METHOD FOR PREPARING FOAM MATERIALS BY SUPERCRITICAL FOAMING

Abstract

The invention relates to the field of foaming technology, in particular to CO8G101/00. A method for preparing chlorinated polyethylene materials by supercritical foaming includes the following steps: (1) Add the chlorinated polyethylene material into the reactor, add water and foaming nucleating agent, and then close the reactor cover; (2) Heat to 50-80 degrees C.; (3) Inject supercritical carbon dioxide into the reactor, so that the chlorinated polyethylene material can achieve saturation adsorption of supercritical carbon dioxide; (4) Remove and treat the chlorinated polyethylene material at 100-150 degrees C. for 1-5 minutes. The preparation method is simple, environmentally friendly, efficient and low-cost, uniform micropores improve the elasticity of the foam material and reduce the density of the foam material, which is 0.2-0.3 g/cm3, and the foam wall is thin.

Claims

1. A method for preparing foam materials by supercritical foaming, wherein the method includes the following steps: (1) add the chlorinated polyethylene material into the reactor, add water and foaming nucleating agent, and then close the reactor cover; (2) heat to 50-80° C.; (3) inject supercritical carbon dioxide into the reactor, so that the chlorinated polyethylene material can achieve saturation adsorption of supercritical carbon dioxide; (4) remove and treat the chlorinated polyethylene material at 100-150° C. for 1-5 minutes.

2. The method of claim 1, wherein in Step (3), supercritical carbon dioxide is injected to make the pressure in the reactor 20-30 MPa.

3. The method of claim 2, wherein in Step (3), supercritical carbon dioxide is injected in a segmented way.

4. The method of claim 3, wherein in Step (3), supercritical carbon dioxide is firstly injected at the rate of 2-5 MPa/s to make the pressure in the reactor reach 8-10 MPa and keep it for 15-20 minutes; then the supercritical carbon dioxide is injected again at the rate of 0.5-1 MPa/s to make the pressure in the reactor reach 12-15 MPa and keep it for 10-15 minutes; finally, the supercritical carbon dioxide is injected at the rate of 2-5 MPa/s to make the pressure in the reactor reach 20-30 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

5. The method of claim 1, wherein in Step (4), the chlorinated polyethylene material is removed and treated at 140° C. for 3 minutes.

6. The method of claim 5, wherein water accounts for 60-80% of the volume of the reactor.

7. The method of claim 6, wherein the foaming nucleating agent accounts for 0.05-0.1 wt % of water.

8. The method of claim 6, wherein the foaming nucleating agent is selected from one or more of calcium carbonate, clay, fibrous crystal, butane and pentane.

9. The method of claim 8, wherein the chlorinated polyethylene material contains graphene.

10. A foam material prepared by the method of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG. 1 is the SEM image of foam material obtained in the example 1 of the invention.

[0051] FIG. 2 is the SEM image of foam material obtained in the example 5 of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The invention is described below by means of embodiments, but is not limited to the examples given below.

EXAMPLE 1

[0053] The example 1 of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0054] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 100 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 10KGy to obtain the chlorinated polyethylene material;

[0055] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 60% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.05 wt % of water, with the weight ratio 4:1 of cyclopentane and n-pentane;

[0056] (3) Heat to 50 degrees C.;

[0057] (4) Inject the supercritical carbon dioxide at the rate of 2 MPa/s to make the pressure in the reactor reach 8 MPa and keep it for 15 minutes; then inject the supercritical carbon dioxide again at the rate of 0.5 MPa/s to make the pressure in the reactor reach 12 MPa and keep it for 10 minutes; finally, inject the supercritical carbon dioxide at the rate of 2 MPa/s to make the pressure in the reactor reach 20 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0058] (5) Remove and treat the chlorinated polyethylene material at 100 degrees C. for 5 minutes.

[0059] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

[0060] The SEM image of the foam material obtained in the embodiment is shown in FIG. 1, from which it can be seen that the foam material has orderly foams and large foam density.

EXAMPLE 2

[0061] The example w of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0062] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 150 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 50KGy to obtain the chlorinated polyethylene material;

[0063] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 80% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.1 wt % of water, with the weight ratio 6:1 of cyclopentane and n-pentane;

[0064] (3) Heat to 80 degrees C.;

[0065] (4) Inject the supercritical carbon dioxide at the rate of 5 MPa/s to make the pressure in the reactor reach 10 MPa and keep it for 20 minutes; then inject the supercritical carbon dioxide again at the rate of 1 MPa/s to make the pressure in the reactor reach 15 MPa and keep it for 15 minutes; finally, inject the supercritical carbon dioxide at the rate of 5 MPa/s to make the pressure in the reactor reach 30 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0066] (5) Remove and treat the chlorinated polyethylene material at 150 degrees C. for 1 minute.

