Polycarbonate / PBT / APT composite material and preparation method thereof

Abstract

The invention relates to a polycarbonate / PBT / APT composite material and a preparation method thereof. The polycarbonate / PBT / APT composite material is characterized by being prepared by mixing polycarbonate, PBT, a polysiloxane-polycarbonate random copolymer, attapulgite treated by a PCA filler dispersant and KT-22. Due to the addition of polysiloxane-polycarbonate, KT-22 and APT, the interfacial compatibility and mechanical properties of the material are effectively improved, the cost performance is higher, the mechanical properties and processing fluidity of the composite material are improved, the requirements of the high-end application field are met, and the application prospect is wider.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a polycarbonate / PBT / APT composite material and its preparation method. Background Technology

[0002] PC / PBT alloys are an important type of commercial engineering polymer, offering excellent performance in a wide variety of applications, including automotive exterior panels and bases, bumpers, various mechanical parts, medical devices, electronic equipment components, computer casings, and internal components. PC has drawbacks such as poor solvent resistance, low fatigue strength, and susceptibility to stress cracking. PBT resin is tasteless, non-toxic, and odorless, possessing outstanding abrasion resistance, heat aging resistance, high mechanical strength, excellent dimensional stability, toughness, and a high heat distortion temperature; it also exhibits excellent electrical properties and good arc resistance, but has high volume resistivity and high-frequency dielectric loss; it burns slowly with a yellow flame and blue edges, continuing to burn after being removed from the flame; it is resistant to hot water, acids, and oils, but has poor resistance to strong acids, strong alkalis, and phenolic compounds; it has low melt viscosity and good molding flowability, but a relatively large shrinkage rate. PC / PBT blends can combine the chemical resistance, stress cracking resistance, and gasoline resistance of PBT with the high ductility, toughness, dimensional stability, and low shrinkage of PC. However, PC / PBT blends exhibit complex morphologies, and PC and PBT are partially compatible. Therefore, adding compatibilizers for compatibilization modification is crucial to prevent delamination during product use and to obtain high-performance alloy materials. The addition of PBT effectively improves the flowability of PC, making PC products more resistant to chemicals, while also addressing issues such as high molding shrinkage, low melt viscosity, and poor thermal properties of PBT. Compared to polypropylene, polyurethane, and other automotive plastic components, PC / PBT alloys are lighter, aligning better with the future trend of lightweight automotive bodies. However, their relatively high price hinders their industrial application. Therefore, resolving the compatibility issue between PC and PBT and improving the cost-effectiveness of products is of great significance. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polycarbonate / PBT / APT composite material and its preparation method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a polycarbonate / PBT / APT composite material, characterized in that it is prepared by mixing the following components in parts by weight: Polycarbonate A 60 parts, polycarbonate B 4.9-7.9 parts; 10-25 portions of PBT; 18-22 parts of polysiloxane-polycarbonate random copolymer; 1-4 parts of attapulgite; Epoxy-modified compatibilizer KT-22, 6-10 parts; Antioxidant 0.5-1.1 parts.

[0005] The preparation method includes the following steps: Step 1, Premixing: Mix the attapulgite and PCA filler dispersant in a high-speed mixer, controlling the speed at 300-350 rpm, the time at 5-8 min, and the temperature at 25-30℃, to obtain a premix with a particle size of 1-5 μm and a specific surface area ≥150 m² / g. Step 2, Mixing: Add the premixed material, polycarbonate A, polycarbonate B, PBT, polysiloxane-polycarbonate random copolymer, epoxy-modified compatibilizer KT-22, and antioxidant to a high-speed mixer at a speed of 400-450 rpm for 10-15 min, and control the material temperature to ≤60℃ to obtain the mixed material. Step 3, melt extrusion: The mixture is melt extruded through a twin-screw extruder, with temperatures in each zone ranging from 150 to 265°C, a heating rate of 5 to 10°C / min, a screw speed of 400 rpm, and a die head pressure of 15 to 20 MPa. Step 4, cooling and granulation: After the extruded material is cooled by water at 20-30℃, it is cut into particles with a diameter of 2-3mm and a length of 2-3mm to obtain the target product.

[0006] Furthermore, the melt flow rate of polycarbonate A is greater than 10 g / (10 min), and the melt flow rate of polycarbonate B is less than 8 g / (10 min). Furthermore, the polysiloxane blocks in the polysiloxane-polycarbonate random copolymer account for 22%-28% of the total weight of the copolymer, and the melt flow rate is 10-15 g / (10min). Furthermore, in step one, the attapulgite, after being treated with PCA filler dispersant, has a particle size of 1-5 μm and a specific surface area ≥150 m² / g; Furthermore, the antioxidant is a mixture of antioxidant 1076 and antioxidant 168, wherein antioxidant 1076 is 0.2-0.5 parts and antioxidant 168 is 0.3-0.6 parts.

[0007] The beneficial effects of this invention are as follows: By introducing polysiloxane-polycarbonate random copolymer and APT into PC / PBT composite materials, and using KT-22 as a compatibilizer, the polysiloxane blocks (22%-28%) of the polysiloxane-polycarbonate random copolymer and the epoxy groups of KT-22 form a synergistic effect, which improves both the interfacial compatibility of PC and PBT and enhances the toughness of the material. After PCA treatment, the APT has enhanced bonding force with the matrix, simultaneously improving rigidity and processing fluidity, resulting in high comprehensive performance and cost-effectiveness. The preparation process is simple and has broad prospects in high-end application fields. Attached Figure Description

[0008] Figure 1 These are SEM cross-sectional images of the PC / PBT / APT composite materials involved in Examples 1-4.

