] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0054] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0055] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0056] Example 5

[0057] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0058] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 9, and let it react for 2h.

[0059] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0060] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0061] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0062] Example 6

[0063] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0064] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 1h.

[0065] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0066] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0067] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0068] Example 7

[0069] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0070] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 1.5h.

[0071] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0072] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0073] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0074] Example 8

[0075] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0076] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 1h.

[0077] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0078] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 1 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0079] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0080] Comparative Example 1

[0081] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0082] 2) Take out the beaker, add 0.4g of cysteine, then add magnetite, and stir in a 50℃ water bath under a magnetic stirrer for 1h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0083] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0084] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0085] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0086] Comparative Example 2

[0087] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0088] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 20℃ water bath under a magnetic stirrer for 1h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0089] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0090] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0091] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0092] Comparative Example 3

[0093] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0094] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 0.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2h.

[0095] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0096] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0097] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0098] Comparative Example 4

[0099] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0100] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 11, and let it react for 2h.

[0101] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0102] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0103] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0104] Comparative Example 5

[0105] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0106] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 2.5h.

[0107] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0108] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 2 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0109] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0110] Comparative Example 6

[0111] 1) Take 10g soy protein and 100ml deionized water, add them to a 250ml beaker, and stir them manually with a glass rod for 5-10 minutes until there are no obvious particles. Then place the beaker in a CNC ultrasonic cleaner for 30 minutes to make it evenly dispersed.

[0112] 2) Take out the beaker, add 0.2g of cysteine, then add magnetite, and stir in a 40℃ water bath under a magnetic stirrer for 1.5h. Then prepare a 10% KOH solution, adjust the pH of the solution in the beaker to 8, and let it react for 1h.

[0113] 3) Prepare a 10% HCl solution and adjust the pH of the solution in the beaker to 4.5. Then centrifuge it in an ultracentrifuge at 7200 rpm / min for 8 minutes, take out the precipitate and dry it in a vacuum oven at 70°C for 1 hour, then take it out and grind it into powder.

[0114] 4) Pour the powder into a beaker, add 10% KOH solution and 10 ml deionized water to adjust the pH of the solution to 7. Add 10 ml epichlorohydrin, place in a 40°C water bath, stir with a glass rod for 10 minutes until completely mixed, and finally add 0.5 g of microcrystalline cellulose, continue stirring in a 40°C water bath for ten minutes to obtain a soy-based-epichlorohydrin adhesive.

[0115] The prepared soybean-based-epichlorohydrin adhesive was subjected to water resistance treatment, high temperature resistance treatment, alkali resistance treatment, acid resistance treatment, antibacterial treatment, etc., and then a tensile test was carried out to reflect the difference in maximum force. Subsequently, its solid content, centrifugal stability and chemical stability were tested. Finally, the adhesive was analyzed by Fourier infrared spectroscopy and scanning electron microscopy to test its water resistance and bonding strength.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soybean-based epichlorohydrin adhesive, characterized in that: The invention is prepared from raw materials in the following dosage ratios: 8-12 parts by weight of isolated soy protein, 0.05-0.3 parts by weight of cysteine, 8-12 parts by volume of epichlorohydrin, and 1-3 parts by weight of microcrystalline cellulose; the ratio of the parts by weight to the parts by volume is g:mL.

2. The soy-based-epichlorohydrin adhesive according to claim 1, characterized in that: The invention is prepared from raw materials in the following dosage ratios: 10±1 parts by mass of isolated soy protein, 0.2±0.1 parts by mass of cysteine, 10±1 parts by volume of epichlorohydrin, and 2±1 parts by mass of microcrystalline cellulose.

3. The soy-based-epichlorohydrin adhesive according to claim 1 or 2, characterized in that: The preparation raw materials also include: KOH solution with a mass fraction of 10±2% and HCl solution with a volume fraction of 10±2%.

4. The method for preparing the soy-based-epichlorohydrin adhesive according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: (1) placing soybean protein and cysteine ​​in a deionized water dispersion system to react and obtain a reaction product; and (2) placing the reaction product in a deionized water dispersion system and reacting it with epichlorohydrin and microcrystalline cellulose in sequence.

5. The preparation method according to claim 4, characterized in that: The reaction in step (1) comprises: dispersing soybean protein in deionized water, adding cysteine, stirring and reacting at 30-70° C. for 1-3 hours; adjusting the pH value of the reaction system to 7-10, standing and reacting for 0.5-2 hours; continuing to adjust the pH value of the reaction system to 4-5, centrifuging to obtain a precipitate; and drying and grinding the precipitate to obtain a powder.

6. The preparation method according to claim 5, characterized in that: The reaction in step (2) comprises: redissolving the powder in deionized water, adjusting the pH value of the dispersed system after redissolution to 6.5-7.5, adding epichlorohydrin, and stirring at 35-45° C.; adding microcrystalline cellulose, and continuing stirring at 35-45° C.

7. The preparation method according to claim 6, characterized in that: The method comprises the following steps: dispersing soybean protein in deionized water, adding cysteine, stirring and reacting at 40-50°C for 1-2h; using a KOH solution with a mass fraction of 10±2% to adjust the pH value of the reaction system to 8-9, and standing and reacting for 1-2h; using a HCl solution with a volume fraction of 10±2% to adjust the pH value of the reaction system to 4-5, and centrifuging at 7200±1000rpm to obtain a precipitate; drying the precipitate at a temperature of 70±5°C for 1±0.5h, grinding to obtain a powder; redissolving the powder in deionized water, adjusting the pH value of the dispersed system after redissolution to 6.5-7.5, adding epichlorohydrin, and stirring at 35-45°C; adding microcrystalline cellulose, and continuing to stir at 35-45°C.

8. Use of the soy-based-epichlorohydrin adhesive according to any one of claims 1 to 3 or the preparation method according to any one of claims 4 to 7 in the production of artificial boards.

Images