[0067] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

EXAMPLE 3

[0068] The example 3 of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0069] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 120 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 35KGy to obtain the chlorinated polyethylene material;

[0070] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 72% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.08 wt % of water, with the weight ratio 5:1 of cyclopentane and n-pentane;

[0071] (3) Heat to 70 degrees C.;

[0072] (4) Inject the supercritical carbon dioxide at the rate of 3 MPa/s to make the pressure in the reactor reach 8 MPa and keep it for 18 minutes; then inject the supercritical carbon dioxide again at the rate of 0.6 MPa/s to make the pressure in the reactor reach 13 MPa and keep it for 12 minutes; finally, inject the supercritical carbon dioxide at the rate of 2 MPa/s to make the pressure in the reactor reach 26 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0073] (5) Remove and treat the chlorinated polyethylene material at 140 degrees C. for 3 minutes.

[0074] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

EXAMPLE 4

[0075] The example 4 of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0076] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 120 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 35KGy to obtain the chlorinated polyethylene material;

[0077] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 72% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.08 wt % of water, with the weight ratio 5:1 of cyclopentane and n-pentane;

[0078] (3) Heat to 70 degrees C.;

[0079] (4) Inject the supercritical carbon dioxide at the rate of 3 MPa/s to make the pressure in the reactor reach 26 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0080] (5) Remove and treat the chlorinated polyethylene material at 140 degrees C. for 3 minutes.

[0081] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

EXAMPLE 5

[0082] The example 5 of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0083] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 120 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 35KGy to obtain the chlorinated polyethylene material;

[0084] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 72% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.08 wt % of water, with the weight ratio 5:1 of cyclopentane and n-pentane;

[0085] (3) Heat to 70 degrees C.;

[0086] (4) Firstly inject the supercritical carbon dioxide at the rate of 3 MPa/s to make the pressure in the reactor reach 8 MPa and keep it for 18 minutes; then inject the supercritical carbon dioxide again at the rate of 0.6 MPa/s to make the pressure in the reactor reach 13 MPa and keep it for 12 minutes; finally, inject the supercritical carbon dioxide at the rate of 2 MPa/s to make the pressure in the reactor reach 26 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0087] (5) Remove and treat the chlorinated polyethylene material at 160 degrees C. for 3 minutes.

[0088] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

[0089] The SEM image of the foam material obtained in the embodiment is shown in FIG. 2, from which it can be seen that there are foams growing in the foams of the foam material.

EXAMPLE 6

[0090] The example 6 of the invention provides a method for preparing foam materials by supercritical foaming, including the following steps:

[0091] (1) Mix 65 parts of chlorinated polyethylene, 10 parts of natural rubber, 3 parts of calcium-zinc stabilizer, 10 parts of graphene, 0.2 part of stearic acid and 10 parts of dioctyl phthalate by weight, extrude and granulate through a single screw extruder, and then extrude at 120 degrees C. to get a molding plate; irradiate and crosslink the molding plate with the crosslinking irradiation dose of 35KGy to obtain the chlorinated polyethylene material;

[0092] (2) Add the chlorinated polyethylene material to the reactor, add water accounting for 72% of the volume of the reactor, and add the foaming nucleating agent to close the reactor cover, in which the foaming nucleating agent accounts for 0.08 wt % of water, with the weight ratio 2:1 of cyclopentane and n-pentane;

[0093] (3) Heat to 70 degrees C.;

[0094] (4) Firstly inject the supercritical carbon dioxide at the rate of 3 MPa/s to make the pressure in the reactor reach 8 MPa and keep it for 18 minutes; then inject the supercritical carbon dioxide again at the rate of 0.6 MPa/s to make the pressure in the reactor reach 13 MPa and keep it for 12 minutes; finally, inject the supercritical carbon dioxide at the rate of 2 MPa/s to make the pressure in the reactor reach 26 MPa and keep it for a period of time until the chlorinated polyethylene material achieves saturation adsorption of supercritical carbon dioxide.

[0095] (5) Remove and treat the chlorinated polyethylene material at 140 degrees C. for 3 minutes.

[0096] The chlorinated polyethylene is purchased from Sichuan Jinsen Plastic Co., Ltd., and the brand is JS; the natural rubber is purchased from Taizhou Zhonghong Waste Rubber Comprehensive Utilization Co., Ltd., and the commodity name is natural reclaimed fine rubber; the calcium-zinc stabilizer is purchased from Jinan Hui Jinchuan Trading Co., Ltd.; the graphene is purchased from Shandong Xiangzhao New Material Co., Ltd., the brand is Xiangzhao, and the model is 001.

[0097] Performance Assessment

[0098] Foam morphology: The morphologies of the foams for the foam materials obtained in the examples 1-6 were respectively observed with an electron microscope to record whether the foams are regular and whether there are foams overlapped. Foam overlap refers to the presence of foams in the foams.

[0099] Foam density: The foam density of the foam materials obtained in the examples 1-6 were calculated respectively. Foam density refers to the number of foams per unit volume, in/cm 3. If the foam density is more than 9×10.sup.7/cm.sup.3, the material will be qualified; if the foam density is less than 9×10.sup.7/cm.sup.3, the material will be unqualified.

TABLE-US-00001 TABLE 1 Foam Foam morphology density Example 1 The foams are regular Qualified without overlap Example 2 The foams are regular Qualified without overlap Example 3 The foams are regular Qualified without overlap Example 4 The foams are regular Unqualified without overlap Example 5 The foams are irregular Qualified and overlapped Example 6 The foams are irregular Unqualified and overlapped