A low water absorption, fast curing polyurethane mixture and a method for preparing the same

Abstract

The application provides a low-water-permeation and fast-curing polyurethane mixture for road paving and a preparation method thereof. The polyurethane mixture is prepared from a single-component wet-curing polyurethane adhesive, a combined limestone material, a compounded curing agent and a compounded catalyst through a certain preparation process, and compared with the existing polyurethane mixture for road paving, the polyurethane mixture realizes a lower water permeation coefficient effect, shortens the opening time to 24 hours, and solves the problems of the existing polyurethane pavement, such as high water permeation coefficient and long opening time.

Description

Technical Field

[0001] This invention belongs to the field of road materials, specifically relating to a low-permeability, fast-curing polyurethane mixture and its preparation method. Background Technology

[0002] Asphalt, as a binder, can be mixed with stone to form road surfaces, which is the most common type of asphalt pavement. However, due to the inherent properties of asphalt, asphalt pavements are prone to various defects such as rutting, loosening, cracking, and potholes under the influence of temperature changes, vehicle traffic, and rainwater soaking, seriously affecting driving safety. To address the problems of asphalt pavements, new binders such as acrylic esters, epoxy resins, and polyurethanes have emerged in recent years. Among them, polyurethane materials have become a research hotspot due to their excellent designability. By adjusting the ratio of soft and hard segments in their molecular structure and adding various additives, polyurethane can balance strength and toughness, making it an ideal material to replace asphalt for road paving.

[0003] The publication number CN114292048B, "A high-strength dense-graded polyurethane concrete and its preparation method," utilizes a single-component polyurethane binder to mix with aggregates to obtain polyurethane concrete with excellent strength and low expansion rate. However, it has the disadvantages of strong water permeability and slow strength formation time.

[0004] The publication number CN116003023A, "A Modified Glass Fiber Powder Reinforced Polyurethane Concrete and Its Preparation Method," provides a modified glass fiber powder reinforced polyurethane concrete. By using a silane coupling agent to modify the glass fiber, the mechanical properties of the concrete are improved and the thermal stability is enhanced. However, this polyurethane concrete and its preparation method have the disadvantages of high cost and inconvenient construction. Summary of the Invention

[0005] To address the problems of high permeability and long open-to-traffic time associated with current polyurethane concrete, this invention provides a low-permeability, fast-curing polyurethane mixture and its preparation method. Polyurethane pavements constructed using this mixture exhibit a permeability coefficient as low as 32 mL / min, a 24-hour Marshall stability of 75 kN, and a splitting tensile strength of up to 4.0 MPa. This method also offers the advantage of ease of construction.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A low-water-permeability, fast-curing polyurethane compound comprising the following raw materials in parts by weight:

[0008]

[0009] In this invention, the single-component moisture-curing polyurethane adhesive is a prepolymer of polyether polyol and isocyanate diluted with a plasticizer, and the NCO content of the adhesive is 6wt%-16wt%, preferably 8%-14%, and more preferably 10%-12%.

[0010] The polyether polyol has a functionality of 2 and an average molecular weight of 600-4000 g / mol, preferably 800-3000 g / mol, and more preferably 1000-2000 g / mol.

[0011] The isocyanate is one or more of MDI-100, MDI-50, and PM-200;

[0012] The plasticizer is one or more of the following: dioctyl phthalate, dibutyl phthalate, diisodecyl phthalate, palm oil, soybean oil, and rapeseed oil.

[0013] In this invention, the limestone aggregate composition, with gradations such as AC-13, AC-10, AC-20, and AC-25, is a conventional aggregate gradation in the field of road paving.

[0014] In this invention, the compound curing agent is composed of water and small molecule diols, and the small molecule diols account for 10%-50% of the weight of the compound curing agent, preferably 15%-40%, and more preferably 25%-30%; the small molecule diols are one or more of ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol.

