CN117362774B

CN117362774B - Rapidly degradable foaming material for soles and preparation method thereof

Info

Publication number: CN117362774B
Application number: CN202311565948.7A
Authority: CN
Inventors: 李卫平
Original assignee: Dongguan Senhong New Material Technology Co ltd
Current assignee: Dongguan Senhong New Material Technology Co ltd
Priority date: 2023-11-22
Filing date: 2023-11-22
Publication date: 2024-04-12
Anticipated expiration: 2043-11-22
Also published as: CN117362774A

Abstract

The application relates to the field of shoe materials, in particular to a rapidly degradable foaming material for soles and a preparation method thereof. A rapidly degradable foaming material for soles comprises the following raw materials in parts by mass: 85-105 parts of natural rubber, 25-45 parts of coffee grounds, 10-20 parts of betel nut fibers, 6-15 parts of red clay, 3-8 parts of silane coupling agent, 0.5-3 parts of vulcanizing agent, 0.5-5 parts of accelerator, 0.1-3 parts of anti-aging agent, 2-6 parts of foaming agent and 1-10 parts of auxiliary agent; the preparation method comprises the following steps: dispersing the silane coupling agent by using an alcohol solution, and then mixing with coffee grounds and betel nut fibers; drying; obtaining a mixture; and mixing the mixture, the red clay, the natural rubber, the vulcanizing agent, the auxiliary agent and the accelerator, carrying out open mixing, adding the foaming agent, continuing open mixing, and discharging to obtain the foaming material. The present application has the advantage of improving the problem of non-degradability of sole materials.

Description

Rapidly degradable foaming material for soles and preparation method thereof

Technical Field

The application relates to the field of shoe materials, in particular to a rapidly degradable foaming material for soles and a preparation method thereof.

Background

Sports shoes are one of the most common articles of daily use, and are updated quickly, and are newly produced every day, and are newly discarded every day. The materials used to make athletic shoes are primarily polymers, which are primarily petroleum-based, and the use of these polymers to make athletic shoes consumes significant amounts of petrochemical resources, and most of these polymers used to make athletic shoes do not quickly decompose in nature. After the shoes are discarded, they become "white garbage" and present a potential threat to the environment.

The EVA foaming shoe material is prepared from the following raw materials: 52 to 72 parts of maleic anhydride grafted EVA resin, 8.5 to 12.5 parts of ethylene-octene copolymer, 2.2 to 5.2 parts of magnesium carbonate, 0.3 to 1.3 parts of benzenesulfonyl hydrazide, 0.2 to 0.8 part of dicumyl peroxide, 0.6 to 1.6 parts of diaminocyclohexane, 1.2 to 3.2 parts of modified nano titanium dioxide and 1.4 to 4.4 parts of filler. The main material of the foaming shoe material is EVA resin, which has good heat insulation, chemical resistance and other properties, but is not degradable. Therefore, there is still a need for improvement.

Disclosure of Invention

In order to solve the problem that the sole material is not degradable, the application provides a rapidly degradable foaming material for soles and a preparation method thereof.

In a first aspect, the present application provides a rapidly degradable foam material for shoe soles, which adopts the following technical scheme: a rapidly degradable foaming material for soles comprises the following raw materials in parts by mass: 85-105 parts of natural rubber, 25-45 parts of coffee grounds, 10-20 parts of betel nut fibers, 6-15 parts of red clay, 3-8 parts of silane coupling agent, 0.5-3 parts of vulcanizing agent, 0.5-5 parts of accelerator, 0.1-3 parts of anti-aging agent, 2-6 parts of foaming agent and 1-10 parts of auxiliary agent.

The foaming material provided by the application uses a large amount of degradable and environment-friendly materials, and becomes an advantageous part for microbial attack during subsequent degradation, thereby being beneficial to the start and progress of biodegradation.

