A recycled composite material based on a double compounding of a substrate and an elastomer and a method of preparation

Abstract

The present application relates to a kind of based on substrate and elastomer double-compound's recycled composite material and preparation method, the raw material of the composite material includes the following mass parts of component: first substrate 20~50 parts, second substrate 20~50 parts, first elastomer 4~10 parts, second elastomer 6~25 parts, naphthenic base rubber oil 1~3 parts, antioxidant 0.2~0.5 parts and lubricant 0.2~0.5 parts, the substrate uses recycled polystyrene, the first substrate uses recycled polystyrene of high melt mass flow rate, the second substrate uses recycled polystyrene of low melt mass flow rate, the elastomer uses styrene block copolymer, the first elastomer uses the styrene block copolymer of high styrene content, the second elastomer uses the styrene block copolymer of low styrene content.Compared with prior art, the present application has excellent toughness, while maintaining higher stiffness.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, and relates to a recycled composite material based on a dual compound of a substrate and an elastomer and its preparation method. Background Technology

[0002] Polystyrene (PS) is a general-purpose plastic widely used in packaging, electronics, construction, and other fields. With increasingly stringent environmental regulations, the recycling and high-value utilization of recycled polystyrene (rPS) has become a hot topic in the industry. However, recycled polystyrene undergoes thermo-mechanical degradation during the recycling process, resulting in a decrease in molecular weight and an increase in gel content. This leads to poor material toughness and high brittleness, making it difficult to use directly in high-performance products.

[0003] In existing technologies, styrene-based block copolymers are commonly used to toughen recycled polystyrene. Styrene-based block copolymers have good compatibility with polystyrene and can effectively improve the impact strength of the material. However, existing technologies have the following problems: 1. Large dispersed phase size leads to low toughening efficiency. In conventional blending processes, styrene block copolymers tend to form large-sized dispersed phases in recycled polystyrene matrices. Even with high addition levels, the impact performance is only slightly improved, and the material modulus decreases while the cost increases. 2. Poor adaptability to viscosity fluctuations in recycled polystyrene. The sources of recycled polystyrene are complex, and the melt mass flow rate (MFR) varies significantly between different batches and from different sources, ranging from 2 to 30 g / 10 min. This leads to a significant difference in the two-phase viscosity ratio (η). SEBS / η rPS The toughening effect is unstable due to fluctuations, and existing technologies do not consider the impact of substrate viscosity on toughening efficiency. 3. Lack of systematic viscosity matching design. In existing technologies, the dispersion of styrene block copolymers in recycled polystyrene often neglects the influence of the substrate viscosity on the dispersion behavior. According to polymer blending theory, the size of the dispersed phase depends on the viscosity ratio of the two phases, the shear rate, and the interfacial tension, among which the viscosity ratio is the key parameter affecting the dispersion effect. When the viscosity ratio deviates from the optimal range, the shear force cannot effectively break the elastomer, resulting in a coarse dispersed phase.

[0004] Therefore, developing a highly efficient toughening solution that can actively control the viscosity ratio of the two phases and adapt to different sources of recycled polystyrene has significant industrial value.

[0005] Patent CN118085467A discloses a recycled polystyrene, its preparation method, and its application. The recycled polystyrene is prepared by pretreating waste polystyrene and mixing it with general-purpose polystyrene, polyethylene, a toughening agent, a compatibilizer, a plasticizer, an initiator, a first antioxidant, and a first lubricant. However, this patent fails to solve the technical problem of unstable elastomer toughening efficiency due to large viscosity fluctuations between batches of recycled polystyrene raw materials, and its toughening system has poor adaptability to recycled materials from different sources.

[0006] Patent CN115873355A discloses a polystyrene material, its preparation method, and its application. It describes a method that improves the material's toughness and flowability while reducing flow marks by compounding low-melt-index and high-melt-index polystyrene resins with styrene-butadiene-styrene block copolymers with oil contents of 0% and 20-50%. While this patent employs the approach of compounding both the substrate and elastomer, its core focus is on improving the overall processing rheology of virgin or recycled materials to eliminate flow marks by adjusting the oil content of the elastomer. Rather than addressing the issues of poor elastomer dispersibility and low toughening efficiency caused by viscosity fluctuations in recycled polystyrene, this patent does not aim to solve these problems. Summary of the Invention

[0007] The purpose of this invention is to overcome at least one of the defects of the prior art and provide a recycled composite material based on a dual compound of a substrate and an elastomer, and a preparation method thereof. This invention has excellent toughness while maintaining high stiffness.