[0015] In this invention, the composite catalyst is a combination of an organometallic catalyst and an amine catalyst, wherein the organometallic catalyst accounts for 6%-16% of the weight of the composite catalyst, preferably 8%-14%, and more preferably 10%-12%; the organometallic catalyst is one or more of stannous octoate, dibutyltin dilaurate, and di(dodecylthio)dibutyltin; the amine catalyst is one or more of bis(dimethylaminoethyl) ether DPG solution (70% concentration), triethylenediamine DPG solution (33% concentration), dimethylcyclohexylamine, and pentamethyldiethylenetriamine.

[0016] The preparation method of the low-permeability, fast-curing polyurethane compound includes the following steps:

[0017] S1: Polyether polyol and isocyanate are placed in a reactor and heated to react, and NCO-terminated prepolymer is obtained. Plasticizer is added to obtain a one-component moisture-curing polyurethane adhesive.

[0018] S2: Mix the single-component moisture-curing polyurethane adhesive obtained in S1 and the limestone aggregate combination (AC-13) in a mixing pot;

[0019] S3: Place the polyurethane mixture obtained in S2 into a mold and roll it into shape using a roller mill.

[0020] S4: Place the molded polyurethane concrete obtained in S3 in an environment with a temperature of 25℃-35℃ and a relative humidity of 60%-80% for a certain period of time to pre-cure; the pre-cure time is 3-16 hours, preferably 7-13 hours, and more preferably 8-10 hours.

[0021] S5: Spray a certain amount of compound curing agent and compound catalyst onto the surface of the polyurethane concrete obtained in S4;

[0022] S6: Place the polyurethane concrete obtained in S5 at room temperature for final curing to obtain low-permeability, fast-curing polyurethane concrete.

[0023] In this invention, the properties of the formed concrete are: permeability coefficient ≤100mL / min, 24-hour Marshall stability ≥50KN, and 24-hour splitting strength ≥2.5MPa.

[0024] The positive effects of this invention are as follows:

[0025] 1. By designing the composition of a single-component moisture-curing polyurethane adhesive, polyurethane concrete can simultaneously possess high strength and high toughness.

[0026] 2. A curing agent is prepared by compounding water and small molecule diol. Under the action of a compound catalyst, the curing agent undergoes a final curing chemical reaction with the single-component polyurethane mixture. Through the balance of foaming / gelation reaction, a synergistic effect is formed on the basis of achieving rapid curing of polyurethane concrete. The fine pore structure generated during curing significantly reduces the porosity of polyurethane concrete, thereby reducing the permeability coefficient of polyurethane pavement.

[0027] 3. By compounding curing agents and catalysts, a balance was achieved between the strength growth of polyurethane concrete and the foaming process, ensuring that the fine pore structure does not cause volume expansion of polyurethane concrete.

[0028] 4. The compound curing agent and compound catalyst addition method used in this invention does not require mixing with the mixture. It can be directly sprayed onto the polyurethane pavement surface and reacts with the polyurethane adhesive in the pavement through penetration. Therefore, it has the characteristics of simple operation and easy construction.

[0029] 5. The polyurethane concrete prepared using this invention can have a permeability coefficient as low as 32 mL / min, a 24-hour Marshall stability of up to 75 KN, and a 24-hour splitting strength of up to 4.0 MPa. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the permeability coefficient test of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments, but the content of the present invention is not limited to the following embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0032] Raw material information:

[0033] One-component moisture-curing polyurethane adhesive is a prepolymer of polyether polyol and isocyanate diluted with a plasticizer, wherein:

[0034] The polyether polyols used are produced by Wanhua Chemical, with the brand names Wanol C2006, Wanol C2010, Wanol C2020, and Wanol C2040. At room temperature, they are all colorless, transparent, and viscous liquids.

[0035] The isocyanates used were produced by Wanhua Chemical, and the brands were Wannate MDI-100, Wannate MDI-50, and Wannate PM-200.

[0036] The plasticizers used include: dioctyl phthalate, dibutyl phthalate, and diisodecyl phthalate produced by Shanghai Kaiyin Chemical Co., Ltd.; palm oil, soybean oil, and rapeseed oil produced by Yantai Yihai Co., Ltd.

