Halogen-free flame-retardant composite plastic and preparation method thereof

Abstract

The invention relates to the technical field of plastics, and discloses a halogen-free flame-retardant composite plastic and a preparation method thereof. The composite plastic is prepared from the following raw materials in parts by weight: 80 to 90 parts of polyethylene glycol terephthalate, 15 to 25 parts of polycarbonate, 8 to 12 parts of modified flame retardant, 0.5 to 1.5 parts of antioxidant and 1 to 3 parts of lubricant, according to the composite plastic, polyethylene glycol terephthalate and polycarbonate are used as main plastic matrixes, and functional aids such as a modified flame retardant, an antioxidant and a lubricant are added to improve the flame retardant property and the mechanical property of the plastic; wherein the modified flame retardant is a compound of an inorganic flame retardant and an organic flame retardant, and compared with the traditional flame-retardant plastic which is added with a single organic flame retardant and an inorganic flame retardant, and the compound combines the organic flame retardant and the inorganic flame retardant, the modified flame-retardant plastic has the effects of small dosage and efficient flame retardance.

Description

Technical Field

[0001] The present invention relates to the technical field of plastics, and particularly relates to a halogen-free flame-retardant composite plastic and a preparation method thereof. Background Art

[0002] With the rapid development of modern industry, plastic materials are increasingly widely used in fields such as electronics and electrical appliances, automobiles, household appliances, and construction. However, the flammability of plastics poses a great fire risk during use. Therefore, the development of flame-retardant plastics has become an important research direction in materials science. Most traditional flame-retardant plastics use halogen-containing flame retardants. Although these flame retardants have high flame-retardant performance in plastics, they will produce a large amount of toxic smoke and corrosive gases during combustion, causing serious harm to the environment and human health. Compared with halogen-containing flame retardants, halogen-free flame retardants do not release toxic gases and corrosive substances, and have better environmental performance and safety.

[0003] Although halogen-free flame-retardant plastics have significant environmental advantages, they still face some technical challenges in practical applications. First, the flame-retardant efficiency of halogen-free flame retardants is relatively low, and usually a higher addition amount is required to achieve an ideal flame-retardant effect, which may have an adverse impact on the mechanical properties and processing properties of plastics; second, some halogen-free flame retardants are prone to precipitation during the processing process, resulting in mold contamination and reduced production efficiency. Therefore, in view of the existing problems of halogen-free flame retardants at the present stage, researchers can develop new halogen-free flame retardants or composite flame retardants to meet the actual application requirements. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a halogen-free flame-retardant composite plastic and a preparation method thereof.

[0005] The object of the present invention can be achieved by the following technical solutions: A halogen-free flame-retardant composite plastic, comprising the following raw materials in parts by weight: 80-90 parts of polyethylene terephthalate, 15-25 parts of polycarbonate, 8-12 parts of a modified flame retardant, 0.5-1.5 parts of an antioxidant, and 1-3 parts of a lubricant; The antioxidant is one of antioxidant 1010 or antioxidant 168; The lubricant is one of calcium stearate or zinc stearate; The modified flame retardant is prepared by the following steps: Step A1: Mix 1-vinylimidazole, 2-mercaptoethanol, and benzoin dimethyl ether evenly, irradiate under 100W, 365nm ultraviolet light for 15-25 min, add n-hexane and stir for 20 min, and perform rotary evaporation to obtain an imidazole derivative; Further, in step A1, the usage ratio of 1-vinylimidazole, 2-mercaptoethanol, benzoin dimethyl ether and n-hexane is 0.1-0.2 mol: 0.1-0.2 mol: 0.04-0.08 g: 50 mL; Step A2, mixing an imidazole derivative and phenylphosphonothioyl dichloride, introducing nitrogen and heating to 80-90°C for reaction for 1 hour, then heating to 130-140°C for reaction for 8 hours, then heating to 160°C for reaction for 1 hour, extracting, filtering, drying, and collecting an organic flame retardant; then mixing and stirring the organic flame retardant, the composite auxiliary agent and deionized water for 2 hours, filtering, washing, and drying to obtain a modified flame retardant; Further, in step A2, the molar ratio of the imidazole derivative and phenylphosphonothioic acid dichloride in the organic flame retardant is 2:1; Furthermore, in step A2, the mass ratio of the organic flame retardant, the composite auxiliary agent and the deionized water in the modified flame retardant is 2-6:1-3:20.

