Application of hydrazide nucleating agent containing long alkyl chain in polyethylene glycol terephthalate
By introducing a nucleating agent containing a long alkyl chain into polyethylene terephthalate, the problem of insufficient toughness was solved, the regular arrangement of molecular chains and the enhancement of interfacial bonding were achieved, and the notched impact strength was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2026-02-06
- Publication Date
- 2026-05-15
AI Technical Summary
The lack of toughness of polyethylene terephthalate limits the expansion of its application range.
By using hydrazide nucleating agents containing long alkyl chains, and uniformly dispersing them in a polyethylene terephthalate matrix, the crystallization behavior is improved to enhance toughness through the lubrication effect of the long alkyl chains and the hydrogen bonding interaction of the -NH groups.
It significantly improves the toughness of polyethylene terephthalate, enhances interfacial bonding, promotes regular molecular chain arrangement, and improves notched impact strength.
Abstract
Description
Technical Field
[0001] This invention relates to the application of a nucleating agent containing a long alkyl chain acylhydrazine in polyethylene terephthalate, belonging to the field of polymer materials technology. Background Technology
[0002] Polyethylene terephthalate (PET), a thermoplastic general-purpose plastic, has been widely used in automotive parts, electronic appliance housings, food packaging, medical devices, and textile fibers due to its excellent abrasion resistance, chemical resistance, dimensional stability, and good processing flowability. However, the presence of rigid benzene rings in the PET molecular chain results in strong intermolecular forces and limited chain segment mobility, leading to insufficient toughness, which has become a core bottleneck restricting its further expansion of applications.
[0003] Therefore, improving the toughness of polyethylene terephthalate (PET) is an important issue in its high-value utilization. There is an urgent need to develop a nucleating agent that can be uniformly dispersed in the PET matrix and can enhance its toughness by improving the crystallization behavior of PET, so as to solve the practical problems of PET and broaden its application range. Summary of the Invention
[0004] This invention provides the application of a long-alkyl-chain acylhydrazine nucleating agent in polyethylene terephthalate (PET). The long alkyl chain structure in this acylhydrazine nucleating agent acts as a lubricant within the PET matrix, promoting the regular arrangement of its molecular chains. Simultaneously, the abundant -NH groups on the nucleating agent's molecular chain can form hydrogen bonds, significantly enhancing the interfacial bonding between the two and ensuring uniform dispersion within the PET matrix, thereby maximizing its toughening effect.
[0005] This invention provides a nucleating agent containing a long alkyl chain acylhydrazine, prepared according to the following method: S1. Dissolve 18.4 g of cyanuric chloride in 300 mL of acetone, keeping the system temperature at 0 °C. Then dissolve 23.2 g of sodium phenolate in 100 mL of distilled water. Add the above sodium phenolate aqueous solution dropwise to the system over 30 min and stir at 400 rpm for 6 h. After the reaction is complete, add 300 mL of distilled water to the system to precipitate the product. Filter the product and wash it with 200 mL of distilled water. Then dry the product at 80 °C to constant weight to obtain intermediate product A. S2. Dissolve 15.2 g of p-hydroxybenzoyl hydrazide in 100 mL of acetone and 4 g of sodium hydroxide in 50 mL of distilled water. Mix the two solutions and stir at 400 rpm for 2 h. After the reaction is complete, add 29.9 g of intermediate product A to the system, keep the system temperature at 0 °C, and stir at 400 rpm for 8 h. After the reaction is complete, add 150 mL of distilled water to precipitate the product, filter, wash with 200 mL of distilled water, and then dry the product at 80 °C to constant weight to obtain intermediate product B. S3. Dissolve 41.5 g of intermediate product B in 150 mL of acetone, add 8 mL of pyridine, and simultaneously dissolve 30.3 g of stearoyl chloride in 100 mL of acetone. Add the above acetone solution of stearoyl chloride dropwise to the system over 30 min, and stir the reaction at 400 rpm for 12 h at room temperature. After the reaction is complete, add 200 mL of distilled water to the system to extract the product, filter it, and wash it with ethanol until neutral. Then dry the product at 80 °C to constant weight to obtain the nucleating agent containing a long alkyl chain hydrazide.