[0009] Wherein: a-Example 1; b-Example 2; c-Example 3; d-Example 4. Detailed Implementation

[0010] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention. Example 1

[0011] A method for preparing a polycarbonate / PBT / APT composite material includes the following steps: Step 1, Premixing: Mix the attapulgite and PCA filler dispersant in a high-speed mixer, controlling the speed at 300-350 rpm, the time at 5-8 min, and the temperature at 25-30℃, to obtain a premix with a particle size of 1-5 μm and a specific surface area ≥150 m² / g. Step 2, Mixing: Add the premixed material, polycarbonate A, polycarbonate B, PBT, polysiloxane-polycarbonate random copolymer, epoxy-modified compatibilizer KT-22, antioxidant 1076 and antioxidant 168 to a high-speed mixer according to the weights in Table 1, at a speed of 400-450 rpm for 10-15 min, and control the material temperature to ≤60℃ to obtain the mixed material; Step 3, melt extrusion: The mixture is melt extruded through a twin-screw extruder. The temperature of each temperature zone is controlled as shown in Table 2. The heating rate is 5-10℃ / min, the screw speed is 400rpm, and the die head pressure is 15-20MPa. Step 4, cooling and granulation: After the extruded material is cooled by water at 20-30℃, it is cut into particles with a diameter of 2-3mm and a length of 2-3mm to obtain the target product.

[0012] The performance indicators of the composite material are shown in Table 3. The SEM cross-sectional analysis of the composite material is shown in [Table 3]. Figure 1 (a) in the middle.

[0013] The above materials are from: Polycarbonate A: Luxi Chemical LXTY1615, melt flow rate 15 g / (10min); Polycarbonate B: Mitsubishi E2000, melt flow rate 5 g / (10 min); Polysiloxane-polycarbonate random copolymer: Gansu Yinguang Juyin Chemical Co., Ltd., melt flow rate 10-15 g / (10 min), polysiloxane block weight 22-28%; PBT: BM434 from Zhejiang Yizheng Chemical Fiber Engineering Plastics Factory; KT-22: Shenyang Ketong Plastics Co., Ltd. LXTY1609T-11. Example 2

[0014] A method for preparing a polycarbonate / PBT / APT composite material is the same as in Example 1.

[0015] However, the SEM cross-sectional analysis of the composite material is shown in [the image]. Figure 1 (b) in the middle. Example 3

[0016] A method for preparing a polycarbonate / PBT / APT composite material is the same as in Example 1.

[0017] However, the SEM cross-sectional analysis of the composite material is shown in [the image]. Figure 1 (c) in the middle. Example 4

[0018] A method for preparing a polycarbonate / PBT / APT composite material is the same as in Example 1.

[0019] However, the SEM cross-sectional analysis of the composite material is shown in [the image]. Figure 1 (d) in the middle.

[0020]

[0021]

[0022]

[0023] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A polycarbonate / PBT / APT composite material, characterized in that: It is prepared by mixing the following components in parts by weight: Polycarbonate A 60 parts, polycarbonate B 4.9-7.9 parts; 10-25 portions of PBT; 18-22 parts of polysiloxane-polycarbonate random copolymer; 1-4 parts of attapulgite; Epoxy-modified compatibilizer KT-22, 6-10 parts; Antioxidant 0.5-1.1 parts.

2. The method for preparing a polycarbonate / PBT / APT composite material according to claim 1, characterized in that, Includes the following steps: Step 1, Premixing: Mix the attapulgite and PCA filler dispersant in a high-speed mixer, controlling the speed at 300-350 rpm, the time at 5-8 min, and the temperature at 25-30℃ to obtain the premix. Step 2, Mixing: Add the premixed material, polycarbonate A, polycarbonate B, PBT, polysiloxane-polycarbonate random copolymer, epoxy-modified compatibilizer KT-22, and antioxidant to a high-speed mixer at a speed of 400-450 rpm for 10-15 min, and control the material temperature to ≤60℃ to obtain the mixed material. Step 3, melt extrusion: The mixture is melt extruded through a twin-screw extruder, with temperatures in each zone ranging from 150 to 265°C, a heating rate of 5 to 10°C / min, a screw speed of 400 rpm, and a die head pressure of 15 to 20 MPa. Step 4, cooling and granulation: After the extruded material is cooled by water at 20-30℃, it is cut into particles with a diameter of 2-3mm and a length of 2-3mm to obtain the target product.

3. The polycarbonate / PBT / APT composite material according to claim 1, characterized in that, The polycarbonate A has a melt flow rate greater than 10 g / (10 min), and the polycarbonate B has a melt flow rate less than 8 g / (10 min).

4. A polycarbonate / PBT / APT composite material according to claim 1, characterized in that: The polysiloxane-polycarbonate random copolymer has a polysiloxane block weight accounting for 22-28% of the total copolymer weight, and a melt flow rate of 10-15 g / (10min).

5. A polycarbonate / PBT / APT composite material according to claim 1, characterized in that, In step one, the attapulgite, after being treated with PCA filler dispersant, has a particle size of 1-5 μm and a specific surface area ≥150 m² / g.

6. A polycarbonate / PBT / APT composite material according to claim 1, characterized in that, The antioxidant is a mixture of antioxidant 1076 and antioxidant 168, wherein antioxidant 1076 is 0.2-0.5 parts and antioxidant 168 is 0.3-0.6 parts.

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