WO2013107096A1 - Tungsten-high molecular polymer composite material and preparation process therefor - Google Patents

Abstract

Disclosed are a tungsten-high molecular polymer composite material and a preparation process therefor. The present invention is composed of the following components by weight ratio: a high molecular polymer 20-100, tungsten powder 950-1000, tungsten fibres 0-50, a coupling agent 0.5-5 and other aids 0.5-10, wherein the tungsten powder used is produced by airflow crushing and surface modification. The tungsten powder in the present invention is highly compacted and flows easily, and is able to bear a high amount of loading. The composite material of the present invention has good physico-mechanical performance and weathering resistance, and good chemical and organic solvent resistance. The material can not only be used in the field of ray shields, but also in fields such as vibration isolation, weight counterbalancing, heat conduction, ordnance and ammunition, etc.

Description

Tungsten-polymer composite material and preparation method thereof  Technical field

 The invention belongs to the field of material engineering, and particularly relates to a tungsten-polymer composite material and a preparation method thereof.

 Background technique

The nuclear power plant reactor is a huge source of radiation, which produces neutron and gamma radiation during fission of nuclear fuel. The fission products produced by the fission reaction and the activation products generated by the activation reaction also produce a, b and gamma radiation. Nuclear power plant facilities have great potential hazards and must be shielded from radiation to avoid possible accidents. At the same time, the disposal of nuclear waste is also crucial. The so-called nuclear waste includes low- and medium-level radioactive nuclear waste and high-level nuclear waste. The former mainly refers to radioactive waste liquid and waste generated by nuclear power plants during power generation, accounting for 99% of all nuclear waste, while the latter It refers to the burned nuclear fuel that is exchanged from the reactor core of the nuclear power plant because it is highly radioactive and is commonly known as high-radiation waste. When the above nuclear waste is treated harmlessly, the necessary radiation shielding treatment is also required.

In the prior art, the radiation shielding material is mostly metal lead, which has good shielding effect, low cost and easy processing. However, lead itself is toxic, and lead-containing exhaust gas, waste water, waste residue and the like pollute the atmosphere, water source and crops, and may endanger nearby residents. Therefore, it is imperative to replace lead with other materials in the field of nuclear radiation shielding.

Studies have shown that the radiation resistance of a substance is related to its atomic number and material density. The higher the atomic number and the higher the material density, the better the shielding performance. Tungsten has an atomic number of 74 and a density of 19.35g /cm ³ . It has good radiation shielding properties and is the best choice for shielding materials. However, tungsten is a high melting point refractory metal, which is difficult to form and process. It is easy to be limited by shape. In the prior art, a high-density tungsten-polymer composite material is prepared by using a polymer as a matrix and a tungsten powder as a filler to solve the above problems. The surgical glove prepared by using the natural rubber emulsion and the tungsten powder of the patent US5001354 has radiation protection performance. Patent US7304105B2 produces a radiation-proof composite material with tungsten powder filled with different particle sizes, which has good flexibility and processing properties, but requires three different particle sizes of tungsten powder to match each other to increase the loading of tungsten. Quantity, manufacturing process is complex. The tungsten powder used in the prior art is usually produced by a conventional grinding technique such as ball milling, so that the tungsten powder particles obtained are severely agglomerated, irregular in shape, poor in fluidity and compactness, and load in the composite material. It is not easy to be uniformly dispersed in the polymer matrix, resulting in poor physical and mechanical properties of the composite.

 Summary of the invention

The object of the present invention is to overcome the defects of the prior art and provide a tungsten-polymer composite material with good physical and mechanical properties and a preparation method thereof.

The technical solution of the present invention is as follows:

A tungsten-polymer composite material comprising the following components by weight:

Polymer 20~100

Tungsten powder 950~1000

Tungsten fiber 0~50

Coupling agent 0.5~5

Other additives 0.5~10.

The tungsten fiber has a diameter of 10 to 30 μm and an aspect ratio of 50 to 150. Preferably, the number of parts is 10 to 40.

The tungsten powder is a mixture of a tungsten powder having a particle size of 0.4 μm to 60 μm or a tungsten powder of several particle sizes.

