Bio-based flexible cementing material and cold-mix asphalt mixture

Abstract

The invention discloses a bio-based flexible cementing material and a cold-mix asphalt mixture, and relates to the field of adhesives. The bio-based flexible cementing material comprises 80-85 wt% of a component A and 15-20 wt% of a component B, the component A comprises bio-based polyol, natural asphalt, natural rubber, a tackifier and a bio-based plasticizer according to a weight ratio of (160-180): (45-55): (75-85): (140-160): (380-410), and the component B is an isocyanate cross-linking agent. The bio-based flexible cementing material is used as a cementing material of a cold-mixed asphalt mixture, can be directly constructed at low temperature or normal temperature, does not need to be heated to improve the flowability, is convenient to construct, can form a stable skeleton structure through crosslinking, and can form a stable structure under the cooperation of natural rubber and natural asphalt. The bio-based flexible cementing material has both high temperature resistance and low temperature resistance, and the stability of a road structure can be improved.

Description

Technical Field

[0001] This application relates to the field of adhesives, and in particular to a bio-based flexible binder and a cold-mix asphalt mixture. Background Technology

[0002] Traditional asphalt binders are mainly rubber-modified petroleum asphalt. Rubber imparts better low-temperature flexibility and high-temperature stability to petroleum asphalt. However, these binders are semi-solid or solid at room temperature and low temperatures, which cannot meet the fluidity and workability required for construction. During construction, they often need to be heated to 170-180℃ to improve fluidity before being mixed with aggregates, resulting in high energy consumption and environmental problems. Summary of the Invention

[0003] In order to improve the problems of high energy consumption and environmental pollution in the construction of binders in related technologies, while ensuring the high temperature resistance and low temperature flexibility of binders, this application provides a bio-based flexible binder and a cold-mix asphalt mixture.

[0004] The first invention, the bio-based flexible binder provided in this application, adopts the following technical solution: A bio-based flexible binder comprises 80-85 wt% component A and 15-20 wt% component B, wherein component A comprises bio-based polyol, natural asphalt, natural rubber, tackifier and bio-based plasticizer in a weight ratio of (160-180):(45-55):(75-85):(140-160):(380-410), and component B is an isocyanate crosslinking agent.

[0005] In this application, the bio-based flexible binder is a two-component form comprising component A and component B. Component A and component B are stored separately and can be mixed in proportion before use. Compared with conventional petroleum asphalt binders, the bio-based flexible binder of this application has a dynamic viscosity of 60-120 mPa·s at 25°C and remains flowable from -30°C to room temperature. During construction, it can be directly and uniformly mixed with asphalt milling aggregate and aggregate without heating, offering the advantage of convenient construction.

[0006] In this application, the bio-based components in the bio-based flexible binder, such as the combination of bio-based polyols and bio-based plasticizers, can quickly penetrate into the aged asphalt of natural asphalt or asphalt milling aggregate, causing the aged asphalt of natural asphalt and asphalt milling aggregate to change from a gel state to a flowable sol-gel state. The addition of natural rubber can give the binder flexibility and improve its low-temperature brittleness. In addition, the active groups in the bio-based polyols can react and crosslink with isocyanate crosslinking agents to form the skeleton structure of the binder, simultaneously improving the problem of conventional binders easily softening and becoming flowable at high temperatures.

[0007] In other words, using the bio-based flexible binder of this application as the binder for cold-mix asphalt mixtures allows for direct construction at low or normal temperatures without the need for heating to improve fluidity, thus offering the advantage of convenient construction. Furthermore, the bio-based flexible binder of this application can form a stable skeleton structure through cross-linking, and with the combination of natural rubber and natural asphalt, it addresses both high-temperature and low-temperature resistance issues, which is beneficial for improving the stability of road structures.

[0008] In some specific embodiments, the bio-based polyol is at least one of castor oil polyether polyol and epoxidized soybean oil polyether polyol.

[0009] In some specific embodiments, the bio-based polyol includes castor oil polyether polyol and epoxidized soybean oil polyether polyol, wherein the weight ratio of castor oil polyether polyol to epoxidized soybean oil polyether polyol is 1:(3-4).

[0010] In this application, the bio-based polyol is preferably a combination of castor oil polyether polyol and epoxidized soybean oil polyether polyol in a specific ratio, which is beneficial to improving the compatibility of the binder with the aged asphalt in the asphalt milling material, and can further improve the strength performance of cold-mix asphalt mixture.

[0011] In some specific embodiments, the castor oil polyether polyol is obtained by reacting castor oil with a hydroxyl value of 160-170 mgKOH / g, after removing impurities, with diepoxy polyether and p-methoxyphenyl glycidyl ether under the action of an alkaline catalyst. The epoxidized soybean oil polyether polyol is obtained by reacting epoxidized soybean oil with an epoxy equivalent of 400-500 g / eq with a small molecule polyol under the action of an acidic catalyst, and then reacting it with a diepoxy polyether and p-methoxyphenyl glycidyl ether.

