A phosphonamide derivative nucleating agent and its preparation method and application

Abstract

The invention discloses a phosphonamide derivative nucleating agent and a preparation method and application thereof. A methoxyphenol compound is oxidized by iodophenyl diacetate and then reacted with an excess of glycine ethyl ester hydrochloride to prepare a methoxyaniline compound, and then the methoxyaniline compound is reacted with phenylphosphonyl dichloride to obtain a phosphonamide derivative nucleating agent. The nucleating agent of the invention is used for preparing a polylactic acid composition, can provide good nucleation efficiency for polylactic acid during the preparation process, and the nucleation effect is very stable. At a low content, the phosphonamide derivative nucleating agent of the application can not only effectively improve the crystallization ability of PLA, but also achieve the flame retardant effect of PLA. The nucleating agent of the application has the potential for application in multiple fields, is easy to realize large-scale production, and can be widely used in the preparation of industrial polylactic acid plastic products.

Description

Technical Field

[0001] The invention belongs to the technical field of plastic additives, and particularly relates to a phosphonamide derivative nucleating agent for improving the flame retardancy and crystallization ability of polylactic acid, and a preparation method and application thereof. Background Art

[0002] In the past few decades, petrochemical-based plastics have been increasingly used in people's daily lives due to their advantages such as easy processing, light weight and excellent comprehensive performance. However, with the large-scale disposal of non-degradable plastics, the problem of white pollution has attracted widespread attention. Polylactic acid (PLA), a biodegradable polyester derived from corn, cassava and sugar beet extracts, is a promising biodegradable alternative to traditional petroleum-based plastics such as polystyrene (PS) and polyethylene terephthalate (PET). Nowadays, new application areas of PLA have been explored, such as electrical equipment, automotive materials, textiles, etc. However, the shortcomings of PLA resin such as brittleness, flammability, slow crystallization rate and poor crystallinity have seriously hindered the development of PLA in various fields.

[0003] To date, many flame retardants based on halogens, minerals and other compounds have been developed and can actually solve the flame retardancy problem of PLA. However, some of these compounds, especially halogenated flame retardants, have been gradually avoided or banned due to their negative impact on the environment and health, and the excessive use of flame retardants with a single function will also further limit the application field of PLA. In order to overcome the above problems, the flame retardancy and crystallization ability of PLA are usually improved by adding two or more additives, but the poor compatibility of multiple additives will lead to a decrease in the mechanical properties of PLA products, which also limits the wider application of degradable PLA with a sustainable development strategy. Therefore, it is a significant task to develop a sustainable multifunctional bio-based nucleating agent to expand the application scope of PLA. Summary of the invention

[0004] The object of the present invention is to overcome the above technical defects and provide a multifunctional phosphamide derivative nucleating agent for improving the flame retardancy of polylactic acid and accelerating the crystallization rate of PLA during the molding process to improve the crystallinity, heat resistance and impact strength of PLA.

[0005] The present invention is achieved through the following technical solutions:

[0006] A phosphamide derivative nucleating agent, wherein the phosphamide derivative nucleating agent has the following structure:

[0007]

[0008] Wherein, R is a methoxy group, and R is substituted at the 2-position, 3-position or 4-position of the benzene ring.

[0009] When R is substituted at the 2-position of the benzene ring, it is N,N′-bis(2-methoxyphenyl)-phenylphosphine diamide, and its structure is as follows:

[0010]

[0011] When R is substituted at the 3-position of the benzene ring, it is N,N′-bis(3-methoxyphenyl)-phenylphosphine diamide, and its structure is as follows:

[0012]

[0013] When R is substituted at the 4-position of the benzene ring, it is N,N′-bis(4-methoxyphenyl)-phenylphosphonic acid diamide, and its structure is as follows:

[0014]

[0015] The present invention provides a method for preparing a phosphamide derivative nucleating agent, comprising the following steps:

[0016] S1: dissolving a methoxyphenol compound in solvent a, adding iodophenyl diacetate for oxidation reaction, adding an excess of glycine ethyl ester hydrochloride for reaction, and obtaining a methoxyaniline compound;