[0006] The various reaction conditions and parameters in the preparation method of the acylhydrazine nucleating agent containing a long alkyl chain described in this invention are all optimal conditions that have been experimentally verified.
[0007] The reaction temperature and time of this invention are determined based on the boiling point and reactivity of the solvent, and the above-mentioned reaction conditions are the optimal conditions verified by experiments.
[0008] The present invention has been verified that the solvents, their amounts, temperatures, and drying conditions used in the impurity removal process during the reaction are all determined based on the solubility of the impurities that may appear during the reaction and the boiling point of the solvent. The above-mentioned impurity removal methods are all optimal conditions verified by experiments, which can fully remove unreacted impurities and ensure economy. In addition, if the drying temperature of the product is too high or too low, the drying effect cannot be guaranteed.
[0009] The present invention also provides the application of a nucleating agent containing a long alkyl chain acylhydrazine in polyethylene terephthalate, wherein the amount of the nucleating agent containing the long alkyl chain acylhydrazine is 0.5%-2% of the mass of polyethylene terephthalate.
[0010] Preferably, the amount of the nucleating agent containing a long alkyl chain hydrazide is 0.7% of the mass of polyethylene terephthalate.
[0011] The amount of the nucleating agent containing long alkyl chains synthesized in this invention must be appropriate. If the amount added is too small, the expected effect will not be achieved. If the amount added is too large, the performance improvement limit will be reached, resulting in the waste of the nucleating agent containing long alkyl chains. The above-mentioned addition amount is the optimal condition verified by experiments.
[0012] Compared with the prior art, the present invention has the following technical effects.
[0013] 1. The long alkyl chain structure in the aforementioned alkyl-containing hydrazide nucleating agent acts as a lubricant in the polyethylene terephthalate matrix, promoting the regular arrangement of its molecular chains and thus improving its toughness.
[0014] 2. The abundant -NH on the molecular chain of the long alkyl chain hydrazide nucleating agent can form hydrogen bonds with polyethylene terephthalate, greatly enhancing the interfacial bonding force between the two and allowing it to be uniformly dispersed in the polyethylene terephthalate matrix, thereby ensuring the full realization of its toughening effect. Specific implementation methods
[0015] To make the technical problems, technical solutions and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0016] The polyethylene terephthalate (brand name: WK-801), cyanuric chloride (CAS: 108-77-0), sodium phenolate (CAS: 139-02-6), p-hydroxybenzoyl hydrazine (CAS: 5351-23-5), sodium hydroxide (CAS: 1310-73-2), and stearoyl chloride (CAS: 112-76-5) used in this invention are all commercially available in this technical field.
[0017] Example 1 18.4 g of cyanuric chloride was dissolved in 300 mL of acetone, and the system temperature was maintained at 0 °C. Then, 23.2 g of sodium phenolate was dissolved in 100 mL of distilled water. The sodium phenolate aqueous solution was added dropwise to the system over 30 min, and the mixture was stirred at 400 rpm for 6 h. After the reaction was completed, 300 mL of distilled water was added to the system to precipitate the product. The product was filtered, washed with 200 mL of distilled water, and then dried at 80 °C to constant weight to obtain intermediate product A. 15.2 g of p-hydroxybenzoyl hydrazine was dissolved in 100 mL of acetone, and 4 g of sodium hydroxide was dissolved in 50 mL of distilled water. The two solutions were mixed and stirred at 400 rpm for 2 h. After the reaction was completed, 29.9 g of intermediate product A was added to the system, and the system temperature was maintained at 0 °C. The mixture was stirred at 400 rpm for 8 h. After the reaction was completed, 150 mL of distilled water was added to the system to precipitate the product. The product was filtered, washed with 200 mL of distilled water, and then dried at 80 °C to constant weight to obtain intermediate product A. The product was dried to constant weight at ℃ to obtain intermediate product B; 41.5 g of intermediate product B was dissolved in 150 mL of acetone, 8 mL of pyridine was added, and 30.3 g of stearoyl chloride was dissolved in 100 mL of acetone. The above acetone solution of stearoyl chloride was added dropwise to the system over 30 min, and the reaction was stirred at 400 rpm for 12 h at room temperature. After the reaction was completed, 200 mL of distilled water was added to the system to extract the product, which was then filtered and washed with ethanol until neutral. The product was then dried to constant weight at 80 ℃ to obtain the nucleating agent containing a long alkyl chain hydrazide. The long-alkyl-chain acylhydrazine nucleating agent and polyethylene terephthalate were mixed in a high-speed mixer at a mass ratio of 0.7:100 (mixing speed 3000 rpm, mixing time 3 min). After extrusion and granulation in a conventional twin-screw extruder, samples were prepared and their notched impact strength was measured according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0018] Example 2 This embodiment is basically the same as Example 1, except that the sample was prepared by using the long-alkyl-chain acylhydrazine nucleating agent synthesized in Example 1 and polyethylene terephthalate at a mass ratio of 2:100. The test data are shown in Table 1.
