Degradable ABS material and preparation method thereof

Abstract

This invention relates to the field of polymer materials technology and discloses a biodegradable ABS material and its preparation method. The preparation method of the biodegradable ABS material is as follows: First, polylactic acid, flame retardant, modified nano-silica, maleic anhydride-grafted polylactic acid, and antioxidant 1010 are added to a high-speed mixer and stirred for 5-10 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 170-180°C, followed by granulation to obtain polylactic acid masterbatch. Next, the polylactic acid masterbatch and ABS resin are added to a high-speed mixer and stirred for 2-3 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 185-210°C, followed by granulation to obtain the biodegradable ABS material. The biodegradable ABS material of this invention has good mechanical properties, flame retardant properties, and biodegradability.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a biodegradable ABS material and its preparation method. Background Technology

[0002] ABS resin, with its excellent impact resistance, processing fluidity, and cost advantages, is widely used in electronics, automotive parts, and daily consumer goods. However, traditional ABS resin is a non-biodegradable polymer material, extremely difficult to degrade in the natural environment. Long-term accumulation can disrupt the ecological balance, contradicting the globally advocated green and sustainable development concept. To reduce the environmental impact of traditional plastics, blending and modifying ABS resin with biodegradable components has become a hot research topic in the industry. Among these, polyester biodegradable plastics are one of the most commonly used modification components due to their good biodegradability, mechanical compatibility, and processing adaptability. However, ABS resin and most polyesters are inherently flammable, posing a fire safety hazard. Therefore, avoiding this flammability is key to solving the problem. For example, Chinese invention patent CN117304642B discloses a 3D-printed ABS antibacterial biodegradable composite material and its preparation method. This invention uses an ABS / PLA composite material, which improves the flowability and interlayer adhesion strength of ABS while also possessing antibacterial and biodegradable properties. It can be used to produce medical ABS materials, but its flame retardant properties need improvement. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a biodegradable ABS material and its preparation method. The biodegradable ABS material of the present invention has good mechanical properties, flame retardant properties and biodegradability.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a biodegradable ABS material, comprising the following weight components: 60-80 parts by weight of ABS resin, 30-40 parts by weight of polylactic acid, 8-10 parts by weight of flame retardant, 1-1.5 parts by weight of modified nano-silica, 4-6 parts by weight of maleic anhydride-grafted polylactic acid, and 0.2-0.3 parts by weight of antioxidant 1010; The flame retardant is obtained by reacting diphenylphosphinoyl chloride and diethyl iminodiacetate to obtain intermediate 1, intermediate 1 reacts with 4-aminobenzaldehyde to obtain intermediate 2, and finally intermediate 2 reacts with o-aminothiophenol to obtain the final product. Modified nano-silica is obtained by modifying nano-silica with 3-glycidyl etheroxypropyltrimethoxysilane.

[0005] Furthermore, the method for preparing the flame retardant is as follows: S1: Add 4.8-4.9 g of diethyl iminodiacetic acid, 0.04-0.05 g of 4-dimethylaminopyridine, and 20-25 mL of chloroform to the reactor. Then, dissolve 5-5.1 g of diphenylphosphine chloride in 10-12 mL of chloroform in a constant-pressure dropping funnel. Under nitrogen protection, add 2.56-2.58 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature over a period of 5-6 minutes. After the addition of chloroform is complete, the reaction is carried out at 70-80℃. After the reaction is complete, 60-80 mL of chloroform is added to the reactor. The mixture is washed with 30-35 mL of 1% sodium hydroxide aqueous solution, 30-35 mL of dilute hydrochloric acid with a pH of 3-4, and 30-35 mL of saturated sodium chloride solution, respectively. The mixture is dried with anhydrous sodium sulfate. After drying, the mixture is filtered, rotary evaporated, and allowed to stand until crystals precipitate. The crystals are then filtered and washed with a small amount of ethyl acetate to obtain intermediate 1. S2: Under nitrogen protection, intermediate 1, 4-aminobenzaldehyde was added to tetrahydrofuran solvent, mixed evenly, and reacted at 60-70℃ for 18-24h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. S3: Under nitrogen protection, add intermediate 2 and o-aminothiophenol to anhydrous ethanol solvent, stir and mix, then add ammonium chloride, heat at 75-80℃ for 22-26h, after the reaction is complete, cool to room temperature, filter, wash and dry to obtain flame retardant.