[0037] The limestone aggregate composition (graded AC-13) is a combination of limestone with different particle size ranges, which conforms to the standard of "JTG E42-2005 Highway Engineering Aggregate Test Procedure", Yantai Taihua Road and Bridge Company;

[0038] The water is ordinary tap water;

[0039] Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, Jintenglong Chemical Co., Ltd., industrial grade;

[0040] Stannous octoate, dibutyltin dilaurate, di(dodecylthio)dibutyltin, Shanghai Xindian Chemical Materials Co., Ltd., industrial grade;

[0041] DPG solution of bis(dimethylaminoethyl) ether (70% concentration), DPG solution of triethylenediamine (33% concentration), dimethylcyclohexylamine, pentamethyldiethylenetriamine, Air Chemical, industrial grade.

[0042] Equipment Information:

[0043] Fully automatic mixing machine, Shanghai Changji, SYD-F02-20;

[0044] Roller forming machine, Shanghai Changji, SYD-0703-2;

[0045] Constant temperature and humidity chamber, High-speed rail testing instrument company, GT-7005-A2L;

[0046] Fully automatic mixture pressure testing machine, Shanghai Changji, SYD-0730A;

[0047] Permeability coefficient meter, Shandong Luda, HHDS-II.

[0048] The permeability coefficient shall be performed in accordance with T 0971 of the "Specifications for Field Testing of Highway Subgrade and Pavement"; the Marshall stability and splitting tensile strength test methods shall be performed in accordance with T0709 and T0716 of the "JTG E20-2011 Specifications for Testing Asphalt and Asphalt Mixtures in Highway Engineering".

[0049] Comparative Example 1:

[0050] 1. Preparation of single-component moisture-curing adhesive: 340g of polyether polyol C2010 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 480g of isocyanate PM-200 was added, and the reaction was carried out for 2 hours. The temperature was then lowered to 50℃, and 180g of plasticizer dibutyl phthalate was added to obtain single-component moisture-curing polyurethane adhesive No. 0, with an NCO content of 12%.

[0051] 2. Polyurethane mixture molding and pre-curing: Take 550g of single-component moisture-curing adhesive No. 0 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm*5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 7 hours.

[0052] 3. Final curing of polyurethane concrete: The polyurethane concrete obtained in the previous step was placed at room temperature for final curing, and the permeability coefficient, Marshall stability and splitting tensile strength were tested (the test time was 24 hours after compaction).

[0053] Comparative Example 2:

[0054] 1. Preparation of single-component moisture-curing adhesive: 340g of polyether polyol C2010 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 480g of isocyanate PM-200 was added, and the reaction was carried out for 2 hours. The temperature was then lowered to 50℃, and 180g of plasticizer dibutyl phthalate was added to obtain single-component moisture-curing polyurethane adhesive No. 0, with an NCO content of 12%.

[0055] 2. Polyurethane mixture molding and pre-curing: Take 550g of single-component moisture-curing adhesive No. 0 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm*5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 7 hours.

[0056] 3. Final curing by spraying a single curing agent and a single catalyst: First, spray 3.3g of the single catalyst, dibutyltin dilaurate, evenly onto the surface of the polyurethane mixture specimen obtained in the previous step. Then, continue to spray 33g of the single curing agent (water) evenly. After final curing at room temperature, a low-permeability, fast-curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability, and splitting tensile strength (test time is 24 hours after compaction).

[0057] Example 1:

[0058] 1. Preparation of single-component moisture-curing adhesive: 440g of polyether polyol C2020 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 350g of isocyanate MDI-100 was added, and the reaction was carried out for 2 hours. The temperature was then lowered to 50℃, and 210g of plasticizer dioctyl phthalate was added to obtain single-component moisture-curing polyurethane adhesive No. 1 with an NCO content of 10%.

[0059] 2. Polyurethane mixture molding and pre-curing: Take 660g of single-component moisture-curing adhesive No. 1 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm#5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 8 hours.

[0060] 3. Final curing by spraying compound curing agent and catalyst: First, spray 4.4g of compound catalyst (weight ratio of stannous octoate: DPG solution of triethylenediamine (concentration 33%) = 10:90) evenly onto the surface of the polyurethane mixture specimen obtained in the previous step, and then continue to spray 110g of compound curing agent (ethylene glycol weight ratio 25%) evenly. After final curing at room temperature, low permeability and fast curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability and splitting tensile strength (test time is 24 hours after rolling).

