High-strength water-resistant starch adhesive and preparation method thereof

Abstract

The invention discloses a high-strength water-resistant starch adhesive and a preparation method thereof, and belongs to the technical field of preparation of environment-friendly adhesives. The problems of strength and mildew resistance of the starch adhesive are solved. The preparation method comprises the following steps: preparing 5-10g of polyethyleneimine into a 30-60wt% solution, weighing a certain mass of urea according to a molar ratio of (1-5): 1, adding the weighed urea into the prepared polyethyleneimine solution, and reacting for 8-14 hours in an oil bath to obtain a first branched polymer; 20-50 g of dialdehyde starch and 60-90 g of polyvinyl alcohol are added into a flask to prepare a starch solution, then the reaction temperature is set, uniform stirring is performed for gelatinization treatment, a second gelatinized solution is obtained, and after mixing reaction, a prefabricated high-strength water-resistant starch adhesive is obtained; and adding 5-10 g of cassava starch filler and 5-10 g of polymethyl silicon polyphenyl isocyanate, and stirring for 10-30 minutes to obtain the high-strength water-resistant starch adhesive.

Description

Technical Field

[0001] This invention belongs to the field of environmentally friendly adhesive preparation technology, specifically relating to a high-strength water-resistant starch adhesive and its preparation method. Background Technology

[0002] Using cassava starch as a raw material for adhesives can reduce production costs. However, using benzaldehyde to modify cassava starch poses risks. Prolonged use of benzaldehyde may irritate the eyes and respiratory mucous membranes, and long-term exposure can also have adverse effects on the skin and blood. Therefore, even if it can improve the adhesive strength of starch adhesives, it poses a risk to human health, and prolonged exposure can easily cause irreversible damage. Moreover, starch adhesives currently suffer from low strength and poor mold resistance. Summary of the Invention

[0003] The problem to be solved by this invention is to improve the strength and mildew resistance of starch adhesives, and to propose a high-strength water-resistant starch adhesive and its preparation method.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for preparing a high-strength, water-resistant starch adhesive includes the following steps:

[0006] S1. Prepare a 30-60 wt% solution of 5-10 g of polyethyleneimine (PEI), then weigh a certain mass of urea (U) at a molar ratio of 1-5:1, add the weighed urea to the prepared polyethyleneimine solution, and then react in an oil bath at 120-150℃ for 8-14 hours to obtain the first branched polymer.

[0007] S2. Add 20-50g of dialdehyde starch (OS) and 60-90g of polyvinyl alcohol (PVA) to a flask to prepare a 20-50wt% starch solution. Then set the reaction temperature to 70-90℃ and stir evenly for 15-45 minutes to perform gelatinization treatment to obtain a second gelatinized solution.

[0008] S3. Adjust the pH of the second gelatinized solution obtained in step S2 to 2-4, then add the first branched polymer prepared in step S1 under stirring and react for 100-140 minutes. Then measure the pH again and adjust it to 2-4. Add 5-10 grams of epichlorohydrin and stir for 70-100 minutes to obtain a pre-made high-strength water-resistant starch adhesive.

[0009] S4. Weigh 60-90 g of the pre-made high-strength water-resistant starch adhesive obtained in step S3, add 5-10 g of cassava starch filler and 5-10 g of polymethyl silicone polyphenyl isocyanate PM-200, stir for 10-30 minutes to obtain a high-strength water-resistant starch adhesive.

[0010] Further, in step S1, 8 grams of polyethyleneimine (PEI) are prepared into a 50 wt% solution, and then a certain mass of urea (U) is weighed according to a molar ratio of 1:1. The weighed urea is added to the prepared polyethyleneimine solution, and then reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer.

[0011] Furthermore, the concentration of the polyvinyl alcohol solution in step S2 is 20%.

[0012] Further, in step S2, 40g of dialdehyde starch (OS) and 70g of polyvinyl alcohol (PVA) are added to the flask to prepare a 30wt% starch solution. Then, the reaction temperature is set to 75℃, and the mixture is stirred evenly for 40 minutes to perform gelatinization treatment, thereby obtaining a second gelatinized solution.

[0013] Further, in step S3, the pH of the second gelatinized solution obtained in step S2 is adjusted to 3, and then the first branched polymer prepared in step S1 is added under stirring conditions and reacted for 120 minutes. Then the pH is measured again and adjusted to 3, and then 8 grams of epichlorohydrin is added and stirred for 90 minutes to obtain a pre-made high-strength water-resistant starch adhesive.

