PC / PBT alloy material with high resistance to chemical and preparation method thereof

Abstract

This invention provides a PC / PBT material with high chemical resistance and its preparation method. The PC / PBT material, by weight, comprises the following raw material components: PC resin: 55-80 parts, PBT resin: 20-45 parts, compatibilizer: 1-5 parts, transesterification inhibitor: 0.1-1 parts, toughening agent: 1-10 parts, inorganic nanoparticles: 1-5 parts, antioxidant: 0.1-1 parts, and lubricant: 0.2-1 parts. The preparation method involves adding hexagonal boron nitride nanotubes to the PC / PBT alloy system and subjecting the alloy material to radiation treatment. Utilizing the cross-linking structure between PC and PBT molecular chains and the anchoring synergistic effect of the hexagonal boron nitride nanotubes, the movement of the PC / PBT molecular chains is effectively restricted, and the opportunity for carbonate groups to be exposed to adverse chemical environments is reduced, thereby significantly improving the overall chemical resistance of the material. This high-performance material has broad application prospects in aerospace, energy, and other fields.

Description

Technical Field

[0001] This invention relates to the field of polymer composite material processing, specifically to a PC / PBT alloy material with high chemical resistance and its preparation method. Background Technology

[0002] PC / PBT alloy is an engineering plastic composite made of PC and PBT, combining the toughness and excellent dimensional stability of PC with the rigidity, excellent heat resistance, and chemical corrosion resistance of PBT. This alloy material has high surface hardness and excellent mechanical properties, while also resisting high-temperature deformation and stress cracking, thus finding wide application in many fields such as automotive manufacturing and electronic equipment. However, the chemical corrosion resistance of traditional PC / PBT alloys has certain limitations. When exposed to certain highly corrosive chemicals or specific organic solvents, finished products may exhibit stress marks, cracks, or even further cracking, especially when applying highly corrosive exterior paints.

[0003] Currently available chemically resistant PC / PBT alloy materials can meet certain requirements for resistance to commonly used cleaning agents and detergents in everyday life. However, their performance remains insufficient for high-end applications such as aerospace and energy. For example, in the aerospace field, some special fuels, lubricants, and other chemicals, as well as highly corrosive cleaning agents used during cleaning and maintenance, can corrode PC / PBT alloy materials, leading to material performance degradation and affecting component lifespan and safety. In the energy field, battery electrolytes, insulating oils, and other chemicals are highly corrosive to materials. Long-term contact with these substances may cause PC / PBT alloy materials to swell and become embrittled, reducing equipment reliability. Therefore, developing highly chemically resistant PC / PBT alloy materials is of great significance for promoting their application in high-end fields such as aerospace and energy. Summary of the Invention

[0004] Given the limitations of current technology, this invention proposes a PC / PBT alloy material with high chemical resistance. By incorporating hexagonal boron nitride nanotubes into the PC / PBT alloy system and subjecting the alloy material to radiation treatment, the following effects are achieved: On the one hand, radiation treatment can stimulate the PC and PBT molecular chains to generate a large number of active free radicals. These free radicals initiate reactions between the molecular chains, thereby strengthening the chemical connection between PC and PBT and forming an interconnected network structure. On the other hand, radiation treatment also increases the surface activity of hexagonal boron nitride nanotubes and facilitates reactions with the active groups on PC / PBT, thereby improving the compatibility between the organic matrix and inorganic substances in the system. Because the hexagonal boron nitride nanotubes themselves have a planar hexagonal network structure, they become entangled with the molecular chains as they move, thus playing a role in strong anchoring. The cross-linking structure between the PC and PBT molecular chains and the anchoring effect of the hexagonal boron nitride nanotubes work synergistically to restrict the movement of the PC / PBT molecular chains. Meanwhile, hexagonal boron nitride nanotubes further increase the complexity of chemical penetration pathways, reducing the chance of carbonate groups being exposed to harsh chemical environments. This makes the alloy material less susceptible to damage and dissolution when faced with corrosive substances, thus significantly improving its overall chemical resistance. The provided high-chemical-resistant PC / PBT alloy material exhibits excellent resistance to harsh chemical environments such as acids, alkalis, and organic solvents, and therefore has broad application prospects in high-end fields such as aerospace and energy.

