CN108610466A - A kind of polyurea elastomer and preparation method thereof substituting polyethers completely with polysiloxanes - Google Patents

Abstract

The invention relates to a polyurea elastomer which completely replaces polyether with polysiloxane and a preparation method thereof. The preparation method comprises the steps of: (1) adding a calculated amount of amine-propylene into a mixed solvent of organic solvents A and B, respectively Group-terminated polydimethylsiloxane C and diisocyanate compound, at 0-50°C, stirred and reacted for 10-80min to generate isocyanate-group-terminated low-molecular-weight prepolymer D; (2) Step (1) The prepolymer D generated in the above reaction reacts with the terminal amino compound at 0-30°C for 10-500min to obtain a mixed solution containing polysiloxane-polyurea polymer; then volatilize and remove the solvent to obtain the product. The invention adopts a mixed solvent and adjusts the molecular weight of polydimethylsiloxane terminated by aminopropyl group to reduce the sharp microscopic phase separation between the soft segment and the hard segment, thereby greatly improving the mechanical properties of the elastomer.

Description

A kind of polyurea elastomer that completely replaces polyether with polysiloxane and preparation method thereof

technical field

The invention relates to a polyurea elastomer in which polyether is completely replaced by polysiloxane and a preparation method thereof, and belongs to the technical field of synthesis of organosilicon polymer materials.

Background technique

Polysiloxane has a unique molecular structure composed of Si-O-Si main chain and organic side chains. It combines organic-inorganic dual characteristics and functions, and has an extremely low glass transition temperature (-123°C) , high and low temperature resistance, oxidation resistance, weather resistance, low surface energy and good hydrophobicity and other excellent properties.

Thermoplastic polyurea elastomer (TPU) is a series of heterogeneous block polymers with excellent mechanical properties and good elasticity, strong hardness, wear resistance and chemical resistance. The polysiloxane-polyurea elastomer prepared with polysiloxane as the soft segment has both the excellent properties of polysiloxane and polyurea, which not only overcomes the defects of poor mechanical properties of polysiloxane, but also It makes up for the poor weather resistance of polyurea, and has a wide range of applications in the construction industry, automotive interiors, biomaterials and clothing industries.

Of course, the mechanical properties of these polysiloxane-polyurea elastomers are still far inferior to the traditional polyurea prepared from polyether as a soft segment. The microscopic phase separation of soft and hard segments is the reason why thermoplastic polyurea has a high modulus of stability, but due to the solubility parameter of polydimethylsiloxane (15.6(Jcm ^-3 ) ^1/2 ) and polyurea's The difference in solubility parameter (45.6(Jcm ^-3 ) ^1/2 ) is too large, and the preparation of polyurea with polysiloxane as the soft segment may lead to macroscopic phase separation during the reaction, making it impossible to generate large molecular weight polyurea. polymer, thereby affecting its mechanical properties. Or even if there is no macroscopic phase separation, the prepared polymer will have a sharp microphase separation at the phase interface between the polysiloxane aggregate phase and the polyurea aggregate phase, and this sharp phase interface will also cause tension The effect of transfer from the soft segment region to the hard segment region is reduced, affecting the mechanical strength of the elastomer.

To avoid sharp microscopic phase separations, the conventional approach is to use polysiloxanes in combination with polyethers. The solubility parameter of polyether is 23.5(Jcm ^-3 ) ^1/2 , and the interaction energy between urea group and ether (19.2kJmol ^-1 ) is greater than the interfacial energy between urea group and siloxane (7.5kJmol ^-1 ). This creates a transition phase between polysiloxane and polyurea, reducing microphase separation. The specific method is mostly to prepare polyurea elastomer by blending amino-terminated polysiloxane and polyether and then reacting with isocyanate compound, but this method still cannot avoid the connection of polysiloxane and isocyanate compound, and cannot avoid sharp The microphase separation and the impact on the mechanical properties of the elastomer, while the introduction of polyether will also affect the performance of the excellent performance of polysiloxane in the elastomer. At the same time, the performance of the thermoplastic elastomer obtained by this method is unstable, and the reproducibility of material properties is poor, which greatly restricts the popularization and application of this method.