[0006] Furthermore, the reaction time in S1 is 22-26 hours.

[0007] Furthermore, the ratio of tetrahydrofuran, intermediate 1,4-aminobenzaldehyde in S2 is 15-18 mL: 4-4.1 g: 2.7-2.8 g.

[0008] Furthermore, the ratio of anhydrous ethanol, intermediate 2, o-aminothiophenol, and ammonium chloride in S3 is 40-50 mL: 3.1-3.2 g: 1.7-1.8 g: 0.2-0.3 g.

[0009] In the above steps, diphenylphosphine chloride and diethyl iminodiacetate undergo an amidation reaction under alkaline conditions to generate intermediate 1 containing a PN bond. The ester group of intermediate 1 undergoes ammonolysis with the amino group of 4-aminobenzaldehyde to generate intermediate 2 containing an aldehyde group. The aldehyde group of intermediate 2 undergoes dehydration with the amino group of o-aminothiophenol to form an imine. The thiol group on the same molecule nucleophilically attacks the imine carbon to form a CS bond, constituting a five-membered ring, thus obtaining a flame retardant containing a rigid heterocycle of benzothiazole and having a phosphorus-nitrogen-sulfur ternary synergistic system.

[0010] Further, the modified nano-silica is prepared by adding deionized water and anhydrous ethanol to a reactor and mixing them to obtain a solvent. Nano-silica and 3-glycidyl etheroxypropyltrimethoxysilane are then added to the solvent. The pH is adjusted to 4-5 with 1 mol / L dilute hydrochloric acid. After ultrasonic treatment for 40-50 min, the mixture is reacted at 45-55℃ for 2-3 h. After the reaction is completed, the mixture is centrifuged at high speed for 40-45 min, washed, and vacuum dried at 55-65℃ for 22-26 h to obtain modified nano-silica.

[0011] Furthermore, the ratio of deionized water, anhydrous ethanol, nano silica, and 3-glycidyl etheroxypropyltrimethoxysilane is 12-15 mL: 36-45 mL: 1.6-1.7 g: 0.64-0.66 g.

[0012] Further, the preparation method of the biodegradable ABS material is as follows: First, polylactic acid, flame retardant, modified nano silica, maleic anhydride-grafted polylactic acid, and antioxidant 1010 are added to a high-speed mixer and stirred for 5-10 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 170-180°C, granulated, to obtain polylactic acid masterbatch. Next, the polylactic acid masterbatch and ABS resin are added to a high-speed mixer and stirred for 2-3 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 185-210°C, granulated, to obtain the biodegradable ABS material.

[0013] In the above steps, a two-step melt blending method is used to prepare biodegradable ABS materials. The first step is to prepare polylactic acid masterbatch, which is beneficial for the uniform dispersion of nanofillers and flame retardants in the polylactic acid matrix. The second step is to blend with ABS resin. The short stirring time is to avoid prolonged high-temperature exposure of ABS resin and protect its structural integrity.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: This invention modifies nano-silica by modifying nano-silica with 3-glycidyl etheroxypropyltrimethoxysilane. The epoxy functional groups on the surface of the modified nano-silica react chemically with the anhydride groups of maleic anhydride-grafted polylactic acid and the hydroxyl groups at the polylactic acid end groups, forming strong chemical bonds. This significantly improves the interfacial bonding force between the nano-silica and the matrix, achieving uniform dispersion at the nanoscale and enhancing the mechanical properties of the biodegradable ABS material. The flame retardant, possessing a phosphorus-nitrogen-sulfur ternary synergistic system, can exert its flame-retardant effect in both the condensed phase and the gas phase. The synergistic catalysis of phosphorus and sulfur elements promotes the formation of a dense, continuous, and high-strength structure during combustion. The carbon layer effectively insulates against heat and oxygen, while nitrogen releases inert gases to dilute oxygen. These three elements work synergistically to achieve highly efficient flame retardancy, enhancing the flame retardant performance of biodegradable ABS materials. Furthermore, the benzothiazole closed-ring structure of the flame retardant possesses suitable polarity and rigidity, enabling it to form a good physical interaction with the ABS matrix, improving interfacial compatibility and avoiding interfacial defects and stress concentration caused by the addition of flame retardants. The polylactic acid in the material provides a basis for biodegradation, and the sulfur element in the complete flame retardant helps promote the hydrolysis of polylactic acid bonds. At the same time, the flame retardant is halogen-free and environmentally friendly, producing no toxic or harmful gases during combustion, which aligns with the trend of green development. Attached Figure Description