[0014] Further, in step S4, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 is weighed, 10 g of cassava starch filler and 10 g of polymethyl silicone polyphenyl isocyanate PM-200 are added, and the mixture is stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0015] A method for preparing a high-strength, water-resistant starch adhesive. The high-strength, water-resistant starch adhesive does not exhibit mold growth at room temperature for half a month.

[0016] The beneficial effects of this invention are:

[0017] The present invention discloses a method for preparing a high-strength water-resistant starch adhesive. The prepared high-strength water-resistant starch adhesive improves wet shear strength and dry shear strength, and also has a certain degree of mildew resistance, which can keep it free from mold for half a month. The production method of the present invention is simple and easy to implement. Attached Figure Description

[0018] Figure 1 This is a comparison chart of shear strength obtained from embodiments and comparative examples of the present invention based on different reaction ratios of polyethyleneimine and urea;

[0019] Figure 2 This is a comparison chart of shear strength obtained from photographs of wood damage based on different reaction times of polyethyleneimine and urea in this invention.

[0020] Figure 3 These are photographs of damaged wood obtained from different embodiments and comparative examples of the present invention;

[0021] Figure 4 The transmittance curves of the adhesives obtained in different embodiments and comparative examples of the present invention are shown.

[0022] Figure 5 This is a schematic diagram illustrating the principle of adhesive synthesis in this invention.

[0023] Figure 6 These are comparative photographs showing the antifungal resistance of adhesives obtained from different embodiments and comparative examples of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0025] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0026] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 - Appendix Figure 6 Detailed explanation is as follows:

[0027] Example 1:

[0028] A method for preparing a high-strength, water-resistant starch adhesive involves preparing a 50% solution of 8 grams of polyethyleneimine (PEI), with a urea (U) to polyethyleneimine molar ratio of 1:1. The urea is then added to the polyethyleneimine solution and mixed thoroughly. The mixture is reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer. Alternatively, using dialdehyde starch (OS) as a raw material, 40 g of OS and 70 g of polyvinyl alcohol (PVA) are added to a four-necked flask to prepare a starch solution with a 30% solid content. The reaction temperature is set to... The mixture was stirred evenly for 40 minutes for gelatinization. The reaction pH was then adjusted to 3.00, the first branched polymer was added, and the mixture was stirred for 120 minutes. The pH was then measured again and adjusted to 3.00. 8 g of epichlorohydrin was added to the reaction system and stirred for 90 minutes to obtain a pre-prepared high-strength water-resistant starch adhesive. Then, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 was weighed, and 10 g of cassava starch filler and 10 g of polymethylsiloxane polyphenyl isocyanate PM-200 were added. The mixture was stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0029] Furthermore, the concentration of the polyvinyl alcohol solution is 20%.

[0030] Example 2:

[0031] A method for preparing a high-strength, water-resistant starch adhesive involves preparing a 50% solution of 8 grams of polyethyleneimine (PEI), with a urea (U) to polyethyleneimine molar ratio of 2:1. Urea is then added to the polyethyleneimine solution and mixed thoroughly. The mixture is reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer. Alternatively, using dialdehyde starch (OS) as a raw material, 40 g of OS and 70 g of polyvinyl alcohol (PVA) are added to a four-necked flask to prepare a starch solution with a 30% solid content. The reaction temperature is set to... The mixture was stirred evenly for 40 minutes for gelatinization. The reaction pH was then adjusted to 3.00, the first branched polymer was added, and the mixture was stirred for 120 minutes. The pH was then measured again and adjusted to 3.00. 8 g of epichlorohydrin was added to the reaction system and stirred for 90 minutes to obtain a pre-prepared high-strength water-resistant starch adhesive. Then, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 was weighed, and 10 g of cassava starch filler and 10 g of polymethylsiloxane polyphenyl isocyanate PM-200 were added. The mixture was stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0032] Furthermore, the concentration of the polyvinyl alcohol solution is 20%.

[0033] Example 3:

[0034] A method for preparing a high-strength, water-resistant starch adhesive involves preparing a 50% solution of 8 grams of polyethyleneimine (PEI), with a urea (U) to polyethyleneimine molar ratio of 3:1. Urea is added to the polyethyleneimine solution and mixed thoroughly. The mixture is then reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer. Alternatively, using dialdehyde starch (OS) as a raw material, 40 g of OS and 70 g of polyvinyl alcohol (PVA) are added to a four-necked flask to prepare a starch solution with a 30% solid content. The reaction temperature is set to... The mixture was stirred evenly for 40 minutes for gelatinization. The reaction pH was then adjusted to 3.00, the first branched polymer was added, and the mixture was stirred for 120 minutes. The pH was then measured again and adjusted to 3.00. 8 g of epichlorohydrin was added to the reaction system and stirred for 90 minutes to obtain a pre-prepared high-strength water-resistant starch adhesive. Then, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 was weighed, and 10 g of cassava starch filler and 10 g of polymethylsiloxane polyphenyl isocyanate PM-200 were added. The mixture was stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0035] Furthermore, the concentration of the polyvinyl alcohol solution is 20%.