[0006] The composite auxiliary agent is prepared by the following steps: Step B1, dispersing cerium chloride heptahydrate and sodium phosphate dodecahydrate in deionized water respectively, recorded as cerium chloride solution and sodium phosphate solution; mixing the sodium phosphate solution and the cerium chloride solution, vigorously stirring at room temperature for 15 minutes, adjusting the pH to 1, and then hydrothermally reacting at 170°C for 12 hours, centrifuging, washing, and drying to obtain CePO 4 Nanomaterials; Furthermore, in step B1, the pH is adjusted to pH=1 using a 25wt% hydrochloric acid solution; Further, in step B1, the ratio of cerium chloride heptahydrate to deionized water in the cerium chloride solution is 1.12-3.36 g:15 mL, and the ratio of sodium phosphate dodecahydrate to deionized water in the sodium phosphate solution is 1.14-3.42 g:15 mL; Further, in step B1, the hydrothermal reaction is carried out in an autoclave; Step B2: CePO 4 The nanomaterial, cationic polyacrylamide (CPAM) and deionized water were mixed and stirred for 2 h, then ultrasonically treated for 48 h, centrifuged, washed and dried to obtain CPAM-CePO. 4 Nanomaterials; Further, in step B2, CePO 4 The dosage ratio of nanomaterial, CPAM and deionized water is 1-2 g:2-6 g:20 mL; Step B3, mixing boron nitride powder and deionized water evenly, adjusting the pH, and then ultrasonically treating for 20-30 hours, centrifuging, washing, and drying to obtain hydroxylated boron nitride; CPAM-CePO 4The nanomaterial, hydroxylated boron nitride and deionized water are mixed, ultrasonically treated for 48 hours, centrifuged, washed and dried to obtain a composite additive; Further, in step B3, the mass ratio of boron nitride powder to deionized water in the hydroxylated boron nitride is 1:1, and the CPAM-CePO in the composite additive is 4 The mass ratio of nanomaterial, hydroxylated boron nitride and deionized water is 1:1:10; Furthermore, in step B3, the pH is adjusted to 12-13 using 10wt% sodium hydroxide solution.

[0007] A method for preparing a halogen-free flame-retardant composite plastic comprises the following steps: Raw materials are weighed by weight, polyethylene terephthalate, polycarbonate, modified flame retardant, antioxidant and lubricant are mixed and stirred evenly, and then transferred to a twin-screw extruder for melt extrusion, and then cooled, granulated and dried to obtain a halogen-free flame retardant composite plastic.

[0008] Beneficial effects of the present invention: The composite plastic in the present invention uses polyethylene terephthalate and polycarbonate as the main plastic matrix, and adds functional additives such as modified flame retardants, antioxidants and lubricants to improve the flame retardant properties and mechanical properties of the plastic; wherein the modified flame retardant is a composite of an inorganic flame retardant and an organic flame retardant. Compared with the halogen flame retardant added in traditional flame retardant plastics, the composite combines the two and has the effects of small dosage, non-toxicity and high efficiency flame retardancy.

[0009] The modified flame retardant in the present application is a composite of an inorganic flame retardant and an organic flame retardant, which is introduced into the composite plastic to significantly improve the flame retardant properties of the plastic matrix; wherein the composite additive acts as an inorganic filler flame retardant in the plastic matrix, and is a composite of boron nitride and CPAM-CePO 4 The electrostatic interaction between nanomaterials is compounded. Boron nitride can form a protective ceramic layer during the combustion of plastic, blocking oxygen and heat, thereby preventing the spread of flames. CePO 4 The composite can not only use the rare earth element (cerium) it contains to capture the free radicals generated by combustion, but also use the decomposition products of phosphorus to promote the carbonization of the polymer matrix and form a dense carbon layer. The imidazole structure, phosphorus and sulfur elements are introduced into the organic flame retardant to synergistically improve the flame retardant properties of the matrix. The imidazole structure absorbs heat through chemical reactions to consume the energy of the ignition material, reducing the heat released by the plastic during combustion and delaying the combustion process. The sulfur element can inhibit the pyrolysis reaction, thereby preventing the plastic from decomposing violently too early. At the same time, it can also combine with oxygen to slow down the spread of the flame. DETAILED DESCRIPTION