[0061] Example 2:

[0062] 1. Preparation of single-component moisture-curing adhesive: 300g of polyether polyol C2006 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 540g of isocyanate MDI-50 was added, and the reaction was carried out for 2 hours. The temperature was then lowered to 50℃, and 160g of plasticizer diisodecyl phthalate was added to obtain single-component moisture-curing polyurethane adhesive No. 2 with an NCO content of 14%.

[0063] 2. Polyurethane mixture molding and pre-curing: Take 440g of single-component moisture-curing adhesive No. 2 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm#5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 16 hours.

[0064] 3. Final curing by spraying compound curing agent and catalyst: First, spray 3.3g of compound catalyst (weight ratio of dibutyltin dilaurate: DPG solution of bis(dimethylaminoethyl) ether (concentration 70%) = 16:84) evenly onto the surface of the polyurethane mixture specimen obtained in the previous step, and then continue to spray 165g of compound curing agent (propylene glycol weight ratio 50%) evenly. After final curing at room temperature, low permeability and fast curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability and splitting tensile strength (test time is 24 hours after rolling).

[0065] Example 3:

[0066] 1. Preparation of single-component moisture-curing adhesive: 300g of polyether polyol C2040 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 220g of isocyanate MDI-100 and 300g of isocyanate PM-200 were added. The mixture was reacted for 2 hours, then cooled to 50℃. 180g of plasticizer palm oil was added to obtain single-component moisture-curing polyurethane adhesive No. 3 with an NCO content of 16%.

[0067] 2. Polyurethane mixture molding and pre-curing: Take 440g of single-component moisture-curing adhesive No. 3 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm#5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 3 hours.

[0068] 3. Final curing by spraying compound curing agent and catalyst: First, spray 5.5g of compound catalyst (weight ratio of di(dodecylthio)dibutyltin:dimethylcyclohexylamine = 6:94) evenly onto the surface of the polyurethane mixture specimen obtained in the previous step. Then, continue to spray 33g of compound curing agent (10% by weight of diethylene glycol). After final curing at room temperature, low-permeability, fast-curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability and splitting tensile strength (test time is 24 hours after compaction).

[0069] Example 4:

[0070] 1. Preparation of single-component moisture-curing adhesive: 500g of polyether polyol C2020 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 110g of isocyanate MDI-50 and 150g of isocyanate PM-200 were added. The mixture was reacted for 2 hours, then cooled to 50℃. 240g of plasticizer soybean oil was added to obtain single-component moisture-curing polyurethane adhesive No. 4, with an NCO content of 6%.

[0071] 2. Polyurethane mixture molding and pre-curing: Take 770g of single-component moisture-curing adhesive No. 4 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm#5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 10 hours.

[0072] 3. Final curing by spraying compound curing agent and catalyst: First, spray 6.6g of compound catalyst (weight ratio of dibutyltin dilaurate: pentamethyldiethylenetriamine = 10:90) evenly onto the surface of the polyurethane mixture specimen obtained in the previous step, and then continue to spray 55g of compound curing agent (30% by weight of dipropylene glycol). After final curing at room temperature, low permeability and fast curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability and splitting tensile strength (test time is 24 hours after rolling).

[0073] Example 5:

[0074] 1. Preparation of single-component moisture-curing adhesive: 440g of polyether polyol C2010 was placed in a three-necked flask, which was then placed in an oil bath and heated. After the temperature reached 80℃, 210g of isocyanate MDI-100 and 150g of isocyanate PM-200 were added. The mixture was reacted for 2 hours, then cooled to 50℃. 200g of plasticizer rapeseed oil was added to obtain single-component moisture-curing polyurethane adhesive No. 5 with an NCO content of 8%.

[0075] 2. Polyurethane mixture molding and pre-curing: Take 770g of single-component moisture-curing adhesive No. 5 and add it to 11000g of limestone aggregate (AC-13). Mix it evenly using a fully automatic mixer. Then, use a roller mill to roll it into a 30cm*30cm*5cm specimen. Place the specimen in a constant temperature and humidity chamber at 25℃ / 60% for pre-curing for 13 hours.

