阅读说明：本技术 纳米改性沥青改性剂及其制备方法 (Nano modified asphalt modifier and preparation method thereof ) 是由 刘滨 相丽敬 高刚 于 2021-09-23 设计创作，主要内容包括：本发明涉及沥青改性剂技术领域,具体涉及一种纳米改性沥青改性剂及其制备方法。所述纳米改性沥青改性剂,包含以下重量份数的原料：丁苯橡胶SBR100份,多壁碳纳米管0.5～3份,硬脂酸1～5份,碳酸钙20～40份,软化剂3～10份,聚乙烯蜡1～5份,塑解剂0.3～0.8份,偶联剂0.1～2份,分散助剂0.1～2份,隔离剂0.3～1份。本发明的自粘防水卷材沥青改性剂,只需要少量添加即可提高道路用沥青的相应性能,改性后的沥青低温性能好,软化点高,运动粘度小,耐磨性、抗撕裂性、导热性大幅提高,增加了道路寿命。(The invention relates to the technical field of asphalt modifiers, in particular to a nano modified asphalt modifier and a preparation method thereof. The nano modified asphalt modifier comprises the following raw materials in parts by weight: 100 parts of styrene butadiene rubber SBR, 0.5-3 parts of multi-walled carbon nanotube, 1-5 parts of stearic acid, 20-40 parts of calcium carbonate, 3-10 parts of softener, 1-5 parts of polyethylene wax, 0.3-0.8 part of peptizer, 0.1-2 parts of coupling agent, 0.1-2 parts of dispersing aid and 0.3-1 part of separant. The self-adhesive waterproof coiled material asphalt modifier can improve the corresponding performance of the road asphalt by only adding a small amount of the asphalt modifier, and the modified asphalt has good low-temperature performance, high softening point, low kinematic viscosity, greatly improved wear resistance, tear resistance and thermal conductivity and prolonged service life.)

1. The nanometer modified asphalt modifier is characterized by comprising the following raw materials in parts by weight:

2. the nano-modified asphalt modifier according to claim 1, wherein: the tube diameter of the multi-walled carbon nanotube is 8-15 nm, and the specific surface area is 230-280 m²The microstructure is an array structure.

3. The nano-modified asphalt modifier according to claim 1, wherein: the softening agent is at least one of polycyclic aromatic hydrocarbon rubber oil, naphthenic base rubber oil and aromatic base rubber.

4. The nano-modified asphalt modifier according to claim 1, wherein: the average molecular weight of the polyethylene wax is 2000-5000-.

5. The nano-modified asphalt modifier according to claim 1, wherein: the coupling agent is at least one of a silane coupling agent KH580, a silane coupling agent KH550 and a silane coupling agent KH 792.

6. The nano-modified asphalt modifier according to claim 1, wherein: the dispersing auxiliary agent is unsaturated fatty acid zinc salt.

7. The nano-modified asphalt modifier according to claim 1, wherein: the isolating agent is calcium stearate.

8. A method for preparing the nano modified asphalt modifier of any one of claims 1 to 7, which is characterized in that: the method comprises the following steps:

(1) adding Styrene Butadiene Rubber (SBR) into an internal mixer, pressing and banburying for 15-30s, extracting the bolt, adding the carbon nano tube, banburying for 50-80s, extracting the bolt, and discharging the glue to obtain carbon nano tube master batch with the mass fraction of the carbon nano tube of 10-20%;

(2) adding carbon nanotube master batch into an internal mixer, carrying out internal mixing for 15-30s, carrying out bolt extraction, adding stearic acid, calcium carbonate, a softening agent, polyethylene wax, a peptizer, a coupling agent and a dispersing aid, carrying out internal mixing for 70-100s, carrying out bolt extraction, carrying out bolt pressing for 15-30s, carrying out rubber discharge, putting the internally mixed rubber material into an extruder for granulation, cooling rubber particles in a vibrating bed, adding a separant, and mixing uniformly to obtain the nano modified asphalt modifier.

9. The method for preparing the nano modified asphalt modifier according to claim 8, wherein the method comprises the following steps: in the step (1) and the step (2), the rotating speed of the internal mixer is 40-60r/min, and the top plug pressure is 0.3-0.5 Mpa.

10. The method for preparing the nano modified asphalt modifier according to claim 8, wherein the method comprises the following steps: in the step (1) and the step (2), the glue discharging temperature is not more than 90 ℃.

Technical Field

The invention relates to the technical field of asphalt modifiers, in particular to a nano modified asphalt modifier and a preparation method thereof.