[0010] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] Example 1: The composite auxiliary agent is prepared by the following steps: Step B1, 1.12g of cerium chloride heptahydrate and 1.14g of sodium phosphate dodecahydrate were dispersed in 15mL of deionized water, recorded as cerium chloride solution and sodium phosphate solution; the sodium phosphate solution and the cerium chloride solution were mixed, vigorously stirred at room temperature for 15min, and adjusted to pH=1 with 25wt% hydrochloric acid solution, and then hydrothermally reacted at 170°C in an autoclave for 12h, centrifuged, washed, and dried to obtain CePO 4 Nanomaterials; Step B2: 1 g CePO 4 The nanomaterial, 2 g of cationic polyacrylamide and 20 mL of deionized water were mixed and stirred for 2 h, then ultrasonically treated for 48 h, centrifuged, washed and dried to obtain CPAM-CePO. 4 Nanomaterials; Step B3, 10g of boron nitride powder and 10g of deionized water were mixed evenly, and the pH was adjusted to 12 with 10wt% sodium hydroxide solution, and then ultrasonically treated for 20h, centrifuged, washed, and dried to obtain hydroxylated boron nitride; 3g of CPAM-CePO 4 The nanomaterial, 3 g of hydroxylated boron nitride and 30 g of deionized water are mixed, and ultrasonically treated for 48 hours, centrifuged, washed and dried to obtain a composite auxiliary agent.

[0012] The modified flame retardant is prepared by the following steps: Step A1, 0.1 mol 1-vinyl imidazole, 0.1 mol 2-mercaptoethanol and 0.04 g benzoin dimethyl ether were mixed evenly, irradiated under 100 W, 365 nm ultraviolet light for 15 min, added with 50 mL n-hexane, stirred for 20 min, and rotary evaporated to obtain an imidazole derivative; Step A2, 0.2 mol of imidazole derivative and 0.1 mol of phenylphosphonothioate dichloride are mixed, nitrogen is introduced and the temperature is raised to 80°C for reaction for 1 hour, then the temperature is raised to 130°C for reaction for 8 hours, and then the temperature is raised to 160°C for reaction for 1 hour, extraction, filtration, drying, and collecting the organic flame retardant; then 2 g of the organic flame retardant, 1 g of the composite auxiliary agent and 20 g of deionized water are mixed and stirred for 2 hours, filtered, washed and dried to obtain the modified flame retardant.

[0013] Example 2: The composite auxiliary agent is prepared by the following steps: Step B1, 2.24g of cerium chloride heptahydrate and 2.28g of sodium phosphate dodecahydrate were dispersed in 15mL of deionized water, recorded as cerium chloride solution and sodium phosphate solution; the sodium phosphate solution and the cerium chloride solution were mixed, vigorously stirred at room temperature for 15min, and adjusted to pH=1 with 25wt% hydrochloric acid solution, and then hydrothermally reacted at 170°C in an autoclave for 12h, centrifuged, washed, and dried to obtain CePO 4 Nanomaterials; Step B2: 1.5 g CePO 4 The nanomaterial, 4 g of cationic polyacrylamide and 20 mL of deionized water were mixed and stirred for 2 h, then ultrasonically treated for 48 h, centrifuged, washed and dried to obtain CPAM-CePO. 4 Nanomaterials; Step B3, 10g of boron nitride powder and 10g of deionized water were mixed evenly, and the pH was adjusted to 12.5 with 10wt% sodium hydroxide solution, and then ultrasonically treated for 25h, centrifuged, washed, and dried to obtain hydroxylated boron nitride; 3g of CPAM-CePO 4 The nanomaterial, 3 g of hydroxylated boron nitride and 30 g of deionized water are mixed, and ultrasonically treated for 48 hours, centrifuged, washed and dried to obtain a composite auxiliary agent.

