Flame-retardant modified ABS plastic and its preparation method

Abstract

The application belongs to the technical field of functional plastics, and particularly relates to a flame-retardant modified ABS plastic and a preparation method thereof. The flame-retardant modified ABS plastic comprises the following components in parts by weight: ABS resin 70-90 parts, flame retardant 6-10 parts, ultraviolet absorber 0.5-1.5 parts, lubricant 0.2-1 part, reinforcing agent 1-1.5 parts, and calcium carbonate 0.5-1.5 parts; the structural formula of the flame retardant is as follows: the ABS plastic has excellent mechanical properties and aging resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of functional plastics, and in particular relates to a flame retardant modified ABS plastic and a preparation method thereof. Background Art

[0002] Acrylonitrile-butadiene-styrene (ABS) plastic is a thermoplastic material with excellent overall properties, featuring high strength, high toughness, and good rigidity. ABS plastic also offers excellent processing properties, making it suitable for a variety of molding processes. Its high surface gloss makes it easy to color and decorate. ABS plastic also possesses excellent chemical resistance, dimensional stability, electrical insulation, and is somewhat recyclable.

[0003] However, ABS plastic also has some limitations: For example, ABS plastic has poor weather resistance and is easily aged by UV rays and weather conditions; ABS plastic has limited heat resistance and a low heat deformation temperature; and while ABS plastic has a high surface hardness, it is easily scratched; ABS plastic is also sensitive to organic solvents such as esters and ketones, and produces black smoke and a distinctive odor when burned, requiring the addition of flame retardants. Furthermore, the relatively high cost of ABS plastic may limit its use in some cost-sensitive applications.

[0004] Therefore, developing a flame retardant modified ABS plastic with weather resistance, mechanical properties and good compatibility is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a flame retardant modified ABS plastic having excellent mechanical properties and anti-aging properties.

[0006] One of the purposes of the present invention is achieved by the following technical solution:

[0007] A flame-retardant modified ABS plastic comprises the following components, in parts by weight: 70-90 parts of ABS resin, 6-10 parts of flame retardant, 0.5-1.5 parts of ultraviolet absorber, 0.2-1 part of lubricant, 1-1.5 parts of reinforcing agent, and 0.5-1.5 parts of calcium carbonate; the structural formula of the flame retardant is: .

[0008] Preferably, the method for preparing the flame retardant comprises the following steps:

[0009]

[0010] (1) DL-phenylglycinol and 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal were added to methanol for reaction, and sodium cyanoborohydride was added for stirring at room temperature. After purification, intermediate 1 was obtained;

[0011] (2) The intermediate 1 of step (1) is added to acetone, and after cooling, phosphorus oxychloride is added. The reaction is carried out for 40 to 60 minutes, and then the temperature is raised to room temperature and the reaction is continued for 2 to 4 hours. Then, a methanol solution of sodium methoxide is added and heated to react. After purification, a flame retardant is obtained.

[0012] Preferably, in step (1), the molar ratio of DL-phenylglycinol, 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal, and sodium cyanoborohydride is (10-12) mmol:10 mmol:(10-12) mmol; the reaction temperature is 50-70°C, and the reaction time is 2.5-4.5 h; the stirring reaction temperature is 50-70°C, and the stirring reaction time is 5-7 h.

[0013] Preferably, the molar ratio of the intermediate 1, phosphorus oxychloride, and sodium methoxide in step (2) is 10 mmol: (8-10) mmol: (8-10) mmol.

[0014] Preferably, the temperature after cooling in step (2) is 3-8°C; the temperature during the addition of phosphorus oxychloride is controlled at 8-10°C; the temperature of the heating reaction is 60-70°C, and the heating reaction time is 1-2 hours.

[0015] Preferably, the preparation method of the enhancer is as follows:

[0016] Ascorbic acid and hexamethyldisilazane are added to acetonitrile for stirring and reaction, and an enhancer is obtained after purification.

