Method for preparing environment-friendly asphalt material from recycled plastic and recycled oil

Abstract

The invention relates to the field of high polymer materials, in particular to a method for preparing an environment-friendly asphalt material from recycled plastic and recycled oil. The method comprises the following steps: (1) preparing pretreated recovered oil; (2) preparing pretreated polymer powder; (3) heating the pretreated recycled oil, and adding the pretreated polymer powder at a certain rate to prepare a component A; and (4) adding the component A and the functional additive into the matrix asphalt at 140-170 DEG C according to a certain rate, and fully stirring to obtain the environment-friendly asphalt material. According to the scheme, recycled plastic and recycled oil are selected as raw materials, the range of the raw materials is widened, and meanwhile cyclic utilization of resources is facilitated; according to the preparation process, all the components can be fully dispersed, so that the environment-friendly asphalt material with relatively good performance can be obtained after recycled plastic and recycled oil enter the matrix asphalt.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly relates to a method for preparing an environmentally friendly asphalt material from recycled plastics and recycled oils. Background Art

[0002] Modified asphalt is an important way for the resource utilization of polymer waste and various waste oils. However, there are many types of recycled polymeric waste, and not all types can be well compatible with asphalt. Moreover, asphalt is a substance with complex components, and the light asphalt therein will cause the polymer to swell, thereby affecting the performance. Recycled oils such as waste engine oil and waste cooking oil may contain a large amount of impurities (metal particles, moisture, acidic substances), and the mixing of these substances will also deteriorate the performance of asphalt.

[0003] CN 110948726 A discloses a method for preparing a waste plastic modified environmentally friendly asphalt material, which includes the following steps: Step 1: Break and grind waste plastics, and centrally collect the ground powder; Step 2: Mix asphalt concrete and a modifier and feed them into a mixing chamber for stirring; Step 3: While stirring, feed the ground powder obtained in Step 1 into the mixing chamber; Step 4: While stirring, feed steam into the mixing chamber; Step 5: After each feeding of the ground powder, stir for 30 minutes and output the mixture. This method directly adds waste plastics in solid form, and how to uniformly disperse plastic particles in asphalt is a common problem.

[0004] CN 113683897 B proposes an environmentally friendly modified asphalt and its preparation method, belonging to the technical field of building materials, and solving the technical problem of poor anti-aging performance of recycled asphalt in the prior art. The environmentally friendly modified asphalt includes the following raw materials in parts by weight: 75-80 parts of aged asphalt, 60-70 parts of new asphalt, 12-18 parts of styrene-butadiene rubber powder, and 7-11 parts of a regenerant. The preparation method of this asphalt: Blend the aged asphalt and the new asphalt, use waste engine oil for lubrication and dilution and supplement the oil content, then add styrene-butadiene rubber powder and rubber oil to make the rubber powder absorb the oil and swell to improve the plasticity of asphalt, and finally add a regenerant containing an antioxidant and use coal ash powder as a filler to adjust the hardness of asphalt. Among them, the antioxidant uses nano-silica as a carrier and grafts imino groups, which has an anti-aging effect. The nano-scale powder and its unique spatial network structure are dispersed in asphalt to improve the strength of asphalt. This scheme mainly recycles aged asphalt and does not propose the utilization of recycled plastics. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a method for preparing an environmentally friendly asphalt material from recycled plastics and recycled oils. The prepared environmentally friendly asphalt material has good performance, can meet the engineering requirements, and is conducive to environmental protection and resource recovery at the same time.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A method for preparing an environmentally friendly asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 2% - 5% of the weight of the recycled oil to the recycled oil, stir well for 30 min - 60 min, and then filter to obtain pretreated recycled oil; the composition of the recycled oil is 85% - 90% recycled engine oil, and the rest is liquid kitchen waste grease; Step (2): Wash, dry, crush the recycled plastics, and sieve them through a 20 - mesh to 50 - mesh sieve, and take the sieved part as pretreated polymer powder; Step (3): Heat the pretreated recycled oil obtained in step (1) to 180°C - 200°C, introduce nitrogen, and under stirring conditions, add the pretreated polymer powder at a rate of 1% - 3% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 0.5 - 1 times that of the pretreated recycled oil, and then add the pretreated polymer powder at a rate of 0.3% - 0.5% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 3 - 5 times that of the pretreated recycled oil, continue stirring for 30 min - 60 min, filter out particulate matter, and cool down to 140°C - 170°C to obtain component A; Step (4): Heat the base asphalt to 140°C - 170°C, and under stirring conditions, add component A at a rate of 0.05% - 0.1% of the weight of the base asphalt per minute until the mass of component A is 5% - 10% of the weight of the base asphalt; at the same time, add a functional additive at a rate of 0.025% - 0.1% of the weight of the base asphalt per minute until the mass of the functional additive is 3% - 5% of the weight of the base asphalt; after the addition is completed, continue stirring for 30 min - 60 min to obtain an environmentally friendly asphalt material; the functional additive includes: by weight, 5 - 8 parts of modified filler, 0.5 - 1 part of antioxidant, and 0.5 - 1 part of pH regulator; the preparation method of the modified filler includes: by weight, add 10 - 20 parts of nano - filler and 0.1 - 0.3 part of coupling agent to 10 - 30 parts of water, ball - mill for 120 min - 180 min, unload, and dry to obtain the modified filler.