[0005] A PC / PBT alloy material with high chemical resistance, characterized in that it comprises the following raw material components in parts by weight:

[0006] PC resin: 55-80 parts

[0007] PBT resin: 20-45 parts

[0008] Compatibilizer: 1-5 parts

[0009] Transesterification inhibitor: 0.1-1 part

[0010] Toughening agent: 1-10 parts

[0011] Inorganic nanopowder: 1-5 parts

[0012] Antioxidant: 0.1-1 part

[0013] Lubricant: 0.2-1 part

[0014] The PC resin is bisphenol A type polycarbonate, and its melt flow index is 10-20 g / min under the test conditions of 300℃ / 1.2kg.

[0015] The intrinsic viscosity of the PBT resin is 0.8-1.2 dL / g.

[0016] The compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

[0017] The transesterification inhibitor is one or more of trimethyl phosphate, triphenyl phosphate, and diphenyl isooctyl phosphate, preferably triphenyl phosphate.

[0018] The toughening agent is MBS resin, in which the core is styrene-butadiene rubber and the shell is a copolymer of styrene and methyl methacrylate.

[0019] The inorganic nanopowder is hexagonal boron nitride nanotubes.

[0020] The antioxidant is one or more of 1010, 1076 and 168.

[0021] The lubricant is one or more of pentaerythritol stearate, calcium stearate, and stearamide.

[0022] In addition, the present invention also provides a method for preparing PC / PBT alloy materials with high chemical resistance, the preparation steps of which include PC / PBT alloy material preparation and radiation treatment.

[0023] The PC / PBT alloy material is prepared by high-speed stirring and uniform mixing of PC resin, PBT resin, compatibilizer, transesterification inhibitor, toughening agent, inorganic nanoparticles, antioxidant and lubricant, and adding the mixture to the feed port of a twin-screw extruder for melt extrusion granulation. The temperature of each section of the extruder is 240-270℃, the screw speed is 300-400rpm, and the screw length-to-diameter ratio is 40:1.

[0024] The radiation treatment involves irradiating the PC / PBT alloy material with an electron beam generated by a high-energy accelerator, with a radiation dose of 50-200 kGy.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) By irradiating the PC / PBT alloy material, the compatibility between PC and PBT is effectively improved, and the molecular chains are encouraged to form an interconnected network structure.

[0027] 2) Hexagonal boron nitride nanotubes are introduced into the PC / PBT alloy system and chemically bonded to the matrix resin through radiation treatment. The unique planar hexagonal network structure of the hexagonal boron nitride nanotubes creates a strong anchoring effect between them and the PC / PBT alloy material.

[0028] 3) The cross-linking structure between PC and PBT molecular chains, along with the anchoring effect of hexagonal boron nitride nanotubes, synergistically restricts the movement of molecular chains. Furthermore, this structural feature reduces the opportunity for carbonate groups in PC / PBT alloys to be exposed to adverse chemical environments, making them less susceptible to damage and dissolution by corrosive substances, thus significantly improving the overall chemical resistance of the material. Detailed Implementation

[0029] The following specific embodiments further illustrate the substantive content of the present invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0030] The raw material composition of Examples 1-5, in parts by mass, is detailed in Table 1, and the preparation methods are as follows:

[0031] First, PC / PBT alloy material is prepared by mixing PC resin, PBT resin, compatibilizer, transesterification inhibitor, toughening agent, hexagonal boron nitride carbon nanotubes, antioxidant and lubricant at high speed. The mixture is then added to the feed port of a twin-screw extruder for melt extrusion granulation. During extrusion, the temperature of each section of the extruder is 240-270℃, the screw speed is 300-400rpm, and the screw length-to-diameter ratio is 40:1.

[0032] Then, the above PC / PBT alloy material was subjected to radiation treatment using an electron beam generated by a high-energy accelerator. The radiation dose is shown in Table 1.

