Foaming material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of foaming materials, and discloses a foaming material as well as a preparation method and application thereof. The preparation method of the foaming material comprises the following steps: (1) mixing and drying 30 to 65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, 20 to 32 parts of polypropylene, 25 to 43 parts of polyvinylidene fluoride, 10 to 20 parts of fluorinated ethylene propylene, 8 to 15 parts of polyethylene and 6 to 12 parts of polycarbonate to obtain a dried blend; (2) uniformly mixing the dry blend prepared in the step (1), 2-6 parts of an insulating toughening agent and 1-4 parts of an additive in an internal mixer to obtain a mixture; (3) at high temperature and high pressure, compacting and molding the mixture by a press vulcanizer until the thickness is 1-2cm, cooling to room temperature, and cutting into a sample; and (4) preparing the foaming material. The foam material prepared by the invention has good insulativity and mechanical properties, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming materials, and specifically relates to a foaming material, a preparation method thereof and an application thereof. Background Art

[0002] Polymer foaming materials can be understood as composite materials with polymers as the matrix and gases as the fillers. Through the foaming process, the polymer is lightened, the cost of the material is reduced, the cost performance is improved, and at the same time, specific properties are imparted to the foaming material through the design of the cell structure. Polymer foam materials have many advantages, such as low density, high specific strength, sound insulation and heat insulation, shock absorption and high impact resistance, etc. Their excellent properties make them widely used in packaging materials, automotive parts, aerospace, sound absorption and heat insulation, and building engineering materials and other fields.

[0003] The preparation methods of polymer foaming materials are mainly divided into chemical foaming methods and physical foaming methods. The chemical foaming method involves the use of some chemical reagents and small molecule compounds in the process of preparing microporous materials, and these chemical reagents and residual small molecules may harm the environment and human health. The physical foaming method directly uses gases, low-boiling liquids or expandable microspheres as foaming agents, mixes the polymer with the gas evenly at a certain temperature and pressure, and then obtains the polymer foam material by controlling the changes in temperature and pressure to cause phase separation, but the effect is not good. Summary of the Invention

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a foaming material, by weight, comprising the following raw materials: 30-65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), 20-32 parts of polypropylene (PP), 25-43 parts of polyvinylidene fluoride (PVDF), 10-20 parts of perfluoroethylene-propylene copolymer (FEP), 8-15 parts of polyethylene (PE), 6-12 parts of polycarbonate (PC), 2-6 parts of insulating toughening agent, 1-4 parts of additive.

[0005] Preferably, the additive includes one or more of dioctyl phthalate, trioctyl trimellitate, diisononyl phthalate, fatty acid ester.

[0006] Preferably, the preparation method of the insulating toughening agent includes the following steps:

[0007] S1: Add 30-50 g of montmorillonite into an acetic acid solution with a pH of 3-4, stir at 40-60 °C for 10-30 min, centrifuge, add 15-75 g of octadecyltrimethylammonium chloride, stir evenly, stir at 40-60 °C for 20-30 min, let stand, add the suspension to deionized water and wash 3-5 times, dry at 60-70 °C for 10-14 h, grind, and pass through a 100-300 mesh sieve to obtain organically modified montmorillonite;

[0008] S2: Mix 10 g of organically modified montmorillonite with 100 mL of an ethanol aqueous solution, stir and ultrasonically treat at 60 - 80 °C for 2 - 4 h to obtain an organically modified montmorillonite suspension; add 5 - 10 g of KH550 to the ethanol aqueous solution to pre-hydrolyze to obtain a hydrolyzed silane coupling agent, add the hydrolyzed silane coupling agent to the organically modified montmorillonite suspension, stir for 10 - 20 min, dry at 60 - 70 °C for 12 - 36 h, grind, and pass through a 100 - 300 mesh sieve to obtain an insulating toughening agent.

