CN113980331A

CN113980331A - Recyclable rubber-plastic foam material and preparation method and recycling method thereof

Info

Publication number: CN113980331A
Application number: CN202111204747.5A
Authority: CN
Inventors: 姜永柱; 张振秀; 高伟民
Original assignee: Shenzhou Energy Conservation Technology Group Co ltd
Current assignee: Shenzhou Energy Conservation Technology Group Co ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-01-28
Anticipated expiration: 2041-10-15
Also published as: CN113980331B

Abstract

The invention provides a recyclable rubber-plastic foam material, and a preparation method and a recovery method thereof. The invention comprises the following raw materials: 40-65 parts of ethylene propylene diene monomer, 30-40 parts of polypropylene or propylene copolymer, 5-25 parts of chlorosulfonated polyethylene, 10-25 parts of filler, 5-40 parts of plasticizer, 2-7 parts of compatibilizer, 2-5 parts of acid absorbent, 1-2.5 parts of stabilizer, 1-2 parts of anti-aging agent, 1.3-2 parts of vulcanizing agent and 0.6-1.1 part of vulcanization accelerator; the invention also provides a preparation method of the rubber and plastic foaming material, which is obtained by pretreatment, rubber material preparation, primary vulcanization, foaming molding and secondary vulcanization; the rubber-plastic foaming material can be recycled and recycled through crushing, remilling, shaping and foaming. The invention takes rubber as a main material and plastic as a support, has ultralow density and small compression permanent deformation, can be recycled, does not need to add any auxiliary agent in the recycling process, and is convenient to recycle.

Description

Recyclable rubber-plastic foam material and preparation method and recycling method thereof

Technical Field

The invention relates to the technical field of foaming materials, in particular to a recyclable rubber-plastic foaming material and a preparation method and a recycling method thereof.

Background

ethylene-Propylene-Diene monomer, a copolymer of ethylene, Propylene and a small amount of non-conjugated Diene, is one of ethylene-Propylene rubbers, and has excellent aging resistance such as ozone resistance, heat resistance, weather resistance and the like because the main chain thereof is composed of chemically stable saturated hydrocarbons and only contains unsaturated double bonds in the side chain, as represented by EPDM (ethylene Propylene Diene monomer). EPDM foamed materials are widely used in the automotive industry, construction industry and ship engineering for sealing, damping vibration, sound absorption and insulation, and water absorption. EPDM foamed materials are generally polymeric elastomeric materials, also known as thermoplastic vulcanizates (TPVs), prepared by a dynamic vulcanization process with plastic as the continuous phase and rubber as the dispersed phase.

Chinese patent CN112745681A discloses an injection-moldable foamed TPV material, and provides that the injection-moldable foamed TPV material comprises the following components in parts by weight: 5-15 parts of low-melting-index PP resin, 10-20 parts of high-melting-index PP resin, 20-30 parts of EPDM rubber, 10-20 parts of SEBS elastomer, 30-40 parts of paraffin oil, 0.3-1.2 parts of vulcanizing agent, 0.5-1 part of vulcanization accelerator, 0.3-0.6 part of antioxidant, 0.3-0.8 part of light stabilizer, 0.2-0.5 part of lubricant and 1-3 parts of foaming master batch; mixing low-melting-index PP resin, high-melting-index PP resin, EPDM rubber, a vulcanization accelerator, an antioxidant and a light stabilizer, adding the mixture into a main feeding port of a double-screw extruder, adding paraffin oil into a No. 3 screw cylinder of the double-screw extruder, adding a vulcanizing agent into a No. 6 screw cylinder of the double-screw extruder, melting, mixing, extruding and granulating to obtain a first TPV granule; mixing the first TPV granules, the SEBS elastomer and the lubricant, adding the mixture into a double-screw extruder, and performing melt extrusion granulation to obtain second TPV granules; and uniformly mixing the foaming agent master batch and the second TPV granules to obtain the TPV material. The TPV material obtained by the method has a good foaming effect, the hardness after foaming is low, the foam holes are uniform, and the foaming multiplying power is more than or equal to 1.2; however, the TPV material capable of being injection-molded and foamed still has high density and high use cost, and the TPV material capable of being injection-molded and foamed cannot be foamed after being recycled, so that the resource waste is serious.

Disclosure of Invention

The invention aims to provide a recyclable rubber-plastic foam material, and a preparation method and a recovery method thereof, and aims to solve the problems that in the prior art, TPV foam material has high density, cannot be regenerated into foam material after being recovered, and is difficult to recycle, so that the cost is high and the resource waste is serious.

In order to solve the technical problem, the technical scheme of the invention is realized as follows:

in one aspect, the recyclable rubber-plastic foaming material comprises the following raw materials in parts by weight: 40-65 parts of ethylene propylene diene monomer, 30-40 parts of polypropylene or propylene copolymer, 5-25 parts of chlorosulfonated polyethylene, 10-25 parts of filler, 5-40 parts of plasticizer, 2-7 parts of compatibilizer, 2-5 parts of acid absorbent, 1-2.5 parts of stabilizer, 1-2 parts of anti-aging agent, 1.3-2 parts of vulcanizing agent and 0.6-1.1 part of vulcanization accelerator.

The Ethylene Propylene Diene Monomer (EPDM) is used as a main material, the excellent ozone resistance, heat resistance and weather resistance of the EPDM are fully utilized, and meanwhile, the EPDM is subjected to pretreatment and then blended with chlorosulfonated polyethylene (CSM), so that the defects of poor mutual adhesion and self adhesion, poor oil resistance, flame retardance, air tightness, low vulcanization rate and the like of the EPDM due to the molecular structure are overcome; the invention also takes the plastic phase-polypropylene or propylene copolymer as a support, the plastic phase serves as a stationary phase in the preparation process of the rubber and plastic foaming material, the stability of the rubber and plastic foaming material is fully supported, and the plastic phase also provides the characteristic of recycling for the rubber and plastic foaming material; the ethylene propylene diene monomer, the polypropylene or the propylene copolymer and the chlorosulfonated polyethylene mutually act and supplement each other, and the obtained rubber-plastic foam material has ultralow density which is less than 0.1g/cm³Low thermal conductivity, low pressureThe shrinkage permanent deformation is small, the compression permanent deformation at 25 ℃ for 24h is less than 25%, the method can be widely applied to the fields of automobile parts, building materials, railway transportation, subway engineering, pipeline transportation and the like, can be recycled, does not need to add any auxiliary agent in the recycling process, is convenient to recycle, and can obtain the rubber and plastic foam material with the same low density.

As a preferred embodiment, the filler is a flame-retardant filler which is a mixture of aerogel, zinc borate and carbon black in a weight ratio of 1-3:4-12: 4-10. The flame-retardant filler is selected, so that the mechanical property of the rubber-plastic foam material is improved, and the rubber-plastic foam material also has flame retardant property; firstly, the aerogel can block certain heat, reduce the heat diffusion rate of the material and slow down the heat transfer during combustion; the aerogel is also a nano filler, can play a role of a nucleating agent in the foaming process, and is beneficial to more uniform foaming and foam pores; in addition, the zinc borate is an environment-friendly non-halogen flame retardant, and has the advantages of no toxicity, low water solubility, high thermal stability, small granularity, small specific gravity and good dispersibility; and secondly, the carbon black and the rubber have good bonding property, and the mechanical property of the foaming material can be improved. The flame-retardant filler obtained by mixing the three fillers is added into the rubber material, and the flame-retardant property of the material can be obviously improved by adding a small amount of the flame-retardant filler, and the foaming effect of the material is not influenced. The plasticizer of the present invention preferably uses paraffin oil.