[0017] S2: dissolving the methoxyaniline compound obtained in S1 in solvent b, dispersing it evenly, and dropping an acid-binding agent to obtain a mixed solution;

[0018] S3: adding phenylphosphonyl dichloride to solvent c to obtain a phenylphosphonyl dichloride solution;

[0019] S4: The reaction temperature is -10 to 20°C, and the phenylphosphonic acid dichloride solution of S3 is added dropwise to the mixed solution of S2. After the addition is completed, the mixture is kept warm under stirring, and then the temperature is raised to 60 to 80°C and the stirring reaction is continued. After stopping the stirring, a reaction solution is obtained;

[0020] S5: The reaction solution of S4 is filtered to obtain a filtrate, and the phosphonamide derivative nucleating agent is obtained after precipitation, washing, suction filtration and drying.

[0021] Preferably, the methoxyphenol compound in S1 is selected from any one of 2-methoxyphenol, 3-methoxyphenol or 4-methoxyphenol; the obtained methoxyaniline compound is any one of the corresponding 2-methoxyaniline, 3-methoxyaniline or 4-methoxyaniline; the solvent a is selected from any one or more of methanol or ethanol; the temperature of the oxidation reaction is -10 to 10°C; and the time of the oxidation reaction is 1 to 3 hours.

[0022] Methoxyphenol compounds can be purchased commercially or extracted from lignin. The conventional method for extracting methoxyphenol compounds from lignin is to obtain methoxyphenol compounds from pine wood rich in guaiacol-type lignin by platinum / carbon catalytic reduction and depolymerization.

[0023] Anisidine compounds can be prepared by reacting methoxyphenol compounds, or can be purchased commercially.

[0024] Preferably, the solvent b in S2 and the solvent c in S3 are selected from any one or more of anhydrous tetrahydrofuran, anhydrous acetonitrile, anhydrous dioxane, N-methylpyrrolidone or N,N-dimethylformamide; and the dispersion method in S2 is ultrasonic dispersion.

[0025] Preferably, the molar concentration of the methoxyaniline compound in the mixed solution in S2 is 0.2-1.2 mol / L; the acid-binding agent in S2 is selected from any one or more of triethylamine, pyridine or diisopropylethylamine, and the molar concentration of the acid-binding agent is 0.5-1.5 mol / L.

[0026] Preferably, the molar concentration of the phenylphosphonic dichloride solution in S3 is 0.1 to 0.4 mol / L.

[0027] Preferably, the dropping process in S4 is carried out in a nitrogen atmosphere, the total time for dropping the phenylphosphonic dichloride solution of S3 into the mixed solution of S2 in S4 is 1 to 3 hours, the temperature of the insulation reaction is -10 to 10°C, and the insulation reaction time is 1 to 3 hours; the time for continuing to stir the reaction at 60 to 80°C in S4 is 12 to 36 hours.

[0028] Preferably, the precipitation liquid used in the precipitation process in S5 is selected from deionized water, and the washing liquid used in the washing process is selected from ethanol.

[0029] The present invention provides application of the above-mentioned phosphonamide derivative nucleating agent for preparing a polylactic acid composition.

[0030] The present invention also provides a polylactic acid composition, comprising the phosphonamide derivative nucleating agent and polylactic acid.

[0031] The present invention has the following beneficial effects:

[0032] (1) The present invention uses methoxyphenol compounds as raw materials and prepares phosphonamide derivative nucleating agents through two-step synthesis. The raw materials are derived from bio-based materials and are green and environmentally friendly. The final product processing cost is low, and the nucleating agent yield reaches more than 80%.

[0033] (2) The nucleating agent of the present invention has a significant effect of promoting the crystallization of PLA in polylactic acid, can provide good nucleation efficiency for polylactic acid during the preparation process, and the nucleation effect is very stable. After adding the nucleating agent, the impact strength of PLA is improved. This is because the addition of the nucleating agent of the present application improves the crystallinity of PLA. Under the condition of adding 1wt% of the nucleating agent of the present application, the PLA composition has good crystallinity and excellent mechanical properties.

[0034] (3) After adding the nucleating agent of the present application, the heat deformation temperature (HDT) of PLA increased significantly, and increased with the extension of annealing time. After annealing for 40 seconds, the HDT of the PLA material to which the nucleating agent of the present application was added reached above 117°C.