[0007] The purpose of this solution is to prepare an environmentally friendly asphalt material from recycled plastics and recycled oils. This solution has the following characteristics: 1. Recycled plastics and recycled oils are selected as raw materials to prepare environmentally friendly asphalt, which is conducive to resource recycling. The general idea of this solution is as follows: The recycled plastics and recycled oils are purified separately, mainly to remove impurities, such as sand grains mixed in the recycled plastics, metal particles, carbon particles, acidic substances, etc. in the recycled oils. After the recycled oils are purified, pretreated recycled oils are obtained. The pretreated recycled oils are heated, and then the polymer aggregates are crushed into pretreated polymer powders and slowly added to the pretreated recycled oils. At the beginning of this process, the amount of the pretreated recycled oil phase is large, which can quickly melt and fully disperse the pretreated polymer powders. As the addition amount of the pretreated polymer powders increases, the melting rate of the pretreated polymer powders slows down. Therefore, the addition rate should be slowed down accordingly until the expected addition amount is reached. Due to the high temperature, this process requires a certain atmosphere protection, and at the same time, this nitrogen atmosphere can also remove the moisture in the pretreated recycled oils. During this process, a part of the liquid kitchen waste grease in the pretreated recycled oils contains a certain amount of vegetable oils, such as soybean oil, etc., which is similar to a plasticizer and can reduce the melting temperature of the pretreated polymer powders. Moreover, the pretreated recycled oils can improve the fluidity of component A, so that component A can be fully dispersed in the matrix asphalt under the conditions of 140°C to 170°C. At the same time, to further ensure the dispersibility of component A, in this solution, component A is added to the matrix asphalt at a certain rate, and at the same time, modified fillers are added. After adding to the preset mass, continue to stir for a certain time to ensure the uniformity of dispersion, and then cool to obtain the environmentally friendly asphalt material.

[0008] 2. The fluidity of the molten recycled plastics is improved by the pretreated recycled oils and incorporated into the matrix asphalt in a liquid state. The pretreated polymer powders prepared in step (2) of this solution only pass through a 20-mesh to 50-mesh sieve. This is mainly because during the crushing process of the recycled plastics, surface micro-melting occurs, resulting in agglomeration, and it is difficult to obtain finer powders through simple screening. Due to the problem of interfacial compatibility between the thermosetting recycled plastics and the matrix asphalt, under the particle size conditions of the polymer powders in this solution, it is difficult to be completely combined with the matrix asphalt, which will reduce the strength of the finished asphalt. Moreover, in this solution, to fully disperse the recycled plastics and recycled oils in the matrix asphalt, component A needs to be incorporated in a liquid form. Therefore, in step (3) of the solution, the thermosetting recycled plastics are filtered out, and at the same time, the high-melting-point thermoplastic recycled plastics and some polar thermoplastic recycled plastics that are difficult to melt are also filtered out.

[0009] 3. The present solution adds modified fillers to the functional additives to adjust the final properties of the environmentally friendly asphalt materials. Adding modified nano-fillers can balance the melt viscosity difference. The components in the base asphalt and component A of the present solution are complex. The modified nano-fillers can be selectively distributed in the high-viscosity phase (such as high-viscosity polymers). This is because the modified nano-fillers exist in the gaps between polymer chains, weaken the entanglement between chains, can reduce the flow resistance. At the same time, under the shear force during the stirring process, the modified nano-fillers are arranged along the flow direction, which can promote the slip of the molecular chains of the high-viscosity phase and make the viscosities of the components in the system uniform.

[0010] Preferably, in step (1), the deacidifying agent is activated clay or zeolite powder; the average particle size of the deacidifying agent is 10 μm to 100 μm.

[0011] Preferably, in step (1), the proportion of unsaturated hydrocarbon chains in the recycled oil ≤ 20%.

[0012] A high content of unsaturated hydrocarbon chains in the recycled oil will affect the antioxidant property of the finished product.

[0013] Preferably, in step (2), in the recycled plastics, the mass proportion of non-polar thermoplastic recycled plastics is 85% to 90%.

[0014] To ensure production efficiency, the main component of the recycled plastics should be non-polar thermoplastic recycled plastics. This is mainly because non-polar thermoplastic recycled plastics can be melted and dispersed in the pre-treated recycled oil, while polar thermoplastic recycled plastics may have poor compatibility with the non-polar oil and are prone to phase separation, resulting in unstable performance.