The high molecular polymer is one or more of a plastic, a rubber or a thermoplastic elastomer.

The plastic includes polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyamide, polyimide, polyurethane, polymethyl methacrylate, polyethylene terephthalate, acrylonitrile-styrene One or several of the butadiene copolymers.

The rubber includes one or more of natural rubber, fluororubber, silicone rubber, nitrile rubber, ethylene propylene rubber, neoprene rubber, isoprene rubber, styrene butadiene rubber, and butadiene rubber.

The thermoplastic elastomer styrene thermoplastic elastomer, olefin thermoplastic elastomer, diene thermoplastic elastomer, vinyl chloride thermoplastic elastomer, polyurethane elastomer, polyester elastomer, polyamide thermoplastic elastomer, One or more of a fluorine-containing thermoplastic elastomer and a silicone-based thermoplastic elastomer.

The coupling agent is one or more of a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, or a rare earth coupling agent.

The other auxiliary agent is one or more of a plasticizer, an antioxidant, a flame retardant, an ultraviolet ray inhibitor, a co-crosslinking agent, a vulcanizing agent, and a vulcanization accelerator.

A method for preparing the tungsten-polymer composite material, comprising: the following steps:

(1) pulverizing tungsten powder;

(2) continuously pulverizing the tungsten powder or the tungsten powder and the tungsten fiber in a doping pot, and adding a coupling agent to perform surface modification;

(3) mixing a high molecular polymer, a surface-modified tungsten powder or a mixture of the tungsten powder and the tungsten fiber and other auxiliary agents in the above-mentioned parts by weight, and kneading uniformly to obtain a feed;

(4) Forming: the feed is extruded through an extruder, or injection molded by an injection machine, or molded by a press molding machine;

(5) Post-treatment: The obtained product is cut and chamfered.

The beneficial effects of the invention are:

1. The composite material of the present invention is composed of the following components by weight ratio: high molecular polymer 20~100, tungsten powder 950~1000, tungsten fiber 0~50, coupling agent 0.5~5 and other auxiliary agents 0.5~10 Compared with the prior art, in addition to having good flexibility and processability, the composite material of the present invention has excellent ray shielding performance due to high content of tungsten, and the invention is also provided by the addition of tungsten fibers. Composite materials have good mechanical strength and physical properties.

2. The tungsten powder used in the composite material of the present invention is obtained by jet milling and surface modification. Compared with the prior art, the airflow pulverization process is simple and high in efficiency, and the agglomeration phenomenon of the tungsten powder is greatly reduced. The obtained tungsten powder has a regular shape and good fluidity, and further, through surface modification, the tungsten powder and the polymer matrix are The composite material can be better combined to make it easy to be uniformly dispersed in the polymer matrix, and the loading amount is high. The composite material of the invention prepared by using the tungsten powder has good physical and mechanical properties.

3. The composite material of the invention is added with one or more of a plasticizer, an anti-aging agent, a flame retardant, an anti-UV agent, a co-crosslinking agent, a vulcanizing agent and a vulcanization accelerator to make it resistant to weathering and resistance. It has a wide range of chemical and organic solvent resistance and can be used not only in the field of radiation shielding, but also in the fields of vibration isolation, counterweight, heat conduction, ordnance and ammunition.

detailed description

The invention is further illustrated and described below in accordance with specific embodiments.

Example 1

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Styrene thermoplastic elastomer	33.5
Tungsten powder (Fahrenheit size 10μm)	1000
Anti-aging agent	0.5
Titanate coupling agent	5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above weight parts, and the tungsten powder was subjected to jet milling, the feed pressure was 0.9 MPa, and the pulverization pressure was 1.1 MPa.

(2) continuously stirring the tungsten powder pulverized by the airflow in a doping pot, and adding a titanate coupling agent for surface modification;

(3) Weighing other materials according to the above weight parts, first adding the styrene-based thermoplastic elastomer to the kneader, and then inputting 500 parts by weight of the above tungsten powder, kneading for a suitable time, adding the remaining tungsten powder and the anti-aging agent, and kneading The feed was uniformly prepared by refining, and the above kneading temperature was 140 °C.