Background

Asphalt used for paving roads is generally modified asphalt, and rubber, resin, high molecular polymer, ground rubber powder or other fillers and other external additives (modifiers) are added into the asphalt, so that the performance of the asphalt or asphalt mixture is improved.

Conventional road asphalt modifiers generally refer to polymer modified asphalt and are generally divided into three categories:

thermoplastic rubbers: that is, the thermoplastic elastomer is mainly a styrenic block copolymer such as a block copolymer of styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), styrene-polyethylene/butyl-polyethylene (SB) and the like, and a polyolefin, and is also called a rubber resin because it has properties of both rubber and resin modified asphalt. SBS is currently the most attractive road asphalt modifier in the world due to its good elasticity (self-recovery from deformation and self-healing of cracks).

(ii) rubbers: such as Natural Rubber (NR), styrene-butadiene rubber (SBR), Chloroprene Rubber (CR), Butadiene Rubber (BR), Isoprene (IR), ethylene-propylene rubber (EPDM), acrylonitrile-butadiene copolymer (ABR), and the like. Among them, SBR latex is one of the most widely used modifiers in the world. Chloroprene Rubber (CR) has polarity and is often used as a modifier for coal tar pitch.

③ resins: thermoplastic resins such as ethylene-vinyl acetate copolymer (EVA), Polyethylene (PE), atactic polypropylene (APP), polyvinyl chloride (PVC), Polystyrene (PS), polyamide, ethylene propylene type copolymer (APAO), etc.; thermosetting resins are also used as modifiers, such as epoxy tires (EP) and the like. Due to the difference of the content of the vinyl acetate and the melt index MI, the performances of different grades of EVA are greatly different. The random polypropylene APP is used for modifying asphalt felt more because of low price, and has the defect of low adhesion with stone.

However, the traditional modifier only improves the low-temperature performance of the asphalt, has unobvious improvement effects on wear resistance and tear resistance, and cannot improve the heat conductivity. For example, patent No. cn201710593588.x discloses a modified high-viscosity asphalt, including road petroleum asphalt, butadiene-styrene block copolymer, low molecular weight and high molecular weight synthetic resin, high molecular weight and high molecular weight synthetic resin, and stabilizer. The modified road petroleum asphalt has the advantages of good storage stability, and good toughness, viscosity and toughness and corrosion resistance by carrying out composite modification on the slowly-isolated and non-degradable high polymer resin. But does not improve the wear and tear resistance of road asphalt.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the nano modified asphalt modifier can improve the corresponding performance of the road asphalt by only adding a small amount of the nano modified asphalt modifier, and the modified asphalt has good low-temperature performance, high softening point, low kinematic viscosity, greatly improved wear resistance, tear resistance and thermal conductivity and prolonged service life of the road; the invention also provides a simple and feasible preparation method.

The nanometer modified asphalt modifier comprises the following raw materials in parts by weight:

the pipe diameter of the multi-walled carbon nano-tube is 8-15 nm, and the specific surface area is 230-280 m²The microstructure is an array arrangement structure, commonly called array tube.

Calcium carbonate as filler can improve the high temperature performance of asphalt, raise softening point, lower penetration and improve the processing performance during extrusion and granulation.

The softening agent is at least one of polycyclic aromatic hydrocarbon rubber oil, naphthenic base rubber oil and aromatic base rubber. The softener has the functions of softening rubber, so that all components are more easily and uniformly dispersed in the preparation process, and meanwhile, the softener is added to break macromolecular chains of the rubber, increase plasticity and improve processability; the breaking of the macromolecular chains also makes the product dissolve in the bitumen more rapidly.

The average molecular weight of the polyethylene wax is 2000-5000-.

The peptizer is a mixture of DBD (2,2' -dibenzamidodiphenyl disulfide), a metal organic complex and an organic carrier, and is preferably A89. The peptizer can break the macromolecular chains of the rubber in the mixing stage, reduce the molecular weight of the rubber, increase the plasticity and uniformly disperse all the components; while lowering the molecular weight facilitates the dissolution of the modifier in the asphalt.

The coupling agent is at least one of a silane coupling agent KH580, a silane coupling agent KH550 and a silane coupling agent KH 792. The coupling agent can improve the surface activity of the product, plays a role in an interface between the product and asphalt and accelerates the dissolution in the asphalt; meanwhile, the polar functional group plays a role in bridging and is used as an elastic bridging agent between the polar functional group and the asphalt so that the modifier is more stable in the asphalt.

