A kind of non-polar polymer negative Poisson's ratio foam material and preparation method thereof

Abstract

The invention relates to a non-polar polymer negative poisson ratio foamed material and a preparation method thereof, belongs to the technical field of functional polymer foamed materials, and aims tosolve the technical problems that in the prior art, a preparation method of a negative poisson ratio foamed material is tedious in preparation process, low in preparation efficiency and unbeneficialto large-scale production and has limits on polymers. The preparation method provided by the invention comprises the following steps: firstly, performing composite molding on a non-polar polymer and ahydrophile so as to prepare a composite material, putting the composite material into foaming equipment, introducing a physical foaming agent and water, and carrying out rapid pressure release at a saturation temperature of 80-180 DEG C at saturated pressure of 3-25 MPa in a saturation time of 0.5 hour or longer, thereby obtaining the non-polar polymer negative poisson ratio foamed material. According to the method, the negative poisson ratio foamed material is prepared from the composite material according to a one-step method, the method is simple in preparation process, high in preparationefficiency, high in security, environmentally friendly and applicable to large-scale production, and a large-size negative poisson ratio foamed material can be prepared.

Description

technical field

[0001] The invention belongs to the technical field of functional polymer foam materials, and in particular relates to a nonpolar polymer negative Poisson's ratio foam material and a preparation method thereof. Background technique

[0002] Poisson's ratio (ν) is a mechanical property of a material. French mathematician Simon Poisson defined it as: the material transverse shrinkage strain (ε x ) and longitudinal elongation strain (ε y ) ratio, which is an important parameter to reflect the properties of materials. The formula is as follows:

[0003] ν=-ε x / ε y

[0004] Most materials have a positive Poisson's ratio, such as rubber materials, which contract laterally when stretched and expand laterally when compressed. However, there are also a small number of negative Poisson's ratio materials, also known as auxetic materials. Natural negative Poisson's ratio materials include pyrite, cat skin, etc. Artificial negative Poisson's ratio materials incl...

Examples

preparation example Construction

[0039] Such as figure 1 Shown, the preparation method of nonpolar polymer negative Poisson's ratio foam material of the present invention, the steps are as follows:

[0040] Step 1. Composite the non-polar polymer and the hydrophilic substance first, and form it to obtain the composite material;

[0041] Step 2. Put the composite material obtained in Step 1 into the foaming equipment, introduce physical foaming agent and water, and at the saturation temperature of 80-180°C and the saturation pressure of 3-25MPa, the saturation time is more than 0.5h, and the rapid release Press to obtain a non-polar polymer foam material with negative Poisson's ratio.

[0042] In the above technical scheme, in the process of compounding non-polar polymers and hydrophilic substances, those skilled in the art can also compound additives in the system according to experience and needs, specifically calcium carbonate powder, talc powder, wollastonite powder, Silica powder, alumina, aluminum hydr...

Embodiment 1

[0057] First, add polypropylene (Daqing Petrochemical, T30S) and sodium chloride into the twin-screw extruder according to the mass ratio of 98:2. The temperature in the mixing section is 200°C, the speed is 200 rpm, extruded and granulated, and then the injection molding machine is used to into 10×10×10mm 3 The cubic composite material; then the composite material is placed in 180 ℃, 3MPa CO 2 After 10 hours in the foaming equipment with water, the pressure is released to normal pressure, and the pressure release speed is 2MPa / s. During the process of pressure release and foaming, the composite material is discharged out of the foaming equipment with the pressure release gas to complete foaming, and polypropylene is obtained. Negative Poisson's ratio foam.

[0058] After testing, the foam material has a cell structure with "concave corners", and the SEM photos are as follows figure 2 As shown; the Poisson's ratio of the material is tested according to the GB / T1040.1-2006 s...

