High-molecular modified wollastonite, preparation method thereof and application of high-molecular modified wollastonite in improvement of performance of high-molecular material

Abstract

The invention discloses high-molecular modified wollastonite, a preparation method thereof and application of the high-molecular modified wollastonite in improving the performance of a high-molecular material. The high-molecular modified wollastonite is mainly obtained by modifying wollastonite with a high-molecular polymer. Wollastonite and the macromolecular high polymer are mixed and stirred at a high speed, and the macromolecular modifier wollastonite is obtained. Compared with the prior art, the invention provides the method for modifying the wollastonite by using the macromolecular modifier, the molecular weight of the macromolecular modifier is relatively large, so that a relatively thick modified layer can be formed on the surface of the wollastonite, and the dispersity of the wollastonite in a polymer matrix can be effectively improved. The macromolecular modifier has a longer molecular chain, and can better coat the surface of the wollastonite, so that the compatibility between the wollastonite and a polymer matrix is enhanced, and the interfacial strength of the composite material is improved.

Description

Technical Field

[0001] The invention relates to polymer modified wollastonite and a preparation method thereof and application in improving the performance of polymer materials, belonging to the technical field of wollastonite modification. Background Art

[0002] Wollastonite, with the chemical formula of CaSiO3, is a naturally occurring calcium silicate mineral. It is known for its excellent physical and chemical properties, such as high whiteness, good thermal stability, chemical inertness and mechanical strength. These properties make wollastonite widely used in many fields such as ceramics, plastics, coatings, rubber, etc. However, untreated wollastonite has limitations in some applications, such as poor compatibility with organic materials, which limits its use efficiency in composite materials.

[0003] In recent years, with the development of materials science, surface modification of wollastonite has become one of the research hotspots. Modifying the surface of wollastonite by chemical or physical methods can significantly improve its dispersibility and enhance the interfacial bonding force between it and the matrix material, thereby improving the overall performance of the composite material. Using small molecule modifiers to modify wollastonite is a common method to improve its application performance in composite materials. Small molecule modifiers usually include silane coupling agents, titanate coupling agents, aluminate coupling agents, fatty acids and their derivatives. The mechanism is that the small molecule modifier can form a lipophilic film on the surface of wollastonite through chemical or physical action, thereby improving the compatibility between wollastonite and organic polymers, making wollastonite easier to disperse evenly in the polymer matrix. Compared with some complex modification methods, the small molecule modifier has a lower cost and is easy to operate. For example, patent CN 1462775A discloses "using phthalate coupling agent TC-114 and anhydrous xylene as modifiers to modify wollastonite, so that the original hydrophilic and oleophobic properties are changed to hydrophobic and oleophilic properties". Patent CN111925218A discloses "using a coupling agent to modify wollastonite can further increase the inorganic-philic groups on the surface of wollastonite and increase the combination of wollastonite and inorganic materials in ceramic raw materials".

[0004] However, small molecule modifiers have a small molecular weight and may not be able to completely cover the surface of wollastonite particles, resulting in limited modification effects, especially in the case of high filling amounts, where agglomeration may occur, affecting the overall performance of the composite material. Summary of the invention

[0005] Purpose of the invention: In order to solve the above technical problems, the present invention provides a polymer-modified wollastonite and a preparation method thereof and an application in improving the performance of polymer materials. The polymer-modified wollastonite can significantly improve the mechanical properties of polymer materials.

[0006] Technical solution: In order to achieve the above purpose, the present invention adopts the following technical solution:

[0007] The invention discloses a polymer modified wollastonite, which is mainly obtained by modifying wollastonite with a macromolecular polymer.

[0008] As a specific implementation scheme, the mass ratio of the macromolecular polymer to wollastonite is (1-6):30.

[0009] As a specific embodiment, the macromolecular high polymer is selected from one or a combination of epoxy resin, polyurethane PU and thermoplastic polyurethane TPU.

[0010] Furthermore, the molecular weight of the epoxy resin is 200-600; the molecular weight of the polyurethane is 4000-8000; and the molecular weight of the thermoplastic polyurethane is 30000-40000.

[0011] The present invention also provides a method for preparing the polymer-modified wollastonite, comprising the following steps:

[0012] Wollastonite is mixed with a macromolecular polymer and stirred at high speed to obtain the macromolecular modifier wollastonite.

[0013] As a specific implementation scheme, the conditions for the high-speed stirring are: a rotation speed of 1000-2000 r / min and a temperature of 100-150°C.

[0014] The invention also provides application of the polymer modified wollastonite in improving the mechanical properties of polymer materials.

[0015] Finally, the present invention provides a method for improving the mechanical properties of polymer materials, which comprises mixing the polymer-modified wollastonite with the polymer materials.

[0016] As a specific implementation scheme, the mass ratio of the polymer-modified wollastonite to the polymer material is 30:(60-70).

[0017] As a specific implementation, the polymer material is selected from high-density polyethylene (HDPE).

[0018] Technical effect: Compared with the prior art, the present invention proposes a method for modifying wollastonite using a macromolecular modifier. Since the macromolecular modifier has a large molecular weight, a thicker modified layer can be formed on the surface of wollastonite, which can effectively improve its dispersibility in the polymer matrix. The macromolecular modifier has a longer molecular chain and a stronger coating on the surface of wollastonite, thereby enhancing the compatibility between wollastonite and the polymer matrix, thereby improving the interface strength of the composite material. DETAILED DESCRIPTION

[0019] The present invention is further illustrated below in conjunction with specific examples.