[0033] Components Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Example 1 Example 2 Example 3 Example 4 Example 5 PC 60 60 60 60 60 60 60 60 60 60 PBT 35 35 35 35 35 35 35 35 35 35 Ethylene-methyl acrylate-glycidyl methacrylate 2 2 2 2 2 2 2 2 2 2 Triphenyl phosphate 2 2 2 2 2 2 2 2 2 - diphenyl isooctyl phosphate - - - - - - - - - 2 MBS 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 <![CDATA[Nanometer SiO2]]> - 2.5 - - - - - - - - carbon nanotubes - - - - 2.5 - - - - - Hexagonal boron nitride nanotubes - - 2.5 - - 2.5 2.5 2.5 3.5 2.5 1010 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 168 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Pentaerythritol stearate 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Radiation dose (kGy) 0 0 0 50 50 200 150 50 150 200

[0034] The preparation methods of the PC / PBT alloy materials in Comparative Examples 1-5 are exactly the same as those in Examples 1-5, but there are the following differences: Comparative Example 1 was not irradiated; Comparative Example 2 added nano-SiO2 and was not irradiated; Comparative Example 3 added hexagonal boron nitride nanotubes but was not irradiated; Comparative Example 4 did not add inorganic nanopowder for modification and only underwent 50 kGy irradiation; Comparative Example 5 added carbon nanotubes and underwent 50 kGy irradiation.

[0035] The samples prepared in the above embodiments and comparative examples were tested, and the test data are listed in Table 2.

[0036] Tensile strength was tested according to GB / T 1040.2; flexural strength was tested according to GB / T 9341; and notched impact strength of cantilever beams was tested according to GB / T 1843.

[0037] To evaluate the chemical resistance of PC / PBT alloy materials, immersion tests were conducted according to GB / T 11547. A 10% sulfuric acid solution was used to assess the material's resistance to acidic environments; a 10% NaOH solution was used to assess its resistance to alkaline environments; and toluene and acetone were used to test the material's stability in organic solvents. Immersion conditions: room temperature, 5 minutes. The test values ​​after immersion in different solutions were compared with the values ​​before immersion. A higher performance retention rate indicates better chemical resistance. Five samples were taken from each group for testing, and the average value was calculated. The percentage of tensile strength after immersion in 10% sulfuric acid, 10% sodium hydroxide, toluene, and acetone solutions is represented by T1, T2, T3, and T4, respectively; the percentage of flexural strength is represented by F1, F2, F3, and F4, respectively; and the percentage of cantilever beam notched impact strength is represented by N1, N2, N3, and N4, respectively.

[0038] Test Project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength (MPa) (unsoaked) 54 56 57 60 62.5 73 69 65 74 78 Tensile strength (MPa) (after soaking in 10% sulfuric acid) 28 30 31 33 35 58 51 44 62 59 T1（%） 52 54 54 55 56 79 74 68 84 76 Tensile strength (MPa) (immersion in 10% sodium hydroxide) 24 26 30 33 35 53 47 41 58 55 T2（%） 44 46 53 55 56 73 68 63 78 71 Tensile strength (MPa) (after toluene immersion) 23 26 27 29 30 44 39 34 46 46 T3（%） 43 46 47 48 48 60 57 52 62 59 Tensile strength (MPa) (after acetone soaking) 32 35 37 40 43 61 54 48 66 61 T4（%） 59 63 65 67 69 84 78 74 89 78 Flexural strength (MPa) (unsoaked) 80 83 84 87 90 108 99 95 110 110 Flexural strength (MPa) (immersion in 10% sulfuric acid) 37 42 45 48 50 84 71 63 92 80 F2（%） 46 51 54 55 56 78 72 66 84 73 Flexural strength (MPa) (immersion in 10% sodium hydroxide) 32 37 38 44 47 81 67 59 90 79 F1（%） 40 45 45 51 52 75 68 62 82 72 Flexural strength (MPa) (after toluene immersion) 40 42 45 49 51 80 69 62 86 78 F3（%） 50 51 54 56 57 74 70 65 78 71 Flexural strength (MPa) (after immersion in acetone) 32 36 37 41 47 75 62 54 83 73 F4（%） 40 43 44 47 52 69 63 57 75 66 <![CDATA[Izod impact strength of cantilever beam (kJ / m 2 )(not immersed)]]> 55 56 58 53 55 54 57 60 58 55 <![CDATA[Izod impact strength of cantilever beam (kJ / m 2 )(immersed in 10% sulfuric acid)]]> 28 30 32 30 32 37 38 37 41 35 N1（%） 51 54 55 57 58 69 67 62 71 64 <![CDATA[Izod impact strength of cantilever beam (kJ / m 2 )(soaked in 10% sodium hydroxide solution)]]> 26 28 29 28 30 34 34 34 37 33 N2（%） 47 50 50 53 55 63 60 57 64 50 <![CDATA[Izod impact strength (kJ / m 2 )(soaked in toluene)]]> 27 29 31 30 31 39 38 38 45 38 N3（%） 49 52 53 57 56 72 67 63 78 69 <![CDATA[Izod impact strength (kJ / m 2 )(acetone immersion)]]> 28 28 31 30 31 39 39 38 44 38 N4（%） 51 50 53 57 56 72 68 63 76 69