[0035] (4) After adding the nucleating agent, the flame retardant properties of PLA are improved. The flame retardant grade of the PLA material with 1wt% of the nucleating agent of the present application all reaches V-0, indicating that at a low content, the phosphonamide derivative nucleating agent of the present application can not only effectively improve the crystallization ability of PLA, but also achieve the flame retardant effect of PLA, and has the potential for application in multiple fields, is easy to achieve large-scale production, and can be widely used in the preparation of industrial polylactic acid plastic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention provides a synthetic route for the phosphamide derivative nucleating agent.

[0037] Figure 2 This is the H NMR spectrum of the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic diamide.

[0038] Figure 3 This is the H NMR spectrum of the nucleating agent N,N′-bis(3-methoxyphenyl)-phenylphosphonic diamide.

[0039] Figure 4 This is the H NMR spectrum of N,N′-bis(4-methoxyphenyl)-phenylphosphonic acid diamide nucleating agent.

[0040] Figure 5 This is the DSC spectrum of N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide nucleating agent added to PLA.

[0041] Figure 6 This is the DSC spectrum of N,N′-bis(3-methoxyphenyl)-phenylphosphonic acid diamide nucleating agent added to PLA.

[0042] Figure 7 This is the DSC spectrum of N,N′-bis(4-methoxyphenyl)-phenylphosphonic acid diamide nucleating agent added to PLA.

[0043] Figure 8This is the DSC spectrum of the commercial nucleating agent ExolitAP added to PLA. DETAILED DESCRIPTION

[0044] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0045] The raw materials used in the present invention are all commercially available.

[0046] Various test methods:

[0047] (1) DSC test: According to the determination method of GB1662-81, the non-isothermal crystallization and melting behavior of polylactic acid was studied on a differential scanning calorimeter, the atmosphere was nitrogen, and the sample amount was 5-10 mg. The temperature was raised from room temperature to 200°C at 20°C / min and kept at this temperature for 5 min; then the temperature was lowered from 200°C to room temperature at a rate of 10°C / min, and the crystallization temperature was recorded; finally, the temperature was raised from room temperature to 200°C at a rate of 10°C / min, and the degree of crystallinity was calculated using the DSC program.

[0048] (2) Heat deformation temperature test: According to GB1634-79 plastic bending load heat deformation temperature test method, a SWB-300D Vicat softening tester was used to test the sample in a three-point simply supported beam mode. The length / width / thickness of the test specimen was 80 / 10 / 4 mm, respectively.

[0049] (3) Impact strength test: The impact test strips obtained by injection molding were subjected to impact test according to GB / T 1843-2008 standard.

[0050] (4) Flame retardant performance test: The standard flame retardant specimens obtained by injection molding were tested for vertical combustion performance and limiting oxygen index performance according to GB / T 8333-2008 and GB / T2406.2-2009, respectively.

[0051] Example 1

[0052] 20mmol 2-methoxyphenol was dissolved in methanol, and 25mmol ethyl iodophenylacetate was added dropwise at -10℃ for oxidation. After 1h of reaction, 140mmol glycine hydrochloride and 180mmol triethylamine were added. After 1h of reaction, the temperature was raised to 38℃ for reaction. The solid product was directly filtered and dried in a vacuum oven at 60℃ to obtain 2-methoxyaniline.

[0053] Example 2

[0054] 20mmol 3-methoxyphenol was dissolved in ethanol, and 25mmol ethyl iodophenyl acetate was added dropwise at 0℃ for oxidation. After reacting for 2h, 140mmol glycine hydrochloride and 180mmol triethylamine were added. After adding glycine hydrochloride and reacting for 2h, the temperature was raised to 40℃ for reaction. The solid product was directly filtered and dried in a vacuum oven at 60℃ to obtain 3-methoxyaniline.

[0055] Example 3

[0056] 20mmol 4-methoxyphenol was dissolved in methanol, and 25mmol ethyl iodophenyl acetate was added dropwise at 10℃ for oxidation. After reacting for 3h, 140mmol glycine hydrochloride and 180mmol triethylamine were added. After adding glycine hydrochloride and reacting for 3h, the temperature was raised to 42℃ for reaction. The solid product was directly filtered and dried in a vacuum oven at 60℃ to obtain 4-methoxyaniline.