[0015] Preferably, in step (3), the moisture content of the nitrogen is less than 0.5%.

[0016] Introducing nitrogen with a moisture content less than 0.5% is mainly to remove the moisture in the pre-treated recycled oil.

[0017] Preferably, in step (3), the particle size of the filtered particulate matter is greater than 50 mesh.

[0018] The particle size of the filtered particulate matter is greater than 50 mesh. That is, after screening through a 50-mesh sieve, the particulate matter is the material that has not passed through the sieve, mainly including thermosetting recycled plastic particles, swollen high-melting-point thermoplastic recycled plastics, etc.

[0019] Preferably, in step (4), the antioxidant is one of phenolic antioxidants, phosphorus antioxidants, and imine antioxidants; the pH regulator is one or more of sodium carbonate, potassium carbonate, sodium hydroxide, or potassium hydroxide; the nano-filler is one or more of nano-metal oxide powder, nano-silica powder, nano-carbonate powder, and nano-carbon elemental powder.

[0020] The nano-metal oxide powders include nano-magnesium oxide, nano-aluminum oxide, nano-titanium oxide, etc.; the nano-carbonate powders include nano-calcium carbonate, nano-magnesium carbonate, etc.; the nano-carbon elemental powders include carbon nanotubes, graphene, etc.

[0021] Preferably, in step (4), the coupling agent is a silane coupling agent or a titanate coupling agent.

[0022] Preferably, in step (4), the matrix asphalt is petroleum asphalt or coal asphalt.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. Recycled plastics and recycled oils are selected as raw materials, which broadens the range of raw materials and is conducive to the recycling of resources at the same time; 2. The preparation process of this solution is mainly aimed at making each component fully dispersed technically, so that the recycled plastics and recycled oils can obtain a better-performing environmental protection asphalt material after entering the matrix asphalt. This solution uses the heated recycled oils to melt the thermoplastic recycled plastics, limits the composition of the recycled oils, the addition rate of the recycled plastics, etc. After the addition of the recycled plastics is completed, the particulate matter is filtered out to reduce the influence of the particulate matter of the thermosetting recycled plastics. Finally, under the conditions of 140°C to 170°C, the recycled plastics and recycled oils can enter the matrix asphalt in a liquid state. At the same time, functional additives are added and the addition rate is limited to ensure the mixing uniformity of each component. Specific Embodiments

[0024] The following describes the preferred embodiments of the present invention. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention. Example 1

[0025] A method for preparing an environmental protection asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil, stir well at a rotation speed of 600 r / min for 60 min, and then filter to obtain pretreated recycled oil; the composition of the recycled oil is 90% recycled engine oil, and the rest is liquid kitchen waste oil; the deacidifying agent is zeolite powder with an average particle size of 50 μm; the proportion of unsaturated hydrocarbon chains in the recycled engine oil is 15%; Step (2): Wash the recycled plastics alternately with alcohol and water, dry them, crush them, and pass through a 50-mesh sieve. Take the sieved part as the pretreated polymer powder; the mass proportion of non-polar thermoplastic recycled plastics is 90%; Step (3): Heat the pretreated recycled oil obtained in step (1) to 190 °C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pretreated polymer powder at a rate of 1% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 0.5 times that of the pretreated recycled oil. Subsequently, add the pretreated polymer powder at a rate of 0.3% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 4 times that of the pretreated recycled oil. Continue stirring for 60 min, then filter out the particulate matter with a particle size greater than 50 mesh, and cool down to 160 °C to obtain component A; the moisture content of nitrogen is less than 0.5%; Step (4): Heat the petroleum asphalt to 160 °C, and under the stirring condition of 600 r / min, add component A at a rate of 0.1% of the weight of the petroleum asphalt per minute until the mass of component A is 8% of the weight of the petroleum asphalt; at the same time, add the functional additive at a rate of 0.025% of the weight of the petroleum asphalt per minute until the mass of the functional additive is 4% of the weight of the petroleum asphalt; after the addition is completed, continue stirring for 60 min to obtain the environmentally friendly asphalt material; the functional additive includes: by weight, 8 parts of modified filler, 1 part of antioxidant, and 0.8 part of pH regulator; the preparation method of the modified filler includes: by weight, mix 15 parts of a mixture of nano-titanium oxide and nano-silica powder in a weight ratio of 1:1, and add 0.2 part of K55 silane coupling agent to 20 parts of water and ball mill for 150 min, unload, and dry to obtain the modified filler; the antioxidant is an imide antioxidant; the pH regulator is a mixture of sodium carbonate and sodium hydroxide with a mass ratio of 3:1. Example 2

