TW202202542A - High-entropy polyurethane and preparation method thereof - Google Patents

Abstract

The invention discloses a high-entropy polyurethane and a preparation method thereof. The high-entropy polyurethane is prepared by the reaction of polyurethane prepolymer and chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight percentage: polyester polyol 38.0%-63.0%, diisocyanate 32.0%-37.0%, and plasticizer 5.0%-25.0%. The high-entropy polyurethane prepared by the invention not only has higher mechanical properties and relatively low glass transition temperature, but also is extremely insensitive to temperature, and can be applied to areas with changeable climates.

Description

High entropy polyurethane and preparation method thereof

The invention relates to the technical field of macromolecular materials, in particular to a high-entropy polyurethane and a preparation method thereof.

High entropy polyurethane (High entropy PU) has a unique long-chain and short-chain hybrid structure, which makes it have excellent comprehensive mechanical properties, including excellent mechanical properties and wear resistance, oil resistance, and aging resistance. , The hardness can be adjusted in a large range, and these excellent comprehensive properties are not found in many other rubbers and plastics. However, in some special use environments, high-entropy polyurethane materials need to have special performance requirements, such as low temperature resistance, the use temperature of high-entropy polyurethane is basically above zero, and the temperature in winter is zero or even minus 20 degrees. Therefore, the prepared high-entropy polyurethane is required to have better low temperature flexibility, that is, it can still show the high elastic state of high-entropy polyurethane in a low temperature environment, but its tear resistance and tensile strength are the minimum values, which cannot meet certain requirements. In some application fields that require higher mechanical properties, high-entropy polyurethane has high tear resistance and tensile strength, but ordinary polyurethane has poor low temperature resistance, which limits its application in low temperature environments.

An object of the present invention is to provide a temperature-insensitive polyurethane with excellent mechanical properties.

In order to achieve the above purpose, the present invention provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester Polyol 38.0%-63.0%, diisocyanate 32.0%-37.0%, plasticizer 5.0%-25.0%.

Further, the weight ratio of the aforementioned polyurethane prepolymer to the chain extender is 100:4.6-7.1.

Further, the aforementioned polyester polyol is prepared from adipic acid and 1,4-butanediol or prepared from adipic acid, ethylene glycol and 1,4-butanediol, and has a functionality of 2 and a number average molecular weight. It is 3000～3200.

Further, the aforementioned diisocyanate is one or a mixture of two of 4,4'-diphenylmethane diisocyanate and carbodiimide-modified diphenylmethane diisocyanate.

Further, the aforementioned plasticizers are butyl benzyl phthalate (BBP), dimethoxyethyl phthalate (DMEP), diisobutyl phthalate (DIBP), dibenzoic acid One or more mixtures of polypropylene glycol esters.

Further, the aforementioned chain extender is 1,4-butanediol or a mixture of 1,4-butanediol and trimethylolpropane.

Further, the content of isocyanate groups in the aforementioned polyurethane prepolymer is 3.5% to 8.0%.

Another object of the present invention is to provide the preparation method of above-mentioned high-entropy polyurethane, comprising the following steps: (1) React polyester polyol, diisocyanate and plasticizer at a temperature of 75 to 85 °C for 2 to 3 hours to obtain a polyurethane prepolymer; and (2) Mix the polyurethane prepolymer and the chain extender at a temperature of 75 to 85 °C, then pour the mixture into a mold with a temperature of 100 to 120 °C, and release the mold after 60 to 90 minutes. The finished product is vulcanized at 100-120°C for 64-80 hours to obtain high-entropy polyurethane.

Further, the content of isocyanate groups in the aforementioned polyurethane prepolymer is 3.5% to 8.0%.

Further, the hardness of the aforementioned polyurethane elastomer is Shore A60-85, and the glass transition temperature is -40--55°C.