Chinese patent document CN103360562A discloses a method for preparing a polysiloxane-polyurea-polyurethane gel material. 100-200 parts of polysiloxane are stirred and reacted with 70-160 parts of diisocyanate at 60°C-90°C for 1-3 hours to prepare a compound with a relative mass percentage of isocyanate groups of 15%-25%. The isocyanate-terminated semi-prepolymer A; the isocyanate-terminated semi-prepolymer A and the amino-terminated compound are stirred and mixed evenly, and poured to prepare polysiloxane-polyurea-polyurethane gel material; wherein the isocyanate-terminated 30-60 parts by mass of semi-prepolymer A, 100-400 parts by mass of amino-terminated compound. What is used in this patent document is hydroxyl-terminated polysiloxane, which has low reactivity, so the temperature required for the reaction is too high and the reaction time is relatively long. And the amino-terminated polyether is contained in the amino-terminated compound used, so the disadvantages of the traditional polysiloxane-polyether-polyurea still exist.

At present, there is no method that can avoid sharp phase separation without affecting the excellent performance of polysiloxane, thereby improving the mechanical properties of polysiloxane polyurea elastomers.

For this reason, the present invention is proposed.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention provides a polyurea elastomer in which polyether is completely replaced by polysiloxane and a preparation method thereof. Use a mixed solvent as the reaction solvent for preparing polyurea elastomers. The mixed use of the two solvents can make the soft segment and the hard segment dissolve in the system better, avoiding macroscopic phase separation during the reaction, so as to ensure the formation of large molecular weight of polymers. At the same time, aminopropyl-terminated polydimethylsiloxane with appropriate molecular weight is selected as the soft segment to synthesize polyurea elastomer, and the sharp microscopic phase separation between the soft segment and the hard segment is reduced by adjusting the molecular weight, thereby Greatly improve the mechanical properties of the elastomer.

Technical scheme of the present invention is as follows:

A kind of polyurea elastomer that fully replaces polyether with polysiloxane, this elastomer has the general formula shown in formula (I):

Among them, n and m are integers greater than or equal to 1;

X is or

_{CH2CH2CH2CH2CH2CH2 ; _ _ _ _}

Y is CH ₂ CH ₂ , CH ₂ CH(CH ₃ )CH ₂ CH ₂ CH ₂ , CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ or

According to the present invention, preferably, 1≤n≤150, 1≤m≤50.

According to the present invention, the above-mentioned preparation method of polyurea elastomer that completely replaces polyether with polysiloxane comprises steps as follows:

(1) In the mixed solvent of organic solvents A and B, add aminopropyl-terminated polydimethylsiloxane C and diisocyanate compound respectively, and stir and react for 10-80min at 0-50°C to generate isocyanate groups End-capped low molecular weight prepolymer D;

(2) React the prepolymer D generated in step (1) with the amine-terminated compound at 0-30°C for 10-500min to obtain a mixed solution containing polysiloxane-polyurea polymer; then volatilize to remove the solvent , that is to obtain a polyurea elastomer that completely replaces polyether with polysiloxane.

According to the preparation method of the present invention, preferably, the organic solvent A described in step (1) is xylene, tetrahydrofuran, dimethyl sulfoxide, toluene, acetone, cyclohexane or dioxane;

Preferably, the organic solvent B is ether, dichloromethane, ethyl acetate, isopropanol or n-hexane;

Preferably, the volume ratio of the organic solvents A and B is (5-15):1.

According to the preparation method of the present invention, preferably, the aminopropyl-terminated polydimethylsiloxane C described in step (1) has the general formula shown in formula (II):

In formula (II), the value of n is identical with formula (I);

Further preferably, the relative molecular weight of the aminopropyl-terminated polydimethylsiloxane C is in the range of 1000-10000 g/mol.