[0019] Example 3 This embodiment is basically the same as Example 1, except that the sample was prepared by using the long alkyl chain acylhydrazine nucleating agent synthesized in Example 1 and polyethylene terephthalate at a mass ratio of 0.5:100. The test data are shown in Table 1.
[0020] Comparative Example 1 After pure polyethylene terephthalate was extruded and granulated in a conventional twin-screw extruder, samples were prepared and their notched impact strength was determined according to the method specified in GB / T1043-2008. The specific data are shown in Table 1.
[0021] Comparative Example 2 The raw materials, cyanuric chloride and polyethylene terephthalate, were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0022] Comparative Example 3 Sodium phenolate and polyethylene terephthalate were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0023] Comparative Example 4 The raw materials p-hydroxybenzoyl hydrazide and polyethylene terephthalate were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0024] Comparative Example 5 Sodium hydroxide and polyethylene terephthalate were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0025] Comparative Example 6 The raw materials, stearoyl chloride and polyethylene terephthalate, were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0026] Comparative Example 7 Intermediate product A and polyethylene terephthalate were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0027] Comparative Example 8 Intermediate product B and polyethylene terephthalate were extruded and granulated in a conventional twin-screw extruder at a mass ratio of 0.7:100. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T 1043-2008. The specific data are shown in Table 1.
[0028] Comparative Example 9 18.4 g of cyanuric chloride, 23.2 g of sodium phenolate, 15.2 g of p-hydroxybenzoyl hydrazine, 4 g of sodium hydroxide, and 30.3 g of stearoyl chloride were conventionally mixed in a high-speed mixer (mixing speed 3000 rpm, mixing time 3 min). Then, they were extruded with polyethylene terephthalate at a mass ratio of 0.7:100 in a conventional twin-screw extruder and granulated. Samples were prepared and their notched impact strength was determined according to the method specified in GB / T1043-2008. The specific data are shown in Table 1.
[0029] Table 1 Test results for each embodiment and comparative example <![CDATA[Izod impact strength (kJ / m 2 )]]> Example 1 3.6 Example 2 3.3 Example 3 3.1 Comparative Example 1 1.8 Comparative Example 2 1.4 Comparative Example 3 1.6 Comparative Example 4 1.9 Comparative Example 5 1.5 Comparative Example 6 1.4 Comparative Example 7 1.7 Comparative Example 8 2.2 Comparative Example 9 1.3 According to the test results in Table 1, the notched impact strength of polyethylene terephthalate (PET) in Examples 1-3 was higher than that in the comparative examples after adding the long-alkyl-chain acylhydrazine nucleating agent prepared in this invention. Example 1, with an addition amount of 0.7%, showed the best performance. Compared to pure PET in Comparative Example 1, this demonstrates that the long-alkyl-chain acylhydrazine nucleating agent synthesized in this invention significantly improves the notched impact strength of PET. Furthermore, both excessive and insufficient addition of the long-alkyl-chain acylhydrazine nucleating agent will adversely affect the notched impact strength of the recovered PET.