[0012] In some specific embodiments, when preparing the castor oil polyether polyol, the weight ratio of castor oil, diepoxy polyether, and p-methoxyphenyl glycidyl ether is 100:(38-42):(5.5-6.0); when preparing the epoxidized soybean oil polyether polyol, the weight ratio of epoxidized soybean oil, small molecule polyol, diepoxy polyether, and p-methoxyphenyl glycidyl ether is 100:(2.8-3.3):(45-50):(1-1.5).

[0013] This application uses diepoxy polyether and p-methoxyphenyl glycidyl ether to modify castor oil or epoxidized soybean oil to prepare castor oil polyether polyol and epoxidized soybean oil polyether polyol. This is beneficial to improving the compatibility of binder and aged asphalt in asphalt milling mix, and can further improve the strength of cold-mix asphalt mixture; at the same time, it improves and ensures the low-temperature toughness and high-temperature stability of binder, and can further improve the stability of cold-mix asphalt mixture in different temperature environments.

[0014] In some specific embodiments, the diepoxy polyether is a diepoxy-terminated polyoxyethylene polyoxypropylene ether, wherein the degree of polymerization of the polyoxyethylene segment is 8-10 and the degree of polymerization of the polyoxypropylene segment is 20-25.

[0015] In this application, the diepoxy polyether is a diepoxy-terminated polyoxyethylene polyoxypropylene ether, and the degree of polymerization of the polyoxyethylene and polyoxypropylene segments is controlled within the above range. This can improve the compatibility of the binder with the aged asphalt in the asphalt milling material, while ensuring the low-temperature toughness and high-temperature stability of the binder.

[0016] In some specific embodiments, the small molecule polyol is at least one of diethylene glycol, triethylene glycol, and dipropylene glycol.

[0017] In this application, the small molecule polyol used to activate epoxidized soybean oil is preferably at least one of diethylene glycol, triethylene glycol, and dipropylene glycol, which is beneficial to improving the compatibility of the binder and the aged asphalt in the asphalt milling material, and can further improve the strength of the cold-mix asphalt mixture.

[0018] In some specific embodiments, the tackifier is a hydrogenated terpene resin, and the bio-based plasticizer is at least one of castor oil, epoxidized soybean oil, and cashew nut oil.

[0019] In some specific embodiments, the isocyanate crosslinking agent is at least one of diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

[0020] Secondly, this application provides a cold-mix asphalt mixture, which includes any of the above-mentioned bio-based flexible binders.

[0021] In summary, this application includes at least the following beneficial technical effects: (1) Using the bio-based flexible binder of this application as the binder of cold-mix asphalt mixture can be directly constructed at low or normal temperature without heating to improve fluidity, which has the advantage of convenient construction. Moreover, the bio-based flexible binder of this application can form a stable skeleton structure through cross-linking, and with the combination of natural rubber and natural asphalt, the bio-based flexible binder can take into account both high temperature resistance and low temperature resistance, which is conducive to improving the stability of road structure.

[0022] (2) In this application, the bio-based polyol is preferably a combination of castor oil polyether polyol and epoxidized soybean oil polyether polyol in a specific ratio, which is beneficial to improving the compatibility of the binder and the aged asphalt in the asphalt milling material, and can further improve the strength performance of the cold-mix asphalt mixture.

[0023] (3) This application uses diepoxy polyether and p-methoxyphenyl glycidyl ether to modify castor oil or epoxidized soybean oil to prepare castor oil polyether polyol and epoxidized soybean oil polyether polyol, which is beneficial to improve the compatibility of binder and aged asphalt in asphalt milling material, and can further improve the strength of cold-mix asphalt mixture; at the same time, it improves and ensures the low-temperature toughness and high-temperature stability of binder, and can further improve the stability of cold-mix asphalt mixture in different temperature environments.

[0024] (4) In this application, the small molecule polyols used to activate epoxidized soybean oil are preferably at least one of diethylene glycol, triethylene glycol and dipropylene glycol, which is beneficial to improving the compatibility of the binder and the aged asphalt in the asphalt milling material, and can further improve the strength of cold-mix asphalt mixture. Detailed Implementation

[0025] The following section provides further explanation of this application in conjunction with specific experiments.

[0026] Example of Castor Oil Polyether Polyol Preparation

Preparation Example 1-1

[0027] In the diepoxy-terminated polyoxyethylene polyoxypropylene ether, the degree of polymerization of the polyoxyethylene segment is 10, and the degree of polymerization of the polyoxypropylene segment is 25.