[0057] Example 4

[0058] The 2-methoxyaniline obtained in Example 1 was dissolved in anhydrous tetrahydrofuran (THF) at a concentration of 0.2 mmol / ml, and ultrasonicated until it was evenly dispersed. Then, 10 ml of triethylamine was added to obtain a mixed solution.

[0059] 4 mmol of phenylphosphonic dichloride was added to 40 ml of anhydrous tetrahydrofuran solvent, and ultrasonicated to disperse it uniformly to obtain a phenylphosphonic dichloride solution.

[0060] Under nitrogen atmosphere, the system temperature was maintained at -10°C. The phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution for 1 hour. After the addition was completed, the mixture was stirred and kept warm for 1 hour at -10°C. The mixture was then heated to 60°C and stirred for 12 hours. After the reaction was completed, the filtrate was filtered to obtain a filtrate. A portion of the filtrate was removed by rotary evaporation. The filtrate was then precipitated with deionized water to obtain a solid product. The solid product was then washed twice with ethanol. The solid product obtained by filtration was then dried in a vacuum oven set at 80°C to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 83.7%.

[0061] The H NMR spectrum of the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphine diamide is shown in Figure 2As shown. The chemical shift at 7.7ppm represents the proton signal peak of C6H5 on the benzene ring; the chemical shift between 7.5-7.4ppm represents the proton signal peaks of C6H5 and C6H4 on the benzene ring; the chemical shift at 7.3ppm represents the proton signal on -NH-; the chemical shifts at 6.9, 6.8 and 6.7ppm represent the proton signal peaks of C6H4 respectively; the chemical shift at 3.9ppm represents the proton signal peak on -OCH3.

[0062] Example 5

[0063] The 3-methoxyaniline obtained in Example 2 was dissolved in anhydrous acetonitrile at a concentration of 0.5 mmol / ml, and ultrasonicated until it was evenly dispersed. Then, 10 ml of pyridine was added to obtain a mixed solution.

[0064] 7 mmol of phenylphosphonic acid dichloride was added to 40 ml of anhydrous acetonitrile, and ultrasonicated to disperse the phenylphosphonic acid dichloride uniformly to obtain a phenylphosphonic acid dichloride solution.

[0065] Under nitrogen atmosphere, the system temperature was maintained at 0°C. The phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution for 2 hours. After the addition was completed, the mixture was stirred and kept warm for 2 hours at 0°C. The mixture was then heated to 70°C and stirred for 24 hours. After the reaction was completed, the filtrate was filtered to obtain a filtrate. A portion of the filtrate was removed by rotary evaporation. The filtrate was then precipitated with deionized water to obtain a solid product. The solid product was then washed twice with ethanol. The solid product obtained by filtration was then dried in a vacuum oven set at 80°C to obtain the nucleating agent N,N′-bis(3-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 88.3%.

[0066] The H NMR spectrum of the nucleating agent N,N′-bis(3-methoxyphenyl)-phenylphosphine diamide is shown in Figure 3 As shown. The chemical shift at 7.9ppm represents the proton signal peak of -NH-; the chemical shift at 7.8ppm represents the proton signal peak of C6H5 on the benzene ring; the chemical shift at 7.6-7.4ppm represents the proton signal peak of C6H5 on the benzene ring; the chemical shifts at 7.0, 6.8-6.7 and 6.4ppm represent the proton signal peaks of C6H4 on the benzene ring; the chemical shift at 3.6ppm represents the proton signal peak of -OCH3.

[0067] Example 6

[0068] The 4-methoxyaniline obtained in Example 3 was dissolved in anhydrous dioxane at a concentration of 0.8 mmol / ml, and ultrasonicated until it was evenly dispersed. Then, 10 ml of diisopropylethylamine was added to obtain a mixed solution.

[0069] 10 mmol of phenylphosphonic acid dichloride was added to 40 ml of anhydrous dioxane solvent, and ultrasonicated to disperse it uniformly to obtain a phenylphosphonic acid dichloride solution.

