Method for the preparation of waste pet plastic based polymer composites for electromagnetic shielding

Abstract

The application relates to the field of waste PET plastic-based polymer composite material preparation, in particular to a preparation method of a waste PET plastic-based polymer composite material for electromagnetic shielding. Through high-temperature melting and blending of waste PET plastic, waste positive electrode material of lead-acid storage battery and attapulgite in a banbury mixer, the waste PET plastic-based polymer composite material with excellent electric conductivity and electromagnetic shielding performance is obtained. The waste PET plastic treatment method has the advantages of extremely low cost, simple operation steps and wide industrial production prospect, and the finally obtained waste PET plastic-based polymer composite material has excellent electric conductivity and electromagnetic shielding performance in a wide frequency range, and shows attractive application potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of waste PET plastic-based polymer composites, in particular to a preparation method of a waste PET plastic-based polymer composite for electromagnetic shielding. BACKGROUND

[0002] With the continuous development of information technology, electromagnetic waves as the carrier of information transmission are widely used in various fields of social development and people's daily life, greatly promoting social progress and improving people's quality of life. At the same time, a large amount of electromagnetic waves cannot be effectively shielded and radiate to the outside, thereby affecting the normal work of some precision instruments and equipment, and even causing irreversible harm to human health. Therefore, electromagnetic waves are recognized as the fourth pollution after air pollution, water pollution and noise pollution. Preparing materials with good electromagnetic shielding performance has become a hot research direction today, which has important research significance.

[0003] Polyethylene terephthalate (PET) has excellent physical and mechanical properties in a wide temperature range, excellent creep resistance, fatigue resistance, friction resistance and dimensional stability, and is widely used in food packaging, automobile industry and electronic and electrical industries. However, due to its stable properties and difficulty in degradation, the treatment of waste PET plastics is very difficult. Lead-acid batteries are widely used in passenger vehicles due to their abundant raw materials, stable performance and low price. With the explosive development of China's passenger vehicle industry, the amount of lead-acid batteries discarded has increased, which has brought a burden to environmental governance. Waste lead-acid batteries contain a large amount of lead, which has strong corrosion resistance and strong anti-radiation penetration performance. Therefore, it is very important to treat waste lead-acid batteries in a green and high-value way.

[0004] Filled polymer composites are attracting attention due to their superior performance. The present application innovatively uses waste lead-acid battery positive materials and attapulgite as fillers to prepare waste PET plastic-based polymer composites with excellent electrical conductivity and electromagnetic shielding performance in a high-temperature melting state in an internal mixer. Not only does it provide a new treatment idea for waste PET plastics and waste lead-acid battery positive materials, but the high-value polymer composites obtained can also have application potential in many fields, which has important practical significance. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of a waste PET plastic-based polymer composite for electromagnetic shielding, which specifically utilizes waste PET plastic, waste lead-acid battery anode material and palygorskite to prepare a waste PET plastic-based polymer composite with excellent electric conductivity and electromagnetic shielding performance, and has extremely low cost, simple operation steps and broad prospects for industrial production, and the obtained waste PET plastic-based polymer composite has excellent electric conductivity and electromagnetic shielding performance in a wide frequency range, and the composite preparation method is simple, inexpensive and easy to obtain, combines the advantages of inorganic and organic materials, and is suitable for industrial production. In order to achieve the above purpose, the following technical solutions are adopted in the present application:

[0006] The preparation method of the waste PET plastic-based polymer composite for electromagnetic shielding comprises the following steps:

[0007] Step one, a small amount of washed waste PET plastic fragments is added to the mixing chamber of the internal mixer for melt mixing, until the waste PET plastic becomes a transparent and shiny fluid.

[0008] Among them, the waste PET plastic is 10-85 parts by weight, the temperature is set to 220-300 DEG C, the mixing time is 5-15 min, and the rotating speed is 30-100 r / min.

[0009] Step two, open the top bolt, and add a small amount of dry waste lead-acid battery positive material and palygorskite mixture to the mixing chamber for mixing.

[0010] Among them, the waste lead-acid battery positive material is 5-30 parts by weight, the palygorskite is 1-15 parts by weight, the temperature is set to 220-300 DEG C, the mixing time is 5-20 min, and the rotating speed is 30-110 r / min.

