CN118496656B - Bionic micropore-induced self-healing hydrolysis-resistant elastomer fender material and preparation process thereof - Google Patents

Abstract

The invention relates to the technical field of microporous self-healing elastomer, in particular to a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material and a preparation process thereof, wherein the fender material comprises the following components: 10-30 parts of modified hydrogel, 50 parts of silane coupling agent, 15-20 parts of 4,4' -diphenylmethane diisocyanate, 5-10 parts of polyadipate polyol, 18-22 parts of 3,3' -dimethyl-4, 4' -biphenyl diisocyanate and 3-4 parts of chain extender, wherein the modified hydrogel is prepared from methyl cellulose, organic fluorine and L-cysteine, and the fender material prepared from the modified hydrogel has the self-healing property of the hydrogel and the water resistance of fluorine-containing organic matters, has the toughening effect of a microporous structure, and improves the mechanical property of the material.

Description

Bionic micropore-induced self-healing hydrolysis-resistant elastomer fender material and its preparation process

Technical Field

The invention relates to the technical field of microporous self-healing elastomers, in particular to a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material and a preparation process thereof.

Background Art

When a ship docks, it will collide with the dock. If a very strong anti-collision device is not installed on the ship and the dock, the hull of the ship will be damaged when docking. The current common practice is to fix waste tires on the ship and the dock to prevent collision. However, due to the limited elasticity of waste tires, they only play an isolation role and cannot protect the hull well. It is also very unsightly to set waste tires on ships and docks. People have also designed fenders with various structures, but most of them have unreasonable structures, resulting in poor elasticity. After absorbing the elastic force, the rebound performance is not ideal, so it is difficult to promote and apply them in the market. In view of this, we propose a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material and its preparation process.

Summary of the invention

The object of the present invention is to provide a bionic micropore-induced self-healing hydrolysis-resistant elastomer fender material and a preparation process thereof, so as to solve the problems raised in the above-mentioned background technology.

To achieve the above object, the present invention provides a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, comprising the following components: 10-30 parts by weight of modified hydrogel, 50 parts by weight of silane coupling agent, 15-20 parts by weight of 4,4'-diphenylmethane diisocyanate, 5-10 parts by weight of polyadipate polyol, 18-22 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3-4 parts by weight of chain extender, wherein the modified hydrogel is prepared by taking methyl cellulose as the hydrogel main body, introducing organic fluorine and grafting L-cysteine, and the chain extender is composed of 100 parts by weight of high molecular weight diol polyethylene glycol adipate polyol (average molecular weight Mn is 2000, hydroxyl value is 56mg KOH/g) and 3 to 10 parts by weight of low molecular weight diol 1,4-butanediol, 2.2 to 8 parts by weight of water, 0.3 to 2.4 parts by weight of stannous octoate catalyst and 0.5 to 2.8 parts by weight of foam stabilizer, i.e., silicone surfactant.

Preferably, the preparation method of the modified hydrogel is as follows:

S1.1. Prepare components: 6-9 parts by weight of methylcellulose, 400-600 parts by weight of dimethyl sulfoxide, 3-5 parts by weight of perfluorooctyl hexanediol, 4-5 parts by weight of L-cysteine, 0.3-0.5 parts by weight of 4-dimethylaminopyridine, and 2-3 parts by weight of dicyclohexylcarbodiimide;

S1.2. Dry the methylcellulose in a vacuum oven. After drying, add the methylcellulose to a three-necked flask containing dimethyl sulfoxide solution. Stir with a stirrer under oil bath conditions until the methylcellulose is completely dissolved. Then add perfluorooctyl hexanediol and L-cysteine. Stop heating. Add 4-dimethylaminopyridine and dicyclohexylcarbodiimide to the three-necked flask. Pass nitrogen for 1 hour to remove oxygen. Then transfer the flask to a water bath. After the reaction is completed, add the above solution to a beaker containing 100 mL of anhydrous ethanol. Precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. Let stand for 30 minutes, filter, wash 3 times, and finally freeze-dry the product for 24 hours to obtain a modified hydrogel.