The beneficial effects of the present invention are embodied in: (3) The high-entropy polyurethane prepared by the present invention has both high mechanical properties and low glass transition temperature, and is extremely insensitive to temperature, which can meet the requirements for polyurethane materials in regions with changeable climates. (4) The preparation method of the high-entropy polyurethane provided by the present invention not only saves energy and is environmentally friendly, but also has the advantages of being simple and easy to operate.

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar drawing numerals. In the drawings, each element or section is not necessarily drawn to actual scale.

The embodiments of the technical solutions of the present invention will be described in detail below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the usual meanings understood by those skilled in the art to which the present invention belongs.

The experimental methods in the following examples are conventional methods unless otherwise specified. The test materials used in the following examples were purchased from conventional biochemical reagent stores unless otherwise specified. The quantitative experiments in the following examples are all set up three repeated experiments, and the data are the mean value or the mean ± standard deviation of the three repeated experiments.

The materials used in the high-entropy polyurethane preparation process of the present invention are as follows: Carbodiimide-modified MDI (liquefied MDI): Modified diphenylmethane diisocyanate with 29.5% isocyanate content. 9-88SG: Benzoate plasticizer, the main component is dipropylene glycol dibenzoate.

Example 1

This embodiment provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 50.0%, 35.0% diisocyanate, 15.0% plasticizer, wherein, polyester polyol is polyester diol PE 4020 with a number average molecular weight of 3000, prepared from adipic acid and 1,4-butanediol, two Isocyanates include 4,4'-diphenylmethane diisocyanate 30% and carbodiimide-modified MDI (liquefied MDI) 5%, plasticizer is butyl benzyl phthalate (BBP), chain extender For 1,4-butanediol.

The preparation method of this high entropy polyurethane comprises the following steps: (1) The polyester polyol, diisocyanate and plasticizer were reacted at a temperature of 80 °C for 2 hours, and the bubbles were removed under vacuum to obtain a polyurethane prepolymer with an isocyanate content of 5.6%; The vacuum degree during bubble is -0.095 MPa; (2) Mix the polyurethane prepolymer and the chain extender at 100:5.5 at a temperature of 80 °C, then pour the mixture into a mold with a temperature of 110 °C, and demold it after 80 minutes. The product was vulcanized at 110 °C for 70 hours to obtain high-entropy polyurethane.

Example 2

This embodiment provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 63.0 %, diisocyanate 32.0%, plasticizer 5.0%, wherein, polyester polyol is polyester diol PE 2420 with a number average molecular weight of 3200, prepared from adipic acid, ethylene glycol, 1,4-butanediol into, wherein the mass ratio of ethylene glycol and 1,4-butanediol is 3:1, and the diisocyanates include 4,4'-diphenylmethane diisocyanate 28% and carbodiimide-modified MDI (liquefied MDI) 5%, the plasticizer is dimethoxyethyl phthalate (DMEP), and the chain extender is a mixture of 1,4-butanediol and trimethylolpropane in a mass ratio of 5:1.

The preparation method of this high entropy polyurethane comprises the following steps: (1) The polyester polyol, diisocyanate and plasticizer were reacted at a temperature of 85 °C for 3 hours, and the bubbles were removed under vacuum to obtain a polyurethane prepolymer with an isocyanate content of 3.5%; The vacuum degree during bubble is -0.095 MPa; (2) Mix the polyurethane prepolymer and the chain extender at 100:4.6 at a temperature of 85 °C, then pour the mixture into a mold with a temperature of 120 °C, and demold it after 70 minutes. The product was vulcanized at 120 °C for 65 hours to obtain high-entropy polyurethane.

Example 3

This embodiment provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 38 %, diisocyanate 37%, plasticizer 25.0%, wherein, polyester polyol is polyester diol PE 2420 with a number average molecular weight of 3000, prepared from adipic acid, ethylene glycol and 1,4-butanediol. into, wherein the mass ratio of ethylene glycol and 1,4-butanediol is 3:1, and the diisocyanates include 4,4'-diphenylmethane diisocyanate 32% and carbodiimide-modified MDI (liquefied MDI) 5%, the plasticizer is 9-88SG, and the chain extender is a mixture of 1,4-butanediol and trimethylolpropane in a mass ratio of 20:3.