[0036] Example 4:

[0037] A method for preparing a high-strength, water-resistant starch adhesive involves preparing a 50% solution of 8 grams of polyethyleneimine (PEI), with a urea (U) to polyethyleneimine molar ratio of 2:1. Urea is then added to the polyethyleneimine solution and mixed thoroughly. The mixture is reacted in an oil bath at 135°C for 8 hours to obtain a first branched polymer. Alternatively, using dialdehyde starch (OS) as a raw material, 40 g of OS and 70 g of polyvinyl alcohol (PVA) are added to a four-necked flask to prepare a starch solution with a 30% solids content. The reaction temperature is set to 75°C, and the mixture is stirred uniformly for 40 minutes for gelatinization. Subsequently, the reaction pH is adjusted to 3.00, the first branched polymer is added, and the mixture is stirred for 120 minutes. Then, the pH was measured again and adjusted to 3.00. 8 g of epichlorohydrin was added to the reaction system and stirred for 90 minutes to obtain a pre-made high-strength water-resistant starch adhesive. Then, 80 g of the pre-made high-strength water-resistant starch adhesive obtained in step S3 was weighed, 10 g of cassava starch filler and 10 g of polymethyl silicone polyphenyl isocyanate PM-200 were added, and stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0038] Furthermore, the concentration of the polyvinyl alcohol solution is 20%.

[0039] Example 5:

[0040] A method for preparing a high-strength, water-resistant starch adhesive involves preparing a 50% solution of 8 grams of polyethyleneimine (PEI), with a urea (U) to polyethyleneimine molar ratio of 2:1. Urea is then added to the polyethyleneimine solution and mixed thoroughly. The mixture is reacted in an oil bath at 135°C for 12 hours to obtain the first branched polymer. Alternatively, using dialdehyde starch (OS) as a raw material, 40 g of OS and 70 g of polyvinyl alcohol (PVA) are added to a four-necked flask to prepare a starch solution with a 30% solid content. The reaction temperature is set to... The mixture was stirred evenly for 40 minutes for gelatinization. The reaction pH was then adjusted to 3.00, the first branched polymer was added, and the mixture was stirred for 120 minutes. The pH was then measured again and adjusted to 3.00. 8 g of epichlorohydrin was added to the reaction system and stirred for 90 minutes to obtain a pre-prepared high-strength water-resistant starch adhesive. Then, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 was weighed, and 10 g of cassava starch filler and 10 g of polymethylsiloxane polyphenyl isocyanate PM-200 were added. The mixture was stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0041] Furthermore, the concentration of the polyvinyl alcohol solution is 20%.

[0042] Comparative Example 1:

[0043] 40 g of dialdehyde starch (OS) was added to a four-necked flask to prepare a starch solution with a 30% solid content. 70 g of a 20% concentration polyvinyl alcohol (PVA) solution was added, and the experimental temperature was set to 75 °C. The mixture was stirred thoroughly for 20 minutes to prepare for gelatinization. The pH of the adhesive was adjusted to 3, and then 16 g of a 50% concentration polyethyleneimine (PEI) solution was added and stirred for 120 minutes. After 120 minutes, the pH was measured and adjusted back to 3. Then, 8 g of epichlorohydrin (ECH) was added uniformly to the mixture and stirred for 90 minutes to obtain a pre-prepared adhesive. 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 was weighed, and 10 g of cassava starch filler and 10 g of polymethylsiloxane polyphenyl isocyanate PM-200 were added. The mixture was stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0044] The adhesives obtained in Examples 1-5 and Comparative Example 1 were applied to the plywood within 10-30 minutes. The plywood used in this work was poplar veneer, with dimensions of 350 mm × 350 mm × 2 mm. The adhesive was evenly applied to both sides of the core board using a brush (adhesive loading rate of 250-300 g / m²). 2 The plywood was hot-pressed at 110-140 °C for 2-3 MPa for 10-20 minutes. The plywood was then allowed to stand at room temperature for 48 hours to relieve internal stress, and then the plywood samples were cut into strips of 100 × 25 mm. The dry shear strength and 3-h hot water (63 °C) wet shear strength of the samples were determined according to GB / T17657-2022 to evaluate the adhesive properties, as shown in Table 1 and Appendix. Figure 1-3 As shown:

[0045] Table 1

[0046]

[0047] As can be seen from Table 1, by averaging the values ​​of each measurement, the dry shear strength and wet shear strength of Comparative Example 1 are 2.05 MPa and 0.29 MPa, respectively. By introducing urea-crosslinked polyethyleneimine to improve the crosslinking network, resulting in a denser internal space and increased strength, the dry shear strength and wet shear strength of Example 2 can reach 4.63 MPa and 1.44 MPa under optimal conditions, which are 125.85% and 396.55% higher than those of Comparative Example 1, respectively.

[0048] Figure 1 This is a comparison chart of shear strength obtained from embodiments and comparative examples of the present invention based on different reaction ratios of polyethyleneimine and urea; from Figure 1 It can be seen that the dry shear strength and wet shear strength of Comparative Example 1 are 2.05 MPa and 0.29 MPa, respectively. After the addition of urea, the strength is improved due to its cross-linking with polyethyleneimine and its tighter grafting with starch. Finally, the dry shear strength and wet shear strength can reach 4.63 MPa and 1.44 MPa, respectively.

[0049] Figure 2 The shear strength of urea reacting with polyethyleneimine at different times is shown. As the reaction time increases, the cross-linking effect is better and the three-dimensional network is denser. However, when the reaction time exceeds 10 hours, excessive cross-linking occurs and by-products are generated, which leads to a decrease in shear strength.

[0050] Figure 3 The images show wood damage photographs obtained from different embodiments and comparative examples of the present invention. It can be observed from the wood damage rate that the wood damage rate of Examples 2, 3 and 5 can be close to 100%, indicating that the degree of grafting is higher than that of Comparative Example 1 and that the wood reacts better.

[0051] Figure 4 The transmittance curves of the adhesives obtained in different embodiments and comparative examples of the present invention are shown below; from Figure 4 It can be seen that, compared with Comparative Example 1, Examples 1, 2, and 3 show improvement at 1645 cm⁻¹. -1 Obvious C=N tensile vibration peaks were observed at all locations, indicating that starch and P / U branched polymer were successfully cross-linked and the grafting effect was obvious;

[0052] Figure 6 These are comparative photographs showing the antifungal resistance of adhesives obtained from different embodiments and comparative examples of the present invention. Figure 6 It can be seen that mold gradually appeared in Comparative Example 1 after a 30-day period, while no mold appeared in Examples 1-3 during the 30-day period. This indicates that modifying the starch base can inhibit the growth of mold and damage the mold.

[0053] Example 6:

[0054] A method for preparing a high-strength, water-resistant starch adhesive includes the following steps:

[0055] S1. Prepare a 30-60 wt% solution of 5-10 g of polyethyleneimine (PEI), then weigh a certain mass of urea (U) at a molar ratio of 1-5:1, add the weighed urea to the prepared polyethyleneimine solution, and then react in an oil bath at 120-150℃ for 8-14 hours to obtain the first branched polymer.

[0056] Further, in step S1, 8 grams of polyethyleneimine (PEI) are prepared into a 50 wt% solution, and then a certain mass of urea (U) is weighed according to a molar ratio of 1:1. The weighed urea is added to the prepared polyethyleneimine solution, and then reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer.

[0057] S2. Add 20-50g of dialdehyde starch (OS) and 60-90g of polyvinyl alcohol (PVA) to a flask to prepare a 20-50wt% starch solution. Then set the reaction temperature to 70-90℃ and stir evenly for 15-45 minutes to perform gelatinization treatment to obtain a second gelatinized solution.

[0058] Furthermore, the concentration of the polyvinyl alcohol solution in step S2 is 20%;

[0059] Further, in step S2, 40g of dialdehyde starch OS and 70g of polyvinyl alcohol PVA are added to the flask to prepare a 30wt% starch solution. Then, the reaction temperature is set to 75℃, and the mixture is stirred evenly for 40 minutes to perform gelatinization treatment to obtain a second gelatinized solution.

[0060] S3. Adjust the pH of the second gelatinized solution obtained in step S2 to 2-4, then add the first branched polymer prepared in step S1 under stirring and react for 100-140 minutes. Then measure the pH again and adjust it to 2-4. Add 5-10 grams of epichlorohydrin and stir for 70-100 minutes to obtain a pre-made high-strength water-resistant starch adhesive.