According to the preparation method of the present invention, preferably, the diisocyanate compound described in step (1) is toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, methyl ring Hexyl diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, terexylylene diisocyanate or tetramethylxylylene diisocyanate;

Further preferred are diphenylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate or dicyclohexylmethane diisocyanate.

According to the preparation method of the present invention, preferably, the molar ratio of the terminal amino group of the aminopropyl-terminated polydimethylsiloxane C described in step (1) to the isocyanate group in the diisocyanate compound is 1:(2-15 ), more preferably 1:(3-8).

The molar ratio of the aminopropyl-terminated polydimethylsiloxane C of the present invention to the isocyanate group in the diisocyanate compound has an important influence on the mechanical properties of the final elastomer, and the mechanical properties of the elastomer will be significantly reduced beyond the scope of the present invention. .

According to the preparation method of the present invention, preferably, the reaction temperature in step (1) is 5-40° C., and the reaction time is 10-50 min. The general structural formula of the isocyanate-terminated low-molecular-weight prepolymer D obtained in step (1) of the present invention is shown in formula (Ⅲ):

According to the preparation method of the present invention, preferably, the amino-terminated compound described in step (2) is ethylenediamine, hexamethylenediamine, bis(p-aminobenzoic acid)propylene glycol ester, 1,2-bis(2-aminobenzene thio)ethane, 2-methyl-1,5-pentanediamine, 3,5-diamino-4-trifluoromethylphenetole or 4,4'-methylenebis(2-ethyl 6-methylcyclohexylamine).

According to the preparation method of the present invention, preferably, the reaction temperature in step (2) is 0-15° C., and the reaction time is 5-20 min.

According to the preparation method of the present invention, preferably, step (2) volatilizes the solvent at room temperature, and the time for volatilizing the solvent is 2-48h.

Everything that is not described in detail in the present invention is the prior art in this field.

Beneficial effects of the present invention:

1. The present invention uses aminopropyl-terminated polydimethylsiloxane C as the soft segment to prepare the polyurea elastomer under the mixed solvent conditions of A and B, and uses the mixed solvent to make the soft segment and the hard segment better Dissolved in the system, the reaction proceeds faster and more thoroughly, greatly improving the reaction rate.

2. The present invention selects aminopropyl-terminated polydimethylsiloxane C of suitable molecular weight as the soft segment for synthesizing polyurea elastomer, which reduces the sharp microscopic phase separation between the soft segment and the hard segment, Thus, the mechanical properties of the elastomer are greatly improved, the mechanical strength is higher, and the tensile strength can reach 21MPa.

3. The reaction process of the present invention is simpler, and the elastic body with superior tensile properties can be obtained by using the least amount of raw materials.

Description of drawings

Fig. 1 is the infrared spectrum of the polyurea elastomer prepared in Example 1 of the present invention in which polyether is completely replaced by polysiloxane.

Detailed ways

The present invention will be further described below in conjunction with embodiment, and following embodiment is illustrative, not limiting, can not limit protection scope of the present invention with following embodiment.

The raw materials used in the examples are conventional commercially available products.

Aminopropyl-terminated polydimethylsiloxane C described in the examples was prepared as follows:

Into a four-necked flask equipped with a thermometer, a spherical condenser, a mechanical stirring device and a nitrogen gas introduction device, add the calculated amount of D ₄ , α,ω-aminopropyl disiloxane and a small amount of KOH solid powder. Under mechanical stirring, the system was heated in an oil bath to 80-120°C, and the reaction was balanced for 8 hours. After the reaction is completed, stop heating, add glacial acetic acid in an equimolar amount to the added KOH for neutralization reaction, carry out vacuum distillation operation, and steam out low boilers. The product was filtered to obtain the aminopropyl terminated polydimethylsiloxane.