As a preferred embodiment, the compatibilizer is an ethylene vinyl acetate rubber and/or a chlorinated polyethylene rubber. The compatibility of the ethylene propylene diene monomer and chlorosulfonated polyethylene is poor, and the problem of poor compatibility of the ethylene propylene diene monomer and chlorosulfonated polyethylene is solved by using the compatibilizer; the ethylene-vinyl acetate rubber (EVM) or chlorinated polyethylene (CM) has strong compatibilization acting force, and can be tightly combined with ethylene-propylene-diene monomer rubber and chlorosulfonated polyethylene, so that the ethylene-propylene-diene monomer rubber and the chlorosulfonated polyethylene are promoted to be compatible; meanwhile, the ethylene vinyl acetate rubber (EVM) and the chlorinated polyethylene (CM) have good flame retardance, and the flame retardance of the rubber-plastic foam material is further improved.

As a preferred embodiment, the vulcanizing agent is a mixture of 1 to 2 parts by weight of sulfur and 0.2 to 1 part by weight of dipentamethylenethiuram tetrasulfide; the vulcanization accelerator is any one or more of N-cyclohexyl-2-benzothiazole sulfonamide, 2' -dithiodibenzothiazole and tetramethyl thiuram disulfide. The invention adopts the compound vulcanizing agent, sulfur (S) promotes the vulcanization of Ethylene Propylene Diene Monomer (EPDM), and dipentamethylenethiuram tetrasulfide (DPTT) promotes the vulcanization of chlorosulfonated polyethylene (CSM), and the compound vulcanizing agent has strong pertinence and good vulcanization effect; the invention avoids using a peroxide vulcanization system, and once peroxide is used, the recyclability of the rubber-plastic foam material is influenced because the peroxide has crosslinking and degradation effects on polypropylene; in the present invention, the plastic phase is not crosslinked, but only the rubber phase is vulcanized and crosslinked. The vulcanization accelerator in the invention is N-cyclohexyl-2-benzothiazole sulfonamide (CZ), 2' -Dithiodibenzothiazyl (DM) or tetramethyl thiuram disulfide (TMTD).

In another aspect, the invention provides a preparation method of a recyclable rubber-plastic foam material, which comprises the following steps: s1 rubber material mixing 1) pretreatment of ethylene propylene diene monomer, taking ethylene propylene diene monomer, adding part of anti-aging agent, mixing for 1-5min at the temperature of 100 ℃ and 120 ℃, discharging, and performing plasma or irradiation treatment to obtain pretreated ethylene propylene diene monomer; 2) preparing a rubber material A, namely mixing chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, a residual antioxidant and the pretreated ethylene propylene diene monomer obtained in the step 1) at the temperature of 100-120 ℃ for 1-5min to obtain the rubber material A; 3) preparing a rubber material B, taking the filler, the plasticizer and the rubber material A obtained in the step 2), continuously mixing for 1-5min at the temperature of 100-120 ℃, discharging and discharging to obtain the rubber material B; 4) preparing a sizing material C by blending polypropylene or propylene copolymer and the sizing material B obtained in the step 3) for 3-6min at the temperature of 150-180 ℃ to obtain a sizing material C; 5) preparing a rubber material D by mixing a vulcanizing agent, a vulcanization accelerator and the rubber material C obtained in the step 4) at the temperature of 110-130 ℃ for 30-50s to obtain a rubber material D; s2 foaming and shaping 6) primary vulcanization of the rubber material D obtained in the step 5) is carried out for 5-32min at the temperature of 140-160 ℃, and a primary vulcanization product is obtained; 7) foaming and forming, namely taking the primary vulcanized product obtained in the step 6), and performing chemical foaming or supercritical foaming to obtain a foamed product; 8) and (3) performing secondary vulcanization on the foaming product obtained in the step 7) at the temperature of 130-160 ℃ for 8-36min to obtain the rubber and plastic foaming material.

The Ethylene Propylene Diene Monomer (EPDM) is pretreated firstly, the antioxidant used in the pretreatment usually accounts for 50-70% of the amount of the antioxidant in the formula, the reaction activity of the pretreated EPDM is greatly improved, and meanwhile, the viscosity of the EPDM is also improved, so that the vulcanization speed is increased, the gas retention capacity of the rubber-plastic foam material is improved, and a foundation is laid for preparing the light rubber-plastic foam material; during the preparation of the rubber material A, the viscosity and the vulcanization speed of the pretreated ethylene propylene diene monomer and the viscosity and the vulcanization speed of the chlorosulfonated polyethylene are better matched, and a co-crosslinking network is easy to form; the rubber compound is mixed with plastic, and finally, a vulcanizing agent and a vulcanization accelerator are added; through primary vulcanization, a cross-linked network is preliminarily formed to control the melt strength of the blending material to be in a proper range, the primary vulcanization is carried out at a relatively low temperature, and only a small part of vulcanizing agents react and are not completely reacted, so that the vulcanizing agents are reserved for secondary vulcanization; the foaming forming is successful in foaming and controls the structure of the foam pores, then, the secondary vulcanization is carried out, the rubber further generates a crosslinking reaction in the secondary vulcanization process so as to ensure the performance of vulcanized rubber, meanwhile, the foam material is formed by being thrown empty, and the plastic phase is called as a fixed phase of a fixed foam pore structure, so that the existing foam pores and density can be maintained for secondary vulcanization. The preparation process of the rubber foaming material has two-step reactions of rubber crosslinking and foaming, the two-step reactions follow a certain matching relationship and influence each other, the rubber material foaming has strict requirements on the matching problem, and the invention successfully solves the problem of matching between rubber vulcanization and foaming. The invention adopts a static vulcanization method in the one-time vulcanization process, the vulcanization crosslinking of rubber is self-capturing, rubber molecules and similar sulfur form a crosslinking network, in the process, the rubber phase is a continuous phase and is a sea in a 'sea island' structure, and the crosslinking degree is controlled by controlling the vulcanization process so as to achieve the vulcanization degree of proper foaming; when foaming, the rubber phase and the plastic are the same and foaming is carried out; the secondary vulcanization realizes the full crosslinking of the rubber phase, thereby improving the mechanical property of the rubber-plastic foam material.

In a preferred embodiment, in the step 7), during the chemical foaming, the amount of the foaming agent is 10-20 parts by weight, the amount of the foaming promoter is 0.3-1.0 part by weight, the foaming agent and the foaming promoter are added into the rubber compound C obtained in the step 4), and the mixture is mixed for 80-100s at the temperature of 120-130 ℃, and then the step 5) is carried out; the temperature of the chemical foaming is 160-230 ℃, and the time of the chemical foaming is 5-10 min. The invention obtains proper melt strength in the process of one-time vulcanization, and simultaneously, gas is kept in the stage of massive decomposition of the foaming agent; at the temperature, the vulcanizing agent is still in vulcanized rubber, the vulcanized rubber and the vulcanized rubber are matched, meanwhile, the plastic phase can be foamed in a melt state, and three phases are foamed, so that the foamed material with ultralow density is obtained. When the temperature is reduced, the plastic phase begins to crystallize to become a stationary phase and become a skeleton structure of rubber and plastic foam material foam pores, so that the problem that the formed foam pores are extruded and retracted due to overlarge further vulcanization elasticity of the rubber phase is solved, and meanwhile, the vulcanizing agent continues to react, so that the rubber phase is further vulcanized on the premise of maintaining the original foam pore structure, and the better mechanical property of the foam material is provided. The chemical foaming operation is simple and can be completed on one line, the rubber material after primary vulcanization is placed into a drying tunnel for foaming and secondary vulcanization, the drying tunnel is divided into two sections, one section is a foaming section, and the other section is a secondary vulcanization section, namely a curing section.

