A high-strength composite polyurethane sealant and its preparation method

Abstract

The present invention discloses a high-strength composite polyurethane sealant and a preparation method thereof. By introducing indium selenide two-dimensional nanomaterials into the polyurethane formulation, a new method is provided for changing the mechanical properties of polyurethane. The indium selenide two-dimensional nanomaterials are dispersed in one or more polyols, one or more isocyanates, or dispersed in one or more polyols and one or more isocyanates, and are respectively mixed and reacted. Due to the large specific surface area of the indium selenide two-dimensional nanomaterials, a small amount of indium selenide two-dimensional nanomaterials are dispersed in the polyurethane matrix, and can be wound together with the polymer main chain through physical adsorption, forming a three-dimensional space network, which increases the strength of the composite material, and a high-strength composite polyurethane sealant is obtained, which has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of sealants, and particularly to a high-strength composite polyurethane sealant and a preparation method thereof Background Art

[0002] Polyurethane adhesives have good low-temperature resistance, excellent flexibility, wear resistance, oil resistance, chemical resistance and other properties, and are widely used in many fields. However, the strength of polyurethane itself is not high. If it is used in the field of sealants, some materials must be added to change its mechanical properties. Adding nanomaterials to polyurethane sealants is a convenient and effective method to improve the mechanical properties of polyurethane products

[0003] In recent years, inorganic / organic nanocomposites have received extensive attention from researchers because they simultaneously possess the advantages of inorganic nanomaterials and organic materials. Two-dimensional materials represented by graphene are commonly used inorganic materials. Due to their simple preparation, chemical inertness, excellent thermal properties and mechanical properties, they are widely used in multi-field composite materials. Indium selenide (InSe) is a new type of two-dimensional nanomaterial with a unique nano-platform with a planar topological structure. Due to its unique morphology, physical and chemical properties, it can effectively improve and change the mechanical properties of polyurethane

[0004] Technical Problems to be Solved

[0005] In view of the challenges existing in the prior art, the purpose of the embodiments of the present invention is to provide a high-strength composite polyurethane sealant and a preparation method thereof. This method applies the addition of indium selenide two-dimensional nanomaterials, which can effectively improve and change the mechanical properties of polyurethane, and is of great significance to polyurethane composites Summary of the Invention

[0006] In order to achieve the above object, the present invention mainly adopts the following technical solutions

[0007] Step 1: Prepare an InSe dispersion liquid, including dispersing indium selenide two-dimensional nanomaterials in (a) one or more polyols, (b) one or more isocyanates, or (c) dispersing in one or more polyols and one or more isocyanates, separately or in combination

[0008] Preferably, the mass percentage of InSe in the InSe dispersion solution is 0.1-40%. Further preferably, the mass percentage of InSe in the dispersion liquid is 0.1-1%

[0009] Preferably, the isocyanates used to prepare polyurethane include aromatic isocyanates and aliphatic and cycloaliphatic isocyanates

[0010] Further preferably, the aromatic isocyanate includes: diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), etc.;

[0011] Further preferably, the aliphatic and cycloaliphatic isocyanates include: 1,6 - hexamethylene diisocyanate (HDI), 3 - isocyanatomethyl - 3,5,5 - trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), and 4,4′ - diisocyanatodicyclohexylmethane;

[0012] Further preferably, the isocyanate for preparing polyurethane is diphenylmethane diisocyanate;

[0013] Preferably, the polyols for preparing polyurethane include polyether polyols and polyester polyols;

[0014] Further preferably, the polyol for preparing polyurethane is a polyether polyol;

[0015] Step two: Mix the dispersion in step one (a) with an isocyanate or (b) the dispersion with a polyol and a catalyst to produce a polymerization reaction; or mix the dispersion in step one (c) and a catalyst to produce a polymerization reaction;

[0016] Preferably, the catalysts for preparing polyurethane include amine compounds or metal complexes;

[0017] Further preferably, the amine compound catalysts include tertiary amines, such as triethylenediamine (TEDA, 1,4 - diazabicyclo[2.2.2]octane or DABCO), dimethylcyclohexylamine (DMCHA), and dimethanolamine (DMEA). The catalyst can also contain a hydroxyl group or a secondary amine, etc.;

[0018] Further preferably, examples of the metal compound catalysts include compounds based on mercury, lead, tin, bismuth, and zinc, including: mercury, bismuth, and zinc carboxylates, alkyltin carboxylates, oxides, and thiolate oxides, etc.;

[0019] Further preferably, the catalyst for preparing polyurethane is dibutyltin dilaurate.