Embodiment 1,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer, and a nitrogen gas feed device, add 30 g of dicyclohexylmethane diisocyanate, and mix with xylene and isopropanol (volume ratio: 6:1) The mixed solvent is completely dissolved, and under strong stirring, 70g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 4000 is completely dissolved and then added dropwise to the above solution through the dropping funnel, and reacted at 40°C 30min, prepolymer D was prepared, and finally 20g of 2-methyl-1,5-pentanediamine was dissolved in the mixed solution, added dropwise into the reactor through the dropping funnel, reacted at 5°C for 10min, and poured the product into In the mold, the solvent is volatilized at room temperature to obtain an elastomer.

The resulting elastomer structure is as follows:

The mechanical property test was performed on it, and the tensile strength was 21MPa, and the elongation at break was 100%.

The infrared spectrogram of the polyurea elastomer prepared in this example with polysiloxane completely replacing polyether is shown in FIG. 1 .

Embodiment 2,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer, and a nitrogen gas feed device, add 20 g of diphenylmethane diisocyanate, and use tetrahydrofuran and dichloromethane (volume ratio: 8:1) The mixed solvent is completely dissolved, and under strong stirring, 60 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 2000 is completely dissolved and then added dropwise to the above solution through the dropping funnel, and reacted at 30°C for 10 minutes , to prepare prepolymer D, and finally dissolve 20g of hexamethylenediamine in the mixed solution, add it dropwise into the reactor through the dropping funnel, react at 10°C for 15min, pour the product into the mold, and remove the solvent by volatilization at room temperature. Get the elastomer.

The resulting elastomer structure is as follows:

Its mechanical properties were tested, and the tensile strength was 20MPa, and the elongation at break was 110%.

Embodiment 3,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, drying tube, mechanical stirring and nitrogen feed device, add 30 g of dicyclohexylmethane diisocyanate, and use dimethyl sulfoxide and n-hexane (volume ratio is 8: 1) The mixed solvent is completely dissolved, and under strong stirring, 70 g of block copolymer A with a molecular weight of 3000 is completely dissolved and then added dropwise to the above solution through a dropping funnel, and reacted at 40°C for 20 minutes to prepare a prepolymer Object D, finally dissolve 20g of 4,4'-methylene bis(2-ethyl 6-methylcyclohexylamine) in the mixed solution, add it dropwise into the reactor through the dropping funnel, and react at 10°C for 20min , Pour the product into a mold, and evaporate the solvent at room temperature to obtain an elastomer.

The mechanical property test was carried out, and the tensile strength was 18MPa, and the elongation at break was 120%.

Embodiment 4,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer, and a nitrogen gas feed device, add 20 g of diphenylmethane diisocyanate, and mix it with toluene and n-hexane (volume ratio 5:1). The solvent is completely dissolved, and under strong stirring, 60 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 5000 is completely dissolved and then added dropwise to the above solution through the dropping funnel, and reacted at 40°C for 30 minutes. Prepare the prepolymer D, and finally dissolve 20g of ethylenediamine in the mixed solution, add dropwise into the reactor through the dropping funnel and react at 10°C for 10min, pour the product into the mold, remove the solvent by volatilization at room temperature, and obtain elasticity body.

Its mechanical properties were tested, and the tensile strength was 19MPa. The elongation at break was 120%.

Embodiment 5,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer and a nitrogen gas feed device, add 30 g of dicyclohexylmethane diisocyanate, and use toluene and isopropanol (volume ratio of 5:1) The mixed solvent is completely dissolved, and under strong stirring, 60 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 2000 is completely dissolved, and then added drop by drop to the above solution through the dropping funnel, and reacted at 30°C for 30 minutes , to prepare prepolymer D, and finally dissolve 20g of hexamethylenediamine in the mixed solution, add dropwise into the reactor through the dropping funnel, react at 20°C for 10min, pour the product into the mold, and remove the solvent by volatilization at room temperature, Get the elastomer.

The mechanical property test was carried out, and the tensile strength was 20MPa, and the elongation at break was 100%.