By adopting the technical scheme, under the common cooperation of the coffee grounds, the betel nut fibers, the red clay and the silane coupling agent, the coffee grounds and the betel nut fibers are mutually interwoven, and the surface is provided with a plurality of rugged sites, when the natural rubber is matched with the natural rubber, the natural rubber can easily enter the sites, and the structure of interweaving the coffee grounds and the betel nut fibers is tightly matched, so that the whole system becomes uniform and integral. In the process, the red clay flexibly moves into the pores of the natural rubber and the sites, so that the combination of the systems is more compact. Under the special matching, the natural rubber has good compatibility with the coffee grounds, the betel nut fibers and the red clay, and the coffee grounds, the betel nut fibers and the red clay are coated by the natural rubber which is uniformly covered. When the foaming material is acted by stress, the stress can be quickly and smoothly diffused in the material through the interface, so that the foaming material has higher strength.

Preferably, the natural rubber is 90-100 parts by weight, the coffee grounds are 32-40 parts by weight, the betel nut fibers are 12-18 parts by weight, and the red clay is 8-12 parts by weight.

By adopting the technical scheme, the mass ratio among the natural rubber, the coffee grounds, the betel nut fibers and the red clay is further limited, enough sites can be provided for the system, and the natural rubber is covered more uniformly, so that the integrity of the foaming material is better.

Preferably, the silane coupling agent is one or more of KH-560, KH540, KH550, A171 and Si69.

Preferably, the weight portion of the silane coupling agent is 4-6 portions.

By adopting the technical scheme, the usage amount of the silane coupling agent is further limited, and the silane coupling agent and hydroxyl on the surfaces of the coffee grounds and the betel nut fibers are subjected to dehydration reaction, so that the compatibility of the coffee grounds and the betel nut fibers in a natural rubber system can be further improved, and the connection is tighter.

Preferably, the particle size of the coffee grounds is 120-150 mesh.

By adopting the technical scheme, the particle size of the coffee grounds is further limited, so that the coffee grounds can be interwoven with betel nut fibers more quickly, the coffee grounds are not easy to fall off, and a site which is firmer and more convenient to connect is provided for the natural fibers and the red clay.

In a second aspect, the present application provides a method for preparing a rapidly degradable foam material for soles, which adopts the following technical scheme:

a preparation method of a rapidly degradable foaming material for soles comprises the following steps:

dispersing the silane coupling agent with alcohol solution, and mixing with coffee grounds and betel nut fiber at 650-750r/min for 15-25min; drying; obtaining a mixture;

mixing the mixture, the red clay, the natural rubber, the vulcanizing agent, the auxiliary agent and the accelerator, carrying out open mill at 40-60 ℃ for 25-35min, adding the foaming agent, continuing open mill for 15-25min, and discharging to obtain the foaming material.

The surface energy of betel nut fiber is higher than that of natural rubber, so the betel nut fiber and the natural rubber are not easy to be uniformly mixed. By adopting the technical scheme, the coffee grounds and the betel nut fibers are mixed in the silane coupling agent, the coffee grounds and the betel nut fibers are mutually interwoven, and meanwhile, the silane coupling agent reacts with part of hydrophilic groups on the surfaces of the coffee grounds and the betel nut fibers to prepare the mixture with special structure and strong hydrophobicity, and the mixture has higher compatibility with the natural rubber.

The silane coupling agent is used for treating the coffee grounds and the betel nut fibers in advance, so that not only can the hydrophobicity of the mixture be improved, but also the roughness of the surface of the mixture can be improved, so that the subsequent red clay and natural rubber have more attachable sites, the overall combination of the system is improved, and the mechanical property of the foaming material is improved.

Preferably, the coffee grounds and the betel nut fibers are mixed and subjected to corona treatment, wherein the corona power strength is 6-8kW, and the conveying speed is 2-5m/min, so that the treated mixed fibers are obtained;

the mixed fiber is treated and mixed with a silane coupling agent dispersed in an alcohol solution to prepare a mixture.

Through adopting above-mentioned technical scheme, carry out corona treatment to coffee grounds, betel nut fibre in advance, under this specific corona treatment, high-speed electron attack coffee grounds, betel nut fibrous surface, produce more cavitys, micropore, can make coffee grounds, betel nut fibrous surface become coarser, be favorable to improving the surface affinity of handling mixed fiber to effectively improve foaming material's intensity.