[0009] A preparation method of a foaming material, comprising the following steps:

[0010] Step (1): Mix 30 - 65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), 20 - 32 parts of polypropylene (PP), 25 - 43 parts of polyvinylidene fluoride (PVDF), 10 - 20 parts of perfluoroethylene-propylene copolymer (FEP), 8 - 15 parts of polyethylene (PE), and 6 - 12 parts of polycarbonate (PC), and dry to obtain a dry blend;

[0011] Step (2): Mix the dry blend prepared in step (1), 2 - 6 parts of the insulating toughening agent, and 1 - 4 parts of the additive uniformly in a kneader to obtain a mixed material;

[0012] Step (3): Under high temperature and high pressure, compact the mixed material into a thickness of 1 - 2 cm by a flat vulcanizing machine, and cut it into samples after cooling to room temperature;

[0013] Step (4): Transfer the samples to a pressure vessel, then seal the pressure vessel, pump supercritical fluid into the autoclave through a supercritical fluid pump to evacuate the air in the autoclave, and then control the saturation conditions of 10 - 20 MPa and 200 - 230 °C / 1 h to maintain the pressure and temperature during the foaming process. After the saturation process, quickly release the pressure in the autoclave to the atmosphere and cool to room temperature to obtain the foaming material.

[0014] Preferably, in step (1), the drying conditions are: drying temperature is 60 - 100 °C, and drying time is 4 - 8 h.

[0015] Preferably, in step (2), the kneader mixing parameters are: temperature 160 - 240 °C, rotation speed 25 - 65 rpm, and mixing time 10 - 35 min.

[0016] Preferably, in step (3), the high temperature and high pressure of the flat vulcanizing machine are: temperature 150 - 250 °C, and pressure 10 - 20 MPa.

[0017] The present invention also provides the application of the foaming material insulating material as a cable material.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. In the present invention, by blending an insulating toughening agent with tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, polypropylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, and polycarbonate, the obtained composite material has high insulation performance, good mechanical properties and heat preservation performance. Preparing a fluoropolymer composite microcellular foaming material using supercritical fluid as a physical foaming agent conforms to the concept of environmental protection.

[0020] 2. The quaternary ammonium salt added to the insulating toughening material prepared in the present invention enters the montmorillonite lamella through a cation exchange reaction, increasing the montmorillonite lamella spacing. At the same time, the surface of the organically treated montmorillonite adsorbs silane coupling agent molecules, further enhancing the compatibility of montmorillonite and changing the composite interface structure of the nanocomposite. The insulating toughening agent in the foaming material attracts free charges to form a diffuse double layer on the surface, significantly improving the structure of the space charge aggregation composite material and inhibiting the carrier transition, thereby improving the overall insulation performance. For the organically modified montmorillonite surface-modified by KH550, the polypropyleneophilic group of KH550 will entangle with the polypropylene molecular chain to form a tighter stretching layer, amplifying the modification effect of montmorillonite and improving the overall insulation of the foaming material. Description of the Drawings

[0021] Figure 1 is the process flow chart of the preparation of the foaming material of the present invention. Detailed Embodiments

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0023] Example 1

[0024] This example discloses a preparation method of an insulating toughening agent, including the following steps:

[0025] S1: Add 40 g of montmorillonite to an acetic acid solution with a pH of 3.5, stir at 50 °C for 20 min, centrifuge, add 50 g of octadecyltrimethylammonium chloride, stir evenly, stir at 50 °C for 25 min, let stand, wash the suspension 4 times with deionized water, dry at 65 °C for 13 h, grind, and pass through a 200-mesh sieve to obtain organically modified montmorillonite;

[0026] S2: Mix the organically modified montmorillonite with an ethanol aqueous solution at a ratio of 10 g:100 mL, stir and ultrasonically treat it at 70 °C for 3 h to obtain an organically modified montmorillonite suspension; dissolve 7 g of KH550 in the ethanol aqueous solution to pre-hydrolyze to obtain a hydrolyzed silane coupling agent, add the hydrolyzed silane coupling agent to the organically modified montmorillonite suspension, stir for 15 min, dry at 65 °C for 24 h, grind, and pass through a 200-mesh sieve to obtain an insulating toughening agent.