(4) Forming: The feed was granulated and then extruded into an extruder at 210 ° C to be cooled, and a strip-shaped product was obtained.

(5) Post-treatment: The obtained product is cut and chamfered.

Example 2

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
EPDM rubber	50
Tungsten powder (Fahrenheit size 5μm)	1000
Plasticizer	3
Co-crosslinking agent	0.75
Vulcanization accelerator	2.75
Vulcanizing agent	1.75
Anti-aging agent	0.5
A silane coupling agent	5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed in the above-mentioned parts by weight, and the tungsten powder was subjected to jet milling, the feed pressure was 0.8 MPa, and the pulverization pressure was 1.0 MPa.

(2) continuously stirring the tungsten powder pulverized by the airflow in a doping pot, and adding a silane coupling agent for surface modification;

(3) Weighing other materials according to the above weight parts, first adding EPDM rubber to the kneader, then inputting 500 parts by weight of the above tungsten powder, and kneading at 120 ° C for a suitable time, all the remaining except the vulcanizing agent The materials are added in sequence, and the mixture is uniformly mixed and discharged. Finally, a vulcanizing agent is added to the open mill, and the mixture is uniformly mixed to obtain a feeding.

(4) Forming: The feed was vulcanized at 170 ° C on a rubber flat vulcanizer to obtain a sheet-like product.

(5) Post-treatment: The obtained product is cut and chamfered.

Example 3

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
natural rubber	35
SBR	15
Tungsten powder (Fahrenheit size 10μm)	950
Tungsten fiber (diameter 10μm, aspect ratio 150)	50
Plasticizer	4.5
Vulcanization accelerator	2.4
Vulcanizing agent	1.6
Anti-aging agent	1.5
Rare earth coupling agent	5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above-mentioned parts by weight, and the tungsten powder was subjected to jet milling, the feed pressure was 0.9 MPa, and the pulverization pressure was 1.0 MPa.

(2) continuously stirring the tungsten powder and the tungsten fiber which are pulverized by the airflow in a doping pot, and adding a rare earth coupling agent for surface modification;

(3) Weigh other materials according to the above weight parts, first add natural rubber to the kneader, then add styrene-butadiene rubber and 500 parts by weight of the above mixture of tungsten powder and tungsten fiber, and knead at 80 ° C for a suitable time. All the remaining materials except the vulcanizing agent are added in sequence, and the mixture is uniformly mixed and discharged, and the discharging temperature is lower than 130 °C. Finally, a vulcanizing agent is added to the open mill, and the mixture is uniformly mixed and then discharged to obtain a feed.

(4) Forming: The feed was vulcanized at 150 ° C on a rubber flat vulcanizer to obtain a sheet-like product.

(5) Post-treatment: The obtained product is cut and chamfered.

Example 4

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Nylon 6	82.5
Tungsten powder (Fahrenheit size 10μm)	800
Tungsten powder (Fei's particle size 2μm)	200
Anti-aging agent	1.5
Aluminate coupling agent	5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above weight parts, and the tungsten powder was subjected to jet milling, the feed pressure was 1.0 MPa, and the pulverization pressure was 1.1 MPa.

(2) continuously stirring the tungsten powder pulverized by the air jet in a doping pot, and adding an aluminate coupling agent for surface modification;

(3) Weigh other materials according to the above weight parts, first add nylon 6 to the kneader, then input 500 parts by weight of the above tungsten powder, knead the appropriate time, add the remaining tungsten powder and anti-aging agent, and knead uniformly to obtain For feeding, the above kneading temperature was 230 °C.

(4) Forming: After the granulation of the feed, injection molding was carried out at 240 ° C on an injection machine to obtain a profiled part.

(5) Post-treatment: The obtained product is cut and chamfered.

Example 5

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Silicone Rubber	100
Tungsten powder (Fahrenheit size 25μm)	750
Tungsten powder (Fei's particle size 2μm)	250
Vulcanizing agent	1.75
Titanate coupling agent	5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above weight parts, and the tungsten powder was subjected to jet milling, the feed pressure was 0.9 MPa, and the pulverization pressure was 0.9 MPa.

