CN-122010737-A - Bio-based hydrophilic chain extender, preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a bio-based hydrophilic chain extender, a preparation method and application thereof. The invention takes malic acid and allyl glycidyl ether as main raw materials to prepare the bio-based hydrophilic chain extender. Then taking polyalcohol, diisocyanate, bio-based hydrophilic chain extender and chain extender solution as main raw materials to prepare the bio-based aqueous polyurethane dispersion. The water-based polyurethane material prepared by the bio-based hydrophilic chain extender has excellent basic performance and the potential of further UV curing crosslinking or functional modification. The bio-based hydrophilic chain extender is a bio-based raw material, replaces a petroleum-based hydrophilic chain extender, remarkably improves the bio-based content of the waterborne polyurethane, and accords with the green environment-friendly trend.

Inventors

• Yuan teng
• TIAN CHAO
• LU JIEHONG
• LU HAOBIAO
• ZHAO WENAI
• CHEN REN

Assignees

• 华南农业大学
• 东莞长联新材料科技股份有限公司

Dates

Publication Date

20260512

Application Date

20260106

Claims (10)

1. 1. The preparation method of the bio-based hydrophilic chain extender is characterized by comprising the following steps: Mixing malic acid, catalyst and allyl glycidyl ether, and reacting at 100-120 ℃ for 2-3h to obtain the product.
2. 2. The preparation method according to claim 1, wherein the catalyst is at least one of p-toluenesulfonic acid, triphenylphosphine, dibutyltin dilaurate and triethylamine, and the amount of the catalyst is 0.03% -0.2% of the sum of the masses of malic acid and allyl glycidyl ether.
3. 3. The preparation method according to claim 1 or 2, wherein the mass ratio of allyl glycidyl ether to malic acid is (10-50): 10-60.
4. 4. A biobased hydrophilic chain extender prepared by the process of any one of claims 1 to 3.
5. 5. The use of the bio-based hydrophilic chain extender of claim 4 in the preparation of bio-based aqueous polyurethane.
6. 6. The preparation method of the bio-based aqueous polyurethane dispersion is characterized by comprising the following steps: Reacting polyol and diisocyanate at 60-90 ℃ for 2-3 hours, adding the bio-based hydrophilic chain extender of claim 4, reacting at 60-80 ℃ for 2-4 hours, cooling to below 50 ℃, adding a solvent for dilution, adding a neutralizing agent for neutralization for 20-40 minutes, adding water for emulsification for 5-15 minutes, adding a chain extender solution for chain extension reaction, and continuing emulsification for 0.5-2 hours to obtain the modified polyurethane foam.
7. 7. The method of claim 6, wherein the polyol is at least one of polycarbonate diol, cashew nutshell oil polyol, castor oil, palm oil polyol; the diisocyanate is at least one of isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate and L-lysine diisocyanate; The solvent is at least one of acetone, 2-butanone and N, N-dimethylacetamide; The neutralizing agent is at least one of triethylamine, dimethylethanolamine, aminoethylpiperazine and ammonia water; The chain extender solution is obtained by mixing a chain extender and water, wherein the chain extender is at least one of piperazine, ethylenediamine, isophorone diamine and diethylenetriamine, and the mass ratio of the chain extender to the water is 1 (3-6).
8. 8. The preparation method according to claim 6 or 7, wherein the raw materials comprise, by mass, 5-30 parts of polyol, 2-6 parts of diisocyanate, 1-4 parts of bio-based hydrophilic chain extender, 10-40 parts of solvent, 0.8-3.6 parts of neutralizer, 35-60 parts of water and 0.1-0.8 part of chain extender solution.
9. 9. A biobased aqueous polyurethane dispersion prepared by the preparation method of any one of claims 6 to 8.
10. 10. Use of the bio-based aqueous polyurethane dispersion according to claim 9 for the preparation of paints, adhesives, leather finishes, inks, flexible sensors, wearable electronics, biomedical products, smart packaging, triboelectric nano-generators.

