Recycled plastic-based PC / ABS composite material and preparation method thereof

Abstract

The invention discloses a recycled plastic-based PC / ABS composite material and a preparation method thereof, and belongs to the technical field of high polymer materials, the recycled plastic-based PC / ABS composite material comprises the following raw materials by weight: 45-55 parts of recycled PC resin, 15-30 parts of ABS resin, 3-5 parts of a flame retardant, 5-8 parts of nano silica, and 0.3-1 part of an antioxidant; in the synthesis process of the flame retardant, an intermediate is firstly prepared, the structure of the intermediate has a carbon skeleton of pentaerythritol and also has a six-membered spiro structure, the intermediate has excellent thermal stability and char forming property, the introduced phosphate structure can endow the intermediate with flame retardant property, and then carbon-carbon double bonds on the intermediate react with phosphorus-hydrogen bonds on DOPO, so that the flame retardant is obtained. The introduced DOPO can be used as the flame retardant, and flame retardant molecules formed by reaction can endow the composite material with excellent thermal stability and flame retardance in a manner of cooperating with the DOPO through an intermediate.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a PC / ABS composite material based on recycled plastics and a preparation method thereof. Background Art

[0002] PC / ABS, a copolymer of polycarbonate and acrylonitrile-butadiene-styrene, is a thermoplastic plastic made from an alloy of polycarbonate (Polycarbonate) and polyacrylonitrile (ABS). It combines the excellent properties of both materials: the moldability of ABS with the mechanical properties, impact strength, heat resistance, and UV resistance of PC. It is widely used in automotive interior parts, business machines, communications equipment, household appliances, and lighting equipment.

[0003] When PC / ABS alloys are used in the manufacture of electronic components, flame retardancy is often required. To improve this, flame retardants are often added. Commonly used flame retardants for PC / ABS alloys include halogenated flame retardants such as decabromodiphenyl ether (decabrominated or octabromodiphenyl ether), tetrabromobisphenol A, and bromine-containing carbonate oligomers. Halogenated flame retardants pose safety and environmental concerns. Furthermore, the corrosive gases (HCl, HBr, etc.) produced during the thermal decomposition of halogenated flame retardant materials can damage key components in electronic / electrical equipment, even at very low concentrations, leading to complete equipment failure. Furthermore, the addition of inorganic flame retardants significantly impacts the toughness of ABS flame-retardant materials, severely affecting their mechanical properties. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an environmentally friendly composite material PCABS based on recycled plastics and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 45-55 parts of recycled PC resin, 15-30 parts of ABS resin, 3-5 parts of flame retardant, 5-8 parts of nano-silicon dioxide, and 0.3-1 part of antioxidant; The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 150-170°C, stirring at a uniform speed, reacting for 2-4 hours, and then distilling under reduced pressure to obtain an intermediate, wherein the amount ratio of pentaerythritol, dimethyl allylphosphonate and chlorobenzene is controlled to be 0.1-0.2 mol: 0.2-0.5 mol: 150-200 mL, and the amount of tetramethylammonium chloride is 3-5% of the weight of dimethyl allylphosphonate; In step S1, tetramethylammonium chloride is used as a catalyst, chlorobenzene is used as a solvent, and pentaerythritol and dimethyl allylphosphonate react to prepare an intermediate. The reaction process is as follows:

[0006] The intermediate prepared in step S1 has a carbon skeleton of pentaerythritol and a six-membered spiro ring structure, and has excellent thermal stability and carbon-forming properties. In addition, the introduced phosphate structure can give the intermediate flame retardant properties.

[0007] Step S2: adding DOPO and the intermediate to N,N-dimethylformamide, introducing nitrogen, stirring at a uniform speed, and heating to 120-140° C., and keeping the temperature to react for 4-6 hours. After the reaction is completed, cooling to room temperature to obtain a flame retardant. The dosage ratio of DOPO, the intermediate, and N,N-dimethylformamide is controlled to be 0.2-0.4 mol: 0.1-0.2 mol: 100 mL.