[0015] Figure 1 It is the synthesis reaction formula for flame retardants. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The reagents used in the following specific embodiments are of analytical grade. Additionally: ABS resin: Grade PA757, manufactured by Chi Mei Chemical Industrial Co., Ltd., Taiwan, China; Polylactic acid: grade FY601, manufactured by Anhui Fengyuan Futailai Polylactic Acid Co., Ltd. Maleic anhydride-grafted polylactic acid: grafting rate is 1.1%, manufacturer is Shanghai Yuannuan Polymer Materials Technology Co., Ltd.

[0018] Example 1 (1) Add 4.8 g of diethyl iminodiacetate, 0.04 g of 4-dimethylaminopyridine and 20 mL of chloroform to the reactor. Then dissolve 5 g of diphenylphosphine chloride in 10 mL of chloroform and place it in a constant pressure dropping funnel. Under nitrogen protection, add 2.56 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature for 5 min. After the addition is complete, react at 70 °C for 22 h. After the reaction is complete, add 60 mL of chloroform to the reactor. Wash with 30 mL of 1% sodium hydroxide aqueous solution, 30 mL of dilute hydrochloric acid with pH 3 and 30 mL of saturated sodium chloride aqueous solution, respectively. Dry with anhydrous sodium sulfate. After drying, filter, rotary evaporate, stand until crystals precipitate, filter, wash with a small amount of ethyl acetate to obtain intermediate 1. (2) Under nitrogen protection, 4g of intermediate 1 and 2.7g of 4-aminobenzaldehyde were added to 15mL of tetrahydrofuran solvent, mixed evenly, and reacted at 60℃ for 18h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. (3) Under nitrogen protection, 3.1 g of intermediate 2 and 1.7 g of o-aminothiophenol were added to 40 mL of anhydrous ethanol solvent and stirred. Then, 0.2 g of ammonium chloride was added, and the mixture was heated at 75 °C for 22 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain the flame retardant, as shown below. Figure 1 As shown; (4) Add 12 mL of deionized water and 36 mL of anhydrous ethanol to the reactor and mix to prepare a solvent. Add 1.6 g of nano silica and 0.64 g of 3-glycidyl etheroxypropyltrimethoxysilane to the solvent. Adjust the pH to 4 with 1 mol / L dilute hydrochloric acid. After sonication for 40 min, react at 45 °C for 2 h. After the reaction is completed, centrifuge at high speed for 40 min, wash, and vacuum dry at 55 °C for 22 h to obtain modified nano silica. (5) First, add 30 parts by weight of polylactic acid, 8 parts by weight of flame retardant, 1 part by weight of modified nano silica, 4 parts by weight of maleic anhydride-grafted polylactic acid, and 0.2 parts by weight of antioxidant 1010 to a high-speed mixer and stir for 5 minutes. Then add it to a twin-screw extruder and melt-blend at 170°C and granulate to obtain polylactic acid masterbatch. Then add the polylactic acid masterbatch and 60 parts by weight of ABS resin to a high-speed mixer and stir for 2 minutes. Then add it to a twin-screw extruder and melt-blend at 185°C and granulate to obtain biodegradable ABS material.