Preferably, the temperature of the vacuum oven is set to 60° C. and the drying time is 24 hours.

Preferably, the oil bath temperature is set to 70° C., the speed of the stirrer is 300-400 r/min, and the stirring time is 1.5 h.

Preferably, the water bath temperature is 20-25°C, and the water bath time is 24-30h.

On the other hand, the present invention provides a method for preparing a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, which is used for preparing the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, comprising the following steps:

Add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C for reaction to obtain a polyurethane prepolymer, mix the modified hydrogel with a silane coupling agent and add the mixture together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate into the polyurethane prepolymer, stir with a stirrer to obtain a mixed polyurethane prepolymer, add a chain extender into the obtained mixed polyurethane prepolymer, heat and stir, inject into a mold for molding, demold, and mature to obtain a microporous polyurethane, i.e., a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material.

The method adopts a two-step prepolymer method to prepare the fender material. First, isocyanate and polyol are reacted to form a prepolymer. Due to the excess of isocyanate, the prepolymer has a certain isocyanate content. The prepolymer and the chain extender component are mixed in a reaction container, so that the chain extender consumes the isocyanate in the prepolymer, the group reaction is complete, and the microporous polyurethane elastomer is initiated and cured.

Polyester oligomer polyols will form a soft segment phase in the internal structure of the fender material, while isocyanates and chain extenders will form a hard segment phase in the internal structure. The soft segment and the hard segment appear alternately and are arranged into block polymers. The soft segment is usually a continuous phase and is in a highly elastic state at room temperature, providing low-temperature performance and resilience. The hard segment is usually a dispersed phase and is in a glassy state at room temperature. Because there are a large number of polar groups on its molecular chain and even a crystalline structure, the hard segment has a large polarity, strong intermolecular forces, and a large hydrogen bond effect, which makes the hard segment very rigid. It plays a role similar to physical filling and improving the degree of chemical crosslinking in microporous polyurethane elastomers. The non-polar soft segment and the polar hard segment are connected together by chemical bonds, but they are thermodynamically incompatible, thus forming two phase regions with a scale of only nanometers or micrometers, showing the characteristics of microphase separation.

There are two main types of reactions occurring during the synthesis process, one is the gelling reaction and the other is the foaming reaction. The gelling reaction refers to the reaction of the isocyanate in the isocyanate with the active hydrogen of the oligomer polyol and the alcohol chain extender to generate a carbamate group and replace the urea group, and the foaming reaction refers to the reaction of the isocyanate in the isocyanate with the active hydrogen in the water to generate urea and release carbon dioxide.

Stannous octoate catalyst has a strong catalytic effect on the foaming reaction and can promote the reaction between isocyanate and alcohol. By controlling the speed of gelation and foaming reaction, the morphology and stability of the pores can be controlled to obtain a foaming material with uniform pores, smooth surface and good mechanical properties. If the amount of organic tin catalyst is gradually increased, the gelation speed of the fender material will gradually increase, so that the fender material will be cross-linked before foaming, the viscosity of the system will increase, and the carbon dioxide gas generated by the subsequent foaming reaction cannot be encapsulated, which may cause the product to have more pores in the middle and fewer pores around the foam body. The processing performance will also be affected due to excessive viscosity.

When polyurethane is synthesized with polyols, since it contains more ester groups and urethane groups with high polarity, the hydrogen bonding effect becomes stronger, the intermolecular force increases, and the cohesive energy density becomes larger, making the material strong and wear-resistant.

Water is used as a blowing agent, and carbon dioxide is generated by the reaction of water and isocyanate to expand the polyurethane matrix and produce bubbles. This reaction rapidly increases the viscosity of the system and promotes curing.