[0008] The objective of this invention can be achieved through the following technical solutions: One of the technical solutions of the present invention is to provide a recycled composite material based on a dual compound of a substrate and an elastomer, wherein the raw materials of the composite material include the following components in parts by weight: The composition includes 20-50 parts of a first substrate, 20-50 parts of a second substrate, 4-10 parts of a first elastomer, 6-25 parts of a second elastomer, 1-3 parts of a naphthenic rubber oil, 0.2-0.5 parts of an antioxidant, and 0.2-0.5 parts of a lubricant. The substrate is made of recycled polystyrene (rPS), with the first substrate being recycled polystyrene with a high melt flow rate (MFR) and the second substrate being recycled polystyrene with a low melt flow rate. The elastomer is a styrene-based block copolymer, the first elastomer is a styrene-based block copolymer with high styrene content, and the second elastomer is a styrene-based block copolymer with low styrene content.

[0009] Furthermore, the elastomer is selected from one or more styrene block copolymers selected from styrene-ethylene-butene-styrene block copolymers (SEBS), styrene-ethylene-propylene-styrene block copolymers (SEPS), styrene-butadiene-styrene block copolymers (SBS), and styrene-isoprene-styrene block copolymers (SIS).

[0010] Furthermore, the melt flow rate of the first substrate is 13~16 g / 10 min, preferably 13~14 g / 10 min, and the melt flow rate of the second substrate is 4~6 g / 10 min, preferably 5~6 g / 10 min, and the test conditions are 200 ℃ and 5 kg. The first elastomer has a styrene content of 20-40 wt%, preferably 25-35 wt%, and the second elastomer has a styrene content of 8-18 wt%, preferably 10-15 wt%.

[0011] Furthermore, the mass ratio of the first substrate to the second substrate is 1:3 to 3:1, preferably 1:2 to 2:1, and the mass ratio of the first elastomer to the second elastomer is 1:(1 to 3), preferably 1:(1.3 to 2.7).

[0012] Furthermore, the mass ratio of the substrate to the elastomer is (2~6):1, preferably (3~5):1.

[0013] Furthermore, the kinematic viscosity of the naphthenic rubber oil is 150~200 cSt, the test conditions are 40 ℃, and the naphthenic content is 30~50 wt%. As a softener and dispersant, the naphthenic rubber oil can further adjust the elastomer phase viscosity and improve the dispersion effect.

[0014] Furthermore, the antioxidant is a compound of hindered phenolic antioxidants and phosphite antioxidants, wherein the mass ratio of hindered phenolic antioxidants to phosphite antioxidants is 1:2 to 2:1. The hindered phenolic antioxidants can capture free radicals and terminate the oxidation chain reaction, while the phosphite antioxidants can decompose hydrogen peroxides. The synergistic effect of the two can effectively inhibit the thermo-oxidative aging of materials during processing and use.

[0015] As a preferred technical solution, the hindered phenolic antioxidant is selected from one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010) and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), and the phosphite antioxidant is selected from one or more of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (antioxidant 626), and tris(nonylphenyl) phosphite (antioxidant TNP).

[0016] Furthermore, the lubricant is selected from one or more fatty acid amide lubricants, including fatty acid diamide lubricants and fatty acid monoamide lubricants, and the lubricant can improve processing fluidity and mold release properties.

[0017] As a preferred technical solution, the fatty acid bisamide lubricant is ethylene bis-stearamide (EBS), and the fatty acid monoamide lubricant is selected from one or more of oleamide and stearamide.

[0018] One of the technical solutions of the present invention is to provide a method for preparing the aforementioned recycled composite material based on a dual compound of a substrate and an elastomer, the method comprising the following steps: S1. Mix the first substrate, the second substrate, the first elastomer, the second elastomer, the naphthenic rubber oil, the antioxidant, and the lubricant evenly to obtain a mixture; S2. The mixture is melt-blended and extruded using a screw extruder to obtain extruded strips; S3. The extruded strip is cooled, dried, and pelletized to obtain a recycled composite material based on a dual compound of matrix and elastomer.

[0019] Furthermore, in step S1, the mixing temperature is 10~40 ℃, the time is 5~10 min, and the stirring speed is 500~1000 rpm; In step S2, the screw extrusion length-to-diameter ratio is (30~50):1, the screw speed is 200~400 rpm, and the extrusion temperature is divided into five zones: feeding zone 1 (170~190 ℃), melting zone 2 (180~200 ℃), mixing zone 3 (190~210 ℃), mixing zone 4 (200~220 ℃), homogenization zone 5 (200~220 ℃), and the die head temperature is 190~210 ℃.

