CN112111102A - Inorganic particle filled polymer microporous composite material - Google Patents

Abstract

An inorganic particle filled polymer microporous composite material, comprising a polymer matrix and inorganic particles, the particle size of the inorganic particles is 10 microns to 300 microns, and the inorganic particles are uniformly dispersed in the polymer matrix; the polymer The matrix has a plurality of uniformly distributed micropores, the micropores are ellipsoid-shaped, and the inorganic particles are located in the micropores. The material has the advantages of light weight, high strength, corrosion resistance and aging resistance, and can be widely used in outdoor landscape panels, building wall panels, ship decks, military packaging materials and other fields.

Description

An inorganic particle filled polymer microporous composite material

technical field

The invention relates to the field of polymer microporous composite materials, in particular to an inorganic particle-filled polymer microporous composite material.

Background technique

Polymer materials are widely used in many fields because of their light weight, corrosion resistance, and easy processing. However, their strength and modulus are low, making it difficult to meet the requirements of structural materials. Filling the polymer matrix with inorganic particles is a common method for polymer material reinforcement. Commonly used inorganic particles include calcium carbonate, talc, montmorillonite and silica. Inorganic particle-filled polymer composites have high strength, stiffness, and good wear resistance, and are widely used in building materials, furniture, logistics packaging and other fields. Paying attention to the high performance and light weight of products, ordinary polymer-filled composite materials are gradually unable to meet the needs of the industry. Therefore, further optimizing the production process, improving product performance and reducing product weight have become the current development trend of polymer-filled composite materials.

In recent years, in order to realize the lightweight production of products, the method of using micro-foaming process to produce products has emerged; patent CN201910348103.X adopts chemical foaming process to prepare polycarbonate/acrylonitrile-styrene-acrylate grafts Copolymer (PC/ABS) blended gold micro-foaming material, however, there are strict requirements on the selection and use of foaming agents, the cost of processing equipment is high, the processing process is difficult to achieve green environmental protection, and the mechanical properties of the material are not significantly improved. Patent CN201810697803 .5 The inorganic-filled thermoplastic elastomer and polyolefin micro-foaming material are prepared by physical foaming process, but the foaming process and product shaping process need to be carried out in two steps, the process is complicated, and the equipment requirements are high. It can be seen from the above that the mechanical properties of most of the lightweight polymer microporous materials currently produced are generally not high, and the industry is in urgent need of polymer microporous composite materials with excellent comprehensive properties.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the purpose of the present invention is to provide a lightweight and high-strength inorganic particle-filled polymer microporous composite material and a preparation method thereof. To achieve the above object, the present invention adopts the following technical solutions:

An inorganic particle-filled polymer microporous composite material, comprising a polymer matrix and inorganic particles, wherein the particle size of the inorganic particles is 10 microns to 300 microns, and the inorganic particles are uniformly dispersed in the polymer matrix; the polymer The matrix has a plurality of uniformly distributed micropores, the micropores are ellipsoid-shaped, and the inorganic particles are located in the micropores.

Wherein, the raw materials of the composite material include polymer, inorganic particles and lubricant, wherein the weight content of each component is: 100 parts of polymer, 25-100 parts of inorganic particles, and 0.5-2 parts of lubricant.

Wherein, the polymer is selected from one or more of polyethylene, polypropylene, polyoxymethylene and polylactic acid, and the raw material is in the form of particles with a particle size of 50-1250 meshes.

Wherein, the inorganic particles are selected from one or more of calcium carbonate, magnesium carbonate, talc, and fly ash, and the raw materials are in the form of particles with a particle size of 50-1250 mesh.

Wherein, the lubricant is selected from one or more of zinc stearate, calcium stearate and barium stearate.

