CN1300234C - High performance and high molecular polyethylene/sheet silicate nano composite materials - Google Patents

Abstract

The invention relates to a method for developing a high-performance high-molecular-weight polyethylene composite material. High-molecular-weight polyethylene is a general-purpose thermoplastic with a large output and consumption. It has the characteristics of low price and convenient processing, and has a wide range of applications. However, due to the continuity and flexibility of its macromolecular chain segment, its performance is relatively low compared with engineering plastics, which limits its application and development in the direction of functionalization and high performance. Adding inorganic materials to high molecular weight polyethylene materials is the mainstream of polyolefin plastic engineering development. Composite materials with good interface compatibility combine the rigidity, heat resistance, and wear resistance of inorganic substances with the flexibility, good processability, and plasticity of organic substances, thereby endowing general-purpose materials with engineering, Or some special properties to improve the grade of materials and expand the scope of use of materials.

Description

A High Molecular Weight Polyethylene/Layered Silicate Nanocomposite Material

The invention relates to a method for developing a high-performance high-molecular-weight polyethylene composite material.

High-molecular-weight polyethylene is a general-purpose thermoplastic with a large output and consumption. It has the characteristics of low price and convenient processing, and has a wide range of applications. However, due to the continuity and flexibility of its macromolecular chain segment, its performance is relatively low compared with engineering plastics, which limits its application and development in the direction of functionalization and high performance.

Adding inorganic materials to high molecular weight polyethylene materials is the mainstream of polyolefin plastic engineering development. Composite materials with good interfacial compatibility combine the rigidity, heat resistance, and wear resistance of inorganic substances with the flexibility, good processability, and plasticity of organic substances, thereby endowing general-purpose materials with engineering, Or some special properties to improve the grade of materials and expand the scope of use of materials.

Traditional polyethylene/inorganic filler composites have poor compatibility at the two-phase interface, resulting in poor mechanical properties and other properties of the composite.

The invention provides a preparation method of a high molecular weight polyethylene/layered silicate nanocomposite material with excellent mechanical properties, thermal properties and wear resistance.

The present invention increases the compatibility of organic and inorganic phase interfaces through coupling treatment; through micro-crosslinking, controls the shear strength of polymer melt, promotes the insertion of grafted monomers into layered silicate sheets, and weakens the And further destroy the van der Waals bonding force between two adjacent layers of layered silicate. Therefore, the adhesion force of the organic polymer on the outer surface and between layers of the layered silicate is realized, and a high-performance high-molecular weight polyethylene/layered silicate nanocomposite material is prepared.

Components and contents of the high molecular weight polyethylene/phyllosilicate nanocomposite raw material of the present invention are as follows (parts by weight):

High molecular weight polyethylene 100

Layered silicate 0.03-30

Coupling agent 0.01-10

Cross-linking agent 0.001-3

Dispersing aid 0.5-30

Additives 0.01-3

The high molecular weight polyethylene used in the present invention refers to industrially produced varieties with a viscosity average molecular weight of 200,000 to 800,000.

The layered silicate used in the present invention is a kind of inorganic mineral, and its chemical composition is talc containing: silicon dioxide, magnesium oxide, calcium oxide, aluminum oxide, etc., with a layered structure and a large aspect ratio , Wollastonite. The thickness of layered silicate sheet is generally 1-2nm, and the particle size of sheet is generally 50-200nm. Under the combined effects of thermal shearing, adhesive cutting, and organic micro-crosslinking insertion, the sheet-like structure is easy to damage and maintain the two layers. The van der Waals combination between them forms an inorganic nanostructure with a large diameter-thickness ratio uniformly dispersed in the polymer body, which characterizes a strong nano-effect. In the present invention, the optimal dosage of layered silicate is 3-15 parts.

The coupling agent of the present invention is vinyl triethoxysilane, γ-(methacryloxypropyl) trimethoxysilane, γ-aminopropyl triethoxysilane, sulfonyl azide trimethoxy Silane, vinyltrimethoxysilane, vinyltris(β-methoxyethoxysilane), vinyltrichlorosilane, and the like.

The crosslinking agent of the present invention is 2,5-dimethyl-2,5-bis(tert-butyl peroxy)hexane, di-tert-butyl peroxide (DBP, DTBP), 2,5-dimethyl -2,5-bis(tert-butylperoxyhexane-3), dicumyl peroxide, etc.

The dispersing aid of the present invention is water, acetone, ethanol, white oil and the like.

The additives used in the present invention are antioxidants, anti-light agents and the like. The antioxidant can be antioxidant 1010, antioxidant 1076, etc.; the anti-light agent can be UV327, UV770, UV944, etc.

High molecular weight polyethylene/phyllosilicate nanocomposite material of the present invention is prepared according to the following steps:

0.03-30 parts of phyllosilicate with layered structure and large aspect ratio and 0.01-10 parts of coupling agent are subjected to coupling treatment. The above processing is completed in a high-speed mixer.