[0008] In step S2, the carbon-carbon double bond on the intermediate reacts with the phosphorus-hydrogen bond on DOPO to prepare a flame retardant. The reaction process is as follows:

[0009] The flame retardant structure has both the carbon skeleton of pentaerythritol and a six-membered spiro ring structure, and has excellent thermal stability and carbon-forming properties. In addition, the introduced DOPO itself can be used as a flame retardant. The flame retardant molecules formed by the reaction can impart excellent thermal stability and flame retardancy to the composite material by cooperating with DOPO through intermediates.

[0010] Furthermore, the antioxidant is antioxidant 1010 or antioxidant 168.

[0011] Furthermore, the molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150°C.

[0012] Furthermore, the ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene, and has a weight-average molecular weight of 120,000-150,000.

[0013] A method for preparing a PC / ABS composite material based on recycled plastics comprises the following steps: The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0014] Furthermore, the extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, the temperature of zone 10 is 255-260°C, and the screw speed is 250-550 r / min.

[0015] The beneficial effects of the present invention are as follows: the present invention prepares a composite material based on recycled PC resin, which uses recycled PC resin and ABS resin as a matrix. The addition of nano-silica can improve the mechanical properties of the composite material, and a flame retardant is synthesized. First, an intermediate is prepared. The prepared intermediate structure has both a carbon skeleton of pentaerythritol and a six-membered spirocyclic structure, and has excellent thermal stability and carbon-forming properties. The introduced phosphate structure can give the intermediate flame retardant properties. Then, the carbon-carbon double bond on the intermediate reacts with the phosphorus-hydrogen bond on DOPO to prepare a flame retardant. The introduced DOPO itself can be used as a flame retardant. The flame retardant molecules formed by the reaction can give the composite material excellent thermal stability and flame retardancy by cooperating with DOPO through the intermediate. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention. Example 1

[0017] A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 45 parts of recycled PC resin, 15 parts of ABS resin, 3 parts of flame retardant, 5 parts of nano-silicon dioxide, and 0.3 parts of antioxidant; The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0018] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0019] The antioxidant is antioxidant 1010.

[0020] The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 150° C., stirring at a uniform speed, reacting for 2 hours, and then distilling under reduced pressure to obtain an intermediate, wherein the amount ratio of pentaerythritol, dimethyl allylphosphonate, and chlorobenzene is controlled to be 0.1 mol:0.2 mol:150 mL, and the amount of tetramethylammonium chloride is 3% of the weight of dimethyl allylphosphonate; Step S2: DOPO and the intermediate were added to N,N-dimethylformamide, nitrogen was introduced, the mixture was stirred at a constant speed, and the temperature was raised to 120° C. The mixture was kept at this temperature for 4 hours. After the reaction, the temperature was lowered to room temperature to obtain a flame retardant. The dosage ratio of DOPO, the intermediate, and N,N-dimethylformamide was controlled to be 0.2 mol:0.1 mol:100 mL.

[0021] The molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150° C.

[0022] The ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene and has a weight average molecular weight of 120,000-150,000. Example 2

[0023] A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 50 parts of recycled PC resin, 20 parts of ABS resin, 4 parts of flame retardant, 6 parts of nano-silicon dioxide, and 0.5 parts of antioxidant; The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0024] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0025] The antioxidant is antioxidant 1010.

[0026] The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 160° C., stirring at a uniform speed, reacting for 3 hours, and then distilling under reduced pressure to obtain an intermediate, wherein the amount ratio of pentaerythritol, dimethyl allylphosphonate, and chlorobenzene is controlled to be 0.15 mol:0.3 mol:180 mL, and the amount of tetramethylammonium chloride is 4% of the weight of dimethyl allylphosphonate; Step S2: DOPO and the intermediate were added to N,N-dimethylformamide, nitrogen was introduced, the mixture was stirred at a constant speed, and the temperature was raised to 130° C. The mixture was kept at this temperature for 5 hours. After the reaction, the temperature was lowered to room temperature to obtain a flame retardant. The dosage ratio of DOPO, the intermediate, and N,N-dimethylformamide was controlled to be 0.3 mol:0.1 mol:100 mL.