[0026] A method for preparing an environmentally friendly asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 3% of the weight of the recycled oil to the recycled oil, stir thoroughly at a rotation speed of 600 r / min for 30 min, and then filter to obtain the pretreated recycled oil; the composition of the recycled oil is 85% recycled engine oil, and the rest is liquid kitchen waste oil; the deacidifying agent is activated clay with an average particle size of 56 μm; the proportion of unsaturated hydrocarbon chains in the recycled engine oil is ≤20%; Step (2): Wash the recycled plastic alternately with alcohol and clean water, then dry, crush, and pass through a 40-mesh sieve, and take the sieved part as the pretreated polymer powder; the mass proportion of non-polar thermoplastic recycled plastic is 85%; Step (3): Heat the pretreated recycled oil obtained in step (1) to 180 °C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pretreated polymer powder at a rate of 2% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 1 time that of the pretreated recycled oil. Subsequently, add the pretreated polymer powder at a rate of 0.5% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 5 times that of the pretreated recycled oil. Continue stirring for 60 min, then filter out the particulate matter, and cool down to 150 °C to obtain component A; the water content of the nitrogen is less than 0.5%; the particle size of the particulate matter filtered out is greater than 50 mesh; Step (4): Heat the matrix asphalt to 150 °C, and under the stirring condition of 600 r / min, add component A at a rate of 0.1% of the weight of the matrix asphalt per minute until the mass of component A is 10% of the weight of the matrix asphalt; at the same time, add the functional additive at a rate of 0.1% of the weight of the matrix asphalt per minute until the mass of the functional additive is 5% of the weight of the matrix asphalt; after the addition is completed, continue stirring for 30 min to obtain the environmentally friendly asphalt material; the functional additive includes: by weight, 5 parts of modified filler, 1 part of antioxidant, and 0.5 part of pH regulator; the preparation method of the modified filler includes: by weight, add 5 parts of nano-silica powder and 5 parts of nano-carbon elemental powder, and 0.1 part of titanate coupling agent to 10 parts of water and ball mill for 120 min, unload, and dry to obtain the modified filler; the antioxidant is one of imine antioxidants; the pH regulator is a mixture of potassium carbonate and sodium hydroxide with a mass ratio of 5:1. Example 3

[0027] A method for preparing an environmentally friendly asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil, stir thoroughly at a rotation speed of 600 r / min for 60 min, and then filter to obtain the pretreated recycled oil; the composition of the recycled oil is 88% recycled engine oil, and the rest is liquid kitchen waste grease; the deacidifying agent is zeolite powder with an average particle size of 71 μm; the proportion of unsaturated hydrocarbon chains in the recycled engine oil is 18%; Step (2): Wash the recycled plastic alternately with alcohol and clean water, then dry, crush, and pass through a 20-mesh sieve. Take the sieved part as the pretreated polymer powder; the mass proportion of non-polar thermoplastic recycled plastic is 85%; Step (3): Heat the pre-treated recycled oil obtained in step (1) to 200°C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pre-treated polymer powder at a rate of 3% of the weight of the pre-treated recycled oil per minute until the added mass of the pre-treated polymer powder is 0.5 times that of the pre-treated recycled oil. Subsequently, add the pre-treated polymer powder at a rate of 0.3% of the weight of the pre-treated recycled oil per minute until the added mass of the pre-treated polymer powder is 3 times that of the pre-treated recycled oil. Continue stirring for 60 min, filter out the particulate matter, and cool down to 165°C to obtain Component A; the water content of the nitrogen is less than 0.5%; the particle size of the filtered particulate matter is greater than 50 mesh; Step (4): Heat the matrix asphalt to 165°C, and under the stirring condition of 600 r / min, add Component A at a rate of 0.1% of the weight of the matrix asphalt per minute until the mass of Component A is 10% of the weight of the matrix asphalt; at the same time, add the functional additive at a rate of 0.1% of the weight of the matrix asphalt per minute until the mass of the functional additive is 5% of the weight of the matrix asphalt; after the addition is completed, continue stirring for 60 min to obtain the environmental protection type asphalt material; the functional additive includes: by weight, 5 parts of modified filler, 0.5 part of antioxidant, and 0.5 part of pH regulator; the preparation method of the modified filler includes: by weight, add 20 parts of nano calcium carbonate and 0.2 part of silane coupling agent to 20 parts of water, ball mill for 150 min, unload, and dry to obtain the modified filler; the antioxidant is a phenolic antioxidant; the pH regulator is potassium hydroxide. Comparative Example 1

