A polytetrahydrofuran etheramine polyurea with high elongation at break and its preparation method and use

Abstract

The invention discloses a high-elongation polytetrahydrofuran ether amine polyurea and its preparation method and use, and belongs to the field of polymer technology. Its raw materials include: component (A) is a diisocyanate with a symmetrical linear molecular structure; component (B) is a polytetrahydrofuran ether amine with a symmetrical linear structure, wherein the molar ratio of the NCO functional group of the diisocyanate to the NH2 functional group of the polytetrahydrofuran ether amine is between 1.07-1.00; the molecular structure of the high-elongation polytetrahydrofuran ether amine polyurea is a microphase separation structure composed of a hard segment and a soft segment, and the weight percentage of the hard segment relative to the soft segment is greater than 20%. The high-elongation polytetrahydrofuran ether amine polyurea product of the present invention has an elongation at break of more than 1500%, which can meet the requirements of the expansion joints of high-speed railway ballastless tracks, the expansion joints of highways and airport runways, the potting of electronic components, etc. for the elongation at break of highly elastic materials.

Description

Technical Field

[0001] The invention belongs to the technical field of polymers, and in particular relates to a polytetramethylene ether amine polyurea with high elongation at break, a preparation method thereof and applications thereof. Background Art

[0002] Generally speaking, the term "polyurethane" includes polyurethane and polyurea. Polyurethane and polyurea differ in their molecular structure. Polyurethane is a polymer consisting of multiple carbamate groups (-NH-CO-O-), formed by the reaction of isocyanate (-N=C=O) groups and hydroxyl (-OH) groups. Polyurea is a polymer characterized by urea bonds (-NH-CO-NR-), formed by the reaction of isocyanate (-N=C=O) groups and amino (-NHR-, where R is hydrogen or other substituents) groups.

[0003] In the one-step synthesis of polyurea, a polyamine, a diisocyanate, and a chain extender are simultaneously mixed and reacted to form the product. Linear polyurea is often prepared using a semi-prepolymer method, where an amino-terminated symmetrical linear polyetheramine is reacted with an excess of diisocyanate to form an isocyanate-terminated prepolymer and a certain amount of unreacted diisocyanate. This prepolymer mixture (containing an excess of diisocyanate) is then reacted with a diamine chain extender to form hard segments and increase molecular weight. Generally speaking, an increase in the hard segment content results in an increase in modulus (stiffness) and enhanced tensile strength.

[0004] Currently, caulking and potting materials for specific applications require low-temperature curing, high displacement capacity, excellent bonding properties, and superior durability and fatigue resistance. Some one-component polyurethane adhesives commonly struggle with achieving both tensile strength and elongation at break. While maintaining high tensile strength, elongation at break is often suboptimal. Similarly, even when achieving high elongation at break, tensile strength falls short.

[0005] US Patent No. 5,723,563 discloses a method for preparing polyurethane ureas (SPANDEX, also known as spandex) with high elongation at break. Polypropylene oxide diol and para-diphenylmethane diisocyanate (MDI) are prepolymerized to form an isocyanate-terminated prepolymer. This is then chain-extended with a diamine in a dimethylformamide solvent to produce a polyurethane urea with an elongation at break of 1350%, the highest elongation at break ever achieved. Patent CN101432326 discloses a segmented polyurethane elastomer with high elongation at break. The elastomer preparation method comprises: a) reacting a polyether diol with an isocyanate to form an OH-terminated prepolymer; b) reacting a diisocyanate with the OH-terminated prepolymer to form an isocyanate-terminated prepolymer; c) converting the isocyanate-terminated prepolymer into a polyurethane elastomer using a chain extender, a suitable chain terminator, and other suitable additives; and d) spinning the polyurethane elastomer into fibers, wherein the fibers contain less than 15% by weight of other polyurethane elastomers. Tensile strength 46 MPa; elongation at break 752%. Patent CN101550615 discloses a polyurethane urea elastic yarn with improved elongation and bond strength and its preparation method. The elastic yarn is a polyurethane urea prepared from a polyol, two diisocyanates, and a chain extender. The elastic yarn has an elongation of at least 480% and an interfilament bond strength of at least 600 mg.