[0017] Preferably, the mass ratio of ascorbic acid to hexamethyldisilazane is 1:(2-3); the stirring reaction temperature is 60-70° C., and the stirring reaction time is 3-5 h.

[0018] Preferably, the ultraviolet absorber is ultraviolet absorber UV-531 or ultraviolet absorber UVP-327, and the lubricant is stearic acid or ethylene bisstearamide.

[0019] A second object of the present invention is to provide a method for preparing flame retardant modified ABS plastic, which has simple preparation steps.

[0020] The second object of the present invention is achieved by adopting the following technical solution:

[0021] The method for preparing the flame retardant modified ABS plastic comprises the following steps:

[0022] The raw materials are mixed uniformly according to the weight ratio to obtain a blend; the blend is subjected to extrusion granulation and injection molding.

[0023] Preferably, during the extrusion granulation process, the screw speed of the twin-screw extruder is set to 150-250 rpm, and the temperatures of zones 1-5 are respectively 180°C, 185°C, 195°C, 190°C, and 200°C; and during the injection molding process, the temperature is set to 190-200°C.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The flame-retardant modified ABS plastic of the present invention contains a flame retardant, a reinforcing agent, and other ingredients. The flame retardant is prepared by reacting 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal with DL-phenylglycinol to produce intermediate 1 through reductive amination of the aldehyde group. Intermediate 1 then undergoes a phosphate esterification reaction with phosphorus oxychloride and sodium methoxide to produce the flame retardant. The phosphate ester in the flame retardant decomposes at high temperatures to produce oxygen-containing substances such as phosphoric acid. These substances promote the formation of a carbonized layer on the ABS surface, isolating oxygen and thus inhibiting combustion. The oxygen-containing substances produced by the phosphate decomposition also reduce smoke generation during combustion. The maleimide group in the flame retardant enhances the aging resistance of the ABS plastic, and the three methylene fatty chains in the flame retardant increase the material's flexibility. Furthermore, the benzene ring structure in the flame retardant improves the compatibility of the functional filler with the ABS resin. In summary, the flame retardant of the present invention improves aging resistance and flame retardancy while also enhancing the material's mechanical properties. The reinforcing agent can tightly connect ABS plastic with other functional fillers and improve the mechanical properties of the material by improving the interface compatibility between the materials. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. All reagents or instruments used, unless otherwise specified, are conventional products obtained through commercial channels.

[0027] Example 1

[0028] Example 1 provides a flame retardant modified ABS plastic, which is composed of the following components, in parts by weight: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 parts of stearic acid, 1.2 parts of reinforcing agent, and 1 part of calcium carbonate.

[0029] The structural formula of flame retardant is: .

[0030] The preparation method of the flame retardant comprises the following steps:

[0031]

[0032] (1) DL-phenylglycinol (CAS: 7568-92-5), 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal, and sodium cyanoborohydride were added to 20 mL of methanol in the molar ratio of 11 mmol: 10 mmol: 11 mmol, and the mixture was reacted at 60 °C for 3 h. After the reaction solution was cooled to room temperature, sodium cyanoborohydride (CAS: 25895-60-7) was added in batches, and the mixture was stirred at room temperature for 20 min, then heated to 60 °C and stirred for 6 h. After the reaction was completed, water was added to quench the mixture, and the mixture was extracted three times with dichloromethane. The organic phases were combined and dried over magnesium sulfate. After concentration under reduced pressure, the mixture was purified by reverse phase preparative high performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain intermediate 1. The yield of intermediate 1 was 68.32%.

[0033] The NMR results of intermediate 1 are:

[0034] 1 HNMR (C 15 H 18 N2O3, 400MHz, d6-DMSO) 7.86(s, 2H), 7.36-7.27(m, 5H), 4.16(s, 1H), 4.00(t, 2H), 3.91(t, 1H), 3.60-3.57(m, 2H), 3.34-3.32(m, 1H), 2.53(t, 2H), 1.68-1.66(m, 2H); MS(ESI) m / z=274.14[M]. The above results confirmed that the obtained product was the target product.