[0014] The modified flame retardant is prepared by the following steps: Step A1, 0.15 mol 1-vinyl imidazole, 0.15 mol 2-mercaptoethanol and 0.06 g benzoin dimethyl ether were mixed evenly, irradiated under 100 W, 365 nm ultraviolet light for 20 min, added with 50 mL n-hexane, stirred for 20 min, and rotary evaporated to obtain an imidazole derivative; Step A2, 0.2 mol of imidazole derivative and 0.1 mol of phenylphosphonothioate dichloride are mixed, nitrogen is introduced and the temperature is raised to 85°C for reaction for 1 hour, then the temperature is raised to 135°C for reaction for 8 hours, and then the temperature is raised to 160°C for reaction for 1 hour, and the organic flame retardant is collected by extraction, filtration and drying; then 4 g of organic flame retardant, 2 g of composite auxiliary agent and 20 g of deionized water are mixed and stirred for 2 hours, filtered, washed and dried to obtain a modified flame retardant.

[0015] Example 3: The composite auxiliary agent is prepared by the following steps: Step B1, 3.36g of cerium chloride heptahydrate and 3.42g of sodium phosphate dodecahydrate were dispersed in 15mL of deionized water, respectively, and recorded as cerium chloride solution and sodium phosphate solution; the sodium phosphate solution and the cerium chloride solution were mixed, vigorously stirred at room temperature for 15min, and adjusted to pH=1 with 25wt% hydrochloric acid solution, and then hydrothermally reacted at 170°C in an autoclave for 12h, centrifuged, washed, and dried to obtain CePO 4 Nanomaterials; Step B2: 2 g CePO4 The nanomaterial, 6 g of cationic polyacrylamide and 20 mL of deionized water were mixed and stirred for 2 h, then ultrasonically treated for 48 h, centrifuged, washed and dried to obtain CPAM-CePO. 4 Nanomaterials; Step B3, 10g of boron nitride powder and 10g of deionized water were mixed evenly, and the pH was adjusted to 13 with 10wt% sodium hydroxide solution, and then ultrasonically treated for 30h, centrifuged, washed and dried to obtain hydroxylated boron nitride; 3g of CPAM-CePO 4 The nanomaterial, 3 g of hydroxylated boron nitride and 30 g of deionized water are mixed, and ultrasonically treated for 48 hours, centrifuged, washed and dried to obtain a composite auxiliary agent.

[0016] The modified flame retardant is prepared by the following steps: Step A1, 0.2 mol 1-vinyl imidazole, 0.2 mol 2-mercaptoethanol and 0.08 g benzoin dimethyl ether were mixed evenly, irradiated under 100 W, 365 nm ultraviolet light for 25 min, added with 50 mL n-hexane, stirred for 20 min, and rotary evaporated to obtain an imidazole derivative; Step A2, 0.2 mol of imidazole derivative and 0.1 mol of phenylphosphonothioate dichloride are mixed, nitrogen is introduced and the temperature is raised to 90°C for reaction for 1 hour, then the temperature is raised to 140°C for reaction for 8 hours, and then the temperature is raised to 160°C for reaction for 1 hour, extraction, filtration, drying, and collecting the organic flame retardant; then 6 g of the organic flame retardant, 3 g of the composite auxiliary agent and 20 g of deionized water are mixed and stirred for 2 hours, filtered, washed and dried to obtain the modified flame retardant.

[0017] Embodiment 4: A method for preparing a halogen-free flame-retardant composite plastic comprises the following steps: The raw materials were weighed by weight, and 80 parts of polyethylene terephthalate, 15 parts of polycarbonate, 8 parts of the modified flame retardant prepared in Example 1, 0.5 parts of antioxidant 1010 and 1 part of calcium stearate were mixed and stirred evenly, and then transferred to a twin-screw extruder for melt extrusion, and then cooled, granulated and dried to obtain a halogen-free flame retardant composite plastic.