[0020] The present invention has the following advantages and beneficial technical effects compared with the prior art:

[0021] The method provided by the present invention adds indium selenide two - dimensional nanomaterials to the polyurethane sealant, and the tensile strength, shear strength, and hardness of the product are all significantly improved. Due to the large specific surface area of indium selenide two - dimensional nanomaterials, a small amount of indium selenide two - dimensional nanomaterials are dispersed in the polyurethane matrix, and they can be wound together with the polymer main chain through physical adsorption, forming a three - dimensional space network, which increases the strength of the composite material. Description of the Drawings

[0022] Figure 1 .TEM morphology of indium selenide two-dimensional nanomaterials

[0023] Figure 2 .Tensile strength of polyurethane with InSe added to the polyether phase

[0024] Figure 3 .Tensile strength of polyurethane with InSe added to isocyanate phase

[0025] Figure 4 .Tensile strength of polyurethane added with InSe to a mixture of polyether polyol and isocyanate DETAILED DESCRIPTION

[0026] Example 1

[0027] (1) Preparation of indium selenide two-dimensional nanomaterials.

[0028] InSe crystals were stored in DMF solution, ground in a mortar, ultrasonicated at 1200W for 10 hours, ultrasonicated in a water bath for 10 hours, centrifuged at 5000rpm for 10 minutes to obtain InSe nanosheets with uniform particle size, centrifuged at 14000rpm for 10 minutes, resuspended in anhydrous ethanol solution, centrifuged, and washed to obtain InSe solution for use. The obtained sample was examined for morphology by TEM, and the results are as follows: Figure 1 As shown, the InSe nanosheets are thin-layer flakes with a size between 50-200 nm.

[0029] (2) Preparation of InSe dispersion.

[0030] An InSe dispersion was prepared by dispersing 0.1-40% by mass of InSe two-dimensional nanomaterials in PPG-100 polyether polyol and rapidly stirring for 1 hour to obtain (a) dispersion.

[0031] (3) Mixing step.

[0032] 40 parts of the dispersion (a), 100 parts of liquefied MDI of Wanhua Chemical Model 100LL and 0.02 parts of dibutyltin dilaurate were put into a reaction kettle and stirred under vacuum at 80° C. for 3 hours to cause a polymerization reaction.

[0033] (4) Tensile strength test.

[0034] The colloid tensile test standard: GB / T 1040.2-2006 Determination of tensile properties of plastics Part 2: Test methods for molded and extruded plastics. The obtained polyurethane sealant was tested for tensile strength. The results are as follows Figure 2As shown, when InSe is added to the polyether phase, the tensile strength of the resulting polyurethane is higher than that of the control sample without InSe, and when more InSe is added to the polyether phase, the tensile strength of the polyurethane also increases. In this case, the optimal addition amount is about 0.1% by mass.

[0035] Example 2

[0036] (1) Preparation of indium selenide two-dimensional nanomaterials.

[0037] InSe crystals were stored in DMF solution, ground in a mortar, ultrasonicated with a 1200W probe for 10 h, ultrasonicated in a water bath for 10 h, and centrifuged at 5000 rpm for 10 min to obtain InSe nanosheets with uniform particle size. The crystals were centrifuged at 14000 rpm for 10 min, resuspended in anhydrous ethanol solution, centrifuged, and washed to obtain an InSe solution for use.

[0038] (2) Preparation of InSe dispersion.

[0039] Prepare InSe dispersion: disperse 0.1-40% InSe nanomaterial in liquefied MDI of Wanhua Chemical Model 100LL, and stir rapidly for 1 hour to obtain (b) dispersion.

[0040] (3) Mixing step.

[0041] 100 parts of the dispersion (b), 40 parts of PPG-100 polyether polyol and 0.02 parts of dibutyltin dilaurate were put into a reaction kettle and stirred under vacuum at 80° C. for 3 hours to cause a polymerization reaction.

[0042] (4) Tensile strength test.