The dispersing auxiliary agent is unsaturated fatty acid zinc salt, preferably rubber processing auxiliary agent Aktiplast PP produced by Langshen group. The dispersing aid improves the dispersion quality of the components, makes the dispersion more uniform, is also an internal lubricant, can improve the extrusion process and is also beneficial to the dissolution in asphalt.

The isolating agent is calcium stearate. And (4) after the product is finished, the release agent attached to the surface is placed and bonded into a cluster.

According to the invention, a certain amount of multi-walled carbon nanotubes are added into a modifier, the multi-walled carbon nanotubes have the characteristics of narrow pipe diameter distribution, high specific surface area, high graphitization degree and ultrahigh length-diameter ratio, and the mechanical property of the material can be improved by adding a small amount of the multi-walled carbon nanotubes: the SBR improves the low-temperature performance of the asphalt, and simultaneously increases the tear resistance of the road asphalt through the strong interface effect of the nano-grade material, and can greatly improve the heat conducting performance and quickly diffuse heat due to the unique tubular six-membered ring structure and the unique array tube type arrangement structure. In addition, other auxiliary agents can effectively help the carbon nano tubes with high structure degree to be uniformly dispersed, and meanwhile, the modifier is dissolved in the asphalt. The addition of the softening agent, the peptizer and the dispersing auxiliary agent can enable components such as the carbon nano tube and the like to be dispersed more uniformly, thereby not only improving the processing performance, but also improving the extrusion granulation process; and the performance of the modifier is more stable. Meanwhile, the addition of the softening agent and the peptizer can break chains of rubber molecular chains and reduce the molecular weight of the rubber molecular chains; the dispersing auxiliary agent as an internal lubricant can improve the processing process and is also beneficial to the dissolution of the modifier in the asphalt; the coupling agent can be used as a surfactant to play an interfacial role and accelerate the dissolution of the modifier; meanwhile, the polar functional group can also play a role in bridging, so that the modifier is more stable. The modifier has certain viscosity, and the surface of the product is added with the separant after the preparation, so that the sticking of the connecting block can be effectively prevented.

The preparation method of the nano modified asphalt modifier comprises the following steps:

(1) adding Styrene Butadiene Rubber (SBR) into an internal mixer, pressing and banburying for 15-30s, extracting the bolt, adding the carbon nano tube, banburying for 50-80s, extracting the bolt, and discharging the glue to obtain carbon nano tube master batch with the mass fraction of the carbon nano tube of 10-20%;

(2) adding carbon nanotube master batch into an internal mixer, carrying out internal mixing for 15-30s, carrying out bolt extraction, adding stearic acid, calcium carbonate, a softening agent, polyethylene wax, a peptizer, a coupling agent and a dispersing aid, carrying out internal mixing for 70-100s, carrying out bolt extraction, carrying out bolt pressing for 15-30s, carrying out rubber discharge, putting the internally mixed rubber material into an extruder for granulation, cooling rubber particles in a vibrating bed, adding a separant, and mixing uniformly to obtain the nano modified asphalt modifier.

In the step (1) and the step (2), the rotating speed of an internal mixer is 40-60r/min, the top plug pressure is 0.3-0.5Mpa, and the rubber discharge temperature is not more than 90 ℃.

Compared with the prior art, the invention has the following beneficial effects:

(1) the nano modified asphalt modifier can improve the corresponding performance of the road asphalt by only adding a small amount of the nano modified asphalt modifier, and the modified asphalt has good low-temperature performance, high softening point, low kinematic viscosity, greatly improved wear resistance, tear resistance and thermal conductivity, and prolonged service life of the road;

(2) the nano modified asphalt modifier is granular, is convenient to transport, weigh and use, almost has no dust in the using process, and is more environment-friendly.

Detailed Description

All the starting materials used in the examples are commercially available, except where otherwise indicated.

Examples and comparative examples

Preparing an asphalt modifier according to the composition of the raw materials in the table 1, wherein the softener can be any one or more of polycyclic aromatic hydrocarbon rubber oil, naphthenic base rubber oil and aromatic base rubber, the action of the softeners on the product is the same, and the mutual replacement has little influence on the performance of the product; the coupling agent can be any one or more of a silane coupling agent KH580, a silane coupling agent KH550 and a silane coupling agent KH792, the effects of the coupling agents on the product are the same, and the mutual replacement has little influence on the performance of the product. For comparison convenience, the softening agents of the examples and the comparative examples adopt polycyclic aromatic hydrocarbon rubber oil, the coupling agent adopts KH550, and in the rest auxiliary agents, the multi-walled carbon nano-tubes adopt the carbon nano-tubes with the tube diameter of 8-15 nm and the specific surface area of 230-280 m²The multi-wall carbon nano tube has a structure of being arrayed in a microstructure, wherein the peptizer adopts peptizer A89, the polyethylene wax adopts the polyethylene wax with the average molecular weight of 2000-5000 and the melting point of 60-70 ℃, the dispersion auxiliary agent adopts Aktiplast PP produced by Langshen group, and the isolating agent adopts calcium stearate.