Comparative example 1,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, drying tube, mechanical stirring and nitrogen gas introduction device, add 30 g of dicyclohexylmethane diisocyanate, and completely use toluene solvent, under strong stirring, 70 g of dicyclohexylmethane diisocyanate After the aminopropyl-terminated polydimethylsiloxane C is completely dissolved, it is added dropwise to the above solution through a dropping funnel, and reacted at 40°C for 30 minutes to prepare a prepolymer D. Finally, 20 g of 2-methyl- 1,5-Pentanediamine was dissolved in the mixed solution, added dropwise into the reactor through the dropping funnel, reacted at 5°C for 10 minutes, poured the product into a mold, and volatilized at room temperature to remove the solvent to obtain an elastomer.

The mechanical performance test was carried out, and the tensile strength was 4MPa, and the elongation at break was 110%.

This comparative example uses a single solvent, because the single solvent cannot fully dissolve the soft segment and the hard segment, and macroscopic phase separation occurs during the reaction, which makes the reaction unable to proceed completely and affects the mechanical properties of the product.

Comparative example 2,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer, and a nitrogen feed device, add 40 g of diphenylmethane diisocyanate, and use tetrahydrofuran and dichloromethane (volume ratio: 8:1) The mixed solvent is completely dissolved, and under strong stirring, 60 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 2000 is completely dissolved and then added dropwise to the above solution through the dropping funnel, and reacted at 30°C for 10 minutes , to prepare prepolymer D, and finally dissolve 20g of hexamethylenediamine in the mixed solution, add it dropwise into the reactor through the dropping funnel, react at 10°C for 15min, pour the product into the mold, and remove the solvent by volatilization at room temperature. Get the elastomer.

The mechanical performance test was carried out on it, and the tensile strength was 3MPa. The elongation at break was 90%.

In this comparative example, the ratio of the terminal amino group of the aminopropyl-terminated polydimethylsiloxane C to the isocyanate group in the diisocyanate compound is too low (the addition of diphenylmethane diisocyanate is too large), resulting in poor mechanical properties of the elastomer. high.

Comparative example 3,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, drying tube, mechanical stirring and nitrogen feed device, add 30 g of dicyclohexylmethane diisocyanate, and use dimethyl sulfoxide and n-hexane (volume ratio is 8: 1) The mixed solvent is completely dissolved, and under strong stirring, 70 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 20,000 is completely dissolved and then added drop by drop to the above solution through the dropping funnel, at 40°C React for 20 minutes to prepare prepolymer D. Finally, dissolve 20g of 4,4'-methylene bis(2-ethyl 6-methylcyclohexylamine) in the mixed solution, and add it dropwise to the reaction through the dropping funnel. React in a container at 10°C for 20 minutes, pour the product into a mold, and evaporate the solvent at room temperature to obtain an elastomer.

The mechanical property test was performed on it, and the tensile strength was 3MPa, and the elongation at break was 230%.

In this comparative example, the molecular weight of the aminopropyl-terminated polydimethylsiloxane C is too large, so that the phase separation between the soft segment and the hard segment is too obvious, and the sharp microphase separation reduces the mechanical properties of the elastomer.

Comparative example 4,

A kind of preparation method of the polyurea elastomer that completely replaces polyether with polysiloxane, comprises steps as follows:

In a four-necked flask equipped with a constant pressure dropping funnel, a drying tube, a mechanical stirrer, and a nitrogen gas feed device, add 20 g of diphenylmethane diisocyanate, and mix it with toluene and n-hexane (volume ratio 5:1). The solvent is completely dissolved, and under strong stirring, 60 g of aminopropyl-terminated polydimethylsiloxane C with a molecular weight of 5000 is completely dissolved and then added dropwise to the above solution through the dropping funnel, and reacted at 40°C for 30 minutes. Prepare the prepolymer D, and finally dissolve 20g of ethylenediamine in the mixed solution, add it dropwise into the reactor through the dropping funnel and react at 50°C for 10min, pour the product into the mold, remove the solvent by volatilization at room temperature, and obtain elasticity body.