[0020] As a preferred technical solution, the cooling method in step S3 is water cooling, the drying method is air drying, and after pelleting, it is dried at 70~90 ℃ for 3~5 h.

[0021] One of the technical solutions of the present invention is to provide an application of a recycled composite material based on a dual compound of a substrate and an elastomer in office supplies, electronic appliances, toys, and packaging materials.

[0022] As a preferred technical solution, the composite material is used for injection molding of printer housings, coffee machine housings, keyboards, television frames, and air conditioner panels.

[0023] The composite material has a notched impact strength of 140~170 J / m, a flexural modulus of 1775~1950 MPa, a tensile strength of 30~34 MPa, and a flexural strength of 39~42 MPa.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) The first proposed linkage design strategy of substrate compounding and elastomer compounding -- This invention actively adjusts the rheological properties of the substrate phase by compounding substrates with different melt flow rates, and actively adjusts the rheological properties and rigidity of the elastomer phase by compounding elastomers with different styrene contents. Combined with the substrate compounding ratio, the total ratio of substrate to elastomer and the elastomer compounding ratio are dynamically adjusted to achieve precise matching of the rheological properties of the substrate phase and the elastomer phase. The toughening efficiency is greatly improved and the rigidity and toughness are well balanced. It breaks the limitation of the traditional technology of passively adapting to raw materials. In particular, it provides an adaptive solution to the pain point of the large impact of batch fluctuations of recycled materials on processing and performance. (2) Achieving significant miniaturization of the elastomer dispersion phase -- This invention achieves optimal matching of the rheological properties of the two phases, and the shear force can efficiently break the elastomer into fine and uniform particles. At the same time, with the assistance of the cycloalkyl rubber oil for dispersion and the synergistic thermal and oxygen protection of the compounded antioxidant, the size of the elastomer dispersion phase of the composite material is significantly refined compared with the prior art, with uniform dispersion, no agglomeration, and stable performance. (3) Environmental benefits and cost advantages -- This invention uses a large amount of recycled polystyrene, realizing the high-value utilization of waste foam. It selects fatty acid amide lubricants to improve processing fluidity, and through the optimization of the ratio of substrate and elastomer and extrusion process, it effectively adapts to the fluctuation of rheological properties of recycled materials. At the same time, all components used are commercially available materials, making the overall cost more advantageous. Attached Figure Description

[0025] Figure 1 This is a transmission electron microscope (TEM) image of the recycled composite material based on the dual compounding of substrate and elastomer in Example 1 of the present invention; Figure 2 This is a transmission electron microscope image of the recycled composite material in Comparative Example 1 of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0027] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," "third," etc., used to describe a common object only indicate different instances of the same object, and do not imply that the objects described in this way must be in a given order, whether temporally, spatially, sequentially, or in any other way.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Unless otherwise specified, the equipment used in the following embodiments is conventional equipment in the art; unless otherwise specified, the reagents used are commercially available products or prepared by conventional methods in the art. In the following embodiments, unless otherwise described in detail, conventional experimental methods in the art can be used.

[0030] Unless otherwise specified, the following procedures are generally performed at room temperature and atmospheric pressure.

[0031] Example 1: A recycled composite material based on a dual compound of a matrix and an elastomer, with the raw material components sourced as follows: The first recycled polystyrene rPS-A is made from waste polystyrene foam (EPS) through hot melt physical recycling and granulation. It has high fluidity and a melt mass flow rate (MFR) of 13.4 g / 10 min. The test conditions are 200 ℃ and 5 kg. It was purchased from Wanrong Rili. The second recycled polystyrene rPS-B was recycled and granulated from waste polystyrene foam using a hot melt physical method. It has low fluidity and a melt mass flow rate of 5.6 g / 10 min. The test conditions were 200 ℃ and 5 kg. It was purchased from Wanrong Rili. The second recycled polystyrene rPS-C was recycled and granulated from waste refrigerator drawers using a hot melt physical method. It has low fluidity and a melt mass flow rate of 4.1 g / 10 min. The test conditions were 200 ℃ and 5 kg. It was purchased from Wanrong Rili. The first styrene-ethylene-butene-styrene block copolymer SEBS-A has a styrene content of 30 wt%, a linear structure, and is designated as Baling Petrochemical YH-501. The second styrene-ethylene-butene-styrene block copolymer SEBS-B has a styrene content of 13 wt%, a linear structure, and is designated as Baling Petrochemical YH-688. Naphthenic rubber oil, industrial grade, kinematic viscosity 166 cSt, tested at 40 ℃, cycloalkane content 40wt%, model is Karamay KN4010; Antioxidants, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester (antioxidant 1076) and tris(2,4-di-tert-butylphenyl) phosphite ester (antioxidant 168) are compounded in a mass ratio of 1:1, and the models are BASF Irganox 1076 and Irganox 168; Lubricant, ethylene bis-stearamide (EBS), model number HI-LUBE BEAD / 300P from Shinwon Korea.