[0019] Example 2 (1) Add 4.9 g of diethyl iminodiacetate, 0.05 g of 4-dimethylaminopyridine and 25 mL of chloroform to the reactor. Then dissolve 5.1 g of diphenylphosphine chloride in 12 mL of chloroform and place it in a constant pressure dropping funnel. Under nitrogen protection, add 2.58 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature for 6 min. After the addition is complete, react at 80 °C for 26 h. After the reaction is complete, add 80 mL of chloroform to the reactor. Wash with 35 mL of 1% sodium hydroxide aqueous solution, 35 mL of dilute hydrochloric acid with pH 4 and 35 mL of saturated sodium chloride aqueous solution, respectively. Dry with anhydrous sodium sulfate. After drying, filter, rotary evaporate, stand until crystals precipitate, filter, wash with a small amount of ethyl acetate to obtain intermediate 1. (2) Under nitrogen protection, 4.1 g of intermediate 1 and 2.8 g of 4-aminobenzaldehyde were added to 18 mL of tetrahydrofuran solvent, mixed evenly, and reacted at 70 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. (3) Under nitrogen protection, 3.2g of intermediate 2 and 1.8g of o-aminothiophenol were added to 50mL of anhydrous ethanol solvent, stirred and mixed, and then 0.3g of ammonium chloride was added. The mixture was heated at 80℃ for 26h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed and dried to obtain the flame retardant. (4) Add 15 mL of deionized water and 45 mL of anhydrous ethanol to the reactor and mix to prepare a solvent. Add 1.7 g of nano silica and 0.66 g of 3-glycidyl etheroxypropyltrimethoxysilane to the solvent. Adjust the pH to 5 with 1 mol / L dilute hydrochloric acid. After sonication for 50 min, react at 55 °C for 3 h. After the reaction is completed, centrifuge at high speed for 45 min, wash, and vacuum dry at 65 °C for 26 h to obtain modified nano silica. (5) First, add 40 parts by weight of polylactic acid, 10 parts by weight of flame retardant, 1.5 parts by weight of modified nano silica, 6 parts by weight of maleic anhydride-grafted polylactic acid, and 0.3 parts by weight of antioxidant 1010 to a high-speed mixer and stir for 10 minutes. Then add it to a twin-screw extruder and melt-blend at 180°C and granulate to obtain polylactic acid masterbatch. Then add the polylactic acid masterbatch and 80 parts by weight of ABS resin to a high-speed mixer and stir for 3 minutes. Then add it to a twin-screw extruder and melt-blend at 210°C and granulate to obtain biodegradable ABS material.

[0020] Example 3 (1) Add 4.85 g of diethyl iminodiacetate, 0.04 g of 4-dimethylaminopyridine and 22 mL of chloroform to the reactor. Then dissolve 5.05 g of diphenylphosphine chloride in 11 mL of chloroform and place it in a constant pressure dropping funnel. Under nitrogen protection, add 2.57 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature for 5 min. After the addition is complete, react at 75 °C for 24 h. After the reaction is complete, add 70 mL of chloroform to the reactor. Wash with 32 mL of 1% sodium hydroxide aqueous solution, 33 mL of dilute hydrochloric acid with pH 3 and 32 mL of saturated sodium chloride aqueous solution, respectively. Dry with anhydrous sodium sulfate. After drying, filter, rotary evaporate, stand until crystals precipitate, filter, wash with a small amount of ethyl acetate to obtain intermediate 1. (2) Under nitrogen protection, 4.05 g of intermediate 1 and 2.75 g of 4-aminobenzaldehyde were added to 16 mL of tetrahydrofuran solvent, mixed evenly, and reacted at 65 °C for 21 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. (3) Under nitrogen protection, 3.15 g of intermediate 2 and 1.75 g of o-aminothiophenol were added to 45 mL of anhydrous ethanol solvent, stirred and mixed, and then 0.25 g of ammonium chloride was added. The mixture was heated at 78 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed and dried to obtain the flame retardant. (4) Add 13 mL of deionized water and 39 mL of anhydrous ethanol to the reactor and mix to prepare a solvent. Add 1.65 g of nano silica and 0.65 g of 3-glycidyl etheroxypropyltrimethoxysilane to the solvent. Adjust the pH to 4 with 1 mol / L dilute hydrochloric acid. After sonication for 45 min, react at 50 °C for 2 h. After the reaction is completed, centrifuge at high speed for 42 min, wash, and vacuum dry at 60 °C for 24 h to obtain modified nano silica. (5) First, add 35 parts by weight of polylactic acid, 9 parts by weight of flame retardant, 1.2 parts by weight of modified nano silica, 5 parts by weight of maleic anhydride-grafted polylactic acid, and 0.2 parts by weight of antioxidant 1010 to a high-speed mixer and stir for 8 minutes. Then add it to a twin-screw extruder and melt-blend at 175°C and granulate to obtain polylactic acid masterbatch. Then add the polylactic acid masterbatch and 70 parts by weight of ABS resin to a high-speed mixer and stir for 2 minutes. Then add it to a twin-screw extruder and melt-blend at 200°C and granulate to obtain biodegradable ABS material.

