CN111849069A

CN111849069A - Composite rubber thermoplastic elastomer and preparation method thereof

Info

Publication number: CN111849069A
Application number: CN202010470176.9A
Authority: CN
Inventors: 彭旭锵; 金辉乐; 王舜; 樊宏斌; 杜晋辉; 王宗垒
Original assignee: Wenzhou University
Current assignee: Wenzhou University
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2020-10-30

Abstract

The invention relates to the field of thermoplastic elastomers, and discloses a composite rubber thermoplastic elastomer and a preparation method thereof, wherein the thermoplastic elastomer contains composite rubber and polypropylene, the mass ratio of the composite rubber to the polypropylene is 4:6, and the composite rubber contains 75 parts by mass of styrene butadiene rubber, 25 parts by mass of butadiene rubber, zinc oxide, stearic acid, white carbon black, an anti-aging agent 4010, an accelerator M, an accelerator DM, sublimed sulfur and a plasticizer DOP. The invention has the beneficial effects that: 1. the composite rubber thermoplastic elastomer prepared by the invention adopts a specific combination formula of SBR (styrene butadiene rubber) and BR (proportion of BR to 75: 25), the elongation at break of the material is up to 132%, and the elongation at break of the material is increased by 29.33% compared with that of single SBR. 2. The invention adopts 4010 as the anti-aging system, the tensile strength, the bending strength and the bending modulus of the elastomer reach the maximum values, and the tensile strength of the thermoplastic elastomer is the maximum when the using amount is 1.5 parts. The aging prevention system is that the melt flowability of the elastomer is optimal when the aging prevention system is 4010.

Description

Composite rubber thermoplastic elastomer and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of high polymer materials, and particularly relates to a thermoplastic elastomer of vulcanized polypropylene/styrene butadiene rubber/butadiene composite rubber and a preparation method thereof.

Background

The thermoplastic elastomer has the characteristics of rubber and thermoplastic resin, generates plastic flow at high temperature, shows rubber elasticity at normal temperature, can adopt processing technologies such as extrusion, blow molding, injection molding and the like, can efficiently and economically produce general rubber products, and can be recycled.

Polypropylene is a plastic with excellent overall properties. However, they have a large molding shrinkage, insufficient abrasion resistance, low-temperature impact resistance and low impact strength. After the butadiene rubber is vulcanized, the wear resistance, elasticity and cold resistance are good, and the butadiene styrene rubber is wear-resistant, heat-resistant and ageing-resistant. The polypropylene, the styrene butadiene rubber and the butadiene rubber are all nonpolar and have better compatibility, so that the polypropylene/styrene butadiene rubber/butadiene composite rubber thermoplastic elastomer prepared by dynamically vulcanizing the polypropylene, the styrene butadiene rubber and the butadiene rubber is hopeful to obtain the thermoplastic elastomer with high strength, good elasticity, wear resistance, aging resistance and wide use temperature range, and can be used in the fields of wires and cables, sealing elements, automobile parts and the like.

Patent CN 110791030A discloses a zinc-free halogenated butyl rubber/polypropylene thermoplastic elastomer. The halogenated butyl rubber, polypropylene, filler, plasticizer and the like are subjected to banburying by an internal mixer, a vulcanizing agent is added at room temperature, and then granulation is carried out by a rubber granulator. Because the sulfur is added separately at room temperature after banburying, the uniformity of mixing is difficult to ensure. The amount of polypropylene is less than 50 parts by mass per 100 parts of rubber. The tensile strength of the prepared elastomer is less than 9MPa, and the phenomenon of cutter sticking exists during bracing and granulating. The particles may also be rough.

Patent CN 106220922 a discloses a dynamically vulcanized flame retardant polypropylene/nitrile rubber thermoplastic elastomer. The thermoplastic elastomer is prepared by using a flame-retardant system comprising polypropylene, nitrile rubber, a crosslinking agent, a compatibilizer, ammonium polyphosphate, pentaerythritol, rare earth oxide and the like according to a certain proportion through one or two devices of an open mill, an internal mixer or a double-screw extruder, wherein the dynamic vulcanization process is realized in the open mill or the internal mixer, and the thermoplastic elastomer with the oxygen index up to 35 percent can be prepared. The preparation process has long existence time, and particularly the preparation process needs to stay in a double-screw extruder for more than 10 min. The prepared elastomer has the tensile strength of 8.5MPa at most, the elongation at break of no more than 160 percent and does not well embody the advantages of rubber in the aspect of toughness.