[0070] Under nitrogen atmosphere, the system temperature was maintained at 10°C. The phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution for 3 hours. After the addition was completed, the mixture was stirred and kept warm for 3 hours at 10°C. The mixture was then heated to 80°C and stirred for 36 hours. After the reaction was completed, the filtrate was filtered to obtain a filtrate. A portion of the filtrate was removed by rotary evaporation. The filtrate was then precipitated with deionized water to obtain a solid product. The solid product was then washed twice with ethanol. The solid product obtained by filtration was then dried in a vacuum oven set at 80°C to obtain the nucleating agent N,N′-bis(4-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 89.2%.

[0071] The H NMR spectrum of the nucleating agent N,N′-bis(4-methoxyphenyl)-phenylphosphine diamide is shown in Figure 4 As shown. The chemical shift at 7.7ppm represents the proton signal peak of C6H5 on the benzene ring; the chemical shift at 7.6ppm represents the proton signal peak of -NH-; the chemical shift at 7.5ppm represents the proton signal peaks of C6H5 and C6H4 on the benzene ring; the chemical shift at 7.1ppm represents the proton signal peak of C6H4 on the benzene ring; the chemical shift at 6.7ppm represents the proton signal peak of C6H4 on the benzene ring; the chemical shift at 3.6ppm represents the proton signal peak of -OCH3.

[0072] Example 7

[0073] The 2-methoxyaniline obtained in Example 1 was dissolved in N-methylpyrrolidone at a concentration of 1.0 mmol / ml, and ultrasonicated until it was evenly dispersed. Then, 10 ml of triethylamine was added to obtain a mixed solution.

[0074] 13 mmol of phenylphosphonic acid dichloride was added to 40 ml of N-methylpyrrolidone solvent, and ultrasonicated to disperse it uniformly to obtain a phenylphosphonic acid dichloride solution.

[0075] Under nitrogen atmosphere, the system temperature was maintained at 20°C. The phenylphosphonic acid dichloride solution was slowly added to the mixed solution for 2 hours. After the addition was completed, the mixture was stirred and kept warm for 2 hours at 0°C. The mixture was then heated to 60°C and stirred for 24 hours. After the reaction was completed, the filtrate was filtered to obtain a filtrate. A portion of the filtrate was removed by rotary evaporation. The filtrate was then precipitated with deionized water to obtain a solid product. The solid product was then washed twice with ethanol. The solid product obtained by filtration was then dried in a vacuum oven set at 80°C to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 90.7%.

[0076] Example 8

[0077] The 2-methoxyaniline obtained in Example 1 was dissolved in N,N-dimethylformamide at a concentration of 1.2 mmol / ml, and ultrasonicated until it was evenly dispersed. Then, 10 ml of triethylamine was added to obtain a mixed solution.

[0078] 16 mmol of phenylphosphonic acid dichloride was added to 40 ml of N,N-dimethylformamide solvent, and ultrasonicated to disperse it uniformly to obtain a phenylphosphonic acid dichloride solution.

[0079] Under nitrogen atmosphere, the system temperature was maintained at 0°C. The phenylphosphonic acid dichloride solution was slowly added to the mixed solution for 2 hours. After the addition was completed, the mixture was stirred and kept warm for 2 hours at 0°C. The mixture was then heated to 60°C and stirred for 24 hours. After the reaction was completed, the filtrate was filtered to obtain a filtrate. A portion of the filtrate was removed by rotary evaporation. The filtrate was then precipitated with deionized water to obtain a solid product. The solid product was then washed twice with ethanol. The solid product obtained by filtration was then dried in a vacuum oven set at 80°C to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 91.1%.

[0080] Example 9

[0081] Except that the concentration of 2-methoxyaniline was 0.6 mmol / ml, other experimental parameters were the same as those in Example 4, and the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic diamide was obtained with a yield of 85.6%.

[0082] Example 10

[0083] Except that the concentration of 2-methoxyaniline was 1.0 mmol / ml, other experimental parameters were the same as those in Example 4, and the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic diamide was obtained with a yield of 87.2%.