The present invention also provides a method for preparing the above-mentioned inorganic particle-filled polymer microporous composite material, comprising the following steps:

A. Weigh an appropriate proportion of raw materials, place the polymer and inorganic particles in a blast oven for drying for 3-4h, and then place them in a high-speed mixer together with the lubricant to mix for 10-15min;

B, adding the above-mentioned mixed raw materials into the twin-screw extruder and extruding and granulating, then extruding by extruding device melting, plasticizing, and obtaining a blank with constant cross-sectional size through the shaping die;

C. Under the action of the tractor, the blank enters the heat preservation device after cooling, and the heat preservation temperature is in the range of 10-40°C lower than the melting point of the polymer material;

D. Make the blank pass through a secondary molding die with a draw ratio in the range of 2-8, the polymer matrix undergoes plastic yield, and the interface between the inorganic particles and the polymer is debonded to form a plurality of micropores. The temperature of the secondary molding die is equal to The insulation device is the same;

E. The composite material can be obtained after the molding material is cooled and cut to a fixed length.

The technical scheme of the present invention has the following beneficial effects:

In the inorganic particle-filled polymer microporous composite material of the invention, the micropores of the micropores are plastic yielding of the polymer matrix and interface debonding between the inorganic particles and the polymer when the temperature is lower than the melting point of the polymer under a controllable tensile force field. Compared with traditional inorganic particle-filled polymer composite materials, the material density is effectively reduced, and a new solution is provided for the lightweight of inorganic particle-filled polymer composite materials;

In the inorganic particle-filled polymer microporous composite material of the present invention, the polymer matrix of the polymer matrix is highly oriented under the controllable tensile force field to form a "string crystal" or "fibrous crystal" structure, compared with the traditional inorganic particle-filled polymer The mechanical strength of composite materials has been greatly improved, and the high performance of polyolefin materials has been realized;

The inorganic particle-filled polymer microporous composite material provided by the invention provides the material with excellent corrosion resistance, anti-aging properties and long service life;

The inorganic particle-filled polymer microporous composite material provided by the invention has the advantages of simple and high-efficiency preparation process, low equipment requirements, light-weight and high-strength polymer microporous composite material without using physical or chemical foaming agent, and can realize continuous It is in line with the contemporary production concept of green, energy saving and environmental protection, and can be directly applied to industrial production. The material has broad application prospects in outdoor landscape panels, building wall panels, ship decks, military packaging materials and other fields.

Description of drawings

Fig. 1 is the structure schematic diagram of the inorganic particle filled polymer microporous composite material of the present invention;

Fig. 2 is the schematic diagram of the inorganic particle-filled polymer microporous composite material molding equipment of the present invention;

3 is a schematic diagram of the cross-sectional microstructure of the composite material in Example 1 of the present invention;

4 is a schematic diagram of the cross-sectional microstructure of the composite material in Example 2 of the present invention;

5 is a schematic diagram of the cross-sectional microstructure of the composite material in Example 3 of the present invention.

Among them, 1-polymer matrix, 2-inorganic particles, 3-micropore, 4-extrusion device, 5-setting die, 6-insulation device, 7-secondary molding die, 8-tractor.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , the inorganic particle-filled polymer microporous composite material of the present invention includes a polymer matrix 1 and inorganic particles 2 . The particle size of the inorganic particles 2 is 10 μm to 300 μm. The inorganic particles 2 are uniform Disperse in the polymer matrix; the polymer matrix 1 has a plurality of uniformly distributed micropores 3, the micropores 3 are ellipsoid, and the inorganic particles 2 are located in the micropores 3. The raw materials of the composite material include polymers, inorganic particles and lubricants.

The high molecular polymer is selected from one or more of polyethylene, polypropylene, polyoxymethylene, and polylactic acid, and the raw material is in the form of particles with a particle size of 50-1250 mesh, preferably 100-1200 mesh, more preferably 500-1000 mesh. In the present invention, the polymer matrix can be oriented under tensile stress at 10-40°C below the melting point of the polymer, and the molecular chain can be oriented to form a "skeletal" or "fibrous crystal" crystal structure, giving inorganic particles to fill the polymer Excellent mechanical properties of microporous composites. The present invention does not specifically limit the sources of the polyethylene, polypropylene, polyoxymethylene and polylactic acid, and commercially available products well known to those skilled in the art can be used.

