Preparation method and application of hindered amine nanodot light stabilizer

Abstract

This invention discloses a method for preparing hindered amine nanoparticle light stabilizers and their applications. The preparation method includes: adding polyethyleneimine to deionized water and allowing it to dissolve completely; then adding triacetone amine to the polyethyleneimine solution; heating the reaction in a water bath; cooling the reaction solution to room temperature after the reaction is complete; dialyzing the reaction solution using a dialysis bag; and freeze-drying the dialyzed solution to obtain the hindered amine nanoparticle light stabilizer. The hindered amine nanoparticle light stabilizer of this invention has good thermal stability, is simple to synthesize, and exhibits excellent light stabilization effects on polyolefins and polyamides, as well as superior anti-aging effects.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, and particularly relates to the preparation method and application of hindered amine nanodot light stabilizers. Background Technology

[0002] Polymer materials, such as plastics, rubber, and fibers, play an increasingly important role in our production and daily lives. However, during storage and use, organic polymer materials often exhibit aging phenomena such as yellowing, brittleness, cracking, loss of surface gloss, and reduced mechanical and electrical properties under conditions of light, oxygen, and heat, leading to a shortened lifespan. This is mainly because polymer materials undergo photodegradation or photooxidation under ultraviolet light, which damages their structure. Therefore, light stabilizers are typically added to polymer materials to delay photoaging and extend the lifespan of the materials.

[0003] To improve the resistance to photoaging of plastic materials and extend their service life, adding light stabilizers is considered the most effective and convenient method. Currently used light stabilizers can be categorized into ultraviolet absorbers, excitation quenchers, opacifiers, hydroperoxide decomposers, and free radical scavengers. However, most light stabilizers have drawbacks, such as cumbersome reaction steps, harsh reaction conditions, low yield and purity, highly toxic reducing agents, high cost of heavy metal catalysts and reducing agents, and severe pollution, which greatly limit their application. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing hindered amine nanodot light stabilizers and their applications, in order to solve the problems of existing light stabilizers, such as complicated reaction steps, harsh reaction conditions, low yield and purity, high toxicity of reducing agents, high cost of heavy metal catalysts and reducing agents, and serious pollution.

[0005] The present invention adopts the following technical solution: a method for preparing hindered amine nanoparticle light stabilizers for polymer materials, comprising: transferring polyethyleneimine into deionized water, and after it is completely dissolved, adding triacetone amine into the polyethyleneimine solution, heating the reaction in a water bath, cooling to room temperature after the reaction is completed, dialyzing the reaction solution using a dialysis bag, and freeze-drying the dialyzed solution to obtain the hindered amine nanoparticle light stabilizer.

[0006] Furthermore, the mass ratio of polyethyleneimine to triacetoneamine is 2.5:(0.3-2).

[0007] Furthermore, the water bath heating reaction conditions are 70–100°C for 4–8 hours.

[0008] Furthermore, the dialysis conditions are a molecular weight cutoff of 1000 Da and dialysis for 2-5 days.

[0009] A polymeric material containing a hindered amine nanoparticle light stabilizer, wherein the hindered amine nanoparticle light stabilizer is added at a mass fraction of 0.1%-0.5%, and the hindered amine nanoparticle light stabilizer is prepared by the above-described preparation method.

[0010] The beneficial effects of this invention are:

[0011] 1. The hindered amine nanoparticle light stabilizer of the present invention has good thermal stability, light color, good material compatibility, and simple synthesis. It has excellent light stabilization effect on plastic materials such as polyolefins and polyamides, and better anti-aging effect.

[0012] 2. The preparation method of the present invention has a high raw material conversion rate, the conditions are easy to achieve, the overall reaction is simple and easy to operate, the cost is low, the environment is environmentally friendly, it is easy to produce on a large scale, and it has the prospect of industrial production. Attached Figure Description

[0013] Figure 1 The infrared spectrum of the hindered amine nanoparticle light stabilizer synthesized in Example 1 of this invention;

[0014] Figure 2 The mechanical properties of the hindered amine nanodot light stabilizer synthesized in Example 1 of this invention are tested in PE films at different aging times.

[0015] Figure 2 (a) Relationship between aging time and elongation at break retention (%) for different addition amounts;

[0016] Figure 2 (b) Relationship between aging time and tensile strength retention rate (%) for different addition amounts;

[0017] Figure 3 Mechanical property test diagrams of the hindered amine nanodot light stabilizer synthesized in Example 1 of this invention applied to PP film at different aging times;

[0018] Figure 3 (a) Relationship between aging time and elongation at break retention (%) for different addition amounts;

[0019] Figure 3 (b) The relationship between aging time and tensile strength retention rate (%) for different addition amounts. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0022] This invention discloses a method for preparing hindered amine nanoparticle light stabilizers for polymer materials, comprising: transferring polyethyleneimine into deionized water, and after it is completely dissolved, adding triacetone amine to the polyethyleneimine solution, heating the reaction in a water bath, cooling to room temperature after the reaction is completed, dialyzing the reaction solution using a dialysis bag, and freeze-drying the dialyzed solution to obtain the hindered amine nanoparticle light stabilizer.