Patent CN 110498968A discloses a thermoplastic elastomer composite material and a preparation method thereof. The polypropylene/thermoplastic elastomer composite material is prepared by adopting an internal mixer to refine and premix polypropylene, elastomer POE, liquid silicone rubber, nano cerium oxide powder, a cross-linking agent, a compatibilizer, an antioxidant, a coupling agent, a filler and the like, and extruding elastomer premix master batches and the cross-linking agent for 20-23min at the rotating speed of 450-23 r/min on a double-screw extruder at the temperature of 145-210 ℃. The preparation time is long, and the problem of uneven vulcanization of the product is caused by uneven mixing due to the fact that the amount of the cross-linking agent is 0.6-1.3 parts and the cross-linking agent is added in two steps.

Patent CN1077769A discloses a dynamically vulcanized polypropylene composition, which is prepared by adopting two-roll plastication and banburying to prepare elastomer master batches, and extruding and granulating the master batches and auxiliaries such as polypropylene, fillers and antioxidants through a double-screw extruder to prepare the novel polypropylene composition. The dynamic vulcanization process is completed in the plastication or banburying process. The strength of the obtained dynamic vulcanized polypropylene composition is 32MPa, but the elongation at break is only 50%, the polypropylene content is as high as 85-90%, the butadiene content is only 5-20%, the product still has obvious plastic characteristics, and the elasticity characteristic is not very obvious.

Patent CN 103012952a discloses a polypropylene thermoplastic elastomer for automobile airbag cover plate, which comprises high melt strength polypropylene, olefin polymers such as low density polyethylene, ethylene propylene copolymer, styrene thermoplastic elastomers SBS, SEBS, compatilizer, heat stabilizer, and is extruded and granulated by a twin-screw extruder at 230-. The polypropylene thermoplastic elastomer is obtained by using the existing thermoplastic elastomer for blending modification through a simple blending method.

Patent CN101671459A discloses a fully vulcanized polypropylene/acrylate rubber thermoplastic elastomer and a preparation method thereof. The weight ratio of rubber to polypropylene is 30: 7-75:25, adopting fully vulcanized acrylate powdered rubber, and carrying out melt blending granulation on a softener and polypropylene to obtain the fully vulcanized thermoplastic elastomer. The thermoplastic elastomer is prepared by melt blending of vulcanized rubber and polypropylene, and the prepared thermoplastic elastomer has tensile strength of less than or equal to 14MPa and elongation at break of less than or equal to 30%.

The patent CN102516668A discloses a polypropylene thermoplastic elastomer with scratch self-repairing function and a preparation method thereof, wherein the scratch-resistant polypropylene thermoplastic elastomer is obtained by melt extrusion in a double-screw extruder through the combination of 43-84% of polypropylene, 10-30% of hydrogenated styrene-butadiene copolymer, ethylene propylene diene monomer sulfonate ionomer, polyisobutylene adhesive, heat stabilizer and lubricant auxiliary agent. The elasticity is mainly from the hydrogenated styrene-butadiene copolymer in the blend, and the scratch resistance is mainly from the electrostatic attraction of charged ions of the EPDM sulfonate ionomer and the bond repair of the polyisobutylene adhesive.

Patent CN201911224038.6 discloses a zinc-free halogenated butyl rubber/polypropylene thermoplastic elastomer and a preparation method thereof, wherein chlorinated butyl rubber, polypropylene, magnesium oxide, paraffin oil and the like are uniformly mixed in a high-temperature internal mixer, and then are granulated in a rubber granulator. The rubber particles are then dynamically vulcanized in a twin screw extruder to produce the thermoplastic elastomer. The dosage of the prepared thermoplastic elastomer rubber is more than 60 percent, the strength of the thermoplastic elastomer is low, and the tensile strength is less than 6 MPa.