The inorganic particles are selected from one or more of calcium carbonate, magnesium carbonate, talc, and fly ash, and the raw material is in the form of particles with a particle size of 50-1250 mesh, preferably 100-1200 mesh, more preferably 500 mesh. -1000 mesh. Based on the weight of the polymer matrix as 100 parts, the weight content of the inorganic particles is 25-100 parts, preferably 60-100 parts. In the present invention, the inorganic particles play the role of inducing the formation of micropores during processing. Under the action of the controllable tensile force field formed in the secondary molding die, the interface between the inorganic particles and the polymer matrix is debonded. , so that pores are formed before and after the inorganic particles, thereby effectively reducing the density of the polymer microporous composite material filled with inorganic particles, and achieving the effect of light weight. The present invention does not specifically limit the sources of the calcium carbonate, magnesium carbonate, talc, and fly ash, and commercially available products well known to those skilled in the art can be used.

The lubricant preferably includes one or more of zinc stearate, calcium stearate, and barium stearate. The weight content of the lubricant is 0.5-2 parts, preferably 0.6-1.2 parts, based on 100 parts by weight of the polymer matrix. In the present invention, the lubricant can reduce the friction between the polymer and the surface of the processing machine, and can increase the lubricity of the plastic surface during processing, so as to achieve the goal of easy processing and molding without impairing the performance of the plastic. The sources of the zinc stearate, calcium stearate and barium stearate are not specifically limited in the present invention, and commercially available products well known to those skilled in the art can be used.

The device for preparing the inorganic particle-filled polymer microporous composite material is preferably as shown in Figure 2, including an extrusion device 4, a shaping die 5, a heat preservation device 6, a secondary molding die 7 with a convergent shape, and a traction machine connected in sequence. 8.

The preparation method of the inorganic particle filled polymer microporous composite material of the present invention comprises the following steps:

A. Weigh an appropriate proportion of raw materials, place the polymer and inorganic particles in a blast oven for drying for 3-4h, and then place them in a high-speed mixer together with the lubricant to mix for 10-15min;

B, the above-mentioned mixed raw material is added in the twin-screw extruder and extruded and granulated, then extruded by extrusion device 4, melt-plasticized and extruded, and a blank with constant cross-sectional size is obtained through shaping die (5);

C. Under the action of the tractor, the blank enters the heat preservation device 6 after cooling, and the heat preservation temperature is in the range of 10-40°C lower than the melting point of the polymer material;

D. The blank is passed through the secondary molding die 7 with a stretching ratio in the range of 2-8, the polymer matrix undergoes plastic yield, the interface between the inorganic particles and the polymer is debonded to form a plurality of micropores, and the temperature of the secondary molding die is The same as the insulation device;

E. The composite material can be obtained after the molding material is cooled and cut to a fixed length.

In the present invention, the drying treatment is completed in a blast oven, the temperature of the blast oven is preferably 70-90°C, and the drying time is 3-4h, preferably 4h. After the drying treatment, the polymer raw material, the inorganic particle filler and the lubricant are placed in a high-speed mixer and mixed together, and the mixing time is preferably 10-15 minutes, more preferably 12-14 minutes. After the mixing is completed, the material obtained after mixing is granulated. The drying device, mixing device and granulation device are not particularly limited, and a granulation device well known to those skilled in the art can be used.

After the granulation is completed, the material obtained by the granulation is extruded, cooled and shaped to obtain a billet. In the present invention, the extrusion device 4 is preferably a single-screw extruder.

The blank is cooled by air under the action of the tractor 8 and then enters the heat preservation device 6 for heat preservation. The heat preservation temperature is in the range of 10-40°C lower than the melting point of the polymer material, preferably 20-40°C. After that, the heat-insulated blank passes through the secondary molding die 7 closely connected with the insulating device 6; The secondary shaping die 7 is a flow channel structure with a convergence angle, and the convergence angle is preferably 10-40°, more preferably 15-30°. When the convergence angle is within the above range, it is more favorable to form a controllable tensile force field, to promote the high orientation of the molecular chains of the polymer matrix, and to form a "skeletal" or "fibrous crystal" structure. The temperature in the secondary molding die 7 is lower than the melting point of the polymer. Under the action of the tensile force field, the polymer matrix undergoes plastic yield, and the interface debonding occurs with the polymer matrix before and after the inorganic particles, so that the inorganic particles are located in the polymer matrix. In the micropores; the inorganic particles are uniformly dispersed in the composite material to form a plurality of micropores, thereby effectively reducing the overall density of the material.