[0027] The molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150° C.

[0028] The ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene and has a weight average molecular weight of 120,000-150,000. Example 3

[0029] A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 52 parts of recycled PC resin, 25 parts of ABS resin, 4 parts of flame retardant, 7 parts of nano-silicon dioxide, and 0.8 parts of antioxidant; The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0030] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0031] The antioxidant is antioxidant 1010 or antioxidant 168.

[0032] The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 170° C., stirring at a uniform speed, reacting for 4 hours, and then distilling under reduced pressure to obtain an intermediate, wherein the amount ratio of pentaerythritol, dimethyl allylphosphonate, and chlorobenzene is controlled to be 0.2 mol:0.4 mol:180 mL, and the amount of tetramethylammonium chloride is 3-5% of the weight of dimethyl allylphosphonate; Step S2: DOPO and the intermediate were added to N,N-dimethylformamide, nitrogen was introduced, the mixture was stirred at a constant speed, and the temperature was raised to 130° C. The mixture was kept at this temperature for 5 hours. After the reaction, the temperature was lowered to room temperature to obtain a flame retardant. The dosage ratio of DOPO, the intermediate, and N,N-dimethylformamide was controlled to be 0.4 mol:0.2 mol:100 mL.

[0033] The molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150° C.

[0034] The ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene and has a weight average molecular weight of 120,000-150,000. Example 4

[0035] A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 55 parts of recycled PC resin, 30 parts of ABS resin, 5 parts of flame retardant, 8 parts of nano-silicon dioxide, and 1 part of antioxidant; The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0036] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0037] The antioxidant is antioxidant 168.

[0038] The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 170° C., stirring at a uniform speed, reacting for 4 hours, and then distilling under reduced pressure to obtain an intermediate, wherein the amount ratio of pentaerythritol, dimethyl allylphosphonate, and chlorobenzene is controlled to be 0.2 mol:0.5 mol:200 mL, and the amount of tetramethylammonium chloride is 5% of the weight of dimethyl allylphosphonate; Step S2: DOPO and the intermediate are added to N,N-dimethylformamide, nitrogen is introduced, the mixture is stirred at a constant speed, and the temperature is raised to 140° C. The mixture is kept at this temperature for 4-6 hours. After the reaction is completed, the temperature is lowered to room temperature to obtain a flame retardant. The dosage ratio of DOPO, the intermediate, and N,N-dimethylformamide is controlled to be 0.4 mol:0.2 mol:100 mL.

[0039] The molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150° C.

[0040] The ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene and has a weight average molecular weight of 120,000-150,000.

[0041] Comparative Example 1 Compared with Example 1, this comparative example uses aluminum hydroxide as a flame retardant, and the rest is the same as Example 1. The preparation method is as follows: A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 45 parts of recycled PC resin, 15 parts of ABS resin, 3 parts of aluminum hydroxide, 5 parts of nano-silicon dioxide, and 0.3 parts of an antioxidant; The recycled PC resin, ABS resin, aluminum hydroxide, nano-silicon dioxide and antioxidant are uniformly mixed, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0042] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0043] Comparative Example 2 Compared with Example 1, this comparative example uses the intermediate as the flame retardant, and the rest is the same as Example 1. The preparation method is as follows: A PC / ABS composite material based on recycled plastics, comprising the following raw materials in parts by weight: 45 parts of recycled PC resin, 15 parts of ABS resin, 3 parts of intermediate, 5 parts of nano-silicon dioxide, and 0.3 parts of antioxidant; The recycled PC resin, ABS resin, intermediate, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

[0044] The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

[0045] The properties of the composite materials prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 1 below: Flame retardant performance: Test standard GB / T2406-2009.