As described above, the prior art discloses various methods for preparing polypropylene thermoplastic elastomers, and there are problems that the tensile strength of the thermoplastic elastomer is small, generally less than 10MPa, mainly when the rubber content is more than 50%, and the elongation at break of the prepared thermoplastic elastomer is small when the polypropylene content is more than 50%. From the viewpoint of elastomer production techniques, the vulcanization process is usually carried out in an internal mixer, or by the methods of internal mixing, granulation by a rubber machine, and dynamic vulcanization. Process continuity of vulcanization needs to be improved and optimized. In addition, some thermoplastic elastomers are prepared by simply physically blending polypropylene and thermoplastic elastomer products without involving chemical changes, so that the prepared product is actually only a physical blending product.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a dynamically vulcanized polypropylene/butadiene styrene rubber/butadiene rubber composite rubber thermoplastic elastomer and a preparation method thereof. The styrene-butadiene rubber and the butadiene rubber have the same butadiene component and have good compatibility, so that the combination of the polypropylene, the butadiene rubber and the styrene-butadiene rubber can avoid the reduction of the performance of the elastomer material caused by different polarities and can exert the advantages of each component to the greatest extent. The dynamic vulcanization is carried out by adopting banburying-open milling-twin-screw extrusion, so that the production efficiency can be improved, and the uniformity of the product is ensured. The invention selects polypropylene, and the prepared thermoplastic elastomer has high strength, good elasticity, impact resistance and good processability.

In order to achieve the purpose, the rubber-polypropylene composite material comprises composite rubber and polypropylene, wherein the mass ratio of the composite rubber to the polypropylene is 4:6, and the composite rubber comprises the following components in parts by mass:

The invention also provides a preparation method of the dynamic vulcanized polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer.

The invention has the beneficial effects that:

1. the composite rubber thermoplastic elastomer prepared by the invention adopts a specific combination formula of SBR (styrene butadiene rubber) and BR (proportion of rubber) 75:25, the elongation at break of the material is 631.59% at most, and the elongation at break of the material is increased by 29.33% compared with that of single SBR.

2. According to the invention, the anti-aging system is adopted as 4010, the tensile strength, the bending strength and the bending modulus of the elastomer reach the maximum values, the tensile strength of the composite rubber is the maximum when the content is 1.5 parts, and the melt fluidity of the elastomer is optimal when the anti-aging system is 4010.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is within the scope of the present invention for those skilled in the art to obtain other drawings based on the drawings without inventive exercise.

FIG. 1 is a graph showing the relationship between tensile strength of PP/SBR/BR thermoplastic elastomer and an aging system;

FIG. 2 is a graph showing the relationship between the bending strength of PP/SBR/BR thermoplastic elastomer and the aging inhibitor;

FIG. 3 flow Properties of PP/SBR/BR thermoplastic elastomer

FIG. 4 is a graph showing the effect of SBR and BR in different proportions on the tensile strength of the compounded rubber;

FIG. 5 is a test chart of the influence of SBR and BR with different proportions on the tearing strength of materials;

FIG. 6 is a test chart of the influence of SBR and BR with different proportions on the hardness of a material;

FIG. 7 is a graph showing the relationship between different aging systems and the tensile strength of compounded rubber;

FIG. 8 is a graph showing the variation of the tearing property of the compounded rubber under different aging systems;

FIG. 9 is a graph showing the resistance change of the compounded rubber under different anti-aging systems;

FIG. 10 is a graph showing the relationship between tensile strength of PP/SBR/BR thermoplastic elastomer and SBR/BR ratio.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

1. In this embodiment, a preferred technical scheme of the present application is obtained by comparing the experimental examples and the comparative examples and performing experimental tests.

2. The experimental and testing procedures are described below:

the present invention will be described in detail with reference to examples. The materials described in the following specific examples are for illustrative purposes only, and the claimed materials are not limited to the types of materials described below.

The materials used were: polypropylene, PP T30S, Zhenhai refining, melt flow index 3.5g/10 min. Styrene butadiene rubber, SBR1502 gillin petrochemical. Cis-dibutylene rubber, BR9000, beijing yanshan petrochemical. Vulcanizing agent, DCP, commercially available. Vulcanizing agent, sulfur, commercially available. The anti-aging agent is 4010, 4010NA, anti-aging agent MB,1010 and white carbon black. The plasticizer is white oil.

The preparation of the dynamically vulcanized polypropylene/styrene-butadiene rubber/butadiene rubber thermoplastic elastomer is carried out according to the protection method claimed in the application, and comprises the following steps:

s1, mixing the weighed rubber, the antioxidant, the filler, the plasticizer and the auxiliary agent in an internal mixer at 40-50 ℃, preferably 45 ℃ and at 15rpm, and mixing uniformly.