[0018] Embodiment 5: A method for preparing a halogen-free flame-retardant composite plastic comprises the following steps: The raw materials were weighed by weight, and 85 parts of polyethylene terephthalate, 20 parts of polycarbonate, 10 parts of the modified flame retardant prepared in Example 2, 1 part of antioxidant 168 and 2 parts of zinc stearate were mixed and stirred evenly, and then transferred to a twin-screw extruder for melt extrusion, and then cooled, granulated and dried to obtain a halogen-free flame retardant composite plastic.

[0019] Embodiment 6: A method for preparing a halogen-free flame-retardant composite plastic comprises the following steps: The raw materials were weighed by weight, and 90 parts of polyethylene terephthalate, 25 parts of polycarbonate, 12 parts of the modified flame retardant prepared in Example 3, 1.5 parts of antioxidant 1010 and 3 parts of zinc stearate were mixed and stirred evenly, and then transferred to a twin-screw extruder for melt extrusion, and then cooled, granulated and dried to obtain a halogen-free flame retardant composite plastic.

[0020] Comparative Example 1: This comparative example is a flame retardant composite plastic. The difference from Example 6 is that magnesium hydroxide is used instead of the modified flame retardant prepared in Example 3, and the rest is the same.

[0021] Comparative Example 2: This comparative example is a flame retardant composite plastic. The difference from Example 6 is that the composite auxiliary agent prepared in Example 3 is used instead of the modified flame retardant prepared in Example 3, and the rest is the same.

[0022] Comparative Example 3: This comparative example is a flame retardant composite plastic. The difference from Example 6 is that the organic flame retardant prepared in Example 3 is used instead of the modified flame retardant prepared in Example 3, and the rest is the same.

[0023] The flame retardant composite plastics prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to performance tests: Flame retardant performance test: Limiting oxygen index test is carried out according to GB / T 2406.2-2009 standard, and vertical burning test is carried out according to GB / T2408-2008; Tensile strength test: tensile strength test is carried out according to GB / T 1040-2006 standard; The test results are shown in Table 1: Table 1: Performance test results

[0024] As can be seen from Table 1, after the limiting oxygen index and flame retardancy grade tests of the composite plastic prepared by the present invention, the limiting oxygen index is (31.3-32.1)%, and the combustion grade is V-0, indicating that the composite plastic has excellent flame retardancy; after the tensile strength test, the tensile strength is (76.5-78.1) MPa, indicating that the composite plastic has good mechanical properties.

[0025] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A halogen-free flame-retardant composite plastic, characterized in that: The invention comprises the following raw materials in parts by weight: 80-90 parts of polyethylene terephthalate, 15-25 parts of polycarbonate, 8-12 parts of modified flame retardant, 0.5-1.5 parts of antioxidant and 1-3 parts of lubricant; The antioxidant is one of antioxidant 1010 or antioxidant 168; The lubricant is one of calcium stearate or zinc stearate; The modified flame retardant is a composite of an organic flame retardant and a composite auxiliary agent, wherein the organic flame retardant is prepared by reacting an imidazole derivative with phenylphosphonothioyl dichloride, and the imidazole derivative is prepared by reacting 1-vinylimidazole with 2-mercaptoethanol; The composite auxiliary agent is prepared by compounding CPAM-CePO4 nanomaterial and hydroxylated boron nitride, the CPAM-CePO4 nanomaterial is prepared by compounding CePO4 nanomaterial and cationic polyacrylamide, the CePO4 nanomaterial is prepared by hydrothermal reaction of sodium phosphate and cerium chloride, and the hydroxylated boron nitride is prepared by alkali treatment of boron nitride powder.