As a preferred embodiment, the chemical foaming comprises four zones, wherein the temperature of the first zone is 160-. The chemical foaming process of the invention can also adjust different temperatures, firstly, the material begins to soften at the temperature of 160-180 ℃, and the foaming agent does not begin to decompose; then, the temperature is raised to 190-200 ℃, and the foaming agent begins to decompose and slowly releases gas at the moment; then reaching 210 ℃ and 230 ℃, and the gas release amount reaches a peak, at this time, the crosslinking degree of the crosslinking agent is matched with the decomposition speed of the foaming agent to form stable cells, and the crosslinked melt strength can also support the stability of the cells without being largely broken; then, the decomposition speed of the foaming agent is reduced when the temperature is reduced to 170-180 ℃; finally, after secondary vulcanization, the rubber part is further vulcanized, and good mechanical properties are provided. The chemical foaming process is simple.

As a preferred embodiment, in the step 7), the temperature of the supercritical physical foaming is 140-. The invention can also adopt supercritical physical foaming, the supercritical physical foaming is usually carried out in a supercritical physical foaming kettle, and the supercritical physical foaming and the secondary vulcanization are separately operated; the supercritical foaming process can realize foaming without chemical foaming agent residues, but the supercritical foaming also has the problem that vulcanization and supercritical foaming are difficult to match; therefore, how to solve the matching of the two, and obtaining the stable foaming with ultra-low density is realized by the process of primary vulcanization, foaming and secondary vulcanization.

As a preferred embodiment, in the step 1), the voltage at the time of the plasma treatment is 10 to 20eV, and the dose at the time of the irradiation treatment is 5 to 10 kGy. The ethylene propylene diene monomer is pretreated by plasma or irradiation, and the activity of EPDM can be increased by adopting the plasma pretreatment, so that the reactive active sites are increased during vulcanization, and the vulcanization speed is increased; the irradiation pretreatment is adopted, so that a certain crosslinking degree can be given to the EPDM, and the problem of slow vulcanization of the EPDM rubber is solved; therefore, the two pretreatment methods are used for solving the problems that the EPDM rubber is vulcanized slowly and the EPDM rubber is not matched with the CSM rubber in vulcanization.

In another aspect, the invention relates to a recycling method of a recyclable rubber-plastic foam material, which comprises the following steps: taking recyclable rubber-plastic foaming material, crushing, shearing at the temperature of 160-180 ℃, and recycling; setting at 160-; carbon dioxide gas is adopted to carry out supercritical foaming at the temperature of 140-160 ℃ and the pressure of 10-20MPa, so as to obtain the recycled foaming material.

The rubber-plastic foam material can be recycled, can be recycled for multiple times, does not need to add any auxiliary agent in the recycling process, is convenient to recycle, and can obtain the same low-density rubber-plastic foam material. The rubber-plastic foaming material of the invention has the plastic phase in the blending material, and the plastic phase is not crosslinked in the crosslinking process, thereby providing a mobile phase in the recycling process, and the rubber phase has the properties of rubber elasticity and the like although being sheared into particles in the recycling process. In the recovery process of the rubber-plastic foam material, the blend is broken up and mixed again macroscopically under the shearing action, so that the crosslinked rubber phase is dispersed into crosslinked micelles, and at the moment, all crosslinked EPDM has no plasticity any more; however, the plastic phase does not participate in crosslinking in the preparation process, and the plastic phase has fluidity and can be processed, and in the recovery process, the plastic phase is converted into a continuous phase, and the crosslinked rubber micelles are a dispersed phase, so that the phase inversion is realized.

Compared with the prior art, the invention has the beneficial effects that: the Ethylene Propylene Diene Monomer (EPDM) is used as a main material, the excellent ozone resistance, heat resistance and weather resistance of the EPDM are fully utilized, and meanwhile, the EPDM is pre-treated and then blended with the CSM rubber, so that the defects of poor mutual adhesion and self adhesion, poor oil resistance, flame retardance, air tightness, low vulcanization rate and the like of the EPDM due to the molecular structure are overcome; the plastic phase-polypropylene or propylene copolymer is used as a support, the plastic phase serves as a stationary phase in the preparation process of the rubber and plastic foam material, the stability of the rubber and plastic foam material is fully supported, and the plastic phase also provides the characteristic of recycling for the rubber and plastic foam material; the ethylene propylene diene monomer, the polypropylene or the propylene copolymer and the chlorosulfonated polyethylene mutually interact and supplement each other, and the obtained rubber-plastic foam material has ultralow density which is less than 0.1g/cm³The heat conductivity coefficient is low, the compression set is small, the compression set at 25 ℃ for 24h is less than 25%, the heat-resistant material can be widely applied to the fields of automobile parts, building materials, railway transportation, subway engineering, pipeline transportation and the like, can be recycled, does not need to add any auxiliary agent in the recycling process, and can be recycledThus, the rubber-plastic foaming material with the same low density can be obtained.

Drawings

FIG. 1 is a digital electron microscope image of the rubber-plastic foam material of example 11 of the present invention;

FIG. 2 is a digital electron microscope image of the rubber-plastic foam material of example 12 of the present invention;

FIG. 3 is a digital electron microscope image of the rubber-plastic foam material of example 13 of the present invention;

FIG. 4 is a digital electron microscope image of the rubber-plastic foam material of example 14 of the present invention;

FIG. 5 is a digital electron microscope photograph of a comparative example 11 foam material of the present invention;

FIG. 6 is a scanning electron microscope photograph of a prior art control 1TPV material;

FIG. 7 is a scanning electron microscope photograph of the rubber-plastic foamed material according to example 21 of the present invention;

FIG. 8 is a scanning electron microscope photograph of the rubber-plastic foamed material according to example 22 of the present invention;

FIG. 9 is a scanning electron microscope image of the rubber-plastic foam material according to example 23 of the present invention;

FIG. 10 is a scanning electron microscope image of the rubber-plastic foam material according to example 24 of the present invention;

FIG. 11 is a scanning electron microscope photograph of a comparative example 21 foam of the present invention;

FIG. 12 is a scanning electron microscope image of the rubber-plastic foam material of example 11 after being recovered and re-foamed.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to specific embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The recyclable rubber-plastic foaming material comprises the following raw materials in parts by weight: 40-65 parts of ethylene propylene diene monomer, 30-40 parts of polypropylene or propylene copolymer, 5-25 parts of chlorosulfonated polyethylene, 10-25 parts of filler, 5-40 parts of plasticizer, 2-7 parts of compatibilizer, 2-5 parts of acid absorbent, 1-2.5 parts of stabilizer, 1-2 parts of anti-aging agent, 1.3-2 parts of vulcanizing agent and 0.6-1.1 part of vulcanization accelerator.

Preferably, the filler is a flame-retardant filler, and the flame-retardant filler is a mixture of aerogel, zinc borate and carbon black according to a weight ratio of 1-3:4-12: 4-10.

Preferably, the compatibilizer is ethylene vinyl acetate rubber and/or chlorinated polyethylene rubber.