[0011] Step three, when the materials in the mixing chamber are rotated under the rotor, the waste lead-acid battery positive material and palygorskite are evenly distributed in the molten waste PET plastic without obvious particle feeling, and the top bolt is opened to take the material, cut the material, cool, dry and prepare for use.

[0012] Among them, the temperature is set to 220-300 DEG C, the mixing time is 5-20 min, and the rotating speed is 30-110 r / min.

[0013] Step four, add a certain amount of washing material to the mixing chamber, adjust the temperature and rotating speed, so that it is completely melted, and after melting, the rotating speed is adjusted to zero, the device is opened, the washing material attached to the device is removed with a special shovel, and the device is restored.

[0014] The temperature is set to 100-200 DEG C, the mixing time is 5-15 min, and the rotating speed is 30-90 r / min.

[0015] The beneficial effects of the present application are:

[0016] The present application is to use waste PET plastics, waste lead-acid battery anode material and palygorskite to prepare a waste PET plastic-based polymer composite material with excellent electric conductivity and electromagnetic shielding performance. A large amount of waste PET plastics and discarded waste lead-acid batteries need to be safely, cleanly and efficiently recycled. Most of the previous invention patents are based on the characteristics of the two materials and are recycled in reverse. The recycling method is complicated, the cost is high, and there is a safety hazard. The present application combines the lead compounds in the waste lead-acid battery with the unique pore structure of palygorskite, and then fills the waste PET plastics with a conductive network structure by using a mixing machine in a high-temperature melting process to enhance the absorption loss of the composite material to electromagnetic waves and to have certain electric conductivity. The technology not only safely and efficiently processes waste PET plastics and waste lead-acid battery positive materials, but also has excellent electric conductivity and electromagnetic shielding performance, showing potential application value. Therefore, the preparation process of the waste PET plastic-based polymer composite material provided by the present application has important potential for industrial production and practical application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The process flow chart for preparing the waste PET plastic-based polymer composite material of the present application is shown in the figure.

[0018] Figure 2 The effect diagram for preparing the waste PET plastic-based polymer composite material of the present application is shown in the figure.

[0019] Figure 3 The electric conductivity test diagram for preparing the waste PET plastic-based polymer composite material of the present application is shown in the figure.

[0020] Figure 4 The electromagnetic shielding performance test diagram for preparing the waste PET plastic-based polymer composite material of the present application is shown in the figure. DETAILED DESCRIPTION

[0021] The present application will be further described below in combination with examples, and the following examples are intended to illustrate the present application rather than further limit the present application.

[0022] Example 1

[0023] 60 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer in small quantities for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 25 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 15 parts of attapulgite were uniformly mixed, and then were added into the mixing chamber in small quantities for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min, and there was no obvious particle feeling. After complete melting and uniformity, the top bolt was opened to take the material, the material was cut, cooled and dried, and then a polymer composite material with electromagnetic shielding performance was obtained.

[0024] Example 2

[0025] 60 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer in small quantities for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 25 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 15 parts of attapulgite were uniformly mixed, and then were added into the mixing chamber in small quantities for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min, and there was no obvious particle feeling. After complete melting and uniformity, the top bolt was opened to take the material, the material was cut, cooled and dried, and then a polymer composite material with electromagnetic shielding performance was obtained.

[0026] Example 3

[0027] 60 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer in small quantities for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 25 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 15 parts of attapulgite were uniformly mixed, and then were added into the mixing chamber in small quantities for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min, and there was no obvious particle feeling. After complete melting and uniformity, the top bolt was opened to take the material, the material was cut, cooled and dried, and then a polymer composite material with electromagnetic shielding performance was obtained.

[0028] Example 4

[0029] The 70 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 10 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 10 parts of attapulgite were uniformly mixed and added into the mixing chamber for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min. After complete melting and uniformity, the top bolt was opened to take the material, cut the material, cool and dry, and a polymer composite material with electromagnetic shielding performance was obtained.