[0043] The colloid tensile test standard: GB / T 1040.2-2006 Determination of tensile properties of plastics Part 2: Test methods for molded and extruded plastics. The obtained polyurethane sealant was tested for tensile strength. The results are as follows Figure 3 As shown, when InSe is added to the isocyanate phase, advantages can still be obtained at low InSe addition amounts, in this case, the optimal addition amount is about 0.2% by mass.

[0044] Example 3

[0045] (1) Preparation of indium selenide two-dimensional nanomaterials.

[0046] The InSe crystals were stored in a DMF solution, ground in a mortar, sonicated with a 1200W probe for 10 h, sonicated in a water bath for 10 h, centrifuged at 5000 rpm for 10 min to obtain InSe nanosheets with uniform particle size, centrifuged at 14000 rpm for 10 min, resuspended in an absolute ethanol solution, centrifuged, and washed to obtain an InSe solution for standby.

[0047] (2) Preparation of the InSe dispersion.

[0048] To prepare the InSe dispersion, 0.1 - 40% of the InSe nanomaterials were dispersed in 100 parts of liquefied MDI of Wanhua Chemical model 100LL and 40 parts of PPG - 100 polyether polyol, and rapidly stirred for 1 hour to obtain dispersion (c).

[0049] (3) Mixing step.

[0050] Dispersion (c) and 0.02 parts of dibutyltin dilaurate were added into a reaction kettle, and vacuum stirred at 80 °C for 3 hours to carry out a polymerization reaction.

[0051] (4) Tensile strength detection.

[0052] The colloidal tensile test standard: GB / T 1040.2 - 2006 Plastics - Determination of tensile properties - Part 2: Test method for moulded and extruded plastics was adopted to detect the tensile strength of the obtained polyurethane sealant. The results are as Figure 4 shown. In the polyether - isocyanate combination, the optimal InSe dosage is different. In this case, the optimal addition amount is about 0.5% by mass percentage.

[0053] In summary, adding InSe nanosheets to isocyanate has a better effect per unit of InSe and a greater change in mechanical strength.

Claims

1. A preparation method of a high-strength composite polyurethane sealant, characterized in that Introducing indium selenide two-dimensional nanomaterial InSe into the polyurethane formulation includes the following steps: Step 1: Prepare a dispersion of indium selenide two-dimensional nanomaterial, including dispersing InSe in (a) one or more types of polyols, or (b) one or more types of isocyanates, or (c) dispersing in a mixture of one or more types of polyols and one or more types of isocyanates, and respectively mixing to obtain (a) dispersion, (b) dispersion, and (c) dispersion. The mass percentage of InSe in the dispersion is 0.1 - 1%; Step 2: Mix the dispersion in Step 1 (a) with one type of isocyanate and a catalyst to produce a polymerization reaction; or mix the dispersion in Step 1 (b) with one type of polyol and a catalyst to produce a polymerization reaction; or mix the dispersion in Step 1 (c) and a catalyst to initiate a polymerization reaction.

2. The preparation method of a high-strength composite polyurethane sealant according to claim 1, characterized in that: The isocyanates used for preparing polyurethane in Step 1 include aromatic isocyanates and aliphatic and cycloaliphatic isocyanates; Aromatic isocyanates include: diphenylmethane diisocyanate or toluene diisocyanate; Aliphatic and cycloaliphatic isocyanates include: 1,6 - hexamethylene diisocyanate, 3 - isocyanatomethyl - 3,5,5 - trimethylcyclohexyl isocyanate, and 4,4'-diisocyanatodicyclohexylmethane.

3. The preparation method of a high-strength composite polyurethane sealant according to claim 1, characterized in that: The polyols used for preparing polyurethane in Step 1 include polyether polyols and polyester polyols.

4. The preparation method of a high-strength composite polyurethane sealant according to claim 1, characterized in that: The catalysts used for preparing polyurethane in Step 2 include amine compounds or metal compounds; Amine compound catalysts include tertiary amines, and tertiary amines include triethylenediamine, dimethylcyclohexylamine, and dimethylethanolamine; Metal compound catalysts include compounds based on mercury, lead, tin, bismuth, and zinc.

5. A high-strength composite polyurethane sealant as claimed in claim 1.

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