Preferably, the vulcanizing agent is a mixture consisting of 1-2 parts by weight of sulfur and 0.2-1 part by weight of dipentamethylenethiuram tetrasulfide; the vulcanization accelerator is any one or more of N-cyclohexyl-2-benzothiazole sulfonamide, 2' -dithiodibenzothiazole and tetramethyl thiuram disulfide.

The invention relates to a preparation method of a recyclable rubber-plastic foam material, which comprises the following steps:

s1 rubber compounding

1) Pretreatment of ethylene propylene diene monomer

Taking ethylene propylene diene monomer, adding part of anti-aging agent, mixing for 1-5min at the temperature of 100-120 ℃, discharging, and performing plasma or irradiation treatment to obtain pretreated ethylene propylene diene monomer;

2) preparation of rubber A

Mixing chlorosulfonated polyethylene, a compatibilizer, an acid acceptor, a stabilizer, the rest antioxidant and the pretreated ethylene propylene diene rubber obtained in the step 1) at the temperature of 100-;

3) preparation of rubber B

Taking the filler, the plasticizer and the rubber material A obtained in the step 2), continuously mixing for 1-5min at the temperature of 100-120 ℃, discharging and discharging to obtain rubber material B;

4) preparation of rubber composition C

Blending polypropylene or propylene copolymer and the sizing material B obtained in the step 3) for 3-6min at the temperature of 150-180 ℃ to obtain a sizing material C;

5) preparation of rubber D

Mixing a vulcanizing agent, a vulcanization accelerator and the rubber compound C obtained in the step 4) for 30-50s at the temperature of 110-;

s2 foaming and shaping

6) One-time vulcanization

Taking the rubber material D obtained in the step 5), and carrying out primary vulcanization for 5-32min at the temperature of 140-160 ℃ to obtain a primary vulcanization product;

7) foam molding

Taking the primary vulcanized product obtained in the step 6), and carrying out chemical foaming or supercritical foaming to obtain a foamed product;

8) secondary vulcanization

Taking the foaming product obtained in the step 7), and carrying out secondary vulcanization for 8-36min at the temperature of 130-160 ℃ to obtain the rubber and plastic foaming material.

Preferably, in the step 7), during the chemical foaming, the amount of the foaming agent is 10 to 20 parts by weight, the amount of the foaming promoter is 0.3 to 1.0 part by weight, the foaming agent and the foaming promoter are added into the rubber compound C obtained in the step 4), and the mixture is mixed for 80 to 100 seconds at the temperature of 120 ℃ and 130 ℃, and then the step 5) is carried out; the temperature of the chemical foaming is 160-230 ℃, and the time of the chemical foaming is 5-10 min.

Further, the chemical foaming comprises four zones, wherein the temperature of the first zone is 160-.

Preferably, in the step 7), the temperature of the supercritical physical foaming is 140-155 ℃, the pressure is 23-30MPa, and the foaming gas is nitrogen.

Preferably, in the step 1), the voltage during plasma treatment is 10-20eV, and the dose during irradiation treatment is 5-10 kGy.

The invention relates to a recycling method of a recyclable rubber-plastic foaming material, which comprises the following steps: taking recyclable rubber-plastic foaming material, crushing, shearing at the temperature of 160-180 ℃, and recycling; setting at 160-; carbon dioxide gas is adopted to carry out supercritical foaming at the temperature of 140-160 ℃ and the pressure of 10-20MPa, so as to obtain the recycled foaming material.

Example 11

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 45 parts of ethylene propylene diene monomer, 30 parts of polypropylene, 25 parts of chlorosulfonated polyethylene, 20 parts of filler, 10 parts of plasticizer paraffin oil, 7 parts of compatibilizer CM, 5 parts of acid acceptor magnesium oxide, 2 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.4 parts of vulcanizing agent, 0.7 part of vulcanization accelerator, 13 parts of foaming agent AC and 0.3 part of foaming accelerator zinc oxide;

the filler is a flame-retardant filler consisting of 3 parts by weight of silica aerogel, 11 parts by weight of zinc borate and 6 parts by weight of carbon black, the vulcanizing agent consists of 1.0 part by weight of sulfur and 0.4 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.2 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to be 110 ℃, adding ethylene propylene diene monomer and 1.0 part of anti-aging agent, mixing for 2min, discharging, and treating with plasma with the voltage of 10eV to obtain the pretreated ethylene propylene diene monomer.

3) Preparation of rubber A

Setting the temperature of an internal mixer to 100 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 5min to obtain a rubber material A.

4) Preparation of rubber B

And (3) continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 3min at the temperature of 110 ℃, discharging, and discharging to obtain rubber material B.

5) Preparation of rubber composition C

Blending polypropylene and the sizing material B obtained in the step 4) for 3min at 180 ℃ to obtain a sizing material C.

6) Preparation of rubber D

Heating the rubber compound C obtained in the step 5) to 130 ℃, adding a foaming agent and a foaming promoter, mixing for 90s, then adding a vulcanizing agent and a vulcanization promoter, and mixing for 30s to obtain a rubber compound D.

S3 foaming and shaping

7) One-time vulcanization

And (3) carrying out primary vulcanization on the rubber material D obtained in the step 6) at 140 ℃ for 10min to obtain a primary vulcanized product.

8) Foam molding

And (3) placing the primary vulcanized product obtained in the step 7) into a foaming section of a drying tunnel for chemical foaming, wherein the temperature of the first zone is 180 ℃, the foaming time is 2min, the temperature of the second zone is 200 ℃, the foaming time is 2min, the temperature of the third zone is 220 ℃, the foaming time is 3min, the temperature of the fourth zone is 180 ℃, and the foaming time is 2min, so that a foaming product is obtained.

9) Secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 20min at 140 ℃ to obtain the rubber and plastic foaming material.

Example 12

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 55 parts of ethylene propylene diene monomer, 40 parts of ethylene propylene copolymer, 5 parts of chlorosulfonated polyethylene, 15 parts of filler, 8 parts of plasticizer paraffin oil, 2 parts of compatibilizer CM, 2 parts of acid acceptor magnesium oxide, 1 part of stabilizer zinc stearate, 1 part of anti-aging agent, 1.4 parts of vulcanizing agent, 0.7 part of vulcanization accelerator, 15 parts of foaming agent AC and 0.4 part of foaming accelerator zinc oxide;

the filler is a flame-retardant filler consisting of 2 parts by weight of silica aerogel, 9 parts by weight of zinc borate and 4 parts by weight of carbon black, the vulcanizing agent consists of 1.2 parts by weight of sulfur and 0.2 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.2 part by weight of vulcanization accelerator DM.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 120 ℃, adding ethylene propylene diene monomer and 0.6 part of anti-aging agent, mixing for 1min, discharging, irradiating with the dose of 5kGy, and obtaining the pretreated ethylene propylene diene monomer.

3) Preparation of rubber A

Setting the temperature of an internal mixer to 120 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 3min to obtain a rubber material A.

4) Preparation of rubber B

And (3) continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 1min at the temperature of 120 ℃, discharging, and discharging to obtain rubber material B.

5) Preparation of rubber composition C

And (3) blending the ethylene-propylene copolymer and the rubber material B obtained in the step 4) at 150 ℃ for 6min to obtain a rubber material C.

6) Preparation of rubber D

Heating the rubber compound C obtained in the step 5) to 110 ℃, adding a foaming agent and a foaming promoter, mixing for 100s, then adding a vulcanizing agent and a vulcanization promoter, and mixing for 50s to obtain a rubber compound D.

S3 foaming and shaping

7) One-time vulcanization

And (3) carrying out primary vulcanization on the rubber material D obtained in the step 6) at 140 ℃ for 8min to obtain a primary vulcanized product.