[0084] Embodiment 11

[0085] Except that the phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution under a nitrogen atmosphere and the system temperature was maintained at -10°C, the other experimental parameters were the same as those in Example 4 to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 84.7%.

[0086] Example 12

[0087] Except that the phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution under a nitrogen atmosphere and the system temperature was maintained at 10° C., other experimental parameters were the same as those in Example 4 to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 81.2%.

[0088] Example 13

[0089] The polylactic acid and the nucleating agent obtained in Example 4 were dried in an oven at 60°C for 6 hours, and the PLA and the nucleating agent were fully mixed at a mass ratio of 100:1. The temperature zones of the extruder were set to 150, 155, 160, 165, 170, and 180°C. The extruder speed was set to 300r / min. The material was then fed into a twin-screw extruder to obtain a polylactic acid composition with a weight percentage of 1wt% of N,N′-bis(4-methoxyphenyl)-phenylphosphinoic acid diamide, named PLA / NA-1-1wt%. The DSC spectrum of N,N′-bis(2-methoxyphenyl)-phenylphosphinoic acid diamide after adding PLA is shown in the figure. Figure 5 shown.

[0090] Embodiment 14

[0091] The polylactic acid and the nucleating agent obtained in Example 5 were dried in an oven at 60°C for 6 hours, and the PLA and the nucleating agent were fully mixed at a mass ratio of 100:1. The temperature zones of the extruder were set to 150, 155, 160, 165, 170, and 180°C. The extruder speed was set to 300r / min. The material was then fed into a twin-screw extruder to obtain a polylactic acid composition with a weight percentage of 1wt% of N,N′-bis(3-methoxyphenyl)-phenylphosphinoic acid diamine, named PLA / NA-2-1wt%. The DSC spectrum of N,N′-bis(3-methoxyphenyl)-phenylphosphinoic acid diamine after adding PLA is shown in the following figure. Figure 6 shown.

[0092] Embodiment 15

[0093] The polylactic acid and the nucleating agent obtained in Example 6 were dried in an oven at 60°C for 6 hours, and the PLA and the nucleating agent were fully mixed at a mass ratio of 100:1. The temperature zones of the extruder were set to 150, 155, 160, 165, 170, and 180°C. The extruder speed was set to 300r / min. The material was then fed into a twin-screw extruder to obtain a polylactic acid composition with a weight percentage of 1wt% of N,N′-bis(2-methoxyphenyl)-phenylphosphinoic acid diamine, named PLA / NA-3-1wt%. The DSC spectrum of N,N′-bis(4-methoxyphenyl)-phenylphosphinoic acid diamine after adding PLA is shown in FIG. Figure 7 shown.

[0094] Comparative Example 1

[0095] Except that the concentration of 2-methoxyaniline was 0.1 mmol / ml, other experimental parameters were the same as those in Example 4, and the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic diamide was obtained with a yield of 35.4%.

[0096] Comparative Example 2

[0097] Except that the phenylphosphonic acid dichloride solution was slowly added dropwise to the mixed solution under a nitrogen atmosphere and the system temperature was maintained at 25° C., other experimental parameters were the same as those in Example 4 to obtain the nucleating agent N,N′-bis(2-methoxyphenyl)-phenylphosphonic acid diamide with a yield of 41.5%.

[0098] Comparative Example 3

[0099] PLA and commercial nucleating agent ExolitAP were dried in an oven at 60°C for 6 hours, and PLA and nucleating agent were fully mixed at a mass ratio of 100:1. The temperature zones of the extruder were set to 150, 155, 160, 165, 170, and 180°C. The extruder speed was set to 300r / min. The extruder was then fed into a twin-screw extruder to obtain a polylactic acid composition with a weight percentage of ExolitAP of 1wt%, named PLA / AP-1wt%. The DSC spectrum of Exolit AP after adding PLA is shown below. Figure 8 shown.