[0061] Further, in step S3, the pH of the second gelatinized solution obtained in step S2 is adjusted to 3, and then the first branched polymer prepared in step S1 is added under stirring conditions and reacted for 120 minutes. Then the pH is measured again and adjusted to 3, and then 8 grams of epichlorohydrin is added and stirred for 90 minutes to obtain a pre-made high-strength water-resistant starch adhesive.

[0062] S4. Weigh 60-90 g of the pre-made high-strength water-resistant starch adhesive obtained in step S3, add 5-10 g of cassava starch filler and 5-10 g of polymethyl silicone polyphenyl isocyanate PM-200, stir for 10-30 minutes to obtain a high-strength water-resistant starch adhesive.

[0063] Further, in step S4, 80 g of the pre-prepared high-strength water-resistant starch adhesive obtained in step S3 is weighed, 10 g of cassava starch filler and 10 g of polymethyl silicone polyphenyl isocyanate PM-200 are added, and the mixture is stirred for 15 minutes to obtain a high-strength water-resistant starch adhesive.

[0064] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a high-strength, water-resistant starch adhesive, characterized in that, Includes the following steps: S1. Prepare a 30-60 wt% solution of 5-10 g of polyethyleneimine (PEI), then weigh a certain mass of urea (U) at a molar ratio of 1-5:1, add the weighed urea to the prepared polyethyleneimine solution, and then react in an oil bath at 120-150℃ for 8-14 hours to obtain the first branched polymer. S2. Add 20-50g of dialdehyde starch (OS) and 60-90g of polyvinyl alcohol (PVA) to a flask to prepare a 20-50wt% starch solution. Then set the reaction temperature to 70-90℃ and stir evenly for 15-45 minutes to perform gelatinization treatment to obtain a second gelatinized solution. S3. Adjust the pH of the second gelatinized solution obtained in step S2 to 2-4, then add the first branched polymer prepared in step S1 under stirring and react for 100-140 minutes. Then measure the pH again and adjust it to 2-4. Add 5-10 grams of epichlorohydrin and stir for 70-100 minutes to obtain a pre-made high-strength water-resistant starch adhesive. S4. Weigh 60-90 g of the pre-made high-strength water-resistant starch adhesive obtained in step S3, add 5-10 g of cassava starch filler and 5-10 g of polymethyl silicone polyphenyl isocyanate PM-200, stir for 10-30 minutes to obtain a high-strength water-resistant starch adhesive.

2. The method for preparing a high-strength water-resistant starch adhesive according to claim 1, characterized in that: In step S1, 8 grams of polyethyleneimine (PEI) were prepared into a 50 wt% solution. Then, a certain mass of urea (U) was weighed according to a molar ratio of 1:

1. The weighed urea was added to the prepared polyethyleneimine solution, and the mixture was reacted in an oil bath at 135°C for 10 hours to obtain the first branched polymer.

3. The method for preparing a high-strength water-resistant starch adhesive according to claim 2, characterized in that: The concentration of the polyvinyl alcohol solution in step S2 is 20%.

4. The method for preparing a high-strength water-resistant starch adhesive according to claim 3, characterized in that: In step S2, 40g of dialdehyde starch (OS) and 70g of polyvinyl alcohol (PVA) are added to the flask to prepare a 30wt% starch solution. Then, the reaction temperature is set to 75℃, and the mixture is stirred evenly for 40 minutes to perform gelatinization treatment, thereby obtaining a second gelatinized solution.

5. The method for preparing a high-strength water-resistant starch adhesive according to claim 4, characterized in that: In step S3, the pH of the second gelatinized solution obtained in step S2 is adjusted to 3. Then, the first branched polymer prepared in step S1 is added under stirring and reacted for 120 minutes. The pH is then measured again and adjusted to 3. 8 grams of epichlorohydrin are added and stirred for 90 minutes to obtain a pre-made high-strength water-resistant starch adhesive.

6. The method for preparing a high-strength water-resistant starch adhesive according to claim 5, characterized in that: In step S4, weigh 80 g of the pre-made high-strength water-resistant starch adhesive obtained in step S3, add 10 g of cassava starch filler and 10 g of polymethyl silicone polyphenyl isocyanate PM-200, stir for 15 minutes to obtain a high-strength water-resistant starch adhesive.

7. A high-strength, water-resistant starch adhesive prepared by a method according to any one of claims 1-6, characterized in that, The high-strength, water-resistant starch adhesive described herein will not develop mold even after half a month at room temperature.

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