[0021] Example 4 (1) Add 4.82 g of diethyl iminodiacetate, 0.04 g of 4-dimethylaminopyridine and 21 mL of chloroform to the reactor. Then dissolve 5.02 g of diphenylphosphine chloride in 10.5 mL of chloroform and place it in a constant pressure dropping funnel. Under nitrogen protection, add 2.56 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature for 5 min. After the addition is complete, react at 72 °C for 23 h. After the reaction is complete, add 65 mL of chloroform to the reactor. Wash with 31 mL of 1% sodium hydroxide aqueous solution, 32 mL of dilute hydrochloric acid with pH 3 and 32 mL of saturated sodium chloride aqueous solution, respectively. Dry with anhydrous sodium sulfate. After drying, filter, rotary evaporate, stand until crystals precipitate, filter, wash with a small amount of ethyl acetate to obtain intermediate 1. (2) Under nitrogen protection, 4.02 g of intermediate 1 and 2.72 g of 4-aminobenzaldehyde were added to 16 mL of tetrahydrofuran solvent, mixed evenly, and reacted at 62 °C for 20 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. (3) Under nitrogen protection, 3.12 g of intermediate 2 and 1.72 g of o-aminothiophenol were added to 42 mL of anhydrous ethanol solvent, stirred and mixed, and then 0.22 g of ammonium chloride was added. The mixture was heated at 76 °C for 23 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed and dried to obtain the flame retardant. (4) Add 14 mL of deionized water and 42 mL of anhydrous ethanol to the reactor and mix to prepare a solvent. Add 1.62 g of nano silica and 0.64 g of 3-glycidyl etheroxypropyltrimethoxysilane to the solvent. Adjust the pH to 4 with 1 mol / L dilute hydrochloric acid. After sonication for 42 min, react at 48 °C for 2 h. After the reaction is completed, centrifuge at high speed for 41 min, wash, and vacuum dry at 58 °C for 23 h to obtain modified nano silica. (5) First, add 32 parts by weight of polylactic acid, 8 parts by weight of flame retardant, 1 part by weight of modified nano silica, 4 parts by weight of maleic anhydride-grafted polylactic acid, and 0.2 parts by weight of antioxidant 1010 to a high-speed mixer and stir for 6 minutes. Then add it to a twin-screw extruder and melt-blend at 172°C and granulate to obtain polylactic acid masterbatch. Then add the polylactic acid masterbatch and 65 parts by weight of ABS resin to a high-speed mixer and stir for 2 minutes. Then add it to a twin-screw extruder and melt-blend at 190°C and granulate to obtain biodegradable ABS material.

[0022] Example 5 (1) Add 4.88 g of diethyl iminodiacetate, 0.05 g of 4-dimethylaminopyridine and 24 mL of chloroform to the reactor. Then dissolve 5.08 g of diphenylphosphine chloride in 12 mL of chloroform and place it in a constant pressure dropping funnel. Under nitrogen protection, add 2.58 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature for 6 min. After the addition is complete, react at 78 °C for 25 h. After the reaction is complete, add 75 mL of chloroform to the reactor. Wash with 34 mL of 1% sodium hydroxide aqueous solution, 34 mL of dilute hydrochloric acid with pH 4 and 35 mL of saturated sodium chloride aqueous solution, respectively. Dry with anhydrous sodium sulfate. After drying, filter, rotary evaporate, stand until crystals precipitate, filter, wash with a small amount of ethyl acetate to obtain intermediate 1. (2) Under nitrogen protection, 4.08 g of intermediate 1 and 2.78 g of 4-aminobenzaldehyde were added to 17 mL of tetrahydrofuran solvent, mixed evenly, and reacted at 68 °C for 22 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. (3) Under nitrogen protection, 3.18 g of intermediate 2 and 1.78 g of o-aminothiophenol were added to 48 mL of anhydrous ethanol solvent, stirred and mixed, and then 0.28 g of ammonium chloride was added. The mixture was heated at 78 °C for 25 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed and dried to obtain the flame retardant. (4) Add 15 mL of deionized water and 45 mL of anhydrous ethanol to the reactor and mix to prepare a solvent. Add 1.68 g of nano silica and 0.66 g of 3-glycidyl etheroxypropyltrimethoxysilane to the solvent. Adjust the pH to 5 with 1 mol / L dilute hydrochloric acid. After sonication for 48 min, react at 52 °C for 3 h. After the reaction is completed, centrifuge at high speed for 44 min, wash, and vacuum dry at 62 °C for 25 h to obtain modified nano silica. (5) First, add 38 parts by weight of polylactic acid, 10 parts by weight of flame retardant, 1.5 parts by weight of modified nano silica, 6 parts by weight of maleic anhydride-grafted polylactic acid, and 0.3 parts by weight of antioxidant 1010 to a high-speed mixer and stir for 9 minutes. Then add it to a twin-screw extruder and melt-blend at 178°C and granulate to obtain polylactic acid masterbatch. Then add the polylactic acid masterbatch and 75 parts by weight of ABS resin to a high-speed mixer and stir for 3 minutes. Then add it to a twin-screw extruder and melt-blend at 200°C and granulate to obtain biodegradable ABS material.