8) Foam molding

And (3) placing the primary vulcanized product obtained in the step 7) into a foaming section of a drying tunnel for chemical foaming, wherein the temperature of the first area is 160 ℃, the foaming time is 1min, the temperature of the second area is 190 ℃, the foaming time is 3min, the temperature of the third area is 210 ℃, the foaming time is 3min, the temperature of the fourth area is 170 ℃, and the foaming time is 3min to obtain a foaming product.

9) Secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 10min at 130 ℃ to obtain the rubber and plastic foaming material.

Example 13

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 50 parts of ethylene propylene diene monomer, 35 parts of propylene butylene copolymer, 15 parts of chlorosulfonated polyethylene, 10 parts of filler, 5 parts of plasticizer paraffin oil, 5 parts of compatibilizer CM, 3 parts of acid acceptor magnesium oxide, 1.5 parts of stabilizer zinc stearate, 1.0 part of anti-aging agent, 1.4 parts of vulcanizing agent, 0.7 part of vulcanization accelerator, 17 parts of foaming agent AC and 0.4 part of foaming accelerator zinc oxide;

the filler is a flame-retardant filler consisting of 1 part by weight of silica aerogel, 5 parts by weight of zinc borate and 4 parts by weight of carbon black, the vulcanizing agent consists of 1.1 part by weight of sulfur and 0.3 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.2 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 100 ℃, adding ethylene propylene diene monomer and 0.6 part of anti-aging agent, mixing for 5min, discharging, and treating with plasma with the voltage of 15eV to obtain the pretreated ethylene propylene diene monomer.

3) Preparation of rubber A

Setting the temperature of an internal mixer to 110 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 1min to obtain a rubber material A.

4) Preparation of rubber B

And (3) continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 5min at the temperature of 100 ℃, discharging, and discharging to obtain rubber material B.

5) Preparation of rubber composition C

Taking the propylene-butylene copolymer and the sizing material B obtained in the step 4), and blending for 4min at 160 ℃ to obtain a sizing material C.

6) Preparation of rubber D

Heating the rubber compound C obtained in the step 5) to 120 ℃, adding a foaming agent and a foaming promoter, mixing for 80s, then adding a vulcanizing agent and a vulcanization promoter, and mixing for 40s to obtain a rubber compound D.

S3 foaming and shaping

7) One-time vulcanization

And (3) carrying out primary vulcanization on the rubber material D obtained in the step 6) at 150 ℃ for 5min to obtain a primary vulcanized product.

8) Foam molding

And (3) placing the primary vulcanized product obtained in the step 7) into a foaming section of a drying tunnel for chemical foaming, wherein the temperature of the first area is 180 ℃, the foaming time is 2min, the temperature of the second area is 200 ℃, the foaming time is 1min, the temperature of the third area is 230 ℃, the foaming time is 2min, the temperature of the fourth area is 180 ℃, and the foaming time is 1min, so that a foaming product is obtained.

9) Secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 12min at 135 ℃ to obtain the rubber and plastic foaming material.

Example 14

s1 raw Material preparation

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to be 110 ℃, adding ethylene propylene diene monomer and 0.5 part of anti-aging agent, mixing for 2min, discharging, and treating with plasma with the voltage of 15eV to obtain the pretreated ethylene propylene diene monomer.

3) Preparation of rubber A

Setting the temperature of an internal mixer to 110 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 5min to obtain a rubber material A.

4) Preparation of rubber B

5) Preparation of rubber composition C

6) Preparation of rubber D

Heating the rubber compound C obtained in the step 5) to 120 ℃, adding a foaming agent and a foaming promoter, mixing for 90s, then adding a vulcanizing agent and a vulcanization promoter, and mixing for 40s to obtain a rubber compound D.

S3 foaming and shaping

7) One-time vulcanization

8) Foam molding

And (3) placing the primary vulcanized product obtained in the step 7) into a foaming section of a drying tunnel for chemical foaming, wherein the temperature of the foaming section is 220 ℃, and the foaming time is 5min, so as to obtain a foaming product.

9) Secondary vulcanization

Comparative example 11

A preparation method of a rubber-plastic foam material comprises the following steps:

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 70 parts of ethylene propylene diene monomer, 30 parts of polypropylene, 20 parts of filler, 10 parts of plasticizer paraffin oil, 5 parts of acid absorbent magnesium oxide, 2 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.4 parts of vulcanizing agent, 0.7 part of vulcanization accelerator, 20 parts of foaming agent AC and 0.4 part of foaming accelerator zinc oxide;

the filler is a flame-retardant filler consisting of 2 parts by weight of silica aerogel, 12 parts by weight of zinc borate and 6 parts by weight of carbon black, the vulcanizing agent consists of 1.1 parts by weight of sulfur and 0.3 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.2 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 110 ℃, adding ethylene propylene diene monomer rubber and 1.0 part of anti-aging agent, mixing for 2min, discharging and discharging;

3) preparation of rubber A

Setting the temperature of an internal mixer at 110 ℃, adding an acid absorbing agent, a stabilizer, the rest of an anti-aging agent and the ethylene propylene diene monomer obtained in the step 2), and mixing for 5min to obtain a rubber material A;

4) preparation of rubber B

Continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 3min at 100 ℃, discharging and discharging to obtain rubber material B;

5) preparation of rubber composition C

Blending polypropylene and the sizing material B obtained in the step 4) for 3min at 180 ℃ to obtain a sizing material C;

6) preparation of rubber D

Heating the rubber compound C obtained in the step 5) to 130 ℃, adding a foaming agent and a foaming promoter, mixing for 90s, then adding a vulcanizing agent and a vulcanization promoter, and mixing for 30s to obtain a rubber compound D;

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 10min at 140 ℃ to obtain a primary vulcanized product;

8) foam molding

Placing the primary vulcanized product obtained in the step 7) into a foaming section of a drying tunnel for chemical foaming, wherein the temperature of a first area is 180 ℃, the foaming time is 2min, the temperature of a second area is 200 ℃, the foaming time is 2min, the temperature of a third area is 220 ℃, the foaming time is 2min, the temperature of a fourth area is 180 ℃, and the foaming time is 2min, so as to obtain a foaming product;

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 10min at 150 ℃ to obtain a control sample 11.

Example 21

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 50 parts of ethylene propylene diene monomer, 40 parts of propylene butylene copolymer, 10 parts of chlorosulfonated polyethylene, 13 parts of filler, 9 parts of plasticizer paraffin oil, 3 parts of compatibilizer EVM, 2 parts of acid acceptor calcium oxide, 2 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.3 parts of vulcanizing agent and 0.6 part of vulcanization accelerator;

the filler is a flame-retardant filler consisting of 3 parts by weight of silica aerogel, 6 parts by weight of zinc borate and 4 parts by weight of carbon black, the vulcanizing agent consists of 1.1 parts by weight of sulfur and 0.2 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.1 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to be 110 ℃, adding ethylene propylene diene monomer and 1.0 part of anti-aging agent, mixing for 2min, discharging, and irradiating by adopting an electron beam with the irradiation dose of 10KGy to obtain pretreated ethylene propylene diene monomer;

3) preparation of rubber A

Setting the temperature of an internal mixer to 110 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 5min to obtain a rubber material A;

4) preparation of rubber B

Continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 3min at 110 ℃, discharging and discharging to obtain rubber material B;

5) preparation of rubber composition C

Taking the propylene-butylene copolymer and the rubber material B obtained in the step 4), and blending for 6min at 165 ℃ to obtain a rubber material C;

6) preparation of rubber D

Adding a vulcanizing agent and a vulcanization accelerator into the rubber compound C obtained in the step 5), and mixing for 50s at 120 ℃ to obtain a rubber compound D;

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 24min at 150 ℃ to obtain a primary vulcanized product;

8) foam molding

Putting the primary vulcanized product obtained in the step 7) into a supercritical foaming kettle at 140 ℃, introducing nitrogen, saturating for 3h under the pressure of 23MPa, and quickly releasing pressure to obtain a foaming material;

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 36min at the temperature of 150 ℃ to obtain the rubber and plastic foaming material.