[0035] (2) According to the molar ratio of intermediate 1, phosphorus oxychloride and sodium methoxide of 10 mmol:9 mmol:9 mmol, the intermediate 1 of step (1) was added to 30 mL of acetone, cooled to 5 ° C, and phosphorus oxychloride was added. The reaction was controlled at a temperature not exceeding 9 ° C for 50 min, and then the temperature was raised to room temperature and the reaction was continued for 3 h. Then, a 30 wt% methanol solution of sodium methoxide was added to the reaction system, and the reaction was heated to 65 ° C for 1.5 h. After the reaction solution was concentrated, the by-products were dissolved with water, and the mixed solution was extracted with ethyl acetate. The organic phase was separated, collected and dried, and then concentrated to remove ethyl acetate. The residual part was then distilled to obtain a flame retardant. The yield of the flame retardant was 24.17%.

[0036] The NMR results of the flame retardant are:

[0037] 1 HNMR (C 17 H 23 N2O6P, 400MHz, d6-DMSO) 7.86(s, 2H), 7.36-7.27(m, 5H), 4.57-4.32(m, 2H), 4.16(s, 1H), 4.00(t, 2H), 3.91(t, 1H), 3.78(d, 6H), 2.53(t, 2H), 1.68-1.66(m, 2H); MS(ESI) m / z=382.13[M]. The above results confirmed that the obtained product was the target product.

[0038] The preparation method of the above-mentioned enhancer is as follows:

[0039] Ascorbic acid and hexamethyldisilazane were added to acetonitrile in a mass ratio of 1:2.5, stirred at 65° C. for 4 h, and the enhancer was obtained after removing the solvent.

[0040] Example 1 also provides a method for preparing the flame retardant modified ABS plastic. The specific preparation process is as follows:

[0041] The raw materials were mixed uniformly according to the weight ratio to obtain a blend; the blend was added to a twin-screw extruder, the speed of the twin-screw extruder screw was set to 200 rpm, and the temperatures of zones 1-5 were set to 180°C, 185°C, 195°C, 190°C, and 200°C, respectively, for extrusion granulation, and then injection molding was performed by an injection molding machine at 195°C.

[0042] Example 2

[0043] Example 2 provides a flame retardant modified ABS plastic, which is composed of the following components, in parts by weight: 90 parts of ABS resin, 10 parts of flame retardant, 1.5 parts of ultraviolet absorber UVP-327, 1 part of ethylene bisstearamide, 1.5 parts of reinforcing agent, and 1.5 parts of calcium carbonate.

[0044] The structural formula of the flame retardant is the same as that of Example 1.

[0045] The preparation method of the flame retardant comprises the following steps:

[0046] (1) DL-phenylglycinol, 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal, and sodium cyanoborohydride were added to methanol in sequence according to the molar ratio of 1) mmol: 10 mmol: 12 mmol, and the mixture was reacted at 70°C for 2.5 h. After the reaction solution was cooled to room temperature, sodium cyanoborohydride was added in batches, and the mixture was stirred at room temperature for 20 min, then heated to 70°C and stirred for 5 h. After the reaction was completed, water was added to quench the mixture, and the mixture was extracted three times with dichloromethane. The organic phases were combined, dried over magnesium sulfate, concentrated under reduced pressure, and purified by reverse phase preparative high performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain intermediate 1. The yield of intermediate 1 was 63.15%. 1 H-NMR and MS (ESI) m / z were consistent with those in Example 1.