[0027] Example 2

[0028] This example discloses a preparation method of a foaming material, including the following steps:

[0029] Step (1): Mix 40 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, 25 parts of polypropylene, 31 parts of polyvinylidene fluoride, 15 parts of perfluoroethylenepropylene copolymer, 10 parts of polyethylene, and 8 parts of polycarbonate, and dry at 70 °C for 6 h to obtain a dry blend;

[0030] Step (2): Mix the dry blend prepared in step (1), 4 parts of the insulating toughening agent, and 3 parts of dioctyl phthalate evenly in a mixer at a temperature of 200 °C, a rotation speed of 40 rpm, and a mixing time of 17 min to obtain a mixture;

[0031] Step (3): Under high temperature and high pressure, compact and form the mixture to a thickness of 1.5 cm by a flat vulcanizing machine at a temperature of 200 °C and a pressure of 15 MPa, and cut it into samples after cooling to room temperature;

[0032] Step (4): Transfer the samples to a pressure vessel, then seal the pressure vessel, pump supercritical fluid into the autoclave through a supercritical fluid pump to evacuate the air in the autoclave, and then control the saturation conditions of 15 MPa and 220 °C / 1 h to maintain the pressure and temperature during the foaming process. After the saturation process, quickly release the pressure in the autoclave to the atmosphere and cool to room temperature to obtain the foaming material.

[0033] Example 3

[0034] This example discloses a preparation method of a foaming material, including the following steps:

[0035] Step (1): Mix 30 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, 32 parts of polypropylene, 25 parts of polyvinylidene fluoride, 10 parts of perfluoroethylenepropylene copolymer, 15 parts of polyethylene, and 12 parts of polycarbonate, and dry at 100 °C for 4 h to obtain a dry blend;

[0036] Step (2): Mix the dry blend prepared in step (1), 6 parts of an insulating toughening agent, and 1 part of trioctyl trimellitate evenly in a kneader under the conditions of a temperature of 160°C, a rotation speed of 65 rpm, and a mixing time of 10 min to obtain a mixed material;

[0037] Step (3): Under high temperature and high pressure, compact and form the mixed material to a thickness of 2 cm by a flat vulcanizing machine under the conditions of a temperature of 250°C and a pressure of 20 MPa. After cooling to room temperature, cut it into samples;

[0038] Step (4): Transfer the samples to a pressure vessel, then seal the pressure vessel. Pump the supercritical fluid into the autoclave through a supercritical fluid pump to evacuate the air in the autoclave. Then control the saturation conditions of 10 MPa and 230°C / 1 h to maintain the pressure and temperature during the foaming process. After the saturation process, quickly release the pressure in the autoclave to the atmosphere and cool to room temperature to obtain the foamed material.

[0039] Example 4

[0040] This example discloses a preparation method of a foamed material, including the following steps:

[0041] Step (1): Mix 65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, 20 parts of polypropylene, 43 parts of polyvinylidene fluoride, 20 parts of perfluoroethylenepropylene copolymer, 8 parts of polyethylene, and 6 parts of polycarbonate, and dry at 60°C for 8 h to obtain a dry blend;

[0042] Step (2): Mix the dry blend prepared in step (1), 2 parts of an insulating toughening agent, and 4 parts of diisononyl phthalate evenly in a kneader under the conditions of a temperature of 240°C, a rotation speed of 25 rpm, and a mixing time of 35 min to obtain a mixed material;

[0043] Step (3): Under high temperature and high pressure, compact and form the mixed material to a thickness of 1 cm by a flat vulcanizing machine under the conditions of a temperature of 150°C and a pressure of 10 MPa. After cooling to room temperature, cut it into samples;

[0044] Step (4): Transfer the samples to a pressure vessel, then seal the pressure vessel. Pump the supercritical fluid into the autoclave through a supercritical fluid pump to evacuate the air in the autoclave. Then control the saturation conditions of 20 MPa and 200°C / 1 h to maintain the pressure and temperature during the foaming process. After the saturation process, quickly release the pressure in the autoclave to the atmosphere and cool to room temperature to obtain the foamed material.