Example 22

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 40 parts of ethylene propylene diene monomer, 40 parts of propylene butylene copolymer, 20 parts of chlorosulfonated polyethylene, 10 parts of filler, 7 parts of plasticizer paraffin oil, 5 parts of compatibilizer EVM, 3 parts of acid acceptor calcium oxide, 2.5 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.5 parts of vulcanizing agent and 0.6 part of vulcanization accelerator;

the filler is a flame-retardant filler consisting of 2 parts by weight of silica aerogel, 4 parts by weight of zinc borate and 4 parts by weight of carbon black, the vulcanizing agent consists of 1.1 parts by weight of sulfur and 0.4 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.1 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 100 ℃, adding ethylene propylene diene monomer and 1.0 part of anti-aging agent, mixing for 5min, discharging, and irradiating by adopting an electron beam with the irradiation dose of 10KGy to obtain pretreated ethylene propylene diene monomer;

3) preparation of rubber A

Setting the temperature of an internal mixer to 100 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 5min to obtain a rubber material A;

4) preparation of rubber B

Continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 5min at 100 ℃, discharging and discharging to obtain rubber material B;

5) preparation of rubber composition C

6) preparation of rubber D

Adding a vulcanizing agent and a vulcanization accelerator into the rubber compound C obtained in the step 5), and mixing for 40s at 120 ℃ to obtain a rubber compound D;

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 32min at 150 ℃ to obtain a primary vulcanized product;

8) foam molding

Putting the primary vulcanized product obtained in the step 7) into a supercritical foaming kettle at 142 ℃, introducing nitrogen, saturating for 3h under the pressure of 28MPa, and quickly releasing pressure to obtain a foaming material;

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 28min at the temperature of 150 ℃ to obtain the rubber and plastic foaming material.

Example 23

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 65 parts of ethylene propylene diene monomer, 30 parts of polypropylene, 5 parts of chlorosulfonated polyethylene, 15 parts of filler, 12 parts of plasticizer paraffin oil, 3 parts of compatibilizer EVM, 2 parts of acid acceptor calcium oxide, 2 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.8 parts of vulcanizing agent and 1.1 parts of vulcanization accelerator;

the filler is a flame-retardant filler consisting of 3 parts by weight of silica aerogel, 8 parts by weight of zinc borate and 4 parts by weight of carbon black, the vulcanizing agent consists of 1.6 parts by weight of sulfur and 0.2 part by weight of DPTT, and the vulcanization accelerator consists of 0.5 part by weight of vulcanization accelerator CZ and 0.6 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 120 ℃, adding ethylene propylene diene monomer and 1.0 part of anti-aging agent, mixing for 1min, discharging, and pretreating with plasma with the voltage of 20eV to obtain pretreated ethylene propylene diene monomer;

3) preparation of rubber A

Setting the temperature of an internal mixer at 120 ℃, adding chlorosulfonated polyethylene, a compatibilizer, an acid absorbent, a stabilizer, the rest of an anti-aging agent and the pretreated ethylene propylene diene monomer obtained in the step 2), and mixing for 3min to obtain a rubber material A;

4) preparation of rubber B

Continuously adding the filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 3min at 120 ℃, discharging and discharging to obtain rubber material B;

5) preparation of rubber composition C

Blending polypropylene and the sizing material B obtained in the step 4) for 4min at 180 ℃ to obtain a sizing material C;

6) preparation of rubber D

Adding a vulcanizing agent and a vulcanization accelerator into the rubber compound C obtained in the step 5), and mixing for 30s at 130 ℃ to obtain a rubber compound D;

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 10min at 160 ℃ to obtain a primary vulcanized product;

8) foam molding

Putting the primary vulcanized product obtained in the step 7) into a supercritical foaming kettle at 155 ℃, introducing nitrogen, saturating for 3h under the pressure of 30MPa, and quickly releasing pressure to obtain a foaming material;

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 8min at 160 ℃ to obtain the rubber and plastic foaming material.

Example 24

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 50 parts of ethylene propylene diene monomer, 35 parts of polypropylene, 15 parts of chlorosulfonated polyethylene, 25 parts of filler, 40 parts of plasticizer paraffin oil, 4 parts of compatibilizer EVM, 3 parts of acid acceptor calcium oxide, 2 parts of stabilizer zinc stearate, 2.0 parts of anti-aging agent, 2.0 parts of vulcanizing agent and 0.8 part of vulcanization accelerator;

the filler is a flame-retardant filler consisting of 3 parts by weight of silica aerogel, 12 parts by weight of zinc borate and 10 parts by weight of carbon black, the vulcanizing agent consists of 1.5 parts by weight of sulfur and 0.5 part by weight of DPTT, and the vulcanization accelerator consists of 0.2 part by weight of vulcanization accelerator CZ and 0.6 part by weight of vulcanization accelerator TMTD.

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to be 110 ℃, adding ethylene propylene diene monomer and 1.2 parts of anti-aging agent, mixing for 2min, discharging, and pretreating with plasma with the voltage of 10eV to obtain pretreated ethylene propylene diene monomer;

3) preparation of rubber A

4) preparation of rubber B

Adding the flame-retardant filler and the plasticizer into the rubber material A obtained in the step 3), continuously mixing for 5min at 110 ℃, discharging and discharging to obtain a rubber material B;

5) preparation of rubber composition C

6) preparation of rubber D

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 18min at 150 ℃ to obtain a primary vulcanized product;

8) foam molding

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 10min at the temperature of 150 ℃ to obtain the rubber and plastic foaming material.

Comparative example 21

s1 raw Material preparation

1) Weighing the following raw materials in parts by weight: 60 parts of ethylene propylene diene monomer, 40 parts of propylene butylene copolymer, 10 parts of filler, 7 parts of plasticizer paraffin oil, 3 parts of acid absorbent calcium oxide, 2.5 parts of stabilizer zinc stearate, 1.5 parts of anti-aging agent, 1.5 parts of vulcanizing agent and 0.6 part of vulcanization accelerator;

S2 rubber compounding

2) Pretreatment of ethylene propylene diene monomer

Setting the temperature of an internal mixer to 110 ℃, adding ethylene propylene diene monomer and 1.0 part of anti-aging agent, mixing for 2min, discharging, and discharging to obtain ethylene propylene diene monomer;

3) preparation of rubber A

4) preparation of rubber B

5) preparation of rubber composition C

6) preparation of rubber D

s3 foaming and shaping

7) One-time vulcanization

Taking the rubber material D obtained in the step 6), and carrying out primary vulcanization for 32min at 160 ℃ to obtain a primary vulcanized product;

8) foam molding

9) secondary vulcanization

Placing the foaming product obtained in the step 8) in a curing section of a drying tunnel, and carrying out secondary vulcanization for 36min at 140 ℃ to obtain a control sample 21.