[0028] A method for preparing an environmental protection type asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): Wash the recycled plastics alternately with alcohol and water, dry, crush, and pass through a 50-mesh sieve. Take the sieved part as the pre-treated polymer powder; the mass ratio of the non-polar thermoplastic recycled plastics is 90%; Step (2): Add the pre-treated polymer powder to the recycled oil at 4 times the weight of the recycled oil, and stir for 200 min under the stirring condition of 600 r / min to obtain Component A; Step (3): Heat the base asphalt to 150°C. Under the stirring condition of 600 r / min, add Component A at a rate of 0.1% of the weight of the base asphalt per minute until the mass of Component A is 8% of the weight of the base asphalt. At the same time, add the functional additive at a rate of 0.1% of the weight of the base asphalt per minute until the mass of the functional additive is 5% of the weight of the base asphalt. After the addition is completed, continue stirring for 30 min to obtain the environmental protection type asphalt material. The functional additive includes: by weight, 5 parts of modified filler, 1 part of antioxidant, and 0.5 part of pH regulator. The preparation method of the modified filler includes: by weight, add 5 parts of nano-silica powder, 5 parts of nano-carbon elemental powder, and 0.1 part of titanate coupling agent to 10 parts of water and ball mill for 120 min, unload, and dry to obtain the modified filler. The antioxidant is one of imine antioxidants. The pH regulator is a mixture of potassium carbonate and sodium hydroxide with a mass ratio of 5:1. Comparative Example 2

[0029] A method for preparing an environmental protection type asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil, fully stir at a rotation speed of 600 r / min for 60 min, and then filter to obtain the pretreated recycled oil. The composition of the recycled oil is 70% recycled engine oil, and the rest is liquid kitchen waste oil. The deacidifying agent is zeolite powder with an average particle size of 48 μm. The proportion of unsaturated hydrocarbon chains in the recycled engine oil is 15%. Step (2): Wash the recycled plastics alternately with alcohol and clean water, then dry, crush, and pass through a 50-mesh sieve. Take the sieved part as the pretreated polymer powder. The mass proportion of non-polar thermoplastic recycled plastics is 90%. Step (3): Heat the pretreated recycled oil obtained in Step (1) to 190°C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pretreated polymer powder at a rate of 1% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 0.5 times that of the pretreated recycled oil. Subsequently, add the pretreated polymer powder at a rate of 0.3% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 4 times that of the pretreated recycled oil. Continue stirring for 60 min, filter out the particles with a particle size greater than 50 mesh, and cool down to 160°C to obtain Component A. The moisture content of nitrogen is less than 0.5%. Step (4): Heat the petroleum asphalt to 160 °C. Under the stirring condition of 600 r / min, add Component A at a rate of 0.1% of the weight of the petroleum asphalt per minute until the mass of Component A is 8% of the weight of the petroleum asphalt; at the same time, add the functional auxiliary agent at a rate of 0.025% of the weight of the petroleum asphalt per minute until the mass of the functional auxiliary agent is 4% of the weight of the petroleum asphalt; after the addition is completed, continue stirring for 60 min to obtain the environmental protection type asphalt material; the functional auxiliary agent includes: by weight, 8 parts of modified filler, 1 part of antioxidant and 0.8 part of pH regulator; the preparation method of the modified filler includes: by weight, mix 15 parts of a mixture of nano-titanium oxide and nano-silica powder in a weight ratio of 1:1, and 0.2 part of K55 silane coupling agent, add them to 20 parts of water and ball mill for 150 min, unload the material, and dry to obtain the modified filler; the antioxidant is an imine antioxidant; the pH regulator is a mixture of sodium carbonate and sodium hydroxide in a mass ratio of 3:1. Comparative Example 3

[0030] A method for preparing an environmental protection type asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil, stir well at a rotation speed of 600 r / min for 60 min, and then filter to obtain the pretreated recycled oil; the composition of the recycled oil is 90% recycled engine oil, and the rest is liquid kitchen waste oil; the deacidifying agent is zeolite powder with an average particle size of 50 μm; the proportion of unsaturated hydrocarbon chains in the recycled engine oil is 15%; Step (2): Wash the recycled plastics alternately with alcohol and clean water, then dry, crush, and pass through a 50-mesh sieve. Take the sieved part as the pretreated polymer powder; the mass proportion of non-polar thermoplastic recycled plastics is 90%; Step (3): Heat the pretreated recycled oil obtained in Step (1) to 200 °C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pretreated polymer powder at a rate of 5% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 0.5 times that of the pretreated recycled oil, and then add the pretreated polymer powder at a rate of 1% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 5 times that of the pretreated recycled oil. Continue stirring for 60 min, filter out the particulate matter, and cool down to 160 °C to obtain Component A; the moisture content of the nitrogen is less than 0.5%; the particle size of the filtered particulate matter is larger than 50 mesh; Step (4): Heat the petroleum asphalt to 160 °C. Under the stirring condition of 600 r / min, add Component A at a rate of 0.1% of the weight of the petroleum asphalt per minute until the mass of Component A is 8% of the weight of the petroleum asphalt. At the same time, add the functional auxiliary agent at a rate of 0.025% of the weight of the petroleum asphalt per minute until the mass of the functional auxiliary agent is 4% of the weight of the petroleum asphalt. After the addition is completed, continue stirring for 60 min to obtain the environmental protection type asphalt material. The functional auxiliary agent includes: by weight, 8 parts of modified filler, 1 part of antioxidant, and 0.8 part of pH regulator. The preparation method of the modified filler includes: by weight, mix 15 parts of a mixture of nano-titanium oxide and nano-silica powder in a weight ratio of 1:1, and 0.2 part of K55 silane coupling agent, add them to 20 parts of water and ball mill for 150 min, unload the material, and dry it to obtain the modified filler. The antioxidant is an imine antioxidant. The pH regulator is a mixture of sodium carbonate and sodium hydroxide with a mass ratio of 3:1. Comparative Example 4