[0030] Example 5

[0031] The 80 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 10 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 5 parts of attapulgite were uniformly mixed and added into the mixing chamber for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min. After complete melting and uniformity, the top bolt was opened to take the material, cut the material, cool and dry, and a polymer composite material with electromagnetic shielding performance was obtained.

[0032] Example 6

[0033] The 85 parts of washed waste PET plastic chips were added into the mixing chamber of the internal mixer for melt mixing, the temperature was set at 270°C, the mixing time was 15 min, and the rotating speed was 60 r / min, until the waste PET plastic became a transparent and shiny fluid. Then the top bolt was opened, 10 parts of dry waste lead-acid battery positive material (Super battery 60EVF-32.2, the main components of the positive material were PbO2 and PbSO4) and 5 parts of attapulgite were uniformly mixed and added into the mixing chamber for mixing. The waste lead-acid battery positive material and attapulgite were completely melted with the molten waste PET plastic at the same temperature and rotating speed for 10 min. After complete melting and uniformity, the top bolt was opened to take the material, cut the material, cool and dry, and a polymer composite material with electromagnetic shielding performance was obtained.

[0034] As Figure 2The photos of the waste PET plastic based polymer composite materials prepared by the above-mentioned embodiment 1 (left) and embodiment 3 (right) are shown, and it can be seen that the polymer composite material prepared by the method has a silver-gray appearance, the surface is relatively flat, and the existence of the waste PET plastic, the positive material of the waste lead-acid storage battery and the attapulgite cannot be seen, which indicates that the three have completely mixed and melted to form a waste PET plastic based polymer composite integral block material in the high-temperature molten state. Figure 3 The figure is the conductive performance of the waste PET plastic based polymer composite material prepared by embodiment 2, and the test method is as follows: the prepared waste PET plastic based polymer composite material is cut into a 10cm diameter circular sheet, placed in the middle of the ZC-high insulation resistance measuring instrument electrode, then the voltage dial is set to 500V, and the resistance dial is rotated to 10^10Ω for testing. The measured surface resistance result is 420.39*10 10 Ω, which indicates that the prepared waste PET plastic based polymer composite material shows good conductive performance. Figure 4 The figure is the electromagnetic shielding performance test of the waste PET plastic based polymer composite material prepared by embodiments 1-3 (60 parts, 70 parts, 80 parts, 85 parts of waste PET plastic respectively), and the test method is as follows: the electromagnetic shielding performance of the prepared waste PET plastic based polymer composite material at 8.2-12.4GHz is tested by using Agilent E5071C microwave vector network analyzer.

[0035] The above-mentioned is only the preferred embodiment of the present application, and it should be pointed out that: for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A process for the preparation of waste PET plastic based polymeric composite for electromagnetic shielding characterized by: The method steps are as follows: Step one, a small amount of washed waste PET plastic chips are added to the mixing chamber of the internal mixer for melt mixing until the waste PET plastic is transparent and shiny fluid; Step two, open the top bolt, and a small amount of the mixture of washed and dried waste lead-acid battery positive material and attapulgite is added to the mixing chamber for mixing; when the material in the mixing chamber is rotated under the rotor, the waste lead-acid battery positive material and attapulgite are distributed uniformly in the molten waste PET plastic without obvious particle feeling, and the material is taken out, cut, cooled and dried when the mixing chamber is opened; According to the weight parts, the parts of PET are 50-60 parts, the parts of waste lead-acid battery positive material are 15-25 parts, and the parts of attapulgite are 15 parts.

2. The process for the preparation of waste PET plastic based polymeric composite for electromagnetic shielding as claimed in claim 1 wherein: The temperature of step one melt mixing is controlled at 220-280℃.

3. The process for the preparation of waste PET plastic based polymeric composite for electromagnetic shielding as claimed in claim 1 wherein: The mixing temperature of step two is set at 220-300℃, the mixing time is 5-20 min, and the rotating speed is 30-110 r / min.

4. The process for the preparation of waste PET plastic based polymeric composite for electromagnetic shielding as claimed in claim 1 wherein: The cleaning method of the waste lead-acid battery positive material is multiple ultrasonic water washing.

5. A waste PET plastic-based polymer composite material for electromagnetic shielding prepared by the method according to any one of claims 1-4.

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