In the process of generating foam in the matrix, water and isocyanate react to release carbon dioxide and generate a polyurea structure at the same time. The polyurea structure is incompatible with the foam matrix and will destroy the stability of the foam structure. The foam stabilizer relies on its own surface activity to reduce the surface tension of the foam and increase the compatibility between the two. The gas is more easily dispersed into nuclei, and the pressure difference between different pores is reduced. The polyurea structure is evenly dispersed in the foam matrix, reducing the damage of the polyurea structure to the pore matrix, thereby improving the foam stability. Without adding silicone oil foam stabilizer, the foam will rise rapidly and grow larger during the foaming reaction, and the generated urea-based compound will have poor compatibility with the foam, resulting in a rough foam surface and brittle material. In severe cases, foam collapse will occur. Therefore, it is necessary to add an appropriate amount of foam stabilizer to the components.

The bionic microporous structure prepared by the template method is equivalent to an air spring when the fender material is impacted. The huge compression ratio makes the micropores have a toughening effect, causing large areas of silver streaks and shear bands around the micropores, absorbing the energy from the impact, reducing the damage to the fender material, and thus improving the mechanical properties.

The self-healing properties of the material are related to the isocyanate group, in addition to the reaction of methylcellulose and L-cysteine to introduce thiol groups to form dynamic disulfide bonds. This is because the isocyanate group will react with moisture in water or air to form urea bonds or carbamate bonds. The newly generated polyurethane molecules cross-link with other polyurethane molecules on the surface of the material to repair microcracks or damage.

Preferably, the polyadipate polyol has a functionality of 2 to 3, a hydroxyl value of 56 to 140 mg KOH/g, and a number average molecular weight of 2000 to 4000.

Preferably, the NCO content of the polyurethane prepolymer is 6% to 12%.

Preferably, the agitator has a rotation speed of 400-500 r/min.

Preferably, the reaction temperature of the mixed polyurethane prepolymer and the chain extender is 60°C.

Preferably, the mold temperature for molding in the injection mold is 80-85° C., and the mold is matured at 90° C. for 12-20 hours after demoulding.

Compared with the prior art, the present invention has the following beneficial effects:

In the bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material and its preparation process, the bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material is prepared by modified hydrogel, methyl cellulose is used as the hydrogel main body, and the dynamic disulfide bonds formed by grafting L-cysteine are coordinated with hydrogen bonds to achieve self-healing, and hydrophobic organic fluorine is introduced to greatly increase the hydrogen bonds and bond energy, thereby improving the stability and water resistance of the hydrogel, and then the modified hydrogel is chemically coupled with a microporous polyurethane elastomer, so that the bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material has the characteristics of the self-healing performance of the hydrogel and the water resistance of the fluorine-containing organic matter, and at the same time, it also has the toughening effect of the bionic microporous structure, thereby improving the mechanical properties of the material.

DETAILED DESCRIPTION

The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

The bionic microporous induced self-healing hydrolysis-resistant elastomer fender material of the present invention comprises the following components: 10-30 parts by weight of modified hydrogel, 50 parts by weight of silane coupling agent, 15-20 parts by weight of 4,4'-diphenylmethane diisocyanate, 5-10 parts by weight of polyadipate polyol, 18-22 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3-4 parts by weight of chain extender, wherein the modified hydrogel is prepared by taking methyl cellulose as the hydrogel main body, introducing organic fluorine and grafting L-cysteine.

Example 1

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 8 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 2

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 8 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C for reaction to obtain a polyurethane prepolymer, weigh 20 parts by weight of the modified hydrogel and mix with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 3

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 8 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C for reaction to obtain a polyurethane prepolymer, weigh 30 parts by weight of the modified hydrogel and mix with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 4

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 6 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 5

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 6

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 3 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 7

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 500 parts by weight of dimethyl sulfoxide, 5 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 8

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 400 parts by weight of dimethyl sulfoxide, 3 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2.5 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 9

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 450 parts by weight of dimethyl sulfoxide, 5 parts by weight of perfluorooctyl hexanediol, 4.5 parts by weight of L-cysteine, 0.3 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Example 10

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 550 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 5 parts by weight of L-cysteine, 0.4 parts by weight of 4-dimethylaminopyridine, 2 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Embodiment 11

The preparation method of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material comprises the following steps:

S3.1, prepare 9 parts by weight of methylcellulose, 600 parts by weight of dimethyl sulfoxide, 4 parts by weight of perfluorooctyl hexanediol, 4 parts by weight of L-cysteine, 0.5 parts by weight of 4-dimethylaminopyridine, 3 parts by weight of dicyclohexylcarbodiimide, 50 parts by weight of silane coupling agent, 16 parts by weight of 4,4'-diphenylmethane diisocyanate, 8 parts by weight of polyadipate polyol, 20 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3 parts by weight of chain extender;

The chain extender is composed of 100 parts by weight of a high molecular weight diol polyethylene glycol adipate polyol and 5 parts by weight of a low molecular weight diol 1,4-butanediol, 2.8 parts by weight of water, 1.6 parts by weight of a stannous octoate catalyst and 1.1 parts by weight of an organosilicon surfactant, wherein the organosilicon surfactant is an organosilicon surfactant model DC193 produced by American Gas Company.

S3.2, preparation of modified hydrogel: methylcellulose was placed in a vacuum oven at 60 ° C and dried for 24 hours for use. After drying, the methylcellulose was added to a three-necked flask containing dimethyl sulfoxide solution, and stirred at 70 ° C for 1.5 hours with an agitator under oil bath conditions until the methylcellulose was completely dissolved. The speed of the agitator was set to 400r/min, and perfluorooctyl hexanediol and L-cysteine were added. The heating was stopped, and 4-dimethylaminopyridine and dicyclohexylcarbodiimide were added to the three-necked flask. Nitrogen was introduced for 1 hour to remove oxygen. The flask was then transferred to a water bath with a water bath temperature of 25 ° C and a water bath time of 24 hours. After the reaction was completed, the above solution was added to a beaker containing 100 mL of anhydrous ethanol to precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol. The product was allowed to stand for 30 minutes, filtered, and washed 3 times. Finally, the product was freeze-dried for 24 hours to obtain a modified hydrogel.

S3.3. Preparation of bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material: add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C to react to obtain a polyurethane prepolymer, weigh 10 parts by weight of the modified hydrogel and mix it with a silane coupling agent, then add it into the polyurethane prepolymer together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate, set the speed of the stirrer to 500r/min, stir with the stirrer to obtain a mixed polyurethane prepolymer, add the chain extender into the obtained mixed polyurethane prepolymer, heat and stir at 60°C, inject into a mold at a temperature of 80-85°C for molding, and mature at 90°C for 20h after demolding to obtain a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Comparative Example 1

The method of Example 2 was adopted without adding modified hydrogel.

Comparative Example 2

The method of Example 2 was adopted, and the content of the chain extender was increased to 5 parts by weight.

The present invention adopts modified hydrogel to prepare a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, wherein the performance index inspection items and inspection standards of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material are as follows:

Tensile strength is the maximum stress that a material can withstand during the stretching process. It is usually measured at the moment before the material begins to break. It is an important indicator of material strength. By using a universal material testing machine, a standard dumbbell-shaped specimen is fixed between two clamps, and then stretched at a constant speed until it breaks. The maximum force at break is recorded and the tensile strength is calculated by the formula; elongation at break is the percentage increase in the specimen length relative to the original length when the material breaks. It reflects the degree of deformation that the material can withstand before breaking. The test process is similar to that of tensile strength, but the focus is on the change in the length of the specimen at break. The formula for calculating elongation at break is: elongation at break = (length at break − initial length) × 100%; impact rebound is a measure of the material's ability to absorb impact energy and convert it into The ability to recover its shape after deformation energy is usually expressed as a percentage, showing the proportion of the energy that the material can return after being impacted to the total impact energy. A standard metal ball is dropped from a fixed height to hit the surface of the sample, and then the rebound height of the ball is measured to get the impact rebound. The rebound rate calculation formula is: Rebound rate = (rebound height ÷ drop height) × 100%; Water absorption rate refers to the ability of a material to absorb water under specific conditions, usually expressed as a percentage by weight. This is very important for evaluating the performance stability of elastomers in a humid environment. The specific test method is: first measure the weight of the dry sample, then soak it in water at a specific temperature for a period of time, take out the sample, remove the surface moisture and measure the weight again, and calculate the percentage change in weight before and after water absorption.