Experiment 1 foaming Properties

Four parts of the rubber-plastic foam materials obtained in examples 11 to 14 and the control sample 11 obtained in comparative example 11 were observed under a USB 5 type high-definition digital microscope manufactured by Repan company; and four parts of the rubber-plastic foamed materials obtained in examples 21 to 24, the control 22 obtained in comparative example 22, and the injection-moldable foamed TPV material (control 1) prepared by the method described in example 4 of the prior art (CN112745681A) were observed on a scanning electron microscope of JSM-7500F type manufactured by Japanese Electron corporation (JEOL).

As can be seen from the attached drawings 1, 2, 3 and 4, the rubber and plastic foaming material obtained by chemical foaming has uniform cells, large and uniform pore diameter, and the pore diameter of the cells is between 0.2 and 0.7 mm; however, as can be seen from FIG. 5, the phenomenon of large pores and cross pores occurs in the cells of the comparative sample 11, the cell structure is not uniform, and the diameter of the large pores reaches 1 mm; as the pore diameter of the comparative sample 1TPV material is smaller, the observation by a scanning electron microscope is needed, and as can be seen from the attached figure 6, the pores of the comparative sample 1TPV material are fine and uniform, but the pore diameter of the pores of the comparative sample 1TPV material is about 100 μm, which is obviously smaller than the pore diameter of the rubber-plastic foamed materials obtained in examples 11 to 14, and the number of the pores is small and the wall thickness of the pores is thick.

As can be seen from the attached drawings 7, 8, 9 and 10, the rubber-plastic foam material obtained by supercritical foaming and the rubber-plastic foam material obtained by chemical foaming have the same structure, and show that the foam holes are uniform, the pore diameter is larger, the uniformity is consistent, the size of the foam holes of the rubber-plastic foam material obtained by supercritical foaming is small, the number of the foam holes is more than 10 and can reach 50-200 mu m^9-10¹⁰cell/cm³(ii) a However, as can be seen from FIG. 11, in the foamed material of comparative example 21, the rubber phase cell size is small, the plastic phase cell size is large, double peaks occur, and the cell structure is not uniform; referring to fig. 6, the number of the cells of the comparative example 1TPV material is about 100um, and although the pore size is similar to the pore size of the rubber and plastic foam material obtained in examples 21 to 24, the comparative example 1TPV material has a small number of cells, a thick wall, a large cell distance, and the number of the cells per unit area is far smaller than the number of the cells per unit area of the rubber and plastic foam material obtained by supercritical foaming.

TABLE 1 foaming Properties of different foamed materials test results

Sample name	Density (g/cm)³)	Coefficient of thermal conductivity (W/mK)
			Example 11	0.071	0.0309
Example 12	0.067	0.0313
			Example 13	0.063	0.0326
Example 14	0.078	0.0338
			Control sample 11	0.153	0.0417
Example 21	0.072	0.0301
			Example 22	0.068	0.0311
Example 23	0.062	0.0296
			Example 24	0.058	0.0288
Control sample 21	0.228	0.0574
			Control 1	0.731	0.1081

The density and thermal conductivity were measured for four parts of the rubber-plastic foamed materials obtained in examples 11 to 14, four parts of the rubber-plastic foamed materials obtained in examples 21 to 24, and control 11 obtained in comparative example 11, control 22 obtained in comparative example 22, and control 1 obtained according to the prior art (CN112745681A) according to the above-mentioned methods, respectively, wherein the density was measured according to the method specified in GB/T6344-1995, the thermal conductivity was measured according to the method specified in GB10295, the thermal conductivity of the foam sample was measured using a Hot Disk thermal Normal thermal Analyzer (TPS 2500S), and the results are shown in Table 1.

As can be seen from Table 1, the density of the rubber-plastic foam material obtained by the chemical foaming method or the rubber-plastic foam material obtained by the supercritical foaming method is less than 0.1g/cm, and is obviously less than that of the foam material of the control sample 11, 21 and 1 TPV; therefore, the method can obtain the rubber-plastic foaming material with ultralow density. The heat conductivity coefficients of the rubber-plastic foam materials obtained by the method are both less than 0.0338W/mK, which are obviously less than the heat conductivity coefficient of the foam material of the comparative sample 11, also obviously less than the heat conductivity coefficient of the foam material of the comparative sample 21 and far less than the heat conductivity coefficient of the TPV material of the comparative sample 1; therefore, the method can obtain the rubber and plastic foaming material with low heat conductivity coefficient.

Therefore, the rubber-plastic foam material has good foaming performance.

Experiment 2 mechanical Properties

As the comparison of the mechanical properties of the foamed materials with different densities has no guiding significance, the mechanical properties of the four parts of rubber-plastic foamed materials obtained in examples 11 to 14 and the four parts of rubber-plastic foamed materials obtained in examples 21 to 24 are separately measured, including the tensile strength and the elongation at break, and a compression set test is carried out, wherein the tensile strength and the elongation at break are measured according to the method specified in GB/6344-.

TABLE 2 mechanical Property test results for different foams

Sample name	Compression set (%)	Tensile Strength (MPa)	Elongation at Break (%)
				Example 11	15.6	1.22	356
Example 12	16.2	1.56	432
				Example 13	16.5	1.35	378
Example 14	15.3	1.28	384
				Example 21	13.8	1.56	398
Example 22	13.5	1.45	386
				Example 23	14.3	1.38	375
Example 24	14.7	1.25	354

As can be seen from Table 2, the rubber-plastic foam material obtained by the chemical foaming method has the compression set of 15.3-16.5%, the tensile strength of 1.22-1.56MPa and the elongation at break of 356-432%; the rubber-plastic foaming material obtained by the supercritical foaming method has the compression permanent deformation of 13.5-14.7 percent, the tensile strength of 1.25-1.56MPa and the elongation at break of 354-398 percent; therefore, the rubber plastic foaming material also has better mechanical property.

Experiment 2 flame retardant Properties

The four parts of the rubber-plastic foam material obtained in examples 11 to 14, the four parts of the rubber-plastic foam material obtained in examples 21 to 24, and the control 1 obtained in the prior art were subjected to a flame retardant property test, and the oxygen index was measured according to the method specified by GBT24093, and the test results are shown in table 3.

TABLE 3 flame retardancy test results of different foams

Sample name	Oxygen index (%)
		Example 11	30
Example 12	28
		Example 13	28
Example 14	28
		Example 21	29
Example 22	28
		Example 23	29
Example 24	31
		Control 1	21

As can be seen from Table 3, the oxygen index of the rubber-plastic foam material obtained by the chemical foaming method or the supercritical foaming method is 28-31%, while the oxygen index of the control sample 1TPV material is only 21%; therefore, the invention obviously improves the flame retardant property of the rubber and plastic foam material.

Experiment 4 aging resistance

Four parts of the rubber-plastic foam materials obtained in examples 11 to 14, four parts of the rubber-plastic foam materials obtained in examples 21 to 24, a control sample 11 obtained in a comparative example 11, a control sample 22 obtained in a comparative example 22 and a control sample 1 obtained in the prior art are subjected to an aging resistance test, according to a method specified in ASTM D2126-15, the aging environment is 70 ℃ air, and the aging time is 120 hours; and (3) standing at room temperature for 24h, measuring the density, the thermal conductivity coefficient, the compression set, the tensile strength, the elongation at break and the flame retardant property of the aged rubber-plastic foam material according to the method, comparing the compression set, the tensile strength and the elongation at break with the properties before aging for objective comparison, calculating the change rate, and listing the experimental results in a table 4.