[0047] (2) According to the molar ratio of intermediate 1, phosphorus oxychloride and sodium methoxide of 10mmol:10mmol:10mmol, the intermediate 1 of step (1) was added to 30mL of acetone, cooled to 8°C and phosphorus oxychloride was added, and the reaction was carried out for 60min under the condition of controlling the temperature not to exceed 10°C, and then the temperature was raised to room temperature and the reaction was continued for 4h; then a 30wt% methanol solution of sodium methoxide was added to the reaction system, and the reaction was continued for 1h after heating to 70°C; the reaction solution was concentrated and the by-products were dissolved with water, and the mixed solution was extracted with ethyl acetate, the organic phase was separated, collected and dried, and then the ethyl acetate was removed and the residue was distilled to obtain a flame retardant, the yield of the flame retardant was 18.94%, and the flame retardant 1 H-NMR and MS (ESI) m / z were consistent with those in Example 1.

[0048] The preparation method of the above-mentioned enhancer is as follows:

[0049] Ascorbic acid and hexamethyldisilazane were added to acetonitrile in a mass ratio of 1:3, stirred at 70° C. for 3 h, and the enhancer was obtained after removing the solvent.

[0050] Example 2 also provides a method for preparing the flame retardant modified ABS plastic. The specific preparation process is as follows:

[0051] The raw materials were mixed uniformly according to the weight ratio to obtain a blend; the blend was added to a twin-screw extruder, the speed of the twin-screw extruder screw was set to 250 rpm, and the temperatures of zones 1-5 were set to 180°C, 185°C, 195°C, 190°C, and 200°C, respectively, for extrusion granulation, and then injection molding was performed by an injection molding machine at 200°C.

[0052] Example 3

[0053] Example 3 provides a flame retardant modified ABS plastic, which is composed of the following components, in parts by weight: 70 parts of ABS resin, 6 to 10 parts of flame retardant, 0.5 parts of ultraviolet absorber UV-531, 0.2 parts of stearic acid, 1 part of reinforcing agent, and 0.5 parts of calcium carbonate.

[0054] The structural formula of the flame retardant is the same as that of Example 1.

[0055] The preparation method of the flame retardant comprises the following steps:

[0056] (1) DL-phenylglycinol, 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal, and sodium cyanoborohydride were added to 20 mL of methanol in a molar ratio of 10 mmol:10 mmol:10 mmol, and the mixture was reacted at 50°C for 4.5 h. After the reaction solution was cooled to room temperature, sodium cyanoborohydride was added in batches, and the mixture was stirred at room temperature for 20 min, then heated to 50°C and stirred for 7 h. After the reaction was completed, water was added to quench the mixture, and the mixture was extracted three times with dichloromethane. The organic phases were combined, dried over magnesium sulfate, concentrated under reduced pressure, and purified by reverse phase preparative high performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain intermediate 1. The yield of intermediate 1 was 60.55%. 1 H-NMR and MS (ESI) m / z were consistent with those in Example 1.

[0057] (2) According to the molar ratio of intermediate 1, phosphorus oxychloride and sodium methoxide of 10mmol:8mmol:8mmol, the intermediate 1 of step (1) was added to acetone, cooled to 3°C, phosphorus oxychloride was added (, the temperature was controlled not to exceed 8°C, and the reaction was continued for 40 minutes, and then the temperature was raised to room temperature and the reaction was continued for 2 hours; then a 30wt% methanol solution of sodium methoxide was added to the reaction system, and the reaction was heated to 60°C and the reaction was continued for 2 hours; the reaction solution was concentrated and the by-products were dissolved with water, and the mixed solution was extracted with ethyl acetate, the organic phase was separated, collected and dried, and the ethyl acetate was removed, and the residual part was distilled to obtain a flame retardant, and the yield of the flame retardant was 17.23%. 1 H-NMR and MS (ESI) m / z were consistent with those in Example 1.

[0058] The preparation method of the above-mentioned enhancer is as follows:

[0059] According to the mass ratio of ascorbic acid to hexamethyldisilazane of 1:2, ascorbic acid and hexamethyldisilazane were added to acetonitrile, stirred at 60° C. for 5 h, and the enhancer was obtained after removing the solvent.