According to the above standards, the bionic micropore induced self-healing hydrolysis resistant elastomer fender materials prepared in the above Examples 1-11 and Comparative Examples 1-2 were tested, and the obtained data are shown in Table 1:

Table 1 Performance data of Examples 1-11 and Comparative Examples 1-2

The above data, Examples 1-11 and Comparative Examples 1-2 fully demonstrate the effect of the modified hydrogel on the self-healing and water resistance of the bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material.

Since the present invention adopts modified hydrogel to prepare bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, the self-healing ability and hydrolysis resistance are effectively improved through the dynamic disulfide bonds and organic fluorine inside the hydrogel, and the bionic microporous structure further improves the toughness of the material, as follows:

It can be seen from Examples 1-3 that:

With the continuous increase of the content of modified hydrogel, the mechanical properties of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material first increased and then decreased, the impact rebound performance decreased slightly, and the water resistance first increased and then remained basically unchanged. This is because the organic fluorine small molecules on the modified hydrogel have the characteristic of migrating to the polymer surface, and a fluorine film will be formed on the surface of the material. When the material is stretched and torn, this film can provide certain mechanical properties, thereby improving the tensile strength and elongation of the material. At the same time, the fluorine film formed on the surface achieves a lotus leaf effect, the contact angle becomes larger, the surface tension and water absorption rate decrease, and the water resistance is improved. When the content of modified hydrogel is too much, the surface of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material The fluorine content on the surface reaches saturation. At this time, the uncross-linked oligomer molecules inside the material increase to a certain extent, which is equivalent to diluting the density of the cross-linked polymer, making the material that can withstand mechanical impact less, thereby reducing the tensile strength and elongation at break. At the same time, further increase in fluorine content cannot increase the surface fluorine content, the water absorption rate does not change much, and the water resistance remains basically unchanged. In addition, due to the introduction of fluorine elements, the hydrogen bond content increases, the intermolecular force increases, which is conducive to crystallization and the polar hard segment content increases, which is equivalent to the bionic microporous induced self-healing hydrolysis resistant elastomer fender material. The soft segment content that provides flexibility is reduced, and the material's ability to recover deformation becomes worse, thereby increasing the elongation at break and reducing the rebound.

It can be seen from Examples 1, 4 and 5 that the content of methylcellulose affects the properties of the hydrogel, and further affects the performance of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material. This is because methylcellulose is the matrix component of the hydrogel, provides a main chain structure, can form a three-dimensional network, and endows the hydrogel with water holding capacity and a certain mechanical strength. The content of methylcellulose affects the viscosity and mechanical strength of the hydrogel. The higher the content of methylcellulose, the higher the viscosity and mechanical strength of the modified hydrogel formed. A higher viscosity means that the hydrogel will encounter greater internal friction when flowing or deforming, resulting in reduced energy dissipation efficiency and affecting the material's recovery ability after multiple impacts, while a higher mechanical strength means that the elastic recovery performance is weakened when subjected to a large external force; since the lower the content of methylcellulose, the lower the viscosity and mechanical strength of the modified hydrogel formed, when the content of methylcellulose is low, it means that the hydrogel is more likely to deform or rupture when impacted, and thus cannot effectively disperse and absorb the impact energy, resulting in the fender material being easily damaged when impacted, so a suitable methylcellulose content needs to be selected.

It can be seen from Examples 5-7 that with the increase of the content of perfluorooctyl hexanediol, the performance of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material first increases and then decreases. This is because the purpose of perfluorooctyl hexanediol is to modify the hydrogel, reduce the surface tension of the hydrogel, and make the hydrogel surface hydrophobic, which can reduce the adsorption of water and maintain a low water sensitivity, which helps to improve the stability and mechanical properties of the material in a humid environment. At the same time, the fluorine element is used to introduce more hydrogen bonds, increase the intermolecular force of the hydrogel, and improve the thermal stability of the hydrogel, so that the material can still maintain its structural integrity at high temperatures, thereby maintaining good elastic properties. However, when the fluorine content is too high, the polar hard segment content of the elastomer increases, the rigidity increases, and the material's ability to recover deformation becomes worse. When the fluorine content is low, the material's resistance to chemicals such as solvents, acids, alkalis and water decreases, and the material's water resistance weakens, causing the material to react with water in a humid environment, accelerating the aging and degradation of the material, so it is necessary to select a suitable organic fluorine content.