And S2, mixing the obtained mixed rubber, a vulcanizing agent and an accelerator on an open mill to obtain the mixed rubber.

S3, cutting the prepared rubber compound into strip rubber with the width of 10-20mm, and preferably with the width of 10 mm.

S4, a twin-screw extruder is used for the polypropylene and the strip rubber prepared in the step S3. The extruder temperatures were 160 ℃ to 215 ℃ from zone one to the head, respectively. The screw speed was 300 rpm. And carrying out melt blending, dynamic vulcanization extrusion and granulation to obtain the dynamic vulcanized polypropylene/styrene butadiene rubber/butadiene composite rubber thermoplastic elastomer.

S5, performing injection molding on the prepared thermoplastic elastomer on a vertical injection molding machine at the injection molding temperature of 200 ℃, 210 ℃ and 205 ℃ to prepare a performance test sample.

S6, carrying out performance test on the prepared thermoplastic elastomer, wherein: tensile strength, elongation at break were tested according to the method in GB/T1040-2006. The flexural strength was tested according to the method in GB/T9341-2008. The impact strength was tested according to the method in GB/T1843-2008.

Example 1

S1, mixing Styrene Butadiene Rubber (SBR)/Butadiene Rubber (BR) in a ratio of 75:25, 5 parts of zinc oxide, 2 parts of stearic acid, 40 parts of white carbon black, 40102 parts of anti-aging agent, 2 parts of accelerator M, 2 parts of accelerator DM, 4 parts of sulfur and 40 parts of plasticizer DOP. The feeding sequence is as follows: zinc oxide in SBR \ BR 2min, white carbon black in stearic acid 2min, DOP 4min and age inhibitor 10101, and continuously banburying for 2-3 min. Banburying conditions are as follows: t is 45 ℃ and n is 15 rpm. And (3) after internal mixing is finished, taking out the rubber material, placing the rubber material into an open mill for open milling, adding the accelerators DM and M and sublimed sulfur in the open milling process, and taking the rubber material down from the internal mixer when the color of the rubber material is uniform and the surface is smooth and flat. The refining temperature was 45 ℃. The rotation speed n is 15rpm, and the mixture is uniformly mixed. Wherein the anti-aging agent is 4010, and the using amount is 2 parts.

S3, cutting the prepared rubber compound into strip rubber with the width of 10 mm.

S4, using a double-screw extruder to mix the polypropylene and the strip rubber prepared in the step 3. The extruder temperatures were 160 ℃, 165 ℃, 175 ℃, 180 ℃, 190 ℃, 185 ℃, 175 ℃, 160 ℃, 175 ℃ and 175 ℃ from zone one to the head. The screw speed was 300 rpm. And carrying out melt blending, dynamic vulcanization extrusion and granulation to obtain the dynamic vulcanized polypropylene/styrene butadiene rubber/butadiene composite rubber thermoplastic elastomer.

S5, performing injection molding on the prepared thermoplastic elastomer on a vertical injection molding machine, wherein the injection molding temperature is 200 ℃, 210 ℃ and 205 ℃. A performance test specimen was prepared.

S6, carrying out performance test on the prepared thermoplastic elastomer, wherein: tensile strength, elongation at break were tested according to the method in GB/T1040-2006. The flexural strength was tested according to the method in GB/T9341-2008. Izod impact strength was tested according to the method of GB/T1843-2008.

The thermoplastic elastomers obtained are respectively designated M1.

Examples 2 to 3

In examples 2-3, PP/SBR/BR thermoplastic elastomer was prepared in a similar manner to that of example 1, except that the antioxidant was used in a different amount and type. The prepared thermoplastic elastomers are respectively named as M2 and M3 by respectively adopting 2 parts and 10101 parts of antioxidant MB.

As can be seen from FIG. 1, the tensile strength of the PP/SBR/BR thermoplastic elastomer was at its maximum 17.5MPa and the elongation at break was 127% when the antioxidant was 4010. When the antioxidant is 1010, the elongation at break of the elastomer is 332% at the maximum.

As is clear from FIG. 2, the bending strength and the bending modulus of the elastomer were 11.5MPa and 279MPa, respectively, when the antioxidant was 4010.

As can be seen from Table 1, the effect of the antioxidants MB and 1010 was significant in improving the impact properties, and the impact properties of the elastomer were greatly improved.