[0060] Example 3 also provides a method for preparing the flame retardant modified ABS plastic. The specific preparation process is as follows:

[0061] The raw materials were mixed uniformly according to the weight ratio to obtain a blend; the blend was added to a twin-screw extruder, the speed of the twin-screw extruder screw was set to 150 rpm, and the temperatures of zones 1-5 were set to 180°C, 185°C, 195°C, 190°C, and 200°C, respectively, for extrusion granulation, and then injection molding was performed by an injection molding machine at 190°C.

[0062] Comparative Example 1

[0063] Comparative Example 1 provides an ABS plastic, which is composed of the following components, in parts by weight: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 parts of stearic acid, 1.2 parts of reinforcing agent, and 1 part of calcium carbonate.

[0064] The preparation method of the above flame retardant is as follows:

[0065] DL-phenylglycinol, phosphorus oxychloride, and a methanol solution of sodium methoxide were added to acetone at a molar ratio of 10 mmol:9 mmol:9 mmol, mixed evenly, and then cooled to 5°C. Phosphorus oxychloride was added with stirring, the temperature was controlled at 9°C, and the mixture was reacted for 50 minutes, then gradually heated to room temperature and reacted for 3 hours. A 30 wt% methanol solution of sodium methoxide (9 mmol) was then added, and the mixture was heated at 65°C for 1.5 hours. The reaction solution was concentrated, by-products were dissolved with water, and the mixture was extracted with ethyl acetate. The organic phase was separated, collected, and dried, and then concentrated to remove the ethyl acetate. The residue was then distilled to obtain a flame retardant.

[0066] The preparation method of the enhancer is the same as that of Example 1.

[0067] Comparative Example 1 also provides a preparation method of the above-mentioned ABS plastic, which is similar to that of Example 1.

[0068] Comparative Example 2

[0069] Comparative Example 2 provides an ABS plastic, which is composed of the following components, in parts by weight: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 parts of stearic acid, 1.2 parts of hexamethyldisilazane, and 1 part of calcium carbonate.

[0070] The structural formula and preparation method of the flame retardant are the same as those in Example 1.

[0071] Comparative Example 2 also provides a preparation method of the above-mentioned ABS plastic, which is similar to that of Example 1.

[0072] Test example

[0073] The properties of the ABS plastics prepared in Examples 1-3 of the present invention and Comparative Examples 1-2 are described below.

[0074] Oxygen index: tested according to GB / T2406-2008 standard;

[0075] Impact strength: tested according to GB / T1043.1-2018 standard;

[0076] Tensile strength: tested according to GB / T1040.1-2018 standard, the test speed is 50mm / min;

[0077] Yellowing index: according to GB / T16422.2-2022 plastics laboratory light source exposure test method, placed in a xenon lamp exposure light aging test box for irradiation, and then according to GB2409-80 plastic yellow index test method, the yellow index is measured, the test time is 1000h; the results are shown in Table 1.

[0078]

[0079] As can be seen from the above, compared with the flame retardant of Comparative Example 1, the flame retardant prepared by Examples 1-3 of the present application can improve the mechanical properties and light aging resistance of ABS plastic.

[0080] Further analysis shows that the present application uses 3-(2,5-dioxyl-2,5-dihydropyrrole-1-yl) propyl aldehyde as a starting material, and DL-phenylglycinol undergoes reductive amination of aldehyde group to prepare intermediate 1; intermediate 1 and sodium methoxide undergo phosphate esterification and other reactions to prepare the flame retardant. The phosphate ester in the flame retardant decomposes at high temperature to generate oxygen-containing substances such as phosphoric acid, which can promote the formation of a carbonized layer on the surface of ABS, insulating oxygen, thereby inhibiting combustion, and the oxygen-containing substances generated by the decomposition of the phosphate ester can also reduce the generation of smoke during combustion; the maleamide group in the flame retardant improves the anti-aging properties of ABS plastic, and the fatty chain containing three methylene groups in the flame retardant can increase the flexibility of the material. In addition, the benzene ring structure contained in the flame retardant can also improve the compatibility of functional fillers and ABS resin. In summary, the flame retardant of the present application can improve the anti-aging and flame retardant properties while also improving the mechanical properties of the material.