It can be seen from Examples 5, 8, 9, 10 and 11 that dimethyl sulfoxide, perfluorooctyl hexanediol, L-cysteine, 4-dimethylaminopyridine and dicyclohexylcarbodiimide, within a certain range, have relatively little effect on the key performance indicators of the bionic micropore induced self-healing hydrolysis-resistant elastomer fender material, including tensile strength, elongation at break, impact rebound and absorption rate. Although dimethyl sulfoxide, perfluorooctyl hexanediol, L-cysteine, 4-dimethylaminopyridine and dicyclohexylcarbodiimide play their respective roles in the synthesis of the material, such as dimethyl sulfoxide is only used as a solvent to dissolve methyl cellulose, 4-dimethylaminopyridine and dicyclohexylcarbodiimide are catalysts to catalyze the grafting of L-cysteine onto methyl cellulose, but they are not the main influencing factors, so they only need to be added reasonably.

According to the above test experiments, the bionic micropore induced self-healing hydrolysis resistant elastomer fender material prepared according to Example 2 has the best performance, so Example 2 is taken as the best example;

By comparing Example 2 with Comparative Examples 1-2, it can be seen that:

In Comparative Example 1, no modified hydrogel is added, and the mechanical properties and water resistance of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material are significantly reduced. This is because the modified hydrogel is grafted with L-cysteine and organic fluorine is introduced, so that after the hydrogel is coupled with the microporous polyurethane elastomer, the synergistic effect of disulfide bonds and hydrogen bonds is added, the self-healing ability is improved, and part of the C-C bonds are replaced by C-F bonds, which increases the bond energy. The electronegative fluorine element forms hydrogen bonds, which greatly increases the content of hydrogen bonds, thereby greatly improving the mechanical properties of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material. Because of the hydrophobicity of the fluorine element, when it is enriched on the polymer surface, the surface tension is reduced, thereby increasing the hydrophobicity of the polymer, and the water resistance is further improved. Therefore, when the modified hydrogel is not added, the mechanical properties and water resistance are greatly reduced compared with Example 2.

Comparative Example 2 increases the content of the chain extender. As the content of the chain extender increases, the performance of the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material decreases slightly. This is because the chain extender can increase the number of chemical cross-linking points in the hard segment, so that the hard segment can be arranged more tightly, the rigidity of the hard segment is improved, the compatibility of the soft and hard segments is reduced, and the degree of microphase separation is improved, so that the microporous polyurethane elastomer obtains higher impact elasticity. When the amount of the chain extender is too much, there are no extra NCO groups inside the microporous polyurethane to generate the strong polar group urea group, which will weaken the intermolecular force, improve the compatibility of the two phases, and reduce the elongation at break and the impact rebound rate.

In summary, the dynamic disulfide bond formed by methyl cellulose and L-cysteine coordinates with the hydrogen bond to improve the self-healing ability. The introduction of hydrophobic organic fluorine greatly increases the hydrogen bond and bond energy, thereby improving the stability and water resistance of the hydrogel. Therefore, the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material prepared by modified hydrogel not only has the characteristics of hydrogel self-healing performance and water resistance of fluorinated organic matter, but also has the toughening effect of the bionic microporous structure, thereby improving the mechanical properties of the material.