[0023] Comparative Example 1 The main difference between this comparative example and Example 5 is that intermediate 2 is used instead of the flame retardant.

[0024] Comparative Example 2 The main difference between this comparative example and Example 5 is that nano-silica is used instead of modified nano-silica.

[0025] Performance testing The biodegradable ABS materials prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests.

[0026] Tensile strength and elongation at break: tested according to GB / T1040.1-2025, test conditions: 50 mm / min; Bending strength: Tested according to GB / T9341-2008, test conditions: 2mm / min; Flame retardant performance: Tested according to UL94 vertical burning test standard; Biodegradability: Tested according to GB / T19275-2003.

[0027] The test results are shown in Table 1.

[0028] Table 1: Performance Tests Example 1 65.34 25.2 74.26 45.13 V-0 26.1 Example 2 66.82 26.5 76.51 46.28 V-0 26.8 Example 3 66.03 25.8 75.35 45.62 V-0 26.4 Example 4 65.73 25.5 74.82 45.48 V-0 26.3 Example 5 66.47 26.2 75.90 46.01 V-0 26.6 Comparative Example 1 62.95 23.3 72.44 42.15 V-1 23.9 Comparative Example 2 58.24 18.4 67.51 37.24 V-1 20.4 As can be seen from Table 1, the biodegradable ABS materials prepared in Examples 1-5 have good mechanical properties, flame retardant properties and biodegradability.

[0029] The comparison shows that Comparative Example 1, which uses intermediate 2 instead of flame retardant, lacks the benzothiazole closed-ring structure formed after the reaction of o-aminothiophenol. This reduces its interfacial bonding with the matrix, creating stress concentration points that are prone to microcracks under stress. Furthermore, it lacks the synergistic char-forming effect of sulfur, resulting in a loose and porous char layer that cannot effectively prevent flame spread. Sulfur also promotes the hydrolysis of polylactic acid bonds, and its benzothiazole closed-ring structure has little hindering effect on the polylactic acid molecular chain. The absence of this component leads to a decrease in mechanical properties, flame retardant properties, and biodegradability. Example 2 uses nano-silica instead of modified nano-silica. Unmodified nano-silica has extremely strong surface polarity and high surface energy, and its compatibility with ABS resin and polylactic acid is extremely poor. It is very easy to cause severe agglomeration in the matrix. When under stress, the agglomerates directly become crack sources. During combustion, it will cause the char layer in most areas to break and become discontinuous, and it cannot effectively block flames and heat. Moreover, the agglomerates will physically block the contact between the degradation medium and polylactic acid, resulting in local polylactic acid that cannot be degraded. Therefore, the mechanical properties, flame retardant properties and biodegradability of Comparative Example 2 are reduced.

[0030] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0032] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A degradable ABS material, characterized in that, It includes the following components by weight: 60-80 parts by weight of ABS resin, 30-40 parts by weight of polylactic acid, 8-10 parts by weight of flame retardant, 1-1.5 parts by weight of modified nano-silica, 4-6 parts by weight of maleic anhydride-grafted polylactic acid, and 0.2-0.3 parts by weight of antioxidant 1010. The flame retardant is obtained by reacting diphenylphosphinoyl chloride and diethyl iminodiacetate to obtain intermediate 1, intermediate 1 reacts with 4-aminobenzaldehyde to obtain intermediate 2, and finally intermediate 2 reacts with o-aminothiophenol to obtain the final product. Modified nano-silica is obtained by modifying nano-silica with 3-glycidyl etheroxypropyltrimethoxysilane.