[0081] The ABS plastic prepared by Comparative Example 2 using hexamethyldisilazane has excellent mechanical properties. Further analysis shows that the reinforcing agent of the present application can tightly connect ABS plastic with other functional fillers, and improve the mechanical properties of the material by improving the interfacial compatibility between the materials.

[0082] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A flame retardant modified ABS plastic, characterized in that: The composition comprises the following components in parts by weight: 70-90 parts of ABS resin, 6-10 parts of flame retardant, 0.5-1.5 parts of ultraviolet absorber, 0.2-1 parts of lubricant, 1-1.5 parts of reinforcing agent, and 0.5-1.5 parts of calcium carbonate; the structural formula of the flame retardant is: .

2. The flame retardant modified ABS plastic according to claim 1, characterized in that: The preparation method of the flame retardant comprises the following steps: (1) DL-phenylglycinol and 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal were added to methanol for reaction, and sodium cyanoborohydride was added for stirring at room temperature. After purification, intermediate 1 was obtained; (2) The intermediate 1 of step (1) is added to acetone, and after cooling, phosphorus oxychloride is added. The reaction is carried out for 40 to 60 minutes, and then the temperature is raised to room temperature and the reaction is continued for 2 to 4 hours. Then, a methanol solution of sodium methoxide is added and heated to react. After purification, a flame retardant is obtained.

3. The flame retardant modified ABS plastic according to claim 2, characterized in that: In step (1), the molar ratio of DL-phenylglycinol, 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal, and sodium cyanoborohydride is (10-12) mmol:10 mmol:(10-12) mmol; the reaction temperature is 50-70°C, and the reaction time is 2.5-4.5 h; the stirring reaction temperature is 50-70°C, and the stirring reaction time is 5-7 h.

4. The flame retardant modified ABS plastic according to claim 2, characterized in that: The molar ratio of the intermediate 1, phosphorus oxychloride and sodium methoxide in step (2) is 10 mmol: (8-10) mmol: (8-10) mmol.

5. The flame retardant modified ABS plastic according to claim 2, characterized in that: The temperature after cooling in step (2) is 3-8°C; the temperature during the addition of phosphorus oxychloride is controlled at 8-10°C; the temperature of the heating reaction is 60-70°C, and the heating reaction time is 1-2h.

6. The flame retardant modified ABS plastic according to claim 1, characterized in that: The preparation method of the enhancer is as follows: Ascorbic acid and hexamethyldisilazane are added to acetonitrile for stirring and reaction, and an enhancer is obtained after purification.

7. The flame retardant modified ABS plastic according to claim 6, characterized in that: The mass ratio of ascorbic acid to hexamethyldisilazane is 1:(2-3); the stirring reaction temperature is 60-70° C., and the stirring reaction time is 3-5 hours.

8. The flame retardant modified ABS plastic according to claim 1, characterized in that: The ultraviolet absorber is ultraviolet absorber UV-531 or ultraviolet absorber UVP-327, and the lubricant is stearic acid or ethylene bisstearamide.

9. The method for preparing the flame retardant modified ABS plastic according to any one of claims 1 to 8, characterized in that: The following steps are involved: The raw materials are mixed uniformly according to the weight ratio to obtain a blend; the blend is subjected to extrusion granulation and injection molding.

10. The method for preparing flame retardant modified ABS plastic according to claim 9, characterized in that: During the extrusion granulation process, the speed of the twin-screw extruder screw is set to 150-250 rpm, and the temperatures of zones 1-5 are 180°C, 185°C, 195°C, 190°C, and 200°C, respectively; and during the injection molding process, the temperature is set to 190-200°C.

Images