TABLE 1 impact Properties of SBR/BR/PP thermoplastic elastomers

As can be seen from fig. 3, the flowability of the elastomer is optimized when the antioxidant is 4010.

Examples 4 to 6

Styrene Butadiene Rubber (SBR)/Butadiene Rubber (BR) are mixed according to different proportions of 100:0, 75:25, 50:50 and the like, 5 parts of zinc oxide, 2 parts of stearic acid, 40 parts of white carbon black, 40102 parts of anti-aging agent, 2 parts of promoter M, 2 parts of promoter DM, 4 parts of sulfur and 40 parts of plasticizer DOP. The feeding sequence is as follows: SBR \ BR 2min zinc oxide, stearic acid 2min white carbon black and DOP 4min, and banburying conditions are as follows: t is 45 ℃ and n is 15 rpm. And (3) after internal mixing is finished, taking out the rubber material, placing the rubber material into an open mill for open milling, and adding the accelerators DM and M and sublimed sulfur in the open milling process. The accelerators DM and M and the sublimed sulfur are fully and uniformly dispersed in the rubber material by adopting a triangular bag making mode, and the rubber material can be taken down from the internal mixer after the color of the rubber material is uniform and the surface is smooth and flat. Vulcanizing on a flat vulcanizing machine, preparing samples and testing the rubber performance. The compounded rubbers prepared from SBR/BR in the proportion of 100:0, 75:25 and 50:50 are respectively named as M4-M6.

As can be seen from FIG. 4, in the SBR/BR composite rubber, the maximum value is reached at a BR content of 25%. The elongation at break of the rubber is 631.59% at most, which is 29.33% higher than that of single SBR rubber, so that the tensile property of the composite rubber is influenced by the BR content to a certain extent. As can be seen from FIG. 5, the tear strength of the SBR/BR composite rubber increased after decreasing. This may be due to the fact that the intermolecular forces of the two rubbers change with a change in the ratio.

As can be seen from fig. 6, the hardness of the compounded rubber is the highest at SBR: BR of 75:25, and then decreases as the BR content continues to increase.

As can be seen from Table 2, the electrical resistance of the compounded rubber decreased with the increase of the BR content.

TABLE 2 Material resistance Properties of compounded rubbers in different proportions

Examples 7 to 11

In examples 7 to 11, the same procedures as in examples 4 to 6 were carried out to investigate that the antioxidants were MB, 4010 and 1010, and the amounts added were MB 2 parts, 40102 parts, 40101.5 parts, 40102.5 parts and 10101 parts, respectively, and the compounded rubbers thus obtained were designated as M7, M8, M9, M10 and M11, respectively.

As can be seen from FIG. 7, the tensile strength of the compounded rubber was the greatest when the antioxidant 4010 was used in an amount of 1.5 parts. When the anti-aging system is MB, the elongation at break of the compounded rubber is 604.81% at most.

As can be seen from fig. 8, when the anti-aging system is MB, the tear strength of the compounded rubber is the greatest, and the change in the amount of 4010 does not greatly affect the tear strength of the compounded rubber.

As can be seen from fig. 9, when the antioxidant 4010 is used in an amount of 1.5 parts, the volume resistance and surface resistance of the compounded rubber are minimized.

Examples 12 to 14

Examples 12-14 procedures in the same manner as in example 1, styrene-butadiene rubber (SBR)/Butadiene Rubber (BR) were prepared in different ratios of 100:0, 75:25 and 50:50 to prepare PP/SBR/BR thermoplastic elastomers designated as M12, M13 and M14, respectively.

As can be seen from fig. 10, when SBR/BR was 75/25, the tensile strength of the PP/SBR/BR thermoplastic elastomer was 17.16MPa, and the elongation at break reached a maximum of 284%.

As is clear from Table 3, when SBR/BR was 75/25, the flexural strength was 16.5MPa, the flexural modulus was 462MPa, and the impact strength was 25.8KJ/m²。

TABLE 3 influence of different SBR/BR ratios on the thermoplastic elastomer Properties of Polypropylene/styrene-butadiene rubber/butadiene rubber

Sample (I)	Flexural Strength/MPa	Modulus of elasticity/MPa	Impact strength KJ/m²
				M12	16.3	439	15.9
M13	16.5	462	25.8
				M14	15	400	29.7

Examples 15 to 18

In examples 15-18, the process for preparing thermoplastic elastomers was similar to examples 12-14, except that in examples 15-18, the SBR/BR ratio was 75:25, the dynamic vulcanization extrusion conditions were different during the dynamic vulcanization, and Table 4 is the dynamic vulcanization extrusion conditions. The extrusion conditions are referred to as C1, C2, C3 and C4, respectively. The prepared thermoplastic elastomers are respectively named as M15-M18.