[0039] As can be observed from Table 2, Comparative Example 1, serving as a blank control, had tensile strength, flexural strength, and notched impact strength of 54 MPa, 80 MPa, and 55 kJ / m, respectively. 2 Comparative Examples 2 and 3 incorporated 2.5 parts of nano-SiO2 and 2.5 parts of hexagonal boron nitride nanotubes, respectively. Compared to Comparative Example 1, the addition of these two additives resulted in a slight improvement in the mechanical properties of the materials. This is attributed to the high strength and modulus of nano-SiO2 and hexagonal boron nitride nanotubes, which, when uniformly dispersed in the PC / PBT system, partially restrict the movement of polymer molecular chains, thus positively impacting the mechanical properties of the materials. However, since these nanoparticles did not form a strong bond with the matrix material, the improvement in mechanical properties was not significant. Furthermore, Comparative Example 4 had the exact same formulation as Comparative Example 1, the only difference being that Comparative Example 4 underwent 50 kGy radiation treatment. As shown in Table 2, after radiation treatment, the tensile strength of the material increased from 54 MPa to 60 MPa, and the flexural strength increased from 80 MPa to 87 MPa. This indicates that radiation improved the compatibility between materials, and the formation of cross-linked structures between molecular chains significantly improved the mechanical properties of the materials.

[0040] Compared to Comparative Example 1, Examples 1-3 all incorporated 2.5 parts of hexagonal boron nitride nanotubes into the material, differing only in the radiation doses they received: 200 kGy, 150 kGy, and 50 kGy, respectively. Comparative data revealed that the tensile and flexural strengths of the PC / PBT alloy gradually increased with increasing radiation dose. This is because the increased radiation dose leads to the generation of more active free radicals, promoting cross-linking reactions between molecular chains and resulting in a more compact material structure. However, it is noteworthy that the cantilever beam notched impact strength decreased with increasing radiation dose. This is primarily due to the combined effect of nanoparticles and radiation, which increased the crystallinity of the PC / PBT material. Furthermore, a comparison of Comparative Example 5 and Example 3 shows that, under the same radiation dose, the introduction of hexagonal boron nitride into the PC / PBT alloy system resulted in a more significant improvement in mechanical properties. This is thanks to the unique planar hexagonal network structure of hexagonal boron nitride, which enables it to form a stronger interaction with the polymer matrix, thereby helping to improve the overall mechanical properties of the material.

[0041] Under the same radiation dose conditions as in Example 2, Example 4 added 3.5 parts of hexagonal boron nitride nanotubes. Experimental results showed that the tensile strength, flexural strength, and notched cantilever beam impact strength of this material reached 74 MPa, 110 MPa, and 58 kJ / m², respectively, exhibiting the best overall mechanical properties. This is because the addition of more hexagonal boron nitride nanotubes more effectively inhibits crack propagation, allowing the material to maintain good mechanical properties even with defects or damage, thus contributing to improved notched impact strength.