[0006] Based on the above existing polyurea products, the elongation at break of polyurea products does not reach 1500%, which makes it difficult to meet the requirements for sealing and caulking in highly deformable areas. In view of this, those skilled in the art are urgently looking for a polyurea product with high elongation at break.

[0007] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0008] The purpose of the present invention is to solve the technical problem that polyurea products in the prior art cannot meet the high elongation at break requirements for sealing and caulking high-deformation areas, and to provide a high-elongation polytetrahydrofuran ether amine polyurea product that can meet the needs of many applications. The present invention develops a high-elongation polytetrahydrofuran ether amine polyurea product with an elongation at break of over 1500%, and even an elongation at break exceeding 2200%. The polytetrahydrofuran ether amine polyurea product of the present invention can meet the elongation at break requirements of highly elastic materials for expansion joints of high-speed railway ballastless tracks, expansion joints of highways and airport runways, and electronic component potting. The polytetrahydrofuran ether amine polyurea product of the present invention can be applied to various fields such as automobiles, high-speed railways, construction, and aerospace, and is used for bonding, caulking, and sealing high-deformation areas.

[0009] The first aspect of the present invention provides a polytetramethylene etheramine polyurea with high elongation at break, the raw materials of which include: component (A) is a diisocyanate having a symmetrical linear molecular structure; component (B) is a polytetramethylene etheramine having a symmetrical linear structure, wherein:

[0010] The molar ratio of the NCO functional group of the diisocyanate having a symmetrical linear molecular structure to the NH2 functional group of the polytetramethylene ether amine having a symmetrical linear structure is between 1.07 and 1.00;

[0011] The molecular structure of the high-elongation-at-break polytetramethylene ether amine polyurea is a microphase separation structure composed of hard segments and soft segments, and the weight percentage of the hard segments relative to the soft segments is greater than 20%.

[0012] When mixing component A and component B, if component B is excessive, the molecular chain length of the polyurea material may be reduced, resulting in a polyurea material with low molecular weight and / or low mechanical properties.

[0013] Hard segments are regularly arranged within the soft segments. Crystallinity, hydrogen bonding, and van der Waals interactions within the hard segments all contribute to microphase separation, thus affecting elongation at break. Urethane and urea bonds are desirable, as they are chemically stable and provide crystalline domains within the hard segments. The hard segments (crystalline domains) are immiscible with the soft segments (polyethers, etc.). The elongation at break of the resulting polymer is directly related to the degree of microphase separation.

[0014] Thermodynamic incompatibility causes the hard segments to be insoluble in the soft segments, resulting in microphase separation. The soft segments are usually composed of relatively long flexible polyesters or polyether diols. The soft segments are non-crystalline at the use temperature, giving the material softness and flexibility. The hard segments are usually urethane groups, urea groups and small molecule segments. The hard segments help to increase hydrogen bonds, resulting in higher elongation, tensile strength and hardness, but lower recovery rate. The hard segments are characterized by polarity because they contain urethane groups and urea groups, which can form intramolecular and intermolecular hydrogen bonds with ether or ester soft segments and with other urethane groups / urea groups; when bonded with other urethane groups / urea groups, they can separate themselves into structural regions rich in hard segments, and the size of the microphase separation region is small. In addition to the microphase separation caused by the incompatibility between hard and soft segments, the crystallization of the hard segment can also be the driving force for microphase separation.

[0015] In one embodiment of the present invention, the high elongation at break polytetramethylene ether amine polyurea of ​​the present invention has a relatively high elongation at break, and the elongation at break of the high elongation at break polytetramethylene ether amine polyurea is greater than 1500%; further, the elongation at break is greater than 1800%; further, the elongation at break is greater than 2000%; further, the elongation at break is greater than 2150%; further, the elongation at break is greater than 2300%; further, the elongation at break is 2300%-2500%.

[0016] In one embodiment of the present invention, the polytetramethylene ether amine having a symmetrical linear structure is obtained by esterification of polytetramethylene ether glycol with an aminoaromatic carboxylic acid. Furthermore, the aminoaromatic carboxylic acid