The preparation method of this high entropy polyurethane comprises the following steps: (1) The polyester polyol, diisocyanate and plasticizer were reacted at a temperature of 75 °C for 2 hours, and the bubbles were removed under vacuum to obtain a polyurethane prepolymer with an isocyanate content of 8.0%; The vacuum degree during bubble is -0.095 MPa; (2) Mix the polyurethane prepolymer and the chain extender in a ratio of 100:7.1 at a temperature of 75 °C, then pour the mixture into a mold with a temperature of 100 °C, and release the mold after 60 minutes. The product was vulcanized at 100 °C for 80 hours to obtain high-entropy polyurethane.

Comparative ratio 1

This comparative example provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 65.0 %, diisocyanate 35.0%, wherein, polyester polyol is polyester diol PE 2420 with a number average molecular weight of 3200, prepared from adipic acid, ethylene glycol, 1,4-butanediol, wherein ethylene glycol and The mass ratio of 1,4-butanediol is 3:1, the diisocyanates include 4,4'-diphenylmethane diisocyanate 28% and carbodiimide-modified MDI (liquefied MDI) 5%, chain extender It is a mixture of 1,4-butanediol and trimethylolpropane in a mass ratio of 5:1.

The preparation method of this high entropy polyurethane comprises the following steps: (1) The polyester polyol and diisocyanate were reacted at a temperature of 85 °C for 3 hours, and the bubbles were removed under vacuum to obtain a polyurethane prepolymer with an isocyanate content of 3.5%; among them, the vacuum degree during vacuum degassing is -0.095 MPa; (2) Mix the polyurethane prepolymer and the chain extender at 100:4.6 at a temperature of 85 °C, then pour the mixture into a mold with a temperature of 120 °C, and demold it after 70 minutes. The product was vulcanized at 120 °C for 65 hours to obtain high-entropy polyurethane.

Comparative ratio 2

This embodiment provides a high-entropy polyurethane. The high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender. The raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 75.0 %, diisocyanate 20.0%, plasticizer 5.0%, wherein, polyester polyol is polyester diol PE 2420 with a number average molecular weight of 3200, wherein the mass ratio of ethylene glycol and 1,4-butanediol is 3: 1. It is prepared from adipic acid, ethylene glycol and 1,4-butanediol. The diisocyanate includes 20% 4,4'-diphenylmethane diisocyanate, and the plasticizer is dimethoxy phthalate. Ethyl ester (DMEP), the chain extender is a mixture of 1,4-butanediol and trimethylolpropane in a mass ratio of 5:1.

The preparation method of this high entropy polyurethane comprises the following steps: (1) The polyester polyol, diisocyanate and plasticizer were reacted at a temperature of 85 °C for 3 hours, and the bubbles were removed under vacuum to obtain a polyurethane prepolymer with an isocyanate content of 3.5%; The vacuum degree during bubble is -0.095 MPa; (2) Mix the polyurethane prepolymer and the chain extender in a ratio of 100:4.6 at a temperature of 85 °C, then pour the mixture into a mold with a temperature of 130 °C, demold it after 70 minutes, and put the demolded The product was vulcanized at 120 °C for 65 hours to obtain high-entropy polyurethane.