Embodiment 2

[0060] First, high-density polyethylene (Fushun Petrochemical, FHC7260) and sodium stearate are added to the twin-screw extruder at a mass ratio of 96:4. The temperature in the mixing section is 200°C, extruded and granulated, and then made into 50×50 ×20mm 3 The sheet composite material, the temperature of the injection molding machine is 195 ° C; then the composite material is placed in 130 ° C, 25 MPa CO 2After 0.5h in the foaming equipment with water, the pressure is released to normal pressure at a speed of 50MPa / s. During the process of pressure relief and foaming, the composite material remains in the foaming equipment to complete foaming, and then the foaming equipment is opened Take it out to obtain polyethylene negative Poisson's ratio foam material.

[0061] After testing, the foam material has a cell structure with "concave corners", and the SEM photos are as follows image 3 As shown; the Poisson's ratio of the material is tested according to the GB / T1040.1-2006...

technical field

[0001] The invention belongs to the technical field of functional polymer foam materials, and in particular relates to a nonpolar polymer negative Poisson's ratio foam material and a preparation method thereof. Background technique

[0002] Poisson's ratio (ν) is a mechanical property of a material. French mathematician Simon Poisson defined it as: the material transverse shrinkage strain (ε x ) and longitudinal elongation strain (ε y ) ratio, which is an important parameter to reflect the properties of materials. The formula is as follows:

[0003] ν=-ε x / ε y

[0004] Most materials have a positive Poisson's ratio, such as rubber materials, which contract laterally when stretched and expand laterally when compressed. However, there are also a small number of negative Poisson's ratio materials, also known as auxetic materials. Natural negative Poisson's ratio materials include pyrite, cat skin, etc. Artificial negative Poisson's ratio materials incl...

Examples

preparation example Construction

[0039] Such as figure 1 Shown, the preparation method of nonpolar polymer negative Poisson's ratio foam material of the present invention, the steps are as follows:

[0040] Step 1. Composite the non-polar polymer and the hydrophilic substance first, and form it to obtain the composite material;

[0041] Step 2. Put the composite material obtained in Step 1 into the foaming equipment, introduce physical foaming agent and water, and at the saturation temperature of 80-180°C and the saturation pressure of 3-25MPa, the saturation time is more than 0.5h, and the rapid release Press to obtain a non-polar polymer foam material with negative Poisson's ratio.

[0042] In the above technical scheme, in the process of compounding non-polar polymers and hydrophilic substances, those skilled in the art can also compound additives in the system according to experience and needs, specifically calcium carbonate powder, talc powder, wollastonite powder, Silica powder, alumina, aluminum hydr...

Embodiment 1

[0057] First, add polypropylene (Daqing Petrochemical, T30S) and sodium chloride into the twin-screw extruder according to the mass ratio of 98:2. The temperature in the mixing section is 200°C, the speed is 200 rpm, extruded and granulated, and then the injection molding machine is used to into 10×10×10mm 3 The cubic composite material; then the composite material is placed in 180 ℃, 3MPa CO 2 After 10 hours in the foaming equipment with water, the pressure is released to normal pressure, and the pressure release speed is 2MPa / s. During the process of pressure release and foaming, the composite material is discharged out of the foaming equipment with the pressure release gas to complete foaming, and polypropylene is obtained. Negative Poisson's ratio foam.

[0058] After testing, the foam material has a cell structure with "concave corners", and the SEM photos are as follows figure 2 As shown; the Poisson's ratio of the material is tested according to the GB / T1040.1-2006 s...

Embodiment 2

[0060] First, high-density polyethylene (Fushun Petrochemical, FHC7260) and sodium stearate are added to the twin-screw extruder at a mass ratio of 96:4. The temperature in the mixing section is 200°C, extruded and granulated, and then made into 50×50 ×20mm 3 The sheet composite material, the temperature of the injection molding machine is 195 ° C; then the composite material is placed in 130 ° C, 25 MPa CO 2After 0.5h in the foaming equipment with water, the pressure is released to normal pressure at a speed of 50MPa / s. During the process of pressure relief and foaming, the composite material remains in the foaming equipment to complete foaming, and then the foaming equipment is opened Take it out to obtain polyethylene negative Poisson's ratio foam material.

[0061] After testing, the foam material has a cell structure with "concave corners", and the SEM photos are as follows image 3 As shown; the Poisson's ratio of the material is tested according to the GB / T1040.1-2006...

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