Preferably, the betel nut fiber is prepared by the following method:

removing skin and kernel of Arecae semen, pulverizing, and drying;

mixing with alkali solution uniformly, and ball milling;

filtering, mixing the solid with alkali solution, and steaming at 150-160deg.C for 1-2 hr;

taking out the steamed solid, washing, suction filtering and drying to obtain betel nut fiber.

By adopting the technical scheme, betel nuts are treated, and the obtained betel nut fibers have better degradability. The degradation effect of the foaming material can be effectively improved by applying the modified polyurethane to the foaming material. And the betel nut fiber and the coffee grounds and the red clay are matched together, so that the reinforcing effect on the natural rubber can be further improved, and the mechanical property of the foaming material is improved.

Preferably, when the alkali solution is mixed with the crushed material, the alkali solution is sodium hydroxide solution with the mass fraction of 0.05-0.1, and the mass ratio of the crushed material to the alkali solution is 1: (3-7) based on the mass of the pulverized material.

By adopting the technical scheme, the selection, concentration and mass ratio of the alkali solution to the crushed materials are further limited, and impurities such as pectin, lignin and the like can be rapidly removed under the condition of not changing the fiber structure of betel nuts, so that the subsequent matching with coffee grounds, red clay and natural rubber is smoother.

In summary, the present application has the following beneficial effects:

1. the foaming material provided by the application uses a large amount of degradable and environment-friendly materials, and becomes an advantageous part for microbial attack during subsequent degradation, thereby being beneficial to the start and progress of biodegradation.

2. According to the technical scheme provided by the application, specific corona treatment is firstly carried out on coffee grounds and betel nut fibers, first coarse treatment is carried out on the surfaces of the coffee grounds and betel nut fibers, and the coffee grounds and betel nut fibers are combined to form treated mixed fibers; then mixing with silane coupling agent under specific conditions to prepare a mixture with special structure and strong hydrophobicity, and good compatibility with natural rubber. When the mixture is matched with natural rubber and red clay, the natural rubber quickly flows to the position on the mixture, the red clay fills redundant gaps and improves the connection strength, so that the system becomes a uniform and compact organic whole, and the foaming material with high mechanical property and easy degradation is obtained.

3. The betel nut fiber is prepared by a special method, can effectively improve the degradation effect of the foaming material, and can further improve the reinforcing effect on natural rubber under the cooperation of the betel nut fiber, coffee grounds and red clay, thereby improving the mechanical property of the foaming material.

Detailed Description

The present application is described in further detail below with reference to examples.

The raw materials used in the following examples and comparative examples are all commercially available products.

Examples

Example 1

A rapid degradable foaming material for soles comprises the following raw materials: natural rubber, coffee grounds, betel nut fibers, red clay, a silane coupling agent, a vulcanizing agent, an accelerator, an anti-aging agent, a foaming agent and an auxiliary agent.

Natural rubber was purchased from guangzhou middling trade limited.

The particle size of the coffee grounds is 120 mesh.

Red clay was purchased from hebei swiftly precious mineral products limited.

The silane coupling agent is a silane coupling agent Si69.

The vulcanizing agent is sulfur.

The accelerator is accelerator CBS.

The anti-aging agent is an anti-aging agent RD.

The foaming agent is an AC foaming agent.

The auxiliary agent is zinc oxide and stearic acid.

The specific amounts of the raw materials are shown in Table 1.

The embodiment of the application also discloses a preparation method of the rapidly degradable foaming material for the sole, which comprises the following steps:

step 1): preparing betel nut fibers:

step 1 a): removing skin and core of Arecae semen, and pulverizing in pulverizer. Then washing with water, and drying in air at 40 ℃ for 4 hours to obtain the crushed material.

Step 1 b): placing the crushed materials into a ball milling tank, and then pouring an alkali solution for mixing and ball milling.

In the step, the alkali solution is sodium hydroxide solution with the mass fraction of 0.1, and the mass ratio of the crushed material to the alkali solution is 1:7.

Ball milling for 6h, sieving and filtering to obtain solid.

Step 1 c): the solid was washed and then mixed with an alkali solution and cooked for 2h at 150 ℃.

Step 1 d): taking out the steamed solid, washing with water, suction filtering, and drying in hot air at 60deg.C for 6 hr to obtain Areca fiber.