[0032] The specific raw material formulas for each component by weight are shown in Table 1.

[0033] Table 1. Raw material formulations of recycled composite materials based on dual compounding of substrate and elastomer in Examples 1 to 4 The specific steps of the above-mentioned method for preparing recycled composite materials based on a dual compound of substrate and elastomer are as follows: S1. Weigh each component of the raw materials according to the proportion, put them into a high-speed mixer, and mix at a stirring speed of 800 rpm for 8 minutes at room temperature to ensure that each component of the raw materials is fully mixed and uniform, thus obtaining a mixture. S2. The mixture is added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The screw speed is controlled at 300 rpm. The extrusion temperature is divided into five zones: feeding zone 1 at 180 ℃, melting zone 2 at 190 ℃, mixing zone 3 at 200 ℃, mixing zone 4 at 210 ℃, and homogenization zone 5 at 210 ℃. The die head temperature is 200 ℃. The mixture is melted and blended by the screw and then extruded to obtain extruded strips. S3. The extruded strip is water-cooled, air-dried, and pelletized. The resulting pellets are dried at 80 ℃ for 4 h to obtain a recycled composite material based on the dual compounding of matrix and elastomer.

[0034] Example 2: A recycled composite material based on a dual compound of substrate and elastomer and its preparation method are basically the same as in Example 1, except that the mass ratio of recycled polystyrene to styrene-ethylene-butene-styrene block copolymer increases from 3.89:1 to 4.67:1, the mass ratio of first recycled polystyrene to second recycled polystyrene decreases from 1:1 to 0.75:1, and the mass ratio of first styrene-ethylene-butene-styrene block copolymer to second styrene-ethylene-butene-styrene block copolymer increases from 1:2 to 1:1.5. The specific raw material formulations by mass parts are shown in Table 1.

[0035] Example 3: A recycled composite material based on a dual compound of substrate and elastomer and its preparation method are basically the same as in Example 1, except that the mass ratio of recycled polystyrene to styrene-ethylene-butene-styrene block copolymer is reduced from 3.89:1 to 3.33:1, the mass ratio of first recycled polystyrene to second recycled polystyrene is increased from 1:1 to 1.33:1, and the mass ratio of first styrene-ethylene-butene-styrene block copolymer to second styrene-ethylene-butene-styrene block copolymer is reduced from 1:2 to 1:2.5. The specific raw material formulations by mass parts are shown in Table 1.

[0036] Example 4: A recycled composite material based on a dual compound of substrate and elastomer and its preparation method are basically the same as in Example 1, except that the second recycled polystyrene with a melt flow rate of 5.6 g / 10 min is replaced with a second recycled polystyrene with a melt flow rate of 4.1 g / 10 min, the mass ratio of recycled polystyrene to styrene-ethylene-butene-styrene block copolymer decreases from 3.89:1 to 3.5:1, the mass ratio of first recycled polystyrene to second recycled polystyrene increases from 1:1 to 1.33:1, and the mass ratio of first styrene-ethylene-butene-styrene block copolymer to second styrene-ethylene-butene-styrene block copolymer decreases from 1:2 to 1:2.33. The specific raw material formulations by mass parts are shown in Table 1.

[0037] Comparative Example 1: A recycled composite material and its preparation method are basically the same as in Example 1, except that the raw materials are replaced by a double compound of recycled polystyrene and styrene-ethylene-butene-styrene block copolymer with a single high melt flow rate first recycled polystyrene and a single high styrene content first styrene-ethylene-butene-styrene block copolymer. The specific raw material formulation by mass parts is shown in Table 2.