[0100] Table 1 Test results of polylactic acid compositions of Examples 13 to 15 and polylactic acid compositions of Comparative Example 3 and pure polylactic acid

[0101]

[0102] As shown in Table 1, from the comparison between Examples 13 to 15 and Comparative Example 3, it can be seen that the polylactic acid composition to which the nucleating agent of the present application is added has a crystallization temperature of up to 127°C, a crystallinity of up to 61, and a heat deformation temperature of up to 117°C. In the flame retardant performance test, the limiting oxygen index of the polylactic acid composition to which the commercial nucleating agent ExolitAP is added in Comparative Example 3 is 29%, which does not reach the V-0 flame retardant grade. After adding 1 wt% of the phosphonamide derivative nucleating agent by weight, the limiting oxygen index of the polylactic acid composition exceeds 30.0%, and the flame retardant grade reaches V-0, indicating that by adding the nucleating agent of the present application, not only the crystallization performance of the polylactic acid composition can be significantly improved, but also the flame retardant performance of the polylactic acid composition can reach the VO grade. Therefore, the nucleating agent of the present application is an effective multifunctional nucleating agent for polylactic acid.

Claims

1. An application of a phosphamide derivative nucleating agent, characterized in that: For preparing a polylactic acid composition, the phosphonamide derivative nucleating agent has the following structure: ； Wherein, R is a methoxy group, and R is substituted at the 2-position, 3-position or 4-position of the benzene ring.

2. The use of a phosphamide derivative nucleating agent according to claim 1, characterized in that: The preparation method of the phosphamide derivative nucleating agent comprises the following steps: S1: dissolving a methoxyphenol compound in solvent a, adding iodophenyl diacetate for oxidation reaction, adding an excess of glycine ethyl ester hydrochloride for reaction, and obtaining a methoxyaniline compound; S2: dissolving the methoxyaniline compound obtained in S1 in solvent b, dispersing it evenly, and dropping an acid-binding agent to obtain a mixed solution; S3: adding phenylphosphonyl dichloride to solvent c to obtain a phenylphosphonyl dichloride solution; S4: The reaction temperature is -10 to 20°C, and the phenylphosphonic acid dichloride solution of S3 is added dropwise to the mixed solution of S2. After the addition is completed, the mixture is kept warm under stirring, and then the temperature is raised to 60 to 80°C and the stirring reaction is continued. After stopping the stirring, a reaction solution is obtained; S5: The reaction solution of S4 is filtered to obtain a filtrate, and the phosphonamide derivative nucleating agent is obtained after precipitation, washing, suction filtration and drying.

3. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The methoxyphenol compound in S1 is selected from any one of 2-methoxyphenol, 3-methoxyphenol or 4-methoxyphenol; the obtained methoxyaniline compound is any one of the corresponding 2-methoxyaniline, 3-methoxyaniline or 4-methoxyaniline; the solvent a is selected from any one or more of methanol or ethanol; the temperature of the oxidation reaction is -10 to 10°C; and the time of the oxidation reaction is 1 to 3 hours.

4. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The solvent b in S2 and the solvent c in S3 are selected from any one or more of anhydrous tetrahydrofuran, anhydrous acetonitrile, anhydrous dioxane, N-methylpyrrolidone or N,N-dimethylformamide; the dispersion method in S2 is ultrasonic dispersion.

5. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The molar concentration of the methoxyaniline compound in the mixed solution in S2 is 0.2-1.2 mol / L; the acid-binding agent in S2 is selected from any one or more of triethylamine, pyridine or diisopropylethylamine, and the molar concentration of the acid-binding agent is 0.5-1.5 mol / L.

6. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The molar concentration of the phenylphosphonic dichloride solution in S3 is 0.1 to 0.4 mol / L.

7. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The dropping process in S4 is carried out in a nitrogen atmosphere. The total time for dropping the phenylphosphonic dichloride solution of S3 into the mixed solution of S2 in S4 is 1 to 3 hours. The temperature of the insulation reaction is -10 to 10°C, and the insulation reaction time is 1 to 3 hours. The time for continuing to stir the reaction at 60 to 80°C in S4 is 12 to 36 hours.

8. The use of a phosphamide derivative nucleating agent according to claim 2, characterized in that: The precipitation liquid used in the precipitation process in S5 is selected from deionized water, and the washing liquid used in the washing process is selected from ethanol.

9. The use of a phosphamide derivative nucleating agent according to claim 1, characterized in that: The polylactic acid composition comprises the phosphamide derivative nucleating agent according to claim 1 and polylactic acid.

Images