2. The degradable ABS material of claim 1, wherein, The method for preparing the flame retardant is as follows: S1: Add 4.8-4.9 g of diethyl iminodiacetic acid, 0.04-0.05 g of 4-dimethylaminopyridine, and 20-25 mL of chloroform to the reactor. Then, dissolve 5-5.1 g of diphenylphosphine chloride in 10-12 mL of chloroform in a constant-pressure dropping funnel. Under nitrogen protection, add 2.56-2.58 g of triethylamine to the reactor by injection. Add diphenylphosphine chloride dropwise at room temperature over a period of 5-6 minutes. After the addition of chloroform is complete, the reaction is carried out at 70-80℃. After the reaction is complete, 60-80 mL of chloroform is added to the reactor. The mixture is washed with 30-35 mL of 1% sodium hydroxide aqueous solution, 30-35 mL of dilute hydrochloric acid with a pH of 3-4, and 30-35 mL of saturated sodium chloride solution, respectively. The mixture is dried with anhydrous sodium sulfate. After drying, the mixture is filtered, rotary evaporated, and allowed to stand until crystals precipitate. The crystals are then filtered and washed with a small amount of ethyl acetate to obtain intermediate 1. S2: Under nitrogen protection, intermediate 1, 4-aminobenzaldehyde was added to tetrahydrofuran solvent, mixed evenly, and reacted at 60-70℃ for 18-24h. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, washed and dried, and purified by silica gel column chromatography to obtain intermediate 2. S3: Under nitrogen protection, add intermediate 2 and o-aminothiophenol to anhydrous ethanol solvent, stir and mix, then add ammonium chloride, heat at 75-80℃ for 22-26h, after the reaction is complete, cool to room temperature, filter, wash and dry to obtain flame retardant.

3. The degradable ABS material of claim 2, wherein, The reaction time in S1 is 22-26 hours.

4. The degradable ABS material of claim 2, wherein, The ratio of tetrahydrofuran to intermediate 1,4-aminobenzaldehyde in S2 is 15-18 mL: 4-4.1 g: 2.7-2.8 g.

5. The degradable ABS material of claim 2, wherein, The ratio of anhydrous ethanol, intermediate 2, o-aminothiophenol, and ammonium chloride in S3 is 40-50 mL: 3.1-3.2 g: 1.7-1.8 g: 0.2-0.3 g.

6. The degradable ABS material of claim 1, wherein, The modified nano-silica is prepared by adding deionized water and anhydrous ethanol to a reactor and mixing them to obtain a solvent. Nano-silica and 3-glycidyl etheroxypropyltrimethoxysilane are then added to the solvent. The pH is adjusted to 4-5 with 1 mol / L dilute hydrochloric acid. After ultrasonic treatment for 40-50 min, the mixture is reacted at 45-55℃ for 2-3 h. After the reaction is completed, the mixture is centrifuged at high speed for 40-45 min, washed, and vacuum dried at 55-65℃ for 22-26 h to obtain modified nano-silica.

7. The degradable ABS material of claim 6, wherein, The ratio of deionized water, anhydrous ethanol, nano silica, and 3-glycidyl etheroxypropyltrimethoxysilane is 12-15 mL: 36-45 mL: 1.6-1.7 g: 0.64-0.66 g.

8. A method of producing a degradable ABS material as claimed in any one of claims 1 to 7, characterised in that, The preparation method of the biodegradable ABS material is as follows: First, polylactic acid, flame retardant, modified nano silica, maleic anhydride-grafted polylactic acid, and antioxidant 1010 are added to a high-speed mixer and stirred for 5-10 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 170-180°C, granulated, to obtain polylactic acid masterbatch. Next, the polylactic acid masterbatch and ABS resin are added to a high-speed mixer and stirred for 2-3 minutes. Then, the mixture is added to a twin-screw extruder and melt-blended at 185-210°C, granulated, to obtain the biodegradable ABS material.

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