Description

Bio-based hydrophilic chain extender, preparation method and application thereof Technical Field The invention belongs to the technical field of high polymer materials, and particularly relates to a bio-based hydrophilic chain extender, a preparation method and application thereof. Background With the continuous enhancement of global awareness of environmental protection and sustainable development, environmental protection has become a trend of industry transformation of high polymer materials. The aqueous polyurethane takes water as a dispersion medium, has the advantages of low content of volatile organic compounds, safety, innocuity, adjustable performance, strong adhesive force and the like, gradually replaces the traditional solvent polyurethane, and is widely applied to the fields of paint, adhesive, leather finishing, printing ink and the like. However, its performance is highly dependent on the hydrophilic groups introduced. Currently, in the preparation of anionic aqueous polyurethanes, the most commonly used hydrophilic chain extenders are dimethylolpropionic acid (DMPA) and dimethylolbutyric acid (DMBA), the melting point of DMPA is as high as 189-191 ℃, and the melting point of DMBA is 108-115 ℃, all much higher than the conventional reaction temperature (typically 60-90 ℃) for polyurethane synthesis. DMPA and DMBA have inherent defects of high melting point and low solubility, are difficult to melt at the conventional temperature for preparing aqueous polyurethane, and are susceptible to heterogeneous reaction during polymerization. In order to make the polymer melt and uniformly participate in the reaction, researchers often promote the reaction by increasing the reaction temperature or prolonging the reaction time or adding a large amount of organic solvents such as N-methyl pyrrolidone for dissolution, and the scheme not only increases the process complexity, cost and environmental pollution, aggravates the energy consumption and increases the side reaction risk, but also causes wider emulsion particle size distribution, thereby influencing the storage stability of the emulsion. Therefore, the development of the novel hydrophilic chain extender which is liquid at the conventional reaction temperature, is easy to process and has excellent performance has important significance for simplifying the preparation process of the aqueous polyurethane, reducing the energy consumption and the cost and improving the performance of the product. Disclosure of Invention The first object of the invention is to provide a preparation method of the bio-based hydrophilic chain extender, the second object of the invention is to provide the bio-based hydrophilic chain extender prepared by the preparation method, and the third object of the invention is to provide the application of the bio-based hydrophilic chain extender. According to a first aspect of the present invention, there is provided a method of preparing a bio-based hydrophilic chain extender comprising the steps of: Mixing malic acid, catalyst and allyl glycidyl ether, and reacting at 100-120 ℃ for 2-3h to obtain the product. According to the invention, a ring-opening reaction is carried out on carboxyl in malic acid and epoxy groups in allyl glycidyl ether, 1 carboxyl is consumed, and simultaneously, 1 hydroxyl is newly generated through ring opening of epoxy, so that the bio-based hydrophilic chain extender (AGMA) is finally prepared. While the epoxy group of the allyl glycidyl ether is consumed, the allyl double bond is reserved in the AGMA molecule, and when the subsequent AGMA is used as a functional monomer to participate in polyurethane chain extension, the double bond is synchronously connected into the polyurethane main chain along with the AGMA. Therefore, AGMA contains carboxyl in the structure to provide hydrophilicity, hydroxyl to participate in polyurethane chain extension, and allyl double bond to provide modification site. Therefore, AGMA has three functions of hydrophilicity, chain extension and modification. According to the invention, hydrophilic groups, hydroxyl chain extension sites and allyl double bonds are integrated into the same molecule of AGMA, and the AGMA is used as a functional monomer to participate in polyurethane reaction, so that random reaction of the functional groups is avoided, the reaction process is more controllable, byproducts are fewer, the molecular weight distribution of the product is narrower, and the molecular structure regularity is higher. In some embodiments, the catalyst is at least one of p-toluenesulfonic acid, triphenylphosphine, dibutyltin dilaurate, triethylamine in an amount of 0.03% to 0.2% of the sum of the masses of malic acid and allyl glycidyl ether. In some embodiments, the mass ratio of allyl glycidyl ether to malic acid is (10-50): 10-60. According to a second aspect of the present invention there is provided a biobased hydrophilic chain extender prepared by the above preparation met