[0042] Furthermore, the chemical resistance of all comparative examples and embodiments was investigated through immersion tests. Comparative Example 1, without nanoparticle modification and radiation treatment, exhibited a resistance to 10% sulfuric acid, 10% sodium hydroxide, toluene, and acetone ranging from 40% to 59%. This meant that the tensile strength, flexural strength, and notched cantilever beam impact strength of the material all decreased to below 60% of their initial strength, indicating a significant decline in mechanical properties. In contrast, Example 4, which incorporated hexagonal boron nitride nanotubes and underwent 150 kGy radiation treatment, showed an improved resistance to 10% sulfuric acid, 10% sodium hydroxide, toluene, and acetone ranging from 62% to 89%. Example 4 maintained a tensile strength above 46 MPa, a flexural strength above 83 MPa, and a notched cantilever beam impact strength of 37 kJ / m². 2 In summary, its mechanical properties remain quite excellent.

Claims

1. A PC / PBT alloy material with high chemical resistance, comprising the following raw material components by weight: PC resin: 55-80 parts PBT resin: 20-45 parts Compatibilizer: 1-5 parts Transesterification inhibitor: 0.1-1 part Toughening agent: 1-10 parts Inorganic nanopowder: 1-5 parts Antioxidant: 0.1~1 part Lubricant: 0.2~1 part; The inorganic nanopowder is hexagonal boron nitride nanotubes; The PC / PBT alloy is prepared by two steps: material preparation and radiation treatment. The material preparation steps are as follows: PC resin, PBT resin, compatibilizer, transesterification inhibitor, toughening agent, inorganic nanoparticles, antioxidant and lubricant are mixed evenly at high speed, the mixture is added to the feed port of a twin-screw extruder, melt extrusion granulation is performed, the temperature of each section of the extruder is 240~270℃, the screw speed is 300~400rpm, and the screw length-to-diameter ratio is 40:1; The radiation treatment involves irradiating the PC / PBT alloy material with an electron beam generated by a high-energy accelerator, with a radiation dose of 50~200kGy.

2. The PC / PBT alloy material with high chemical resistance according to claim 1, characterized in that, The PC resin is bisphenol A type polycarbonate, and its melt flow index is 10~20 g / min under the test conditions of 300℃ / 1.2kg; the intrinsic viscosity of the PBT resin is 0.8~1.2 dL / g.

3. The PC / PBT alloy material with high chemical resistance according to claim 1, characterized in that, The compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer; the toughening agent is MBS resin, in which the core is styrene-butadiene rubber and the shell is a copolymer of styrene and methyl methacrylate.

4. The PC / PBT alloy material with high chemical resistance according to claim 1, characterized in that, The transesterification inhibitor is one or more of trimethyl phosphate, triphenyl phosphate, and diphenyl isooctyl phosphate.

5. The PC / PBT alloy material with high chemical resistance according to claim 1, characterized in that, The antioxidant is one or more of 1010, 1076 and 168; the lubricant is one or more of pentaerythritol stearate, calcium stearate and stearamide.

6. The method for preparing a PC / PBT alloy material with high chemical resistance according to any one of claims 1 to 5, characterized in that, The preparation steps include the preparation of PC / PBT alloy materials and radiation treatment; The PC / PBT alloy material is prepared by mixing PC resin, PBT resin, compatibilizer, transesterification inhibitor, toughening agent, inorganic nanoparticles, antioxidant and lubricant at high speed until uniform. The mixture is then added to the feed port of a twin-screw extruder for melt extrusion granulation. The temperature of each section of the extruder is 240~270℃, the screw speed is 300~400rpm, and the screw length-to-diameter ratio is 40:

1. The radiation treatment involves irradiating the PC / PBT alloy material with an electron beam generated by a high-energy accelerator, with a radiation dose of 50~200kGy.

7. The PC / PBT alloy material with high chemical resistance according to any one of claims 1 to 6 is applied to the aerospace and energy industries.