[0028]

Preparation Examples 1-2

[0029]

Preparation Examples 1-3

[0030]

Preparation Examples 1-4

[0031]

Preparation Examples 1-5

[0032]

Preparation Examples 1-6

[0033] Example of preparation of epoxidized soybean oil polyether polyol

Preparation Example 2-1

[0034]

Preparation Example 2-2

[0035]

Example 1

[0036]

Example 2

[0037]

Example 3

[0038]

Example 4

[0039]

Example 5

[0040]

Example 6

[0041]

Example 7

[0042]

Example 8

[0043]

Example 9

[0044]

Example 10

[0045] Performance testing The bio-based flexible binder in each embodiment is applied to cold-mix asphalt mixture, wherein the cold-mix asphalt mixture comprises 2 kg of bio-based flexible binder, 6 kg of asphalt milling material, and 2 kg of aggregate. The preparation method of the cold-mix asphalt mixture is as follows: Add asphalt milling material to component A and mix at a speed of 300 r / min for 30 min. Then add aggregate and continue mixing for 10 min. Next, add component B and mix evenly. Transfer to a mold, compact, and cure at room temperature for 2 days.

[0046] According to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), Marshall stability test, shear strength test and freeze-thaw splitting test were conducted on cold-mix asphalt mixtures corresponding to different bio-based flexible binders, and the results are recorded in Table 1 below.

[0047] Table 1

[0048] Based on the above examples 1, 3-4, and the test data in Table 1, it can be seen that the preferred bio-based polyol is a combination of castor oil polyether polyol and epoxidized soybean oil polyether polyol in a specific ratio, which is beneficial to improving the Marshall stability, shear strength, and low-temperature freeze-thaw resistance of cold-mix asphalt mixtures.

[0049] Combining the test data from Examples 4 and 5-9 above and Table 1, it can be seen that modifying castor oil or epoxidized soybean oil with diepoxy polyether and p-methoxyphenyl glycidyl ether to prepare castor oil polyether polyol and epoxidized soybean oil polyether polyol is beneficial to simultaneously improve the Marshall stability, shear strength and low-temperature freeze-thaw resistance of cold-mix asphalt mixture.

[0050] Combining the above examples 4 and 10 with the test data in Table 1, it can be seen that when diethylene glycol is selected as the small molecule polyol for activating epoxidized soybean oil, it is beneficial to improve the Marshall stability, shear strength and low-temperature freeze-thaw resistance of cold-mix asphalt mixture.

[0051] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A bio-based flexible binder, characterized in that: It includes 80-85 wt% component A and 15-20 wt% component B. Component A includes bio-based polyols, natural asphalt, natural rubber, tackifiers and bio-based plasticizers in a weight ratio of (160-180):(45-55):(75-85):(140-160):(380-410). Component B is an isocyanate crosslinking agent.

2. The bio-based flexible binder according to claim 1, characterized in that: The bio-based polyol is at least one of castor oil polyether polyol and epoxidized soybean oil polyether polyol.

3. The bio-based flexible binder according to claim 2, characterized in that: The bio-based polyols include castor oil polyether polyol and epoxidized soybean oil polyether polyol, wherein the weight ratio of castor oil polyether polyol to epoxidized soybean oil polyether polyol is 1:(3-4).

4. The bio-based flexible binder according to claim 3, characterized in that: The castor oil polyether polyol is obtained by reacting castor oil with a hydroxyl value of 160-170 mgKOH / g after removing impurities, with diepoxy polyether and p-methoxyphenyl glycidyl ether under the action of an alkaline catalyst. The epoxidized soybean oil polyether polyol is obtained by reacting epoxidized soybean oil with an epoxy equivalent of 400-500 g / eq with a small molecule polyol under the action of an acidic catalyst, and then reacting it with a diepoxy polyether and p-methoxyphenyl glycidyl ether.

5. The bio-based flexible binder according to claim 4, characterized in that: When preparing the castor oil polyether polyol, the weight ratio of castor oil, diepoxy polyether, and p-methoxyphenyl glycidyl ether is 100:(38-42):(5.5-6.0); when preparing the epoxidized soybean oil polyether polyol, the weight ratio of epoxidized soybean oil, small molecule polyol, diepoxy polyether, and p-methoxyphenyl glycidyl ether is 100:(2.8-3.3):(45-50):(1-1.5). The diepoxy polyether is a diepoxy-terminated polyoxyethylene polyoxypropylene ether, wherein the degree of polymerization of the polyoxyethylene segment is 8-10 and the degree of polymerization of the polyoxypropylene segment is 20-25. The small molecule polyol is at least one of diethylene glycol, triethylene glycol, and dipropylene glycol.

6. The bio-based flexible binder according to claim 1, characterized in that: The tackifier is at least one of terpene resin and hydrogenated terpene resin; the bio-based plasticizer is at least one of castor oil, epoxidized soybean oil, and cashew nut oil.

7. The bio-based flexible binder according to claim 1, characterized in that: The isocyanate crosslinking agent is at least one of diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

8. A cold-mix asphalt mixture, characterized in that, The invention comprises a bio-based flexible binder as described in any one of claims 1-7.

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