The glass transition temperature of the product is tested by a 204 differential scanning calorimeter produced by NETZSCH, Germany. The test conditions are: under the protection of N2, the sample is raised from room temperature to 180 °C, and the temperature is kept constant for 5 minutes to eliminate the thermal history. -70°C and then rise to 180°C again. Example properties are shown in the table below. Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Hardness/Shore A/25℃ 80 60 76 80 79 Low temperature hardness/-10℃ 96 75 88 98 97 Glass transition temperature Tg/℃ -55 -40 -47 -twenty two -30

By comparison, it can be seen that the high-entropy polyurethane of Example 1 of the present invention has better performance. By further comparing the properties of the high-entropy polyurethane of Example 1 of the present invention and the common polyurethane on the market, the results are shown in Figures 1 to 4. Wherein, Figure 1 is the tensile strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane at high temperature, which shows the performance of the high-entropy polyurethane at a temperature of 50 ° C and a relative humidity of 80%; Figure 2 is a The tensile strength of the high-entropy polyurethane of Example 1 of the invention and the existing polyurethane at low temperature, it shows the performance of the high-entropy polyurethane at a temperature of -25 ° C and a relative humidity of 40%; The three-point bending strength of the high-entropy polyurethane and the existing polyurethane at different fixed torques; Figure 4 is the impact strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane at different temperatures. It can be seen from FIG. 1 to FIG. 4 that the high-entropy polyurethane of the present invention can also achieve better mechanical properties at lower temperatures, and can adapt to different climatic conditions.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. The scope of the invention should be included in the scope of the patent application and the description of the present invention.

without.

Fig. 1 is the tensile strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane at high temperature. FIG. 2 is the tensile strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane at low temperature. FIG. 3 is the three-point bending strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane under different fixing torques. FIG. 4 is the impact strength of the high-entropy polyurethane of Example 1 of the present invention and the existing polyurethane at different temperatures.

without.

Claims (10)

A high-entropy polyurethane, the high-entropy polyurethane is prepared by reacting a polyurethane prepolymer with a chain extender, and the raw materials for preparing the polyurethane prepolymer include the following components by weight: polyester polyol 38.0% to 63.0% , 32.0% to 37.0% of diisocyanate and 5.0% to 25.0% of plasticizer. The high-entropy polyurethane according to claim 1, wherein the weight ratio of the polyurethane prepolymer to the chain extender is 100:4.6-7.1. The high-entropy polyurethane according to claim 1, wherein the polyester polyol is prepared from adipic acid and 1,4-butanediol or prepared from adipic acid, ethylene glycol and 1,4-butanediol , the functionality is 2, and the number average molecular weight is 3000-3200. The high-entropy polyurethane according to claim 1, wherein the diisocyanate is one or a mixture of two of 4,4'-diphenylmethane diisocyanate and carbodiimide-modified diphenylmethane diisocyanate. The high-entropy polyurethane according to claim 1, wherein the plasticizer is butyl benzyl phthalate (BBP), dimethoxyethyl phthalate (DMEP), diisobutyl phthalate One or a mixture of two or more esters (DIBP) and dipropylene glycol dibenzoate. The high-entropy polyurethane according to claim 1, wherein the chain extender is 1,4-butanediol or a mixture of 1,4-butanediol and trimethylolpropane. The high-entropy polyurethane according to claim 1, wherein the content of isocyanate groups in the polyurethane prepolymer is 3.5% to 8.0%. A preparation method of the high-entropy polyurethane as described in any one of claims 1-7, comprising the following steps: (1) reacting polyester polyol, diisocyanate and plasticizer at a temperature of 75-85 °C for 2-3 hours to obtain a polyurethane prepolymer; (2) Mix the polyurethane prepolymer and the chain extender at a temperature of 75 to 85 °C, then pour the mixture into a mold with a temperature of 100 to 120 °C, release the mold after 60 to 90 minutes, and release the mold The finished product is vulcanized at 100-120°C for 64-80 hours to obtain high-entropy polyurethane. The preparation method according to claim 8, wherein the content of isocyanate groups in the polyurethane prepolymer is 3.5% to 8.0%. The preparation method according to claim 8, wherein the hardness of the polyurethane elastomer is Shore A60-85, and the glass transition temperature is -40--55°C.

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