[0031] A method for preparing an environmental protection type asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil. After fully stirring at a rotation speed of 600 r / min for 60 min, filter to obtain the pretreated recycled oil. The composition of the recycled oil is 90% recycled engine oil, and the rest is liquid kitchen waste grease. The deacidifying agent is zeolite powder with an average particle size of 50 μm. The proportion of unsaturated hydrocarbon chains in the recycled engine oil is 15%. Step (2): Wash the recycled plastics alternately with alcohol and clean water, then dry, crush, and pass through a 50-mesh sieve. Take the sieved part as the pretreated polymer powder. The mass proportion of non-polar thermoplastic recycled plastics is 90%. Step (3): Pass the pretreated polymer powder obtained in Step (2) into nitrogen for melting. Under the stirring condition of 600 r / min, add the pretreated recycled oil accounting for 25% of the mass of the pretreated polymer powder, stir for 60 min, filter out the particles with a particle size greater than 50 mesh, and cool down to 160 °C to obtain Component A. The moisture content of nitrogen is less than 0.5%. Step (4): heating the petroleum asphalt to 160° C., adding component A at a rate of 0.1% by weight of the petroleum asphalt per minute under stirring conditions of 600 r / min, until the mass of component A is 8% by weight of the petroleum asphalt; at the same time, adding a functional additive at a rate of 0.025% by weight of the petroleum asphalt per minute, until the mass of the functional additive is 4% by weight of the petroleum asphalt; continuing to stir for 60 minutes after the addition is completed, to obtain an environmentally friendly asphalt material; the functional additive comprises: by weight, 8 parts of a modified filler, 1 part of an antioxidant and 0.8 parts of a pH adjuster; the preparation method of the modified filler comprises: by weight, adding 15 parts of a mixture of nano titanium oxide and nano silicon dioxide powder in a weight ratio of 1:1 and 0.2 parts of a K55 silane coupling agent to 20 parts of water, ball milling for 150 minutes, unloading, and drying to obtain a modified filler; the antioxidant is an imine antioxidant; and the pH adjuster is a mixture of sodium carbonate and sodium hydroxide in a weight ratio of 3:1. Comparative Example 5

[0032] A method for preparing environmentally friendly asphalt materials by recycling plastics and recycled oils comprises the following steps: Step (1): adding a deacidifying agent of 5% by weight of the recovered oil to the recovered oil, stirring the recovered oil at a speed of 600 r / min for 60 minutes, and filtering the recovered oil to obtain pretreated recovered oil; the recovered oil is composed of 90% of recovered engine oil and the rest of liquid kitchen waste oil; the deacidifying agent is zeolite powder with an average particle size of 50 μm; the unsaturated hydrocarbon chain accounts for 15% of the recovered engine oil; Step (2): The recycled plastic is washed alternately with alcohol and clean water, then dried, crushed, and passed through a 50-mesh sieve, and the sieved portion is taken as the pre-treated polymer powder; the mass proportion of non-polar thermoplastic recycled plastic is 90%; Step (3): Heat the pretreated recycled oil obtained in step (1) and the heated pretreated polymer powder obtained in step (2) to 160 °C respectively, and simultaneously add them to petroleum asphalt at 160 °C. Under the stirring condition of 600 r / min, the adding rate of the pretreated recycled oil is 0.02% of the weight of the petroleum asphalt per minute, and the adding rate of the pretreated polymer is 0.08% of the weight of the petroleum asphalt per minute, until the total mass of the added pretreated recycled oil and pretreated polymer is 8% of the weight of the petroleum asphalt; at the same time, add a functional additive at a rate of 0.025% of the weight of the petroleum asphalt per minute until the mass of the functional additive is 4% of the weight of the petroleum asphalt; after the addition is completed, continue stirring for 60 min to obtain an environmental protection type asphalt material; the functional additive includes: by weight, 8 parts of modified filler, 1 part of antioxidant and 0.8 part of pH regulator; the preparation method of the modified filler includes: by weight, mix 15 parts of a mixture of nano-titanium oxide and nano-silica powder in a weight ratio of 1:1, and add 0.2 part of K55 silane coupling agent to 20 parts of water and ball mill for 150 min, unload, and dry to obtain the modified filler; the antioxidant is an imine antioxidant; the pH regulator is a mixture of sodium carbonate and sodium hydroxide in a mass ratio of 3:1. Comparative Example 6