2. The halogen-free flame-retardant composite plastic according to claim 1, characterized in that: The modified flame retardant is prepared by the following steps: Step A1, 1-vinyl imidazole, 2-mercaptoethanol and benzoin dimethyl ether are mixed evenly, irradiated under 100 W, 365 nm ultraviolet light for 15-25 min, n-hexane is added, stirred for 20 min, and rotary evaporated to obtain an imidazole derivative; Step A2, mix the imidazole derivative and phenylphosphonothioyl dichloride, introduce nitrogen and heat to 80-90°C for reaction for 1 hour, then heat to 130-140°C for reaction for 8 hours, then heat to 160°C for reaction for 1 hour, extract, filter, dry and collect the organic flame retardant; then mix the organic flame retardant, composite additive and deionized water and stir for 2 hours, filter, wash and dry to obtain the modified flame retardant.

3. The halogen-free flame-retardant composite plastic according to claim 2, characterized in that: In step A1, the usage ratio of 1-vinylimidazole, 2-mercaptoethanol, benzoin dimethyl ether and n-hexane is 0.1-0.2 mol: 0.1-0.2 mol: 0.04-0.08 g: 50 mL.

4. The halogen-free flame-retardant composite plastic according to claim 2, characterized in that: In step A2, the molar ratio of the imidazole derivative to phenylphosphonothioyl dichloride in the organic flame retardant is 2:1, and the mass ratio of the organic flame retardant, the composite auxiliary agent and deionized water in the modified flame retardant is 2-6:1-3:

20.

5. The halogen-free flame-retardant composite plastic according to claim 1, characterized in that: The composite auxiliary agent is prepared by the following steps: Step B1, dispersing cerium chloride heptahydrate and sodium phosphate dodecahydrate in deionized water respectively, recorded as cerium chloride solution and sodium phosphate solution; mixing the sodium phosphate solution and the cerium chloride solution, vigorously stirring at room temperature for 15 minutes, adjusting the pH to 1, and then hydrothermally reacting at 170° C. for 12 hours, centrifuging, washing, and drying to obtain CePO4 nanomaterials; Step B2, mixing CePO4 nanomaterial, cationic polyacrylamide and deionized water for 2 hours, then ultrasonically treating for 48 hours, centrifuging, washing and drying to obtain CPAM-CePO4 nanomaterial; Step B3, mix the boron nitride powder and deionized water evenly, adjust the pH, and then ultrasonically treat for 20-30 hours, centrifuge, wash, and dry to obtain hydroxylated boron nitride; mix the CPAM-CePO4 nanomaterial, hydroxylated boron nitride and deionized water, and ultrasonically treat for 48 hours, centrifuge, wash, and dry to obtain a composite auxiliary agent.

6. The halogen-free flame-retardant composite plastic according to claim 5, characterized in that: Step B1: The ratio of cerium chloride heptahydrate to deionized water in the cerium chloride solution is 1.12-3.36 g:15 mL, and the ratio of sodium phosphate dodecahydrate to deionized water in the sodium phosphate solution is 1.14-3.42 g:15 mL.

7. The halogen-free flame-retardant composite plastic according to claim 5, characterized in that: In step B2, the usage ratio of CePO4 nanomaterial, CPAM and deionized water is 1-2g:2-6g:20mL.

8. The halogen-free flame-retardant composite plastic according to claim 5, characterized in that: In step B3, the mass ratio of boron nitride powder to deionized water in the hydroxylated boron nitride is 1:1, and the mass ratio of CPAM-CePO4 nanomaterial, hydroxylated boron nitride and deionized water in the composite additive is 1:1:

10.

9. The halogen-free flame-retardant composite plastic according to claim 5, characterized in that: In step B3, the pH is adjusted to 12-13 using 10 wt % sodium hydroxide solution.

10. A method for preparing the halogen-free flame-retardant composite plastic according to any one of claims 1 to 9, characterized in that: The following steps are involved: Raw materials are weighed by weight, polyethylene terephthalate, polycarbonate, modified flame retardant, antioxidant and lubricant are mixed and stirred evenly, and then transferred to a twin-screw extruder for melt extrusion, and then cooled, granulated and dried to obtain a halogen-free flame retardant composite plastic.

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