TABLE 4 ageing resistance test results for different foams

As can be seen from Table 4, the density, the thermal conductivity coefficient and the oxygen index of the rubber-plastic foam material obtained by the chemical foaming method or the supercritical foaming method are basically kept unchanged after the rubber-plastic foam material is aged in air at 70 ℃ for 120 hours, and the rubber-plastic foam material still has ultralow density, low thermal conductivity coefficient and good flame retardant property after being aged; the rubber-plastic foam material has the advantages that the retention rate of the tensile strength after aging is about 85%, the retention rate of the elongation at break is about 65%, the change rate of the compression set is small, and the compression set is still relatively low. After the comparative samples 11, 21 and 1 are subjected to heat aging under the same conditions, the density, the thermal conductivity and the oxygen index are basically unchanged, however, the tensile strength retention rates are respectively 70%, 70% and 65%, the tensile elongation retention rates are respectively 50%, 48% and 57%, the compression set change rate is large, and the compression set change rate is larger than that of the rubber and plastic foam material of the invention. Therefore, the rubber plastic foaming material has good aging resistance.

Experiment 5 recovery Properties

The rubber-plastic foamed materials obtained in examples 11 to 14 and 21 to 24 of the present invention were subjected to a recovery test, respectively. The test method comprises the following steps: taking recyclable rubber-plastic foaming material, crushing, shearing at 180 ℃, and refining; shaping at 180 deg.C; and (3) saturating the mixture for 2 hours at 153 ℃ and 13MPa by adopting carbon dioxide gas, and decompressing the mixture to obtain the recycled foam material.

When the recycled foam material is observed on the scanning electron microscope, as can be seen from figure 12, the recycled foam material still has a good cell structure, the small hole part is a rubber phase, the large hole is a plastic phase, and the aperture of the foamed plastic phase is about 100 μm. The density, thermal conductivity, tensile strength, elongation at break, compression set and flame retardant properties of the recovered foam material were measured according to the above methods, and the experimental results are shown in table 5.

TABLE 5 results of the Performance tests after recovery of the different foams

As can be seen from Table 5, the rubber-plastic foam material of the present invention was recovered and subjected to supercritical CO recovery₂The foaming material with lower density and heat conductivity coefficient can be obtained after foaming, and the oxygen index is basically unchanged; therefore, the rubber and plastic foam material can be recycled, any auxiliary agent is not needed to be added in the recycling process, the recycling is convenient, and the rubber and plastic foam material with the same low density can be obtained. Although the mechanical property of the recycled foaming material is reduced and the compression permanent deformation is increased, the recycled rubber is completely crosslinked, the supercritical foaming is only foamed in a plastic phase, and the elasticity of the plastic is low, so the compression permanent deformation is increased; however, the recycled foaming material can be continuously used as a heat insulation material, and is non-toxic and environment-friendly.

Therefore, the beneficial effects of the invention are as follows: the Ethylene Propylene Diene Monomer (EPDM) is used as a main material, the excellent ozone resistance, heat resistance and weather resistance of the EPDM are fully utilized, and meanwhile, the EPDM is pre-treated and then blended with the CSM rubber, so that the defects of poor mutual adhesion and self adhesion, poor oil resistance, flame retardance, air tightness, low vulcanization rate and the like of the EPDM due to the molecular structure are overcome; the plastic phase-polypropylene or propylene copolymer is used as a support, the plastic phase serves as a stationary phase in the preparation process of the rubber and plastic foam material, the stability of the rubber and plastic foam material is fully supported, and the plastic phase also provides the characteristic of recycling for the rubber and plastic foam material; the ethylene propylene diene monomer, the polypropylene or the propylene copolymer and the chlorosulfonated polyethylene mutually interact and supplement each other, and the obtained rubber-plastic foam material has ultralow density which is less than 0.1g/cm³The heat conductivity coefficient is low, the compression set is small, the compression set at 25 ℃ for 24h is less than 25 percent, the heat-resistant material can be widely applied to the fields of automobile parts, building materials, railway transportation, subway engineering, pipeline transportation and the like, can be recycled, and does not need to be added in the recycling processAny auxiliary agent is added, the recovery is convenient, and the rubber and plastic foaming material with the same low density can be obtained.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The recyclable rubber-plastic foam material is characterized by comprising the following raw materials in parts by weight:

40-65 parts of ethylene propylene diene monomer, 30-40 parts of polypropylene or propylene copolymer, 5-25 parts of chlorosulfonated polyethylene, 10-25 parts of filler, 5-40 parts of plasticizer, 2-7 parts of compatibilizer, 2-5 parts of acid absorbent, 1-2.5 parts of stabilizer, 1-2 parts of anti-aging agent, 1.3-2 parts of vulcanizing agent and 0.6-1.1 part of vulcanization accelerator.

2. The recyclable rubber-plastic foamed material according to claim 1, wherein:

the filler is a flame-retardant filler which is a mixture of aerogel, zinc borate and carbon black according to the weight ratio of 1-3:4-12: 4-10.

3. The recyclable rubber-plastic foamed material according to claim 1, wherein:

the compatibilizer is ethylene vinyl acetate rubber and/or chlorinated polyethylene rubber.

4. The recyclable rubber-plastic foamed material according to claim 1, wherein:

the vulcanizing agent is a mixture consisting of 1-2 parts by weight of sulfur and 0.2-1 part by weight of dipentamethylenethiuram tetrasulfide; the vulcanization accelerator is any one or more of N-cyclohexyl-2-benzothiazole sulfonamide, 2' -dithiodibenzothiazole and tetramethyl thiuram disulfide.

5. The preparation method of the recyclable rubber-plastic foam material as claimed in any one of claims 1 to 4, characterized by comprising the following steps:

s1 rubber compounding

1) Pretreatment of ethylene propylene diene monomer

2) preparation of rubber A

3) preparation of rubber B

4) preparation of rubber composition C

5) preparation of rubber D

s2 foaming and shaping

6) One-time vulcanization

7) foam molding

8) secondary vulcanization

6. The method for preparing the recyclable rubber-plastic foam material as claimed in claim 5, wherein the method comprises the following steps:

in the step 7), during chemical foaming, the amount of the foaming agent is 10-20 parts by weight, the amount of the foaming promoter is 0.3-1.0 part by weight, and the foaming agent and the foaming promoter are added into the rubber material C obtained in the step 4), mixed for 80-100s at the temperature of 120-130 ℃, and then subjected to the step 5); the temperature of the chemical foaming is 160-230 ℃, and the time of the chemical foaming is 5-10 min.

7. The method for preparing the recyclable rubber-plastic foam material as claimed in claim 6, wherein the method comprises the following steps:

the chemical foaming comprises four zones, wherein the temperature of the first zone is 160-.

8. The method for preparing the recyclable rubber-plastic foam material as claimed in claim 5, wherein the method comprises the following steps:

in the step 7), the temperature of the supercritical physical foaming is 140-.

9. The method for preparing the recyclable rubber-plastic foam material as claimed in claim 5, wherein the method comprises the following steps:

in the step 1), the voltage during plasma treatment is 10-20eV, and the dose during irradiation treatment is 5-10 kGy.

10. A method for recycling the recyclable rubber-plastic foamed material according to any one of claims 1 to 4, comprising the steps of:

taking recyclable rubber-plastic foaming material, crushing, shearing at the temperature of 160-180 ℃, and recycling; setting at 160-; carbon dioxide gas is adopted to carry out supercritical foaming at the temperature of 140-160 ℃ and the pressure of 10-20MPa, so as to obtain the recycled foaming material.