Step 2): preparing and treating mixed fibers:

uniformly mixing coffee grounds and betel nut fibers, placing the mixture under a electrode plate of a corona device, setting the coffee grounds and betel nut fibers to be 0.8cm below the electrode, setting the corona power intensity to be 8kW, setting the conveying speed to be 5m/min, and carrying out double-sided corona to obtain the treated mixed fibers.

Step 3): preparing a mixture:

mixing and dispersing the silane coupling agent, the alcohol solution and water according to the mass ratio of 1:10:40, and stirring for 15min at room temperature under the condition of 400r/min, wherein the alcohol solution is ethanol.

Then, the mixed fiber was further added and mixed with the above solution containing the silane coupling agent, and the conditions were set at 750r/min and mixed for 15min.

Suction filtration and then drying in hot air at 60 ℃ for 12 hours to obtain a mixture.

Step 4): adding the mixture, red clay, natural rubber, vulcanizing agent, auxiliary agent and accelerator into an open mill, and mixing for 35min at 40 ℃.

Then adding a foaming agent into the open mill, keeping the temperature at 40 ℃, continuing open milling for 15min, and discharging to obtain the foaming material.

Example 2

A rapidly degradable foam material for soles, which differs from example 1 in that:

the particle size of the coffee grounds is 150 mesh.

The amounts of the raw materials used are different.

Details are shown in Table 1.

A method for preparing a rapidly degradable foam material for soles, which is different from example 1 in that:

in the step 1 b), the alkali solution is sodium hydroxide solution with the mass fraction of 0.05, and the mass ratio of the crushed material to the alkali solution is 1:3.

in step 1 c), the mixture is cooked for 1h at 160 ℃.

In step 2), the corona power intensity was 6kW and the conveying speed was 2m/min.

And 3) when the coffee grounds and the betel nut fibers are mixed with the solution containing the silane coupling street, setting the conditions at 650r/min and mixing for 25min.

In the step 4), the open-mixing temperature of the mixture, the red clay, the natural rubber, the vulcanizing agent, the auxiliary agent and the accelerator is 60 ℃, and the open-mixing time is 25min; after the addition of the foaming agent, the open mill time was 25min.

Example 3

A rapidly degradable foam material for soles, which differs from example 1 in that: the amounts of the raw materials are different, and are shown in Table 1 in detail.

Example 4

A rapidly degradable foam material for soles, which differs from example 3 in that: the amounts of the raw materials are different, and are shown in Table 1 in detail.

TABLE 1

Class of	Example 1	Example 2	Example 3	Example 4
					Natural rubber (kg)	85	105	100	90
Coffee grounds (kg)	25	45	40	32
					Areca fiber (kg)	10	20	18	12
Red clay (kg)	6	15	12	8
					Silane coupling agent (kg)	3	8	6	4
Vulcanizing agent (kg)	0.5	3	1.5	1.5
					Promoter (kg)	0.5	5	2.5	2.5
Anti-aging agent (kg)	0.1	3	1.5	1.5
					Foaming agent (kg)	2	6	3	3
Zinc oxide (kg)	0.5	7	5	5
					Stearic acid (kg)	0.5	3	2	2

Example 5

A rapidly degradable foam material for soles, which differs from example 3 in that: the silane coupling agent was 8kg.

Example 6

A method for preparing a rapidly degradable foam material for soles, which is different from example 3 in that: step 2) is omitted.

Namely, when the mixture is prepared in the step 3), coffee grounds and betel nut fibers are mixed with the solution containing the silane coupling agent.

Example 7

A method for preparing a rapidly degradable foam material for soles, which is different from example 3 in that: in the step 1) of preparing betel nut fiber, the alkali solution in the step 1 b) and the step 1 c) is replaced by water.

Example 8

A method for preparing a rapidly degradable foam material for soles, which is different from example 3 in that: in step 1 c), the mass ratio of the crushed material to the alkali solution is 1:10.

Comparative example

Comparative example 1

A rapidly degradable foam material for soles, which differs from example 3 in that: the natural rubber is replaced with butadiene rubber. The natural rubber is 0kg, and the butadiene rubber is 100kg.