Add 100 parts of high molecular weight polyethylene, 0.001-3 parts of crosslinking agent, 0.5-30 parts of dispersing aid, and 0.01-3 parts of additives into a high-speed mixer in sequence, and stir together with the layered silicate after coupling treatment for 3 -30 minutes, mix well.

The above treated mixture is extruded and granulated on a co-rotating parallel twin-screw extruder at 180°C-270°C.

The high molecular weight polyethylene/layered silicate nanocomposite material prepared by the invention embodies the nanometer effect of the material due to the synergistic effect of coupling and micro-crosslinking intercalation. Compared with the bulk material, the indicators of the prepared nanocomposite materials in terms of tensile strength, bending strength, elastic modulus, thermal deformation temperature, and material wear resistance have been greatly improved.

Examples are as follows:

5 parts of layered silicate with a large aspect ratio and 0.1 part of coupling agent are subjected to coupling treatment. The above processing is completed in a high-speed mixer.

Add 95 parts of high molecular weight polyethylene, 0.01 parts of crosslinking agent, 0.3 parts of dispersing aid, and 0.4 parts of additives into a high-speed mixer in sequence, stir at high speed for 5 minutes, and mix well.

The above treated mixture was extruded and granulated on a co-rotating parallel twin-screw extruder, and the temperature of each section of the extruder was set at: 200°C, 220°C, 240°C, 240°C, 240°C. The granulated product is injected into the injection machine for sample preparation. The injection temperature is set at 190°C, 225°C, and 230°C, and the injection pressure is 30Mpa. The performance after testing is shown in the table:

Table 1 Example 1 2 3 4 high molecular weight polyethylene 95 90 85 80 layered silicate 5 10 15 20 coupling agent 0.1 0.2 0.3 0.4 crosslinking agent 0.01 0.02 0.02 0.02 Dispersing aid 0.3 0.3 0.3 0.3 additive 0.4 0.4 0.4 0.4 Tensile Strength 36.1 36.7 33.2 30.5 Bending strength 25 29 32 37 Elastic Modulus 1350 1710 2150 2360 Heat distortion temperature 93 96 96 98 Mortar wear 0.45 0.38 0.40 0.42

Claims (4)

1. A high-performance high-molecular-weight polyethylene/layered silicate nanocomposite material, characterized in that the raw material of the high-molecular-weight polyethylene/layered silicate nanocomposite material comprises the following components and contents, in parts by weight: High molecular weight polyethylene 100 Layered silicate 0.03-30 Coupling agent 0.01-10 Cross-linking agent 0.001-3 Dispersing aid 0.5-30 Additives 0.01-3 The coupling agent is vinyl triethoxysilane, γ-(methacryloxypropyl) trimethoxysilane, γ-aminopropyl triethoxysilane, sulfonyl azide trimethoxy silane, vinyltrimethoxysilane, vinyltris(β-methoxyethoxysilane), vinyltrichlorosilane; The cross-linking agent is 2,5-dimethyl-2,5-bis(tert-butyl peroxy)hexane, di-tert-butyl peroxide DBP, DTBP, 2,5-dimethyl- 2,5-bis(tert-butylperoxyhexane-3), dicumyl peroxide; Described dispersing aid is water, acetone, ethanol, white oil; The additives are antioxidants and anti-light agents; the antioxidants are antioxidant 1010 and antioxidant 1076; the anti-light agents are UV327, UV770, and UV944. 2. A high-performance high-molecular-weight polyethylene/layered silicate nanocomposite material according to claim 1, characterized in that said high-molecular-weight polyethylene is industrially produced with a viscosity-average molecular weight of 200,000 to 800,000 of polyethylene. 3. A high-performance high-molecular-weight polyethylene/layered silicate nanocomposite material according to claim 1, characterized in that said layered silicate is a type of inorganic mineral, and its chemical composition is composed of : Silica, magnesia, calcium oxide, alumina, talc and wollastonite with layered structure and large aspect ratio; layered silicate sheet thickness is 1-2nm, sheet particle size is 50 -200nm. 4. A method for preparing a high-performance high-molecular-weight polyethylene/layered silicate nanocomposite material according to claim 1, characterized in that it is carried out in the following steps: 1) Coupling treatment of 0.03-30 parts of layered silicate with a large aspect ratio and 0.01-10 parts of coupling agent; the above treatment is completed in a high-speed mixer 2) Add 100 parts of high molecular weight polyethylene, 0.001-3 parts of crosslinking agent, 0.5-30 parts of dispersing aid, and 0.01-3 parts of additives into the high-speed mixer in sequence, and combine them with the layered silicate after coupling treatment at high speed Stir for 3-30 minutes to mix well 3) Extrude the above-mentioned treated mixture on a co-rotating parallel twin-screw extruder at 180°C-270°C for granulation 4) The granulated product is injected on the injection machine for sample preparation. The injection temperature is set at 190°C, 225°C, and 230°C, and the injection pressure is 30Mpa.