[0046] Mechanical properties: The test was conducted in accordance with GB / T 1040.2-2006 Plastics - Determination of tensile properties - Part 2: Experimental conditions for molded and extruded plastics; the testing instrument was a 5566 desktop electronic universal materials testing machine.

[0047] Table 1

[0048] It can be seen from Table 1 above that the composite materials prepared in Examples 1-4 of the present invention have good flame retardant properties while maintaining excellent toughness. This indicates that the prepared intermediate structure has both a carbon skeleton of pentaerythritol and a six-membered spirocyclic structure, and has excellent thermal stability and char-forming properties. In addition, the introduced phosphate structure can impart flame retardant properties to the intermediate. Subsequently, the carbon-carbon double bond on the intermediate reacts with the phosphorus-hydrogen bond on DOPO to prepare a flame retardant. The introduced DOPO itself can be used as a flame retardant. The flame retardant molecules formed by the reaction can impart excellent thermal stability and flame retardancy to the composite material through the intermediate in a synergistic manner with DOPO, and have little effect on the toughness of the composite material.

[0049] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A PC / ABS composite material based on recycled plastics, characterized in that: The invention comprises the following raw materials in parts by weight: 45-55 parts of recycled PC resin, 15-30 parts of ABS resin, 3-5 parts of flame retardant, 5-8 parts of nano-silicon dioxide, and 0.3-1 part of antioxidant; The flame retardant is prepared by the following steps: Step S1, adding pentaerythritol and dimethyl allylphosphonate to chlorobenzene, stirring at a uniform speed, adding tetramethylammonium chloride, heating to 150-170° C., stirring at a uniform speed and reacting for 2-4 hours, and then distilling under reduced pressure to obtain an intermediate; Step S2: adding DOPO and the intermediate to N,N-dimethylformamide, introducing nitrogen, stirring at a constant speed, heating to 120-140° C., and keeping the temperature to react for 4-6 hours. After the reaction is completed, cooling to room temperature to obtain a flame retardant.

2. The PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: In step S1, the dosage ratio of pentaerythritol, dimethyl allylphosphonate and chlorobenzene is controlled to be 0.1-0.2 mol: 0.2-0.5 mol: 150-200 mL, and the dosage of tetramethylammonium chloride is 3-5% of the weight of dimethyl allylphosphonate.

3. The PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The dosage ratio of DOPO, intermediate and N,N-dimethylformamide is controlled to be 0.2-0.4 mol: 0.1-0.2 mol: 100 mL.

4. The PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The antioxidant is antioxidant 1010 or antioxidant 168.

5. The PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The molecular weight of the recycled PC resin is 30,000-40,000 g / mol, and the glass transition temperature is 140-150° C.

6. The PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The ABS resin is a graft copolymer composed of acrylonitrile-butadiene-styrene and has a weight average molecular weight of 120,000-150,000.

7. The method for preparing a PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The steps include: The recycled PC resin, ABS resin, flame retardant, nano-silica and antioxidant are mixed evenly, and then extruded and granulated through a twin-screw extruder to prepare a PC / ABS composite material.

8. The method for preparing a PC / ABS composite material based on recycled plastic according to claim 1, characterized in that: The extrusion temperature of the twin-screw extruder is: the temperature of zone 1 is 225-240°C, the temperature of zone 2 is 240-250°C, the temperature of zone 3 is 250-260°C, the temperature of zone 4 is 255-265°C, the temperature of zone 5 is 260-270°C, the temperature of zone 6 is 260-270°C, the temperature of zone 7 is 255-270°C, the temperature of zone 8 is 255-260°C, the temperature of zone 9 is 255-260°C, and the temperature of zone 10 is 255-260°C. The screw speed is 250-550 r / min.

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