[0033] A method for preparing an environmental protection type asphalt material from recycled plastics and recycled oils, comprising the following steps: Step (1): By weight percentage, add a deacidifying agent accounting for 5% of the weight of the recycled oil to the recycled oil, and stir thoroughly at a speed of 600 r / min for 60 min, then filter to obtain the pretreated recycled oil; the composition of the recycled oil is 90% recycled engine oil, and the rest is liquid kitchen waste grease; the deacidifying agent is zeolite powder with an average particle size of 50 μm; the proportion of unsaturated hydrocarbon chains in the recycled engine oil is 15%; Step (2): Wash the recycled plastics alternately with alcohol and water, then dry, crush, and pass through a 50-mesh sieve. Take the sieved part as the pretreated polymer powder; the mass proportion of non-polar thermoplastic recycled plastics is 90%; Step (3): Heat the pretreated recycled oil obtained in step (1) to 190 °C, introduce nitrogen, and under the stirring condition of 600 r / min, add the pretreated polymer powder at a rate of 1% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 0.5 times that of the pretreated recycled oil, and then add the pretreated polymer powder at a rate of 0.3% of the weight of the pretreated recycled oil per minute until the added mass of the pretreated polymer powder is 4 times that of the pretreated recycled oil. Continue stirring for 60 min, then filter out particles with a particle size greater than 50 mesh, and cool down to 160 °C to obtain Component A; the moisture content of nitrogen is less than 0.5%; Step (4): Heat the petroleum asphalt to 160 °C. Under the stirring condition of 600 r / min, add Component A at a rate of 0.1% of the weight of the petroleum asphalt per minute until the mass of Component A is 8% of the weight of the petroleum asphalt. At the same time, add the functional additive at a rate of 0.025% of the weight of the petroleum asphalt per minute until the mass of the functional additive is 4% of the weight of the petroleum asphalt. After the addition is completed, continue stirring for 60 min to obtain the environmental protection type asphalt material. The functional additive includes: by weight, 8 parts of filler, 1 part of antioxidant, and 0.8 part of pH regulator; the filler is a mixture of nano-titanium oxide and nano-silica powder in a weight ratio of 1:1; the antioxidant is an imine antioxidant; the pH regulator is a mixture of sodium carbonate and sodium hydroxide in a mass ratio of 3:1.

[0034] Testing method: 1. Penetration: At a temperature of 25 °C, use a 100-gram standard needle to vertically penetrate the asphalt specimen within 5 seconds. The depth of penetration (in 1 / 10 mm units) indicates that the higher the penetration value, the softer the asphalt and the lower the viscosity.

[0035] 2. Ductility: Measure the elongation length (in cm) at which the asphalt specimen breaks under standard conditions (25 °C, tensile speed of 5 cm / min) using a ductility tester. The larger the ductility value, the stronger the plasticity of the asphalt, and the target is ≥100 cm.

[0036] 3. Softening point: Test using the ring and ball method. Place the asphalt specimen in a copper ring of specific dimensions (diameter 16 mm, height 6 mm), place a standard steel ball on the specimen, and then heat at a specified rate (5 °C / min) until the asphalt softens. The higher the softening point, the better the heat resistance of the asphalt, and the target is 65 °C - 80 °C.

[0037] 4. Low-temperature cracking resistance: The asphalt is made into a beam specimen with a length of 125 ± 1 mm, a width of 12.5 ± 0.1 mm, and a height of 6.25 ± 0.1 mm. Apply a load of 1000 mN at -18 °C and measure the bending deformation of the specimen over time (60 s, 120 s, 240 s), and calculate the creep stiffness and creep rate. The qualified standard is S ≤ 300 MPa and m ≥ 0.3.

[0038] Table 1 Test comparison results

[0039] The purpose of this solution is to recycle waste plastics and waste oils. The physical properties need to meet the requirements of pavement asphalt materials in temperate regions. At 25 °C, the penetration is 60 - 70, and the ductility ≥100 cm. From the results in Table 1, it can be seen that the environmental protection type asphalt materials prepared in Examples 1 - 3 of this solution can meet the requirements in terms of performance.

[0040] The difference between Comparative Example 1 and Example 1 is that the recycled oil was not pretreated. Under the process of this solution, the molten recycled plastic is fully dispersed in the recycled oil. Due to the presence of engine oil, even when added to the matrix asphalt, the polymer swelling has been greatly reduced. However, in Comparative Example 1, the recycled oil was directly applied, which contains metal debris, residual carbon particles in the engine oil, pretreated polymer powder particles, etc., resulting in a low degree of binding with the asphalt and becoming a crack source of the asphalt in the low-temperature state, reducing its low-temperature anti-cracking performance. At the same time, the presence of acidic substances may accelerate the low-temperature anti-cracking performance of the aged asphalt and also affect the service life of the asphalt.