[0030] The long alkyl chain structure in the alkyl hydrazide nucleating agent prepared in this invention acts as a lubricant in the polyethylene terephthalate (PET) matrix, promoting the regular arrangement of its molecular chains. Simultaneously, the abundant -NH groups on the nucleating agent molecular chains can form hydrogen bonds with the PET matrix, significantly enhancing the interfacial bonding force and ensuring uniform dispersion within the PET matrix, thereby guaranteeing the full realization of its toughening effect. In contrast, Comparative Examples 2-9 only added a single raw material, intermediate product, or a simple mixture of raw materials, and therefore could not achieve the desired effect. Specifically, Comparative Examples 2-6 used a single raw material, and the aforementioned effects could not be realized. The addition of cyanuric chloride in Comparative Example 2 and stearoyl chloride in Comparative Example 6 caused chain scission of polyethylene terephthalate (PET). Sodium phenolate in Comparative Example 3 and sodium hydroxide in Comparative Example 5 reacted with the ends of PET to form anionic end groups, resulting in chemical nucleation and chain breakage. Therefore, the notched impact strength of Comparative Examples 2, 3, 5, and 6 decreased significantly. The addition of p-hydroxybenzoyl hydrazine in Comparative Example 4 formed hydrogen bonds with the ester groups in PET, helping to increase the entanglement density of the PET molecular chain and thus slightly improving its notched impact strength. However, p-hydroxybenzoyl hydrazine is highly polar and easily aggregates in PET, resulting in poor dispersibility and affecting its effectiveness. Although intermediate product A added in Comparative Example 7 has a relatively stable chemically synthesized structure, the residual chlorine atoms in its molecule cause chain breakage and generate hydrogen chloride gas during high-temperature processing of polyethylene terephthalate (PET), which easily leads to a decrease in the molecular weight of PET, thus slightly reducing its notched impact strength. Intermediate product B added in Comparative Example 8, due to the presence of an acylhydrazine group in its molecular structure, has a further improved effect compared to Comparative Examples 7 and 4; however, its molecular chain lacks long alkyl chains, therefore its effect is worse than the examples. Comparative Example 9 is a simple physical mixture of raw materials and cannot form the nucleating agent molecular structure described in this invention. Although the addition of multiple raw materials provides favorable conditions such as -NH, its effect is the worst among all examples and comparative examples due to internal decomposition and chain breakage factors.
[0031] 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 and improvements made within the spirit and principles of the present invention should be included within the scope of the present invention.
Claims
1. A nucleating agent containing a long alkyl chain acylhydrazine, characterized in that, Prepared as follows: S1. Dissolve 18.4 g of cyanuric chloride in 300 mL of acetone, keeping the system temperature at 0 °C. Then dissolve 23.2 g of sodium phenolate in 100 mL of distilled water. Add the above sodium phenolate aqueous solution dropwise to the system over 30 min and stir at 400 rpm for 6 h. After the reaction is complete, add 300 mL of distilled water to the system to precipitate the product. Filter the product and wash it with 200 mL of distilled water. Then dry the product at 80 °C to constant weight to obtain intermediate product A. S2. Dissolve 15.2 g of p-hydroxybenzoyl hydrazide in 100 mL of acetone and 4 g of sodium hydroxide in 50 mL of distilled water. Mix the two solutions and stir at 400 rpm for 2 h. After the reaction is complete, add 29.9 g of intermediate product A to the system, keep the system temperature at 0 °C, and stir at 400 rpm for 8 h. After the reaction is complete, add 150 mL of distilled water to precipitate the product, filter, wash with 200 mL of distilled water, and then dry the product at 80 °C to constant weight to obtain intermediate product B. S3. Dissolve 41.5 g of intermediate product B in 150 mL of acetone, add 8 mL of pyridine, and simultaneously dissolve 30.3 g of stearoyl chloride in 100 mL of acetone. Add the above acetone solution of stearoyl chloride dropwise to the system over 30 min, and stir the reaction at 400 rpm for 12 h at room temperature. After the reaction is complete, add 200 mL of distilled water to the system to extract the product, filter it, and wash it with ethanol until neutral. Then dry the product at 80 °C to constant weight to obtain the nucleating agent containing a long alkyl chain hydrazide.
2. The application of the long alkyl chain acylhydrazine nucleating agent according to claim 1 in polyethylene terephthalate.
3. The application of a long-alkyl-chain acylhydrazine nucleating agent according to claim 2 in polyethylene terephthalate, characterized in that, The amount of the nucleating agent containing a long alkyl chain hydrazide is 0.5%-2% of the mass of polyethylene terephthalate.
4. The application of a long-alkyl-chain acylhydrazine nucleating agent according to claim 3 in polyethylene terephthalate, characterized in that, The amount of the nucleating agent containing a long alkyl chain hydrazide is 0.7% of the mass of polyethylene terephthalate.