Bio-based two-component polyurethane with ultralow water permeability and preparation method of bio-based two-component polyurethane

Abstract

The invention discloses bio-based ultralow-water-permeability two-component polyurethane which is characterized in that a component A comprises 20-40 parts of modified castor oil, 5-15 parts of diisooctyl adipate, 1-5 parts of a coupling agent, 60-70 parts of aluminum hydroxide, 5-10 parts of a water removal agent and 1-3 parts of a coloring agent; the component A is polymethylene polyphenyl isocyanate, the component B is composite isocyanate formed by combining two of polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, carbodiimide modified diphenylmethane diisocyanate and isophorone diisocyanate, and the component B is composite isocyanate formed by combining two of polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, carbodiimide modified diphenylmethane diisocyanate and isophorone diisocyanate. The invention further discloses a preparation method. The polyurethane pouring sealant with ultralow water permeability is obtained by optimizing a polyurethane formula and compounding a curing agent component.

Description

Technical Field

[0001] The present invention belongs to the technical field of transducer potting adhesives, and particularly relates to a bio-based polyurethane with ultra-low water permeability and a method for preparing the same. Background Art

[0002] The underwater transducer coating and sealing material has good flexibility and can adapt to the vibration and deformation of the transducer in a complex marine environment. At the same time, it must have excellent sealing ability and low water permeability to prevent seawater from invading the inside of the transducer, prevent electronic components from being damaged by moisture, and ensure the normal operation of the equipment. Conventional polyether-based polyurethane materials are difficult to meet the requirements of low water permeability, and usually the water permeability is 10 -12 g·cm / cm 2 ·s·Pa. The relatively high water permeability makes it impossible for polyether-based polyurethane materials to block the intrusion of water vapor in the underwater environment, resulting in a decrease in the internal electrical insulation performance of the transducer, leading to transducer failure and reducing the underwater service life of the transducer. Moreover, traditional petroleum-based polyurethanes usually have certain toxicity and will have a certain impact on the hydrobiological environment when laid at high density. Therefore, it is necessary to develop a polyurethane that is safe, environmentally friendly and has a low water permeability to meet the growing demand for hydro-environment development.

[0003] The bio-based castor oil polyurethane system is a polyurethane material prepared from renewable castor oil. Compared with traditional petroleum-based polyurethanes, it has many advantages in terms of sustainability, environmental friendliness, performance and application fields. At the same time, the long-chain fatty acid structure in the castor oil molecule endows the polyurethane with good flexibility and impact resistance, and its hydrophobic property can improve the stability of the material in a humid or chemical environment, making the prepared potting adhesive have a lower water permeability. Castor oil-based polyurethanes are non-toxic and compatible with biological tissues, and have better environmental friendliness in marine environment applications. Summary of the Invention

[0004] In order to overcome the above technical problems in the prior art, one of the purposes of the present invention is to provide a bio-based polyurethane with ultra-low water permeability, which has an extremely low water permeability.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a bio-based polyurethane with ultra-low water permeability, comprising component A and component B; the component A includes 20-40 parts of modified castor oil, 5-15 parts of diisooctyl adipate, 1-5 parts of coupling agent, 60-70 parts of aluminum hydroxide, 5-10 parts of water scavenger and 1-3 parts of colorant; the component B is a composite isocyanate composed of two combinations of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and isophorone diisocyanate.

[0006] Furthermore, the composite isocyanate is composed of 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of carbodiimide-modified diphenylmethane diisocyanate.

[0007] Furthermore, the composite isocyanate is composed of 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of isophorone diisocyanate.

[0008] Furthermore, the composite isocyanate is composed of 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate.

[0009] Furthermore, the composite isocyanate is composed of 55 parts of polymethylene polyphenyl polyisocyanate and 45 parts of diphenylmethane diisocyanate.

[0010] Furthermore, the composite isocyanate is composed of 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate.

[0011] Furthermore, the water scavenger is 3A molecular sieve, 4A molecular sieve or 13X molecular sieve.

[0012] Furthermore, the aluminum hydroxide is 800 mesh.

[0013] The second object of the present invention is to provide a preparation method of a bio-based ultra-low water permeability two-component polyurethane, and the steps are as follows: (1) Add modified castor oil, diisooctyl adipate, coupling agent, colorant and water scavenger into a stirrer in sequence for low-speed stirring and dispersion; add aluminum hydroxide into the stirrer for high-speed stirring, the temperature does not exceed 50 °C, and after stirring, remove bubbles under vacuum to obtain component A; (2) Add two of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and isophorone diisocyanate into a stirrer, stir at low speed under vacuum, and the temperature does not exceed 40 °C to obtain component B; (3) Mix component A and component B to obtain a bio-based ultra-low water permeability two-component polyurethane.