[0023] The mass ratio of polyethyleneimine to triacetoneamine is 2.5:(0.3-2).

[0024] The water bath heating reaction conditions are 70-100℃ for 4-8 hours.

[0025] The dialysis conditions are: a molecular weight cutoff of 1000 Da and dialysis for 2-5 days.

[0026] The present invention also discloses a polymeric material containing a hindered amine nanoparticle light stabilizer, wherein the hindered amine nanoparticle light stabilizer is added at a mass fraction of 0.1%-0.5%, and the hindered amine nanoparticle light stabilizer is prepared by the above method.

[0027] Example 1

[0028] 2.5 mL of polyethyleneimine was added to 25 mL of deionized water and allowed to dissolve completely. Then, 0.3 g of triacetone amine was added to the dissolved polyethyleneimine solution. The mixture was heated in a water bath at 80 °C for 6 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was dialyzed for 3 days using a 1000 Da dialysis bag. The dialyzed solution was then freeze-dried to obtain the hindered amine nanoparticle light stabilizer.

[0029] The infrared spectral characteristic absorption peaks of the hindered amine nanodot light stabilizer synthesized in this embodiment are analyzed as follows: Figure 1 As shown, compared to the precursor polyethyleneimine, at 1665 cm⁻¹ -1 The appearance of a C=N bond stretching vibration peak indicates the successful synthesis of the hindered amine nanodot light stabilizer.

[0030] Example 2

[0031] 2.5 mL of polyethyleneimine was added to 25 mL of deionized water and allowed to dissolve completely. Then, 1 g of triacetone amine was added to the dissolved polyethyleneimine solution. The mixture was heated in a water bath at 80 °C for 6 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was dialyzed for 3 days using a 1000 Da dialysis bag. The dialyzed solution was then freeze-dried to obtain the hindered amine nanoparticle light stabilizer.

[0032] Example 3

[0033] 2.5 mL of polyethyleneimine was added to 25 mL of deionized water and allowed to dissolve completely. Then, 2 g of triacetone amine was added to the dissolved polyethyleneimine solution. The mixture was heated in a water bath at 80 °C for 6 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was dialyzed for 3 days using a 1000 Da dialysis bag. The dialyzed solution was then freeze-dried to obtain the hindered amine nanoparticle light stabilizer.

[0034] Example 4

[0035] 2.5 mL of polyethyleneimine was added to 25 mL of deionized water and allowed to dissolve completely. Then, 2 g of triacetone amine was added to the dissolved polyethyleneimine solution. The mixture was heated in a water bath at 100 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was dialyzed for 3 days using a 1000 Da dialysis bag. The dialyzed solution was then freeze-dried to obtain the hindered amine nanoparticle light stabilizer.

[0036] Example 5

[0037] The hindered amine nanodot light stabilizer prepared in Example 1 was doped into PP and PE materials at mass fractions of 0.1%, 0.3%, and 0.5% to prepare PE and PP films, and then photoaging experiments were conducted on the PE and PP films.

[0038] The mechanical properties of the hindered amine nanodot light stabilizer-doped PE film synthesized in Example 1 at different aging times are shown in the figure below. Figure 2 As shown, the results indicate that, compared with the film without added light stabilizer, the addition of a low amount of light stabilizer can significantly improve the anti-aging effect of the PE film.

[0039] The mechanical properties of the hindered amine nanodot light stabilizer-doped PP film synthesized in Example 1 at different aging times are shown in the figure below. Figure 3 As shown, the results indicate that, compared with the film without added light stabilizer, the addition of a low amount of light stabilizer can significantly improve the anti-aging effect of PP film.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing hindered amine nanoparticle light stabilizers for polymer materials, characterized in that, include: Polyethyleneimine was added to deionized water and allowed to dissolve completely. Then, triacetone amine was added to the polyethyleneimine solution and the reaction was carried out in a water bath. After the reaction was completed, the solution was cooled to room temperature and dialyzed using a dialysis bag. The dialyzed solution was then freeze-dried to obtain a hindered amine nanoparticle light stabilizer. The mass ratio of polyethyleneimine to triacetoneamine is 2.5:(0.3-2).

2. The method for preparing hindered amine nanoparticle light stabilizers for polymer materials according to claim 1, characterized in that, The reaction is carried out under water bath heating conditions of 70~100 ℃ for 4~8 hours.

3. The method for preparing hindered amine nanoparticle light stabilizers for polymer materials according to claim 1, characterized in that, The dialysis conditions are a molecular weight cutoff of 1000 Da and dialysis for 2-5 days.

4. A polymeric material containing hindered amine nanoparticle light stabilizers, characterized in that, The hindered amine nanodot light stabilizer is added at a mass fraction of 0.1%-0.5%, and the hindered amine nanodot light stabilizer is prepared according to any one of claims 1-3.

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