TABLE 4 dynamic vulcanization extrusion conditions

As can be seen from Table 5, different dynamic vulcanization extrusion conditions have a greater effect on the properties of the thermoplastic elastomer, with dynamic vulcanization extrusion condition C2 being preferred in view of the properties and process feasibility.

TABLE 5 Effect of dynamic vulcanization extrusion conditions on Polypropylene/styrene butadiene rubber/butadiene rubber thermoplastic elastomer Properties

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. A compounded rubber thermoplastic elastomer characterized in that: the rubber comprises composite rubber and polypropylene, wherein the mass ratio of the composite rubber to the polypropylene is 4:6, and the composite rubber comprises the following components in parts by mass:

75 parts of styrene butadiene rubber;

25 parts of butadiene rubber;

5 parts by mass of zinc oxide;

2 parts by mass of stearic acid;

40 parts of white carbon black;

40102 parts by mass of an antioxidant;

accelerator M2 in parts by mass;

2 parts by mass of an accelerator DM;

3 parts of sublimed sulfur;

40 parts by mass of plasticizer DOP.

2. A dynamic vulcanized polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer is characterized in that: the rubber composition comprises composite rubber and polypropylene, wherein the mass ratio of the composite rubber to the polypropylene is 4:6, and the composite rubber comprises the following components in parts by weight:

50-100 parts of styrene butadiene rubber;

0-50 parts of butadiene rubber;

3 parts of a vulcanizing agent;

2-4 parts of an accelerator;

0-2 parts of an anti-aging agent;

0-40 parts of a filler;

0-40 parts of plasticizer;

the styrene butadiene rubber: the mass ratio of the butadiene rubber satisfies 75: 25.

3. The dynamically vulcanized polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer according to claim 1, wherein: the polypropylene is homo-polypropylene or co-polypropylene, the vulcanizing agent is sulfur, the accelerator is one or a combination of zinc oxide, an accelerator M and an accelerator DM, the anti-aging agent is an anti-aging agent 4010, an anti-aging agent MB or an anti-aging agent 1010, the filler is white carbon black, the plasticizer is DOP, and the using amount of the filler is 0-40 parts.

4. A process for producing the dynamically vulcanized polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer according to any one of claims 2 to 3, which comprises:

s1, weighing the polypropylene, the styrene-butadiene rubber, the vulcanizing agent, the accelerator, the anti-aging agent, the filler and the plasticizer according to the formula dosage;

s2, banburying the styrene-butadiene rubber and the butadiene rubber weighed in the S1, an anti-aging agent, an antioxidant, a filler, a plasticizer and an auxiliary agent in a banbury mixer at the banburying temperature of 40-50 ℃, and uniformly mixing;

S3, mixing the mixed rubber obtained in the step S2, a vulcanizing agent and an accelerator on an open mill to obtain mixed rubber;

s4, cutting the mixed rubber prepared in the S3 into long rubber strips with the width of 10-20 mm;

s5, melting and blending the polypropylene and the long rubber prepared by the S4 by a double-screw extruder at the temperature of 165 ℃ and 205 ℃ and the rotating speed of 150 ℃ and 500rpm to prepare the polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer through dynamic vulcanization extrusion and granulation;

s6, carrying out melt blending and dynamic vulcanization on the polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer and polypropylene to obtain a mixed material;

and S7, extruding and granulating the dynamically vulcanized mixed material to obtain the dynamically vulcanized polypropylene/styrene-butadiene rubber/butadiene composite rubber thermoplastic elastomer.

5. The method of claim 4, wherein in S1, the conditions of the first mixing include: the temperature is 40-50 ℃, the time is 10-15 min, the mixing is carried out in an open mill or an internal mixer, and the rotating speed of the internal mixer is 15-25 rpm.

6. The method of claim 4, wherein the melt blending conditions comprise: the temperature is 165-205 ℃, the time is 3-5min, the melt blending and the dynamic vulcanization are carried out in a double-screw extruder, and the screw rotating speed of the double-screw extruder is 150-300 rpm.