Butadiene rubber was purchased from neutralization chemistry (Shandong) Inc.

Comparative example 2

A rapidly degradable foam material for soles, which differs from example 3 in that: replacing the coffee grounds with tea grounds. 0kg of coffee grounds and 40kg of tea grounds.

Tea leaf residue was purchased from the bioscience company of warrior (Shandong).

Comparative example 3

A rapidly degradable foam material for soles, which differs from example 3 in that: the betel nut fiber is replaced by sugarcane fiber. Betel nut fiber is 0kg, and sugarcane fiber is 18kg.

A method for preparing a rapidly degradable foam material for soles, which is different from example 1 in that: step 1) was omitted and the commercially available sugar cane fiber was used directly.

Sugarcane fiber was purchased from wuhan Hua Xiangke biotechnology limited.

Comparative example 4

A rapidly degradable foam material for soles, which differs from example 3 in that: the red clay was replaced with bentonite. The red clay is 0kg, and the bentonite is 12kg.

Comparative example 5

A rapidly degradable foam material for soles, which differs from example 3 in that: 12kg of coffee grounds, 30kg of betel nut fibers and 28kg of red clay.

Performance test

And (3) placing the foaming materials of the examples 1-8 and the comparative examples 1-5 into a heat setting mold, and controlling the heat setting temperature to be 155 ℃ and the time to be 25 minutes to obtain a foaming rubber finished product.

1. Degradation test: cutting the foam rubber finished products prepared in examples 1-8 and comparative examples 1-5 into samples of 20cm by 5cm, and weighing m ₁ 。

Then buried in natural soil with a buried depth of 20cm and an ambient temperature of 28 ℃.

After 4 months, the sample was taken out and weighed m ₂ The degree of degradation was calculated as shown below. The higher the degradation degree is, the better the degradation effect is.

2. Tensile strength: the finished products of the foamed rubber obtained in examples 1 to 8 and comparative examples 1 to 5 were tested for tensile strength and recorded for tensile strength with reference to GB/T10654-2001 "determination of tensile Strength and elongation at Break of Polymer cellular elastic Material".

3. Tear strength: the finished products of the foamed rubber obtained in examples 1 to 8 and comparative examples 1 to 5 were subjected to the test for tear strength and the tear strength was recorded with reference to GB/T10808-2006 "determination of tear Strength of high Polymer cellular elastic Material".

The test data for the above runs 1-3 are detailed in Table 2.

TABLE 2

The degradation degree of the non-degradable foam rubber products in the market is about 1 percent. Comparative examples 1 to 4 are foaming materials prepared by optionally replacing one of natural rubber, coffee grounds, betel nut fibers and red clay on the basis of example 3, and the foaming materials are prepared into foaming rubber finished products, wherein the degradation degree is between 19 and 25 percent and is lower than the degradation degree of 28.5 percent of example 3. The finished products of the foaming rubber prepared in comparative examples 1-4 have tensile strength of 6-14MPa and tearing strength of 23-36KN/m in terms of mechanical property detection, which are far less than 28.8MPa and 62.5KN/m of example 3.

The foaming material prepared by simply selecting degradable raw materials is applied to a foaming rubber finished product, and has poor mechanical properties although a certain degradation effect can be achieved. When the materials are selected from natural rubber, coffee grounds, betel nut fibers and red clay, the degradation effect can be improved, the degradation is rapid, and finished products with high tensile strength and tearing strength can be obtained.

In combination with comparative example 5, comparative example 5 was obtained by breaking the amount of coffee grounds, betel nut fibers, and red clay in combination with example 3, and had a degree of degradation of 23.6%, a tensile strength of 14.6MPa, and a tear strength of 39.0KN/m. Although slightly better than comparative examples 1-4, the performance is still significantly less excellent than example 3.

The description not only needs to limit the use of natural rubber, coffee grounds, betel nut fibers and red clay in the formula, but also needs to further limit the dosage cooperation between the four materials. If the dosage matching effect among the four materials is destroyed, the foaming material with excellent mechanical properties and quick degradation still cannot be obtained.