[0041] The difference between Comparative Example 2 and Example 1 is that the composition of the recycled oil is different. The proportion of recycled engine oil in the recycled oil is low, and the liquid kitchen waste grease will cause the melting effect to decline. At the same time, the soybean oil contained in the liquid kitchen waste grease has a plasticizer-like effect. If the content of this component is too high, it will cause the softening point to decrease and reduce the rutting resistance of the road surface when applied to the road surface.

[0042] The difference between Comparative Example 3 and Example 1 is that in step (3), the rate of adding the pretreated polymer powder to the pretreated recycled oil is too fast. Adding the pretreated polymer powder too fast will cause some of the pretreated polymer powder to agglomerate. Even non-polar thermoplastic recycled plastics may not be fully melted, resulting in incomplete dispersion and affecting the production rate in production. At the same time, since some non-polar thermoplastic recycled plastic particles may not be fully melted and enter the matrix asphalt, the matrix asphalt is not a pure substance, and the light oil present in it will cause these particles to swell and become a crack source, affecting the low-temperature anti-cracking performance. The same swelling and dispersion problems also exist in Comparative Example 4 and Comparative Example 5. The difference between Comparative Example 4 and Example 1 is that in step (3), the pretreated recycled oil is added to the melted pretreated polymer. When the pretreated recycled oil enters the pretreated polymer, it is found in the experiment that phase separation will occur during the stirring process. This shows that under the stirring action, the melted pretreated polymer is divided into aggregates formed by recycled plastics and cannot be fully dispersed, which makes it swell with the recycled oil or light asphalt. The difference between Comparative Example 5 and Example 1 is that the pretreated polymer powder in step (2) and the pretreated recycled oil in step (1) are heated separately and then added to the matrix asphalt, which also increases the difficulty of dispersion and there is swelling of polymer waste of high molecular weight. It can also be seen from these three comparative examples that the key technical difficulty of this solution lies in dispersion.

[0043] The difference between Comparative Example 6 and Example 1 is that the filler was not modified. The unmodified filler has poor compatibility with components such as asphalt, the filler agglomerates, and is easily a crack source, resulting in a decrease in ductility.

[0044] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for preparing environmentally friendly asphalt materials by recycling plastics and recycled oils, characterized in that: The following steps are involved: Step (1): adding a deacidifying agent to the recovered oil by weight percentage, stirring the oil sufficiently, and filtering the oil to obtain pre-treated recovered oil; the recovered oil comprises 85% to 90% of recovered engine oil and the rest of the recovered oil is liquid kitchen waste oil; Step (2): washing the recycled plastic, drying it, crushing it, and sieving it, and taking the sieved part as the pre-treated polymer powder; in the recycled plastic, the non-polar thermoplastic recycled plastic accounts for 85% to 90% by weight; Step (3): heating the pretreated recovered oil obtained in step (1) to 180°C to 200°C, introducing nitrogen, and slowly adding the pretreated polymer powder under stirring conditions until the added mass of the pretreated polymer powder is 3 to 5 times that of the pretreated recovered oil, continuing to stir, filtering out particulate matter, and cooling to 140°C to 170°C to obtain component A; Step (4): heat the base asphalt to 140°C to 170°C, and slowly add component A and the functional additive respectively under stirring conditions until the mass of component A is 5% to 10% of the weight of the base asphalt, and the mass of the functional additive is 3% to 5% of the weight of the base asphalt; After adding, continue stirring to obtain environmentally friendly asphalt material; The functional additive comprises: by weight, 5 to 8 parts of modified filler, 0.5 to 1 part of antioxidant and 0.5 to 1 part of pH adjuster; the preparation method of the modified filler comprises: by weight, adding 10 to 20 parts of nano filler and 0.1 to 0.3 parts of coupling agent to 10 to 30 parts of water, ball milling, unloading, drying, and obtaining the modified filler.

2. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (1), the deacidifying agent is activated clay or zeolite powder; the average particle size of the deacidifying agent is 10 μm to 100 μm.

3. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (1), the proportion of unsaturated hydrocarbon chains in the recovered engine oil is ≤20%.

4. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (3), the water content of the nitrogen is less than 0.5%.

5. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (3), the particle size of the filtered particles is greater than 50 mesh.

6. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (4), the antioxidant is one of a phenolic antioxidant, a phosphorus antioxidant, and an imine antioxidant; the pH adjuster is one or more of sodium carbonate, potassium carbonate, sodium hydroxide, or potassium hydroxide; and the nanofiller is one or more of nano metal oxide powder, nano silicon dioxide powder, nano carbonate powder, and nano carbon powder.

7. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (4), the coupling agent is a silane coupling agent or a titanate coupling agent.

8. The method for preparing environmentally friendly asphalt materials by recycling plastics and oils as claimed in claim 1, characterized in that: In step (4), the base asphalt is petroleum asphalt or coal asphalt.

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