The compositions of the asphalt modifier raw materials of the examples and comparative examples are shown in table 1, in parts by weight of each raw material.

Table 1 raw material compositions of examples 1 to 4

The asphalt modifier was prepared according to the raw material composition of table 1, with the following steps:

the parameters of the internal mixer are set as follows: rotating at a speed of 50r/min and a top plug pressure of 0.4Mpa, adding Styrene Butadiene Rubber (SBR) into an internal mixer, pressing and internally mixing for 20s, extracting the plug, adding carbon nano tubes, internally mixing for 60s, extracting the plug, cooling to below 90 ℃, and discharging rubber to obtain carbon nano tube master batch; adding the carbon nanotube master batch into the internal mixer again, carrying out internal mixing for 20s, carrying out bolt extraction, adding all auxiliary agents except the separant, carrying out internal mixing for 80s, carrying out bolt extraction, carrying out bolt pressing, carrying out internal mixing for 20s, and cooling to below 90 ℃ to discharge the rubber; and (3) putting the banburying rubber material into an extruder for granulation, cooling the rubber particles in a vibrating bed, adding a separant, and uniformly mixing to obtain the asphalt modifier.

The asphalt modifiers prepared in examples 1-4 and comparative examples 1-4 were used for road asphalt modification as follows: mixing 3 wt% of asphalt modifier, 4 wt% of SBS1301 and 93 wt% of No. 70 petroleum asphalt, shearing at 150 ℃ for 30 minutes at a high speed with a linear velocity of 30m/s, and continuously stirring for 1 hour with the linear velocity of 1m/s to obtain the modified road asphalt.

In addition, set up comparative example 5, without adding asphalt modifier, mix 4 wt% SBS1301, 96 wt% 70# petroleum asphalt, in the shearing emulsifying machine under 150 degrees C under the line speed of 30m/s high speed shear 30 minutes, then with the line speed of 1m/s continued stirring for 1 hour, get modified road asphalt.

The modified road asphalt is prepared into an AC-13C asphalt mixture according to the provisions of technical Specifications for road asphalt pavement construction (JTG F40-2004). Selecting an AC-13C grade, respectively heating the modified road asphalt and mineral aggregate, and uniformly mixing according to the weight ratio of 4.9: 95.1 to obtain an asphalt mixture; wherein the heating temperature of the mineral aggregate is 180 +/-5 ℃, the heating temperature of the asphalt is 165 +/-5 ℃, and the compaction temperature of the asphalt mixture is 160 +/-5 ℃. The gradation of the mineral aggregate used is shown in table 2,

TABLE 2 mineral aggregate grading

Mesh opening in mm	16	13.2	9.5	4.75	2.36	1.18	0.6	0.3	0.15	0.075
											Through rate%	100	94.5	72.7	35.8	27.6	21.5	17.1	12.4	10.9	7.7

The prepared road modified asphalt was subjected to a performance test, and the test results are shown in tables 3 to 4. The prepared asphalt mixture was subjected to a performance test, and the test results are shown in tables 5 to 6.

TABLE 3 test results for road modified asphalt

Test items	Test standard	Example 1	Example 2	Example 3	Example 4
						Ductility, cm at 5 DEG C	T0605-2011	35	37	42	42
Kinematic viscosity (135 ℃ C.), mPas	T0625-2011	815	862	927	966
						Penetration, 0.1mm	T0604-2011	50	47	42	41
Softening point, DEG C	T0606-2011	76	79	78	79
						Thermal conductivity, W/(mK)	ISO 22007-2	0.711	0.768	0.827	0.912

TABLE 4 test results for road modified asphalt

TABLE 5 asphalt mixture test results

TABLE 6 asphalt mixture test results

As can be seen from tables 3-6, the addition of the carbon nanotubes improves the performance of the asphalt, and under the interaction with other additives, the obtained asphalt mixture has higher high-temperature rutting resistance, can greatly improve the wear resistance and tearing damage of roads, and prolongs the service life; meanwhile, the heat conductivity coefficient of the asphalt is greatly improved, the heat conduction effect of the pavement can be effectively improved, and the service life of the road is prolonged.