In example 5, the amount of the silane coupling agent was increased within a certain range while the amounts of the coffee grounds, the betel nut fibers, and the red clay were all unchanged. From comparison of the test data of example 3 and example 5 in table 2, it is understood that although example 5 still shows a good degradation effect, it is affected in mechanical properties. The usage amount of the silane coupling agent is not as high as possible, and the silane coupling agent needs to be limited in a certain range to have better matching effect with coffee grounds, betel nut fibers and red clay. The inventors hypothesize that the increased amount of the silane coupling agent not only affects the cooperation with coffee grounds, betel nut fibers and red clay, but also may affect the viscosity in the preparation process, and affects the foaming material from multiple aspects.

Example 6 was based on example 3, omitting the corona treatment of coffee grounds and betel nut fibers. As can be seen from comparison of the test data of example 3 and example 6 in Table 2, example 6 has a reduced degree of degradation and mechanical properties. The specific corona treatment on the coffee grounds and the betel nut fibers is described, the roughness of the surfaces of the coffee grounds and the betel nut fibers can be effectively increased, the red clay and the natural rubber are more easily matched with the coffee grounds and the betel nut fibers, a more compact structure is generated, and the strength of a finished product prepared from the foaming material is effectively improved.

Examples 7 and 8 are based on example 3, the use of alcohol solution is changed when betel nut fiber is prepared, the degradation degree of the foam rubber finished product prepared by the foam material is reduced, and the tensile strength and the tearing strength are also reduced. The use of the alkali solution can effectively remove impurities in betel nut fibers, and promote a series of subsequent coordination.

The present embodiment is merely illustrative of the present application and is not intended to be limiting, and those skilled in the art, after having read the present specification, may make modifications to the present embodiment without creative contribution as required, but is protected by patent laws within the scope of the claims of the present application.

Claims

1. The rapid degradable foaming material for the sole is characterized by comprising the following raw materials in parts by mass: 85-105 parts of natural rubber, 25-45 parts of coffee grounds, 10-20 parts of betel nut fibers, 6-15 parts of red clay, 3-8 parts of silane coupling agent, 0.5-3 parts of vulcanizing agent, 0.5-5 parts of accelerator, 0.1-3 parts of anti-aging agent, 2-6 parts of foaming agent and 1-10 parts of auxiliary agent, wherein the auxiliary agent is zinc oxide and stearic acid;

the preparation method of the rapidly degradable foaming material for the sole comprises the following steps:

mixing the mixture, the red clay, the natural rubber, the vulcanizing agent, the auxiliary agent and the accelerator, carrying out open mill at 40-60 ℃ for 25-35min, adding the foaming agent, continuing open mill for 15-25min, and discharging to obtain the foaming material;

the betel nut fiber is prepared by the following method:

removing skin and core of Arecae semen, pulverizing, and drying to obtain pulverized material;

uniformly mixing the crushed material with an alkali solution, and performing ball milling;

2. The rapidly degradable foam material for soles according to claim 1, characterized in that: 90-100 parts of natural rubber, 32-40 parts of coffee grounds, 12-18 parts of betel nut fibers and 8-12 parts of red clay.

3. The rapidly degradable foam material for soles according to claim 2, characterized in that: the mass portion of the silane coupling agent is 4-6 portions.

4. The rapidly degradable foam material for soles according to claim 1, characterized in that: the particle size of the coffee grounds is 120-150 meshes.

5. A method for preparing a rapidly degradable foam material for soles based on any one of claims 1-4, characterized in that it comprises the following steps:

6. The method for preparing a rapidly degradable foam material for soles according to claim 5, characterized in that: mixing the coffee grounds and the betel nut fibers, and carrying out corona treatment, wherein the corona power strength is 6-8kW, and the conveying speed is 2-5m/min, so as to obtain treated mixed fibers;

7. The method for preparing a rapidly degradable foam material for soles according to claim 5, characterized in that: the betel nut fiber is prepared by the following method:

8. The method for preparing a rapidly degradable foam material for soles according to claim 7, characterized in that: when the alkali solution is mixed with the crushed material, the alkali solution is sodium hydroxide solution with the mass fraction of 0.05-0.1, and the mass ratio of the crushed material to the alkali solution is 1: (3-7) based on the mass of the pulverized material.