[0076] 3. Final curing by spraying compound curing agent and catalyst: First, spray 5.5g of compound catalyst (stannous octoate: dimethylcyclohexylamine = 12:88) evenly onto the surface of the polyurethane mixture specimen obtained in the previous step, and then continue to spray 88g of compound curing agent (ethylene glycol weight ratio 15%) evenly. After final curing at room temperature, low permeability and fast curing polyurethane concrete is obtained. Test the permeability coefficient, Marshall stability and splitting tensile strength (test time is 24 hours after rolling).

[0077] The performance test data of the polyurethane concrete prepared in comparative examples and Examples 1-5 are as follows:

[0078]

Claims

1. A low water penetration, fast curing polyurethane mixture, comprising the following components, in parts by weight: wherein The single-component moisture-cured polyurethane adhesive is a prepolymer of polyether polyol and isocyanate diluted with a plasticizer, the NCO content of the adhesive being 6-16%; The complex curing agent consists of water and a small molecule diol, the weight ratio of the small molecule diol in the complex curing agent being 10-50%; The complex catalyst is a complex of an organometallic catalyst and an amine catalyst, the weight ratio of the organometallic catalyst in the complex catalyst being 6-16%.

2. The polyurethane mixture according to claim 1, wherein The polyether polyol has a functionality of 2 and an average molecular weight of 600-4000 g / mol.

3. The polyurethane mixture according to claim 1 or 2, characterized in that The isocyanate is one or more of MDI-100, MDI-50, and PM-200.

4. The polyurethane compound of claim 1, wherein, The plasticizer is one or more of dioctyl phthalate, dibutyl phthalate, diisodecyl phthalate, palm oil, soybean oil, and rapeseed oil.

5. The polyurethane compound of claim 1, wherein, The gradation of the limestone aggregate combination is AC-13, AC-10, AC-20, or AC-25.

6. The polyurethane compound of claim 1, wherein, The complex curing agent consists of water and a small molecule diol, the weight ratio of the small molecule diol in the complex curing agent being 15-40%.

7. The polyurethane compound of claim 1, wherein The complex curing agent consists of water and a small molecule diol, the weight ratio of the small molecule diol in the complex curing agent being 25-30%.

8. The polyurethane compound of claim 1, wherein, The small molecule diol is one or more of ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol.

9. The polyurethane compound of claim 1, wherein, The complex catalyst is a complex of an organometallic catalyst and an amine catalyst, the weight ratio of the organometallic catalyst in the complex catalyst being 8-14%.

10. The polyurethane compound of claim 1, wherein The complex catalyst is a complex of an organometallic catalyst and an amine catalyst, the weight ratio of the organometallic catalyst in the complex catalyst being 10-12%.

11. The polyurethane compound of claim 1, wherein The organometallic catalyst is one or more of stannous octoate, dibutyltin dilaurate, and bis(dodecylthio)dibutyltin; the amine catalyst is one or more of a DPG solution of bis(dimethylaminoethyl) ether, a DPG solution of triethylenediamine, dimethylcyclohexylamine, and pentamethyldiethylene triamine.

12. A method for preparing the polyurethane mixture according to any one of claims 1-11, comprising: S1: placing polyether polyol and isocyanate in a reactor to perform a heating reaction, thereby obtaining an NCO-terminated prepolymer, and adding a plasticizer to obtain a single-component moisture-cured polyurethane adhesive; S2: mixing the single-component moisture-cured polyurethane adhesive obtained in S1 with a limestone aggregate combination; S3: performing roller compaction on the polyurethane mixture obtained in S2; S4: pre-curing the shaped polyurethane concrete obtained in S3 for a certain period of time; S5: spraying a complex curing agent and a complex catalyst onto the surface of the polyurethane concrete obtained in S4; S6: performing final curing on the polyurethane concrete obtained in S5 at room temperature.

13. The production method according to claim 12, wherein The pre-curing time is 3-16 hours.

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