[0045] Comparative Example 1

[0046] Compared with Example 2, in the process of preparing the foamed material in Comparative Example 1, polypropylene was not added, and other conditions remained unchanged.

[0047] Comparative Example 2

[0048] Compared with Example 2, in Comparative Example 2, no insulating toughening agent was added during the foaming material process, and other conditions remained unchanged.

[0049] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A foaming material, characterized in that, by weight, it comprises the following raw materials: 30 - 65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), 20 - 32 parts of polypropylene (PP), 25 - 43 parts of polyvinylidene fluoride (PVDF), 10 - 20 parts of perfluoroethylene-propylene copolymer (FEP), 8 - 15 parts of polyethylene (PE), 6 - 12 parts of polycarbonate (PC), 2 - 6 parts of insulating toughening agent, and 1 - 4 parts of additive.

2. The foaming material according to claim 1, characterized in that, the additive includes one or more of dioctyl phthalate, trioctyl trimellitate, diisononyl phthalate, and fatty acid ester.

3. The foaming material according to claim 1, characterized in that, the preparation method of the insulating toughening agent comprises the following steps: S1: Add 30 - 50 g of montmorillonite into an acetic acid solution with a pH of 3 - 4, stir at 40 - 60 °C for 10 - 30 min, centrifuge, add 15 - 75 g of octadecyl trimethyl ammonium chloride, stir evenly, stir at 40 - 60 °C for 20 - 30 min, let stand, add the suspension to deionized water and wash 3 - 5 times, dry at 60 - 70 °C for 10 - 14 h, grind, and pass through a 100 - 300 mesh sieve to obtain organically modified montmorillonite; S2: Mix organically modified montmorillonite with an ethanol aqueous solution at a ratio of 10 g:100 mL, stir and ultrasonically treat at 60 - 80 °C for 2 - 4 h to obtain an organically modified montmorillonite suspension; Pre-hydrolyze 5 - 10 g of KH550 in an ethanol aqueous solution to obtain a hydrolyzed silane coupling agent, add the hydrolyzed silane coupling agent to the organically modified montmorillonite suspension, stir for 10 - 20 min, dry at 60 - 70 °C for 12 - 36 h, grind, and pass through a 100 - 300 mesh sieve to obtain the insulating toughening agent.

4. A preparation method of a foaming material, characterized in that, it comprises the following steps: Step (1): Mix 30 - 65 parts of tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, 20 - 32 parts of polypropylene, 25 - 43 parts of polyvinylidene fluoride, 10 - 20 parts of perfluoroethylene-propylene copolymer, 8 - 15 parts of polyethylene, and 6 - 12 parts of polycarbonate, and dry to obtain a dry blend; Step (2) Mix the dry blend prepared in step (1), 2 - 6 parts of insulating toughening agent, and 1 - 4 parts of additive evenly in a mixer to obtain a mixture; Step (3) Under high temperature and high pressure, compact the mixture into a thickness of 1 - 2 cm by a flat vulcanizing machine, and cut it into samples after cooling to room temperature; Step (4) Transfer the samples to a pressure vessel, then seal the pressure vessel, pump supercritical fluid into the autoclave through a supercritical fluid pump to evacuate the air in the autoclave, and then control the saturation conditions of 10 - 20 MPa and 200 - 230 °C / 1 h to maintain the pressure and temperature during the foaming process. After the saturation process, quickly release the pressure in the autoclave to the atmosphere and cool to room temperature to obtain the foaming material.

5. The foaming material according to claim 4, characterized in that, In the step (1), the drying conditions are as follows: the drying temperature is 60 - 100 °C, and the drying time is 4 - 8 h.

6. The foaming material according to claim 4, wherein, in the step (2), the mixing parameters of the internal mixer are as follows: the temperature is 160 - 240 °C, the rotation speed is 25 - 65 rpm, and the mixing time is 10 - 35 min.

7. The foaming material according to claim 4, wherein, in the step (3), the high temperature and high pressure of the flat vulcanizing machine are as follows: the temperature is 150 - 250 °C, and the pressure is 10 - 20 MPa.

8. Application of the foaming material according to claim 1 as a thermal insulation material.

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