The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims (9)

1. A bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, characterized in that it comprises the following components: 10-30 parts by weight of modified hydrogel, 50 parts by weight of silane coupling agent, 15-20 parts by weight of 4,4'-diphenylmethane diisocyanate, 5-10 parts by weight of polyadipate polyol, 18-22 parts by weight of 3,3'-dimethyl-4,4'-biphenyl diisocyanate and 3-4 parts by weight of chain extender; The modified hydrogel is based on methyl cellulose as the main body of the hydrogel, and the hydrogel is grafted and modified by L-cysteine and organic fluorine. The preparation method of the modified hydrogel is as follows: S1.1. Prepare components: 6-9 parts by weight of methylcellulose, 400-600 parts by weight of dimethyl sulfoxide, 3-5 parts by weight of perfluorooctyl hexanediol, 4-5 parts by weight of L-cysteine, 0.3-0.5 parts by weight of 4-dimethylaminopyridine, and 2-3 parts by weight of dicyclohexylcarbodiimide; S1.2, place the methylcellulose in a vacuum oven to dry, add the dried methylcellulose to a three-necked flask containing dimethyl sulfoxide solution, stir with a stirrer under oil bath conditions until the methylcellulose is completely dissolved, then add perfluorooctyl hexanediol and L-cysteine, stop heating, add 4-dimethylaminopyridine and dicyclohexylcarbodiimide to the three-necked flask, pass nitrogen for 1 hour to remove oxygen, then transfer the flask to a water bath, after the reaction is completed, add the above solution to a beaker containing 100mL of anhydrous ethanol, precipitate the hydrogel and remove the remaining L-cysteine and perfluorooctyl hexanediol, let stand for 30 minutes, filter, wash 3 times, and finally freeze-dry the product for 24 hours to obtain a modified hydrogel; The chain extender is composed of 100 parts by weight of high molecular weight diol polyethylene glycol adipate polyol, 3-10 parts by weight of low molecular weight diol 1,4-butanediol, 2.2-8 parts by weight of water, 0.3-2.4 parts by weight of stannous octoate catalyst and 0.5-2.8 parts by weight of organosilicon surfactant. 2. The bionic microporous induced self-healing hydrolysis-resistant elastomer fender material according to claim 1, characterized in that the temperature of the vacuum oven is set to 60°C and the drying time is 24 hours. 3. The bionic microporous induced self-healing hydrolysis-resistant elastomer fender material according to claim 1 is characterized in that: the oil bath temperature is set to 70°C, the speed of the agitator is 300-400r/min, and the stirring time is 1.5h; the water bath temperature is 20-25°C, and the water bath time is 24-30h. 4. A method for preparing a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material, which is used to prepare the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material according to any one of claims 1 to 3, characterized in that it comprises the following steps: Add 4,4'-diphenylmethane diisocyanate and polyadipate polyol into a beaker, heat in a water bath at 80-85°C for reaction to obtain a polyurethane prepolymer, mix the modified hydrogel with a silane coupling agent and add the mixture together with 3,3'-dimethyl-4,4'-biphenyl diisocyanate into the polyurethane prepolymer, stir with a stirrer to obtain a mixed polyurethane prepolymer, add a chain extender into the obtained mixed polyurethane prepolymer, heat and stir, inject into a mold for molding, demold, and mature to obtain a microporous polyurethane, i.e., a bionic microporous induced self-healing hydrolysis-resistant elastomer fender material. 5. The method for preparing a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material according to claim 4, characterized in that the functionality of the polyadipate polyol is 2 to 3, the hydroxyl value is 56 to 140 mg KOH/g, and the number average molecular weight is 2000 to 4000. 6. The method for preparing the bionic micropore induced self-healing hydrolysis resistant elastomer fender material according to claim 4, characterized in that the NCO content of the polyurethane prepolymer is 6% to 12%. 7. The method for preparing the bionic micropore induced self-healing hydrolysis resistant elastomer fender material according to claim 4, characterized in that the speed of the agitator is 400-500 r/min. 8. The method for preparing the bionic micropore induced self-healing hydrolysis resistant elastomer fender material according to claim 4, characterized in that the reaction temperature of the mixed polyurethane prepolymer and the chain extender is 60°C. 9. The method for preparing the bionic microporous induced self-healing hydrolysis-resistant elastomer fender material according to claim 4, characterized in that the mold temperature during the injection molding is 80-85°C, and the material is aged at 90°C for 12-20 hours after demolding.