(2) continuously stirring the tungsten powder pulverized by the airflow in a doping pot, and adding a titanate coupling agent for surface modification;

(3) Weighing other materials according to the above weight parts, first adding the silicone rubber to the kneader, then adding 500 parts by weight of the above tungsten powder, and kneading at 40 ° C for a suitable time, and then adding all the remaining materials except the vulcanizing agent in sequence, After mixing evenly, the material is discharged, the debinding temperature is lower than 50 ° C; the mixture is naturally cooled to room temperature, then placed in an oven at 140 ° C for 2 h, taken out and naturally cooled, then refining and adding on the open mill The vulcanizing agent is kneaded evenly, and then parked overnight, and then re-refined and discharged to obtain a feed.

(4) Forming: The feed was vulcanized at 200 ° C on a rubber flat vulcanizer to obtain a sheet-like product.

(5) Post-treatment: The obtained product is cut and chamfered.

Example 6

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Olefin thermoplastic elastomer	20
Tungsten powder (Fahrenheit size 60μm)	1000
Anti-aging agent	1.5
Titanate coupling agent	0.5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above weight parts, and the tungsten powder was subjected to jet milling, the feed pressure was 0.9 MPa, and the pulverization pressure was 1.1 MPa.

(2) continuously stirring the tungsten powder pulverized by the airflow in a doping pot, and adding a titanate coupling agent for surface modification;

(3) Weighing other materials according to the above weight parts, first adding the olefinic thermoplastic elastomer to the kneader, and then adding 500 parts by weight of the above tungsten powder, kneading for a suitable time, adding the remaining tungsten powder and the antioxidant, and kneading The feed was uniformly produced, and the above kneading temperature was 140 °C.

(4) Forming: The feed was granulated and then extruded into an extruder at 200 ° C to be cooled, and a rod-shaped product was obtained.

(5) Post-treatment: The obtained product was cut.

Example 7

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Styrene thermoplastic elastomer	40
Tungsten powder (Fahrenheit size 15μm)	970
Tungsten fiber (30μm in diameter, aspect ratio 50)	30
Anti-aging agent	1.5
Titanate coupling agent	0.5

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above-mentioned parts by weight, and the tungsten powder was subjected to jet milling, the feed pressure was 1.0 MPa, and the pulverization pressure was 1.0 MPa.

(2) continuously stirring the tungsten powder and the tungsten fiber which are pulverized by the air jet in a doping pot, and adding a titanate coupling agent for surface modification;

(3) Weighing other materials according to the above-mentioned parts by weight, first adding a styrene-based thermoplastic elastomer to a kneader, and then inputting 500 parts by weight of a mixture of the above-mentioned tungsten powder and tungsten fiber, and kneading the remaining tungsten powder after a suitable time. A mixture of tungsten fibers and an antioxidant are added, and kneading is uniformly performed to obtain a feed, and the above kneading temperature is 140 °C.

(4) Forming: The feed was granulated and then extruded into an extruder at 210 ° C to be cooled, and a tubular product was obtained.

(5) Post-treatment: The obtained product was cut.

Example 8

The high density tungsten-polymer ray shielding composite formulation is:

Component	Parts by weight
Styrene thermoplastic elastomer	80
Polypropylene	20
Tungsten powder (Fahrenheit size 10μm)	950
Tungsten powder (Fei's particle size 0.4μm)	50
Anti-aging agent	1.5
A silane coupling agent	0.3
Titanate coupling agent	0.3

The preparation method of the above tungsten-polymer composite material has the following steps:

(1) The tungsten powder was weighed according to the above-mentioned parts by weight, and the tungsten powder was subjected to jet milling, the feed pressure was 1.0 MPa, and the pulverization pressure was 1.0 MPa.