[0014] The beneficial effects of the present invention are as follows: The present invention uses bio-based modified castor oil as the polyurethane polyol raw material, replacing the conventional petroleum-based polyol, and has good environmental friendliness and sustainability. Modified castor oil is derived from the castor plant, which is a rapidly renewable bio-based raw material, and the greenhouse gas emissions during the production process are significantly lower than those of petroleum-based polyurethanes. Castor oil-based polyurethane is non-toxic and compatible with biological tissues, and is commonly used in the medical field, and has better environmental friendliness in marine environment use.

[0015] The modified castor oil used in the present invention has hydrophobic properties, which can improve the stability of materials in humid or chemical environments. Compared with traditional polyether petroleum-based polyurethanes (water permeability rate of 10 -12 g·cm / cm 2 ·s·Pa), it has a lower water permeability rate (water permeability rate of 10 -14 g·cm / cm 2 ·s·Pa), which can more effectively improve the hydrophobicity of the polyurethane after potting and effectively extend the service life of underwater devices.

[0016] The present invention uses a curing agent composed of a variety of isocyanates in combination. By adjusting the types of isocyanates, the extension orientation and the interval between hard and soft segments of the polymer chain segments are effectively controlled. On the basis of maintaining the toughness of the cured polyurethane, the free volume between the polymer grids is reduced through high cross-linking degree, effectively reducing the permeation ability of water vapor small molecules and further reducing the water permeability rate of the cured polyurethane. Specific Embodiments

[0017] The present invention will be further described below in conjunction with specific embodiments.

[0018] A bio-based two-component polyurethane with ultra-low water permeability disclosed by the present invention, the formulation of component A includes 20-40 parts of modified castor oil, 5-15 parts of diisooctyl adipate, 1-5 parts of coupling agent, 40-70 parts of aluminum hydroxide, 5-10 parts of water scavenger, and 1-3 parts of colorant, and a composite isocyanate composed of a combination of two of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, and isophorone diisocyanate. Example 1

[0019] A bio-based two-component polyurethane with ultra-low water permeability disclosed in this example is prepared as follows.

[0020] (1) Add 30 parts of modified castor oil, 5 parts of diisooctyl adipate, 2 parts of coupling agent, 2 parts of colorant, and 5 parts of 3A molecular sieve to the stirrer in sequence for low-speed stirring and dispersion; add 65 parts of 800-mesh aluminum hydroxide to the stirrer and carry out high-speed stirring at a temperature not exceeding 50 °C. After stirring, remove bubbles under vacuum to obtain component A.

[0021] (2) Add 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of carbodiimide-modified diphenylmethane diisocyanate to the stirrer in sequence, and stir at low speed under vacuum at a temperature not exceeding 40 °C to obtain component B.

[0022] (3) Mix component A and component B to obtain a bio-based two-component polyurethane with ultra-low water permeability. Example 2

[0023] A bio-based two-component polyurethane with ultra-low water permeability disclosed in this embodiment has the following preparation steps.

[0024] (1) Add 35 parts of modified castor oil, 5 parts of diisooctyl adipate, 3 parts of coupling agent, 2 parts of colorant, and 6 parts of 4A molecular sieve into a stirrer in sequence for low-speed stirring and dispersion; add 70 parts of 800-mesh aluminum hydroxide into the stirrer for high-speed stirring, with the temperature not exceeding 50 °C. After stirring, remove air bubbles under vacuum to obtain Component A.

[0025] (2) Add 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of isophorone diisocyanate into a stirrer in sequence, stir at low speed under vacuum, with the temperature not exceeding 40 °C, to obtain Component B.

[0026] (3) Mix Component A and Component B to obtain the bio-based two-component polyurethane with ultra-low water permeability. Example 3

[0027] A bio-based two-component polyurethane with ultra-low water permeability disclosed in this embodiment has the following preparation steps.

[0028] (1) Add 40 parts of modified castor oil, 15 parts of diisooctyl adipate, 5 parts of coupling agent, 3 parts of colorant, and 6 parts of 13X molecular sieve into a stirrer in sequence for low-speed stirring and dispersion; add 70 parts of 800-mesh aluminum hydroxide into the stirrer for high-speed stirring, with the temperature not exceeding 50 °C. After stirring, remove air bubbles under vacuum to obtain Component A.

[0029] (2) Add 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate into a stirrer in sequence, stir at low speed under vacuum, with the temperature not exceeding 40 °C, to obtain Component B.

[0030] (3) Mix Component A and Component B to obtain the bio-based two-component polyurethane with ultra-low water permeability. Example 4

[0031] A bio-based two-component polyurethane with ultra-low water permeability disclosed in this embodiment has the following preparation steps.