[0038] Table 2 Raw material formulations of recycled composite materials in Comparative Examples 1 to 4 Comparative Example 2: A recycled composite material and its preparation method are basically the same as in Example 1, except that the raw materials are replaced by a double compound of recycled polystyrene and styrene-ethylene-butene-styrene block copolymer with a single low melt flow rate second recycled polystyrene and a single low styrene content second styrene-ethylene-butene-styrene block copolymer. The specific raw material formulations by mass parts are shown in Table 2.

[0039] Comparative Example 3: A recycled composite material based on substrate compounding and its preparation method are basically the same as those in Example 1, except that the raw materials are replaced by a double compounding of recycled polystyrene and styrene-ethylene-butene-styrene block copolymer with a mass ratio of 1:1, which is a compounding of first recycled polystyrene and second recycled polystyrene and a single second styrene-ethylene-butene-styrene block copolymer with low styrene content. The specific raw material formulations by mass parts are shown in Table 2.

[0040] Comparative Example 4: A recycled composite material based on elastomer compound and its preparation method are basically the same as those in Example 1, except that the raw materials are replaced by a double compound of recycled polystyrene and styrene-ethylene-butene-styrene block copolymer with a single high melt flow rate first recycled polystyrene and a first styrene-ethylene-butene-styrene block copolymer and a second styrene-ethylene-butene-styrene block copolymer with a mass ratio of 1:2. The specific raw material formulations by mass parts are shown in Table 2.

[0041] The above-mentioned composite materials were subjected to the following tests or experiments, and then the test or experiment results were analyzed.

[0042] Experimental example: The performance of the above-mentioned composite material was tested, and the specific steps are as follows: Notched impact strength (IZOD), tested according to ASTM D256, with a specimen size of 63.5 mm × 12.7 mm × 3.2 mm and a V-notch; Flexural modulus was tested according to ASTM D790, with a specimen size of 127 mm × 12.7 mm × 3.2 mm, a span of 50 mm, and a test speed of 1.3 mm / min. Tensile strength was tested according to ASTM D638, with type I specimen and a test speed of 50 mm / min. Bending strength was tested according to ASTM D790, with a specimen size of 127 mm × 12.7 mm × 3.2 mm, a span of 50 mm, and a test speed of 1.3 mm / min. The dispersed phase morphology was observed using transmission electron microscopy (TEM). The samples were stained after being ultrathinly sectioned.

[0043] The performance test results are shown in Table 3.

[0044] Table 3 Performance test results of recycled composite materials in Examples 1 to 4 and Comparative Examples 1 to 4 like Figure 1 As shown, in Example 1, the elastomer dispersion phase is uniformly spherical, small in size, uniformly dispersed, and without agglomeration.

[0045] like Figure 2 As shown, in Comparative Example 1, the elastomer dispersion phase is large in size and unevenly distributed, with some areas showing agglomeration.

[0046] As shown in Table 3, the performance test results of the recycled composite materials in Examples 1 to 4 and Comparative Examples 1 to 4 are analyzed as follows: 1. The synergistic resilience effect of interconnected relationships, Comparing Comparative Examples 1 and 2 with Example 1, it can be seen that the notched impact strength of the uncomposite composite material in Comparative Example 1 is only 112 J / m, the notched impact strength of the uncomposite composite material in Comparative Example 2 is only 116 J / m, while the notched impact strength of the composite material with both matrix and elastomer in Example 1 is increased to 157 J / m, representing increases of 40% and 35%, respectively. Furthermore, based on the analysis of the dispersed phase morphology, all the above results indicate that the optimal matching of the two-phase viscosity is achieved through the coordinated design of matrix and elastomer compatibility in this invention, significantly improving the toughening efficiency. 2. The impact of missing linkage relationships The notched impact strength of the composite material with matrix compound in Comparative Example 3 was 134 J / m, and the notched impact strength of the composite material with elastomer compound in Comparative Example 4 was 137 J / m. Both of them were not as good as the composite material with matrix and elastomer compound in Example 1. At the same time, the morphology of the dispersed phase was also slightly worse. Especially when facing a matrix with a low melt flow rate, the single compounding strategy is difficult to effectively adjust the viscosity ratio, resulting in a slightly larger dispersed phase and insufficient toughening. This proves that the linkage between matrix compounding and elastomer compounding in this invention is a necessary condition for achieving the optimal toughening effect, and the combination of the two produces a synergistic effect. 3. Balance of rigidity and toughness In the examples, the composite material with dual compounding of substrate and elastomer significantly improves impact performance while maintaining reasonable levels of flexural modulus, tensile strength and flexural strength, exhibiting good stiffness-toughness balance characteristics. Among them, Example 1 achieved excellent balance and had the best comprehensive performance. Compared with traditional toughening systems, the rigidity of the material is effectively maintained by the rigidity compensation of the elastomer with high styrene content in this invention. The balance optimization of stiffness and toughness can be achieved within a certain range by dynamically adjusting the compounding ratio of elastomer. 4. Batch stability verification of recycled materials. The notched impact strengths of the non-recombined composite materials in Comparative Examples 1 and 2 were 112 J / m and 116 J / m, respectively, with low absolute values ​​and a relative fluctuation rate of 3.6%. In contrast, the composite materials in Examples 1 and 4, which were a combination of substrate and elastomer, achieved notched impact strengths of 157 J / m and 154 J / m, respectively, despite using substrates from different sources. This represents an overall improvement of over 35%, with a relative fluctuation rate of only 2%. This demonstrates that the linkage design of the present invention has excellent adaptability to recycled materials from different sources and can maintain a high level of toughening stability even when raw materials fluctuate significantly.