(2) continuously stirring the tungsten powder pulverized by the airflow in a doping pot, and adding a silane coupling agent and a titanate coupling agent for surface modification;

(3) Weighing other materials according to the above weight parts, first adding the styrenic thermoplastic elastomer and polypropylene to the kneader, and then inputting 500 parts by weight of the above tungsten powder, and kneading for a suitable time to leave the tungsten powder and the antioxidant. The mixture was kneaded and uniformly kneaded to obtain a feed, and the above kneading temperature was 180 °C.

(4) Forming: The feed was granulated and then extruded into an extruder at 210 ° C to be cooled, and a strip-shaped product was obtained.

(5) Post-treatment: The obtained product is cut and chamfered.

The above is only the preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, and equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still be covered by the present invention. In the range.

 Industrial applicability

The tungsten powder used in the composite material of the present invention is obtained by jet milling and surface modification. Compared with the prior art, the airflow pulverization process is simple and high in efficiency, and the agglomeration phenomenon of the tungsten powder is greatly reduced. The obtained tungsten powder has a regular shape and good fluidity, and further, through surface modification, the tungsten powder and the polymer matrix are The composite material can be better combined to make it easy to be uniformly dispersed in the polymer matrix, and the loading amount is high. The composite material of the invention prepared by using the tungsten powder has good physical and mechanical properties.

Claims (10)

1.  A tungsten-polymer composite material characterized by comprising the following components by weight:

   Polymer 20~100

   Tungsten powder 950~1000

   Tungsten fiber 0~50

   Coupling agent 0.5~5.
2. The tungsten-polymer composite material according to claim 1, wherein the tungsten fiber has a diameter of 10 to 30 μm, an aspect ratio of 50 to 150, and a fraction of 10 to 40.
3. A tungsten-polymer composite material according to claim 2, wherein the tungsten powder is a tungsten powder having a particle size of 0.4 μm to 60 μm or a mixture of several particle sizes of tungsten powder.
4. A tungsten-polymer composite material according to any one of claims 1 to 3, wherein the polymer is one or more of a plastic, a rubber or a thermoplastic elastomer. .
5. A tungsten-polymer composite material according to claim 4, wherein the plastic comprises polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyamide, polyimide, polyurethane, One or more of polymethyl methacrylate, polyethylene terephthalate, acrylonitrile-styrene-butadiene copolymer.
6. A tungsten-polymer composite material according to claim 4, wherein the rubber comprises natural rubber, fluororubber, silicone rubber, nitrile rubber, ethylene propylene rubber, neoprene rubber, and isoprene rubber. One or more of styrene-butadiene rubber and butadiene rubber.
7. A tungsten-polymer composite material according to claim 4, wherein said thermoplastic elastomer comprises a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, a diene-based thermoplastic elastomer, and a vinyl chloride. One or more of a thermoplastic elastomer, a polyurethane elastomer, a polyester elastomer, a polyamide thermoplastic elastomer, a fluorine-containing thermoplastic elastomer, and a silicone thermoplastic elastomer.
8. A tungsten-polymer composite material according to any one of claims 1 to 3, wherein the coupling agent is a silane coupling agent, an aluminate coupling agent, and a titanate. One or more of a coupling agent or a rare earth coupling agent.
9. A tungsten-polymer composite material according to any one of claims 1 to 3, which further comprises other auxiliary agents having a fraction of 0.5 to 10, and the other auxiliary agent is plasticized. One or more of a agent, an antioxidant, a flame retardant, an ultraviolet ray inhibitor, a co-crosslinking agent, a vulcanizing agent, and a vulcanization accelerator.
10. A method for preparing a tungsten-polymer composite material according to any one of claims 1 to 3, comprising the steps of:

    (1) pulverizing tungsten powder;

    (2) continuously pulverizing the tungsten powder or the tungsten powder and the tungsten fiber in a doping pot, and adding a coupling agent to perform surface modification;

    (3) mixing a high molecular polymer, a surface-modified tungsten powder or a mixture of the tungsten powder and the tungsten fiber and other auxiliary agents in the above-mentioned parts by weight, and kneading uniformly to obtain a feed;

    (4) Forming: The feed is extruded through an extruder, or injection molded by an injection machine, or compression molded by a press forming machine.