[0032] (1) Add 25 parts of modified castor oil, 15 parts of diisooctyl adipate, 1 part of coupling agent, 1 part of colorant, and 10 parts of 4A molecular sieve into a stirrer in sequence for low-speed stirring and dispersion; add 60 parts of 800-mesh aluminum hydroxide into the stirrer for high-speed stirring, with the temperature not exceeding 50 °C. After stirring, remove air bubbles under vacuum to obtain Component A.

[0033] (2) Add 55 parts of polymethylene polyphenyl polyisocyanate and 45 parts of diphenylmethane diisocyanate into a stirrer in sequence, stir at low speed under vacuum, with the temperature not exceeding 40 °C, to obtain Component B.

[0034] (3) Mix component A and component B to obtain a bio-based two-component polyurethane with ultra-low water permeability. Example 5

[0035] A bio-based two-component polyurethane with ultra-low water permeability disclosed in this example is prepared as follows.

[0036] (1) Add 20 parts of modified castor oil, 5 parts of diisooctyl adipate, 1 part of coupling agent, 2 parts of colorant, and 5 parts of 3A molecular sieve to a stirrer in sequence for low-speed stirring and dispersion; add 60 parts of 800-mesh aluminum hydroxide to the stirrer for high-speed stirring at a temperature not exceeding 50°C. After stirring, remove air bubbles under vacuum to obtain component A.

[0037] (2) Add 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate to a stirrer in sequence, and stir at low speed under vacuum at a temperature not exceeding 40°C to obtain component B.

[0038] (3) Mix component A and component B to obtain a bio-based two-component polyurethane with ultra-low water permeability.

[0039] Since the bio-based two-component polyurethane with ultra-low water permeability in the present invention is mainly applied to the potting of transducers, in addition to requiring low water permeability, the polyurethane also needs to have reasonable operability, good adhesion performance, and good insulation strength. The performance test results of the polyurethane potting adhesive corresponding to the examples are shown in the following table.

[0040] .

[0041] The above examples are only for illustrating the technical solutions of the present invention, rather than all examples. Any modifications, equivalent replacements, and improvements made within the principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A bio-based ultra-low water permeability two-component polyurethane, comprising component A and component B; characterized in that: The component A comprises 20-40 parts of modified castor oil, 5-15 parts of diisooctyl adipate, 1-5 parts of coupling agent, 60-70 parts of aluminum hydroxide, 5-10 parts of dehydrating agent and 1-3 parts of colorant; the component B is a composite isocyanate formed by combining two of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide modified diphenylmethane diisocyanate and isophorone diisocyanate.

2. The bio-based ultra-low water permeability two-component polyurethane according to claim 1, characterized in that: The composite isocyanate is composed of 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of carbodiimide modified diphenylmethane diisocyanate.

3. The bio-based ultra-low water permeability two-component polyurethane according to claim 1, characterized in that: The composite isocyanate is composed of 50 parts of polymethylene polyphenyl polyisocyanate and 50 parts of isophorone diisocyanate.

4. The bio-based ultra-low water permeability two-component polyurethane according to claim 1, characterized in that: The composite isocyanate is composed of 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate.

5. The bio-based ultra-low water permeability two-component polyurethane according to claim 1, characterized in that: The composite isocyanate is composed of 55 parts of polymethylene polyphenyl polyisocyanate and 45 parts of diphenylmethane diisocyanate.

6. The bio-based ultra-low water permeability two-component polyurethane according to claim 1, characterized in that: The composite isocyanate is composed of 40 parts of carbodiimide-modified diphenylmethane diisocyanate and 60 parts of isophorone diisocyanate.

7. A bio-based ultra-low water permeability two-component polyurethane according to any one of claims 1 to 6, characterized in that: The dehydrating agent is 3A molecular sieve, 4A molecular sieve or 13X molecular sieve.

8. The bio-based ultra-low water permeability two-component polyurethane according to claim 7, characterized in that: The aluminum hydroxide is 800 meshes.

9. A method for preparing the bio-based ultra-low water permeability two-component polyurethane as claimed in claim 1, characterized in that: Here are the steps: (1) Add modified castor oil, diisooctyl adipate, coupling agent, colorant and dehydrating agent to a stirrer in sequence, stir and disperse at a low speed; add aluminum hydroxide to the stirrer, stir at a high speed at a temperature not exceeding 50° C. After stirring, remove bubbles in a vacuum to obtain component A; (2) Add two of polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and isophorone diisocyanate into a stirrer in sequence, stir at a low speed under vacuum at a temperature not exceeding 40° C., to obtain component B; (3) Component A and component B are mixed to obtain a bio-based ultra-low water permeability two-component polyurethane.