[0020] Unless otherwise defined herein, the scientific and technical terms used in this application should have the meanings commonly understood by those of ordinary skill in the art. Generally, the terms and methods used in association with chemistry, biology, and pharmacology described herein are well known and commonly used in the art.

[0021] The present invention is illustrated by the following examples, but these examples are not to be construed as limiting the rights of the present invention.

[0022] Example 1

[0023] formula:

[0024] raw material Mass Wollastonite 30 Epoxy resin 1 HDPE 68

[0025] Wollastonite was placed in a vertical high-speed mixer, epoxy resin (molecular weight 340) was added, and high-speed stirring was performed at a speed of 1450r / min and a temperature of 120°C to obtain a macromolecular modifier wollastonite product. The modified wollastonite was mixed with PP and high-density polyethylene HDPE to obtain the modified high-density polyethylene HDPE. The melt extrusion molding was performed using a twin-screw extruder, the melt extrusion temperature was 220°C, the screw speed was 400R / MIN, and the screw aspect ratio was 40:1.

[0026] Example 2

[0027] formula:

[0028] raw material Mass Wollastonite 30 PU 2 HDPE 67

[0029] Wollastonite was placed in a vertical high-speed mixer, polyurethane PU (molecular weight 6000) was added, and high-speed stirring was performed at a speed of 1450r / min and a temperature of 120°C to obtain a macromolecular modifier wollastonite product. The modified wollastonite was mixed with PP and high-density polyethylene HDPE to obtain the modified high-density polyethylene HDPE. The melt extrusion molding was performed using a twin-screw extruder, the melt extrusion temperature was 220°C, the screw speed was 400R / MIN, and the screw aspect ratio was 40:1.

[0030] Example 3

[0031] formula:

[0032] raw material Mass Wollastonite 30 TPU 5 HDPE 65

[0033] Wollastonite was placed in a vertical high-speed mixer, thermoplastic polyurethane TPU (molecular weight 35000) was added, and high-speed stirring was performed at a speed of 1450r / min and a temperature of 120°C to obtain a macromolecular modifier wollastonite product. The modified wollastonite was mixed with PP and high-density polyethylene HDPE to obtain the modified high-density polyethylene HDPE. The melt extrusion molding was performed using a twin-screw extruder, the melt extrusion temperature was 220°C, the screw speed was 400R / MIN, and the screw aspect ratio was 40:1.

[0034] Comparative Example 1

[0035] The modified high-density polyethylene HDPE is obtained by mixing KH-550 silane coupling agent and high-density polyethylene HDPE. The modified high-density polyethylene HDPE is melt-extruded by a twin-screw extruder, the melt extrusion temperature is 220°C, the screw speed is 400R / MIN, and the screw aspect ratio is 40:1.

[0036] Example 3 Performance Test

[0037] The composite materials prepared in Examples 1, 2, 3 and Comparative Example 1 were subjected to performance tests. The composite materials were pressed under pressing conditions of 220°C and 10 MPa for 15 minutes to obtain test pieces for mechanical test evaluation with a length of 127 mm, a width of 10.7 mm and a thickness of 4 mm. The test results are shown in the following table.

[0038]

[0039] From the above table, we can see that the tensile strength of epoxy modified wollastonite mixed with HDPE is increased from 25MPa to 32MPa after tensile test. The impact strength of PU modified wollastonite mixed with HDPE is increased from 80kJ / m 2 Increased to 114.96 kJ / m 2 After TPU-modified wollastonite was mixed with HDPE, its elongation at break was increased from the original 250% to 436% after testing.

[0040] It can be seen that wollastonite modified by macromolecules has stronger interface bonding force and better compatibility, and can therefore significantly improve the mechanical properties of the material.

[0041] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A polymer-modified wollastonite, characterized in that: The polymer-modified wollastonite is mainly obtained by modifying wollastonite with a macromolecular polymer.

2. The polymer-modified wollastonite according to claim 1, characterized in that: The mass ratio of the macromolecular polymer to wollastonite is (1-6):

30.

3. The polymer-modified wollastonite according to claim 1, characterized in that: The macromolecular high polymer is selected from one or a combination of epoxy resin, polyurethane and thermoplastic polyurethane.

4. The polymer-modified wollastonite according to claim 1, characterized in that: The molecular weight of the epoxy resin is 200-600; the molecular weight of the polyurethane is 4000-8000; and the molecular weight of the thermoplastic polyurethane is 30000-40000.

5. The method for preparing polymer-modified wollastonite according to any one of claims 1 to 4, characterized in that: The following steps are involved: Wollastonite is mixed with a macromolecular polymer and stirred at high speed to obtain the macromolecular modifier wollastonite.

6. The method for preparing polymer-modified wollastonite according to claim 5, characterized in that: The conditions for the high-speed stirring are: a rotation speed of 1000-2000 r / min and a temperature of 100-150°C.

7. Use of the polymer-modified wollastonite according to any one of claims 1 to 4 in improving the mechanical properties of polymer materials.

8. A method for improving the mechanical properties of polymer materials, characterized in that: The method comprises mixing the polymer-modified wollastonite described in any one of claims 1 to 4 with a polymer material.

9. The method for improving the mechanical properties of polymer materials according to claim 8, characterized in that: The mass ratio of the polymer modified wollastonite to the polymer material is 30:(60-70).

10. The method for improving the mechanical properties of polymer materials according to claim 8, characterized in that: The polymer material is selected from high-density polyethylene (HDPE).

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