The pulling speed of the pulling machine is preferably 0.2-2.0 m/min, more preferably 0.6-1.8 m/min. The source of the tractor is not particularly limited in the present invention, and a tractor well-known to those skilled in the art may be used. The pulling speed of the pulling machine is matched with the extrusion speed of the single-screw extruder, and the extruded blank is pulled to the secondary molding die.

The inorganic particle-filled polymer microporous composite material is preferably cut to length before use. The length of the cut-to-length cutting is not particularly limited in the present invention, and the inorganic particle-filled polymer microporous composite material is filled to a desired length. That's it.

Example 1

According to the inorganic particle-filled polymer microporous composite material of the present invention, the weight ratio of each part is 100 parts of polypropylene, 54.4 parts of talc, 0.8 parts of zinc stearate, and the particle diameters of particulate polypropylene and talc are all 1200 mesh. The polypropylene and talc powder weighed as required are placed in a blast oven for drying for 4 hours; the dried polypropylene powder, talc powder, and zinc stearate are simultaneously added to the high-speed mixing unit and mixed for 12 minutes; The above-mentioned raw materials are added into a twin-screw extruder for extrusion and granulation, and then melted and plasticized and extruded by a single-screw extruder, and a billet with a constant cross-section is obtained through a shaping die, and the cross-sectional size of the product is 18 mm × 12 mm; Under the action of the pulling rate of 2m/min of the machine, the blank enters the heat preservation device after cooling, and the temperature of the heat preservation device is 140 ℃, and then directly passes through the secondary molding die with the drawing ratio of 4, and the mold temperature is 140 ℃; After cooling and cutting to a fixed length, an inorganic particle-filled polymer microporous composite material is obtained.

The density of the high-filled polypropylene microporous composite rod prepared in this example is 0.805 g/cm ³ , the tensile strength is 231 MPa, the bending strength is 196 MPa, and the impact strength is 175.67 KJ/m ³ . The microstructure of the cross-section of the inorganic particle-filled polymer composite prepared in this example is shown in Figure 3.

Example 2

According to the inorganic particle-filled polymer microporous composite material of the present invention, the weight ratio of each part is 100 parts of polyethylene, 83 parts of calcium carbonate, 1.5 parts of calcium stearate, and the particle size of particulate polyethylene and calcium carbonate are equal. 200 meshes. The polyethylene and calcium carbonate weighed as required were placed in a blast oven for drying for 4 hours; the dried polyethylene powder, calcium carbonate, and calcium stearate were simultaneously added to the high-speed mixing unit and mixed for 13 minutes; The above-mentioned raw materials are added to the twin-screw extruder for extrusion and granulation, and then melted and plasticized and extruded by the single-screw extruder, and a blank with a constant cross-section is obtained through the die setting, and the product cross-section is a circle with a diameter of 16 mm; Under the action of the pulling rate of 1.6m/min of the machine, the blank enters the heat preservation device after cooling, and the temperature of the heat preservation device is 130 ℃, and then directly passes through the secondary molding die with the drawing ratio of 8, and the mold temperature is 130 ℃; After cooling and cutting to a fixed length, the inorganic particle-filled polymer microporous composite material is obtained.

The density of the high-filled polyethylene microporous composite rod prepared in this example is 0.916g/cm ³ , the tensile strength is 320MPa, the bending strength is 210MPa, and the impact strength is 192.33KJ/m ³ . The inorganic particles prepared in this example are filled with The microstructure of the cross-section of the polymer composite is shown in Figure 4.

Example 3

According to the inorganic particle-filled polymer microporous composite material of the present invention, the weight ratio of each part is 100 parts of polylactic acid, 67.8 parts of fly ash, 1.7 parts of barium stearate, particulate polylactic acid and fly ash particles. Diameter is 500 mesh. Place the polylactic acid and fly ash weighed as required in a blast oven for drying for 3-4 hours; add the dried polylactic acid powder, fly ash, and barium stearate to the high-speed mixing unit at the same time Mixing for 14min; adding the above-mentioned raw materials into a twin-screw extruder for extrusion and granulation, then melt-plasticizing and extruding by a single-screw extruder, and shaping by a die to obtain a billet with a constant cross-section, and the cross-sectional size of the product is 16mm×4mm ; Under the action of the pulling rate of 1.2m/min of the pulling machine, the blank enters the heat preservation device after cooling, and the temperature of the heat preservation device is 150 ℃, and then directly passes through the secondary molding die with the drawing ratio of 2, and the mold temperature is 150 ℃; After the molding material is cooled and cut to a fixed length, an inorganic particle-filled polymer microporous composite material is obtained.

The density of the high-filled polylactic acid microporous composite rod prepared in this example is 1.046g/cm ³ , the tensile strength is 178MPa, the bending strength is 163MPa, and the impact strength is 158.38KJ/m ³ . The inorganic particles prepared in this example are filled with The microstructure of the cross-section of the polymer composite is shown in Figure 5.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions described in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. An inorganic particle-filled polymer microporous composite material, characterized by comprising a polymer matrix (1) and inorganic particles (2), the particle size of the inorganic particles (2) being 10 to 300 μm, the inorganic particles (2) being uniformly dispersed in the polymer matrix; the polymer matrix (1) is provided with a plurality of micropores (3) which are uniformly distributed, the micropores (3) are in an ellipsoid shape, and the inorganic particles (2) are positioned in the micropores (3).

2. The inorganic particle-filled polymeric microporous composite material according to claim 1, wherein the raw materials of the composite material comprise a polymer, inorganic particles and a lubricant, wherein the weight contents of the components are as follows: 100 parts of polymer, 25-100 parts of inorganic particles and 0.5-2 parts of lubricant.

3. The inorganic particle-filled polymer microporous composite material according to claim 1 or 2, wherein the polymer is one or more selected from polyethylene, polypropylene, polyoxymethylene, and polylactic acid, and the raw material form thereof is fine particles having a particle size of 50 to 1250 mesh.

4. The inorganic particle-filled polymer microporous composite material according to claim 1 or 2, wherein the inorganic particles are selected from one or more of calcium carbonate, magnesium carbonate, talc and fly ash, and the raw material form thereof is fine particles having a particle size of 50 to 1250 mesh.

5. The inorganic particle-filled polymeric microporous composite material according to claim 1 or 2, wherein the lubricant is selected from one or more of zinc stearate, calcium stearate and barium stearate.

6. A method of making the inorganic particle-filled polymeric microporous composite of claims 1-5, comprising the steps of:

A. weighing raw materials in a proper proportion, placing the polymer and the inorganic particles in a blast oven for drying treatment for 3-4h, and then placing the polymer and the inorganic particles together with a lubricant in a high-speed mixer for mixing for 10-15 min;

B. adding the mixed raw materials into a double-screw extruder for extrusion granulation, then carrying out melt plasticizing extrusion by an extrusion device (4), and carrying out shaping by a shaping die (5) to obtain a blank with a constant cross section size;

C. under the action of a tractor, cooling the blank, and then entering a heat preservation device (6) for heat preservation, wherein the heat preservation temperature is lower than the melting point of the polymer material by 10-40 ℃;

D. enabling the blank to pass through a secondary forming die (7) with the stretching ratio within the range of 2-8, enabling the polymer matrix to generate plastic yield, and enabling the inorganic particles and the polymer to generate interface debonding to form a plurality of micropores, wherein the temperature of the secondary forming die is the same as that of the heat preservation device;

E. and cooling and cutting the formed material to a fixed length to obtain the composite material.

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