[0047] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A recycled composite material based on a dual compound of a substrate and an elastomer, characterized in that, The raw materials for this composite material include the following components in parts by weight: The composition includes 20-50 parts of a first substrate, 20-50 parts of a second substrate, 4-10 parts of a first elastomer, 6-25 parts of a second elastomer, 1-3 parts of a naphthenic rubber oil, 0.2-0.5 parts of an antioxidant, and 0.2-0.5 parts of a lubricant. The substrate is made of recycled polystyrene; the first substrate is made of recycled polystyrene with a high melt flow rate, and the second substrate is made of recycled polystyrene with a low melt flow rate. The elastomer is a styrene-based block copolymer, the first elastomer is a styrene-based block copolymer with high styrene content, and the second elastomer is a styrene-based block copolymer with low styrene content.

2. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The elastomer is selected from one or more styrene block copolymers selected from styrene-ethylene-butene-styrene block copolymers, styrene-ethylene-propylene-styrene block copolymers, styrene-butadiene-styrene block copolymers, and styrene-isoprene-styrene block copolymers.

3. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The melt flow rate of the first substrate is 13~16 g / 10 min, and the melt flow rate of the second substrate is 4~6 g / 10 min. The test conditions are 200 ℃ and 5 kg. The first elastomer has a styrene content of 20-40 wt%, and the second elastomer has a styrene content of 8-18 wt%.

4. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The mass ratio of the first substrate to the second substrate is 1:3 to 3:1, and the mass ratio of the first elastomer to the second elastomer is 1:(1 to 3).

5. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The mass ratio of the substrate to the elastomer is (2~6):

1.

6. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The kinematic viscosity of the cycloalkyl rubber oil is 150~200 cSt, the test conditions are 40 ℃, and the cycloalkane content is 30~50wt%.

7. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The antioxidant is a compound of hindered phenolic antioxidants and phosphite antioxidants, wherein the mass ratio of hindered phenolic antioxidants to phosphite antioxidants is 1:2 to 2:

1.

8. The recycled composite material based on a dual compound of a substrate and an elastomer according to claim 1, characterized in that, The lubricant is selected from one or more fatty acid amide lubricants, including fatty acid diamide lubricants and fatty acid monoamide lubricants.

9. A method for preparing a recycled composite material based on a dual compound of a substrate and an elastomer as described in any one of claims 1 to 8, characterized in that, The method includes the following steps: S1. Mix the first substrate, the second substrate, the first elastomer, the second elastomer, the naphthenic rubber oil, the antioxidant, and the lubricant to obtain a mixture; S2. The mixture is melt-blended and extruded using a screw extruder to obtain extruded strips; S3. The extruded strip is cooled, dried, and pelletized to obtain a recycled composite material based on a dual compound of matrix and elastomer.

10. The method for preparing a recycled composite material based on a dual compound of a substrate and an elastomer according to claim 9, characterized in that, In step S1, the mixing temperature is 10~40 ℃, the time is 5~10 min, and the stirring speed is 500~1000 rpm; In step S2, the screw extrusion length-to-diameter ratio is (30~50):1, the screw speed is 200~400 rpm, and the extrusion temperature is divided into five zones: feeding zone 1 (170~190 ℃), melting zone 2 (180~200 ℃), mixing zone 3 (190~210 ℃), mixing zone 4 (200~220 ℃), homogenization zone 5 (200~220 ℃), and the die head temperature is 190~210 ℃.

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