The mechanical performance test was carried out, and the tensile strength was 3MPa, and the elongation at break was 300%.

Because the reaction temperature during the chain extension reaction in this comparative example is too high, the reaction will be too violent, the product will be precipitated in advance, the reaction will not be carried out thoroughly, and the reaction will not be easy to control, and the mechanical properties of the product will be low.

Claims (10)

1. a kind of polyurea elastomer substituting polyethers completely with polysiloxanes, which is characterized in that the elastomer has shown in formula (I) General formula：

Wherein n, m are the integer more than or equal to 1；

X isOr

CH₂CH₂CH₂CH₂CH₂CH₂；

Y is CH₂CH₂、CH₂CH(CH₃)CH₂CH₂CH₂、CH₂CH₂CH₂CH₂CH₂CH₂Or

2. the polyurea elastomer according to claim 1 for substituting polyethers completely with polysiloxanes, which is characterized in that 1≤n≤ 150,1≤m≤50.

3. the preparation method of the polyurea elastomer as claimed in claim 1 or 2 for substituting polyethers completely with polysiloxanes, including step It is as follows：

(1) in the in the mixed solvent of organic solvent A and B, the dimethyl silicone polymer C and two isocyanides of amine propyl sealing end are separately added into Ester compound is stirred to react 10-80min at 0-50 DEG C, generates the prepolymer D of isocyanate-terminated low molecular weight；

(2) the prepolymer D generated in step (1) is reacted into 10-500min at 0-30 DEG C with end amine compound, is contained The mixed solution of polysiloxanes-polyurea polymer；Then volatilization removal solvent substitutes polyethers completely to get to polysiloxanes Polyurea elastomer.

4. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, the organic solvent A described in step (1) is dimethylbenzene, tetrahydrofuran, dimethyl sulfoxide (DMSO), toluene, acetone, hexamethylene or two Six ring of oxygen；

The organic solvent B is ether, dichloromethane, ethyl acetate, isopropanol or n-hexane；

Organic solvent A, the volume ratio of B are (5-15):1.

5. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, the dimethyl silicone polymer C of the amine propyl sealing end described in step (1) has general formula shown in formula (II)：

In formula (II), the value of n is identical as formula (I)；

The relative molecular weight ranging from 1000-10000g/mol of the dimethyl silicone polymer C of amine propyl sealing end.

6. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, the diisocyanate cpd described in step (1) is toluene di-isocyanate(TDI), methyl diphenylene diisocyanate, 1,5- Naphthalene diisocyanate, hexamethylene diisocyanate, Methylcyclohexyl diisocyanate, dicyclohexyl methyl hydride diisocyanate, Isophorone diisocyanate, paraphenylene diisocyanate, terephthalylidene diisocyanate or tetramethylxylene two Isocyanates.

7. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, isocyanide in the Amino End Group and diisocyanate cpd of the dimethyl silicone polymer C of the amine propyl sealing end described in step (1) The molar ratio of perester radical is 1:(2-15), preferably 1:(3-8).

8. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, reaction temperature is 5-40 DEG C in step (1), reaction time 10-50min.

9. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, the end amine compound described in step (2) is ethylenediamine, hexamethylene diamine, bis- (p-aminobenzoic acid) propylene glycol esters, 1,2- bis- (2- aminophenyls are thio) ethane, 2- methyl-1s, 5- pentanediamines, 3,5- diamino -4- trifluoromethyls phenetole or 4,4 '-methylenes Base is bis- (2- ethyl 6- methyl cyclohexylamines).

10. the preparation method of the polyurea elastomer according to claim 3 for substituting polyethers completely with polysiloxanes, feature It is, the reaction temperature described in step (2) is 0-15 DEG C, reaction time 5-20min；

Preferably, the time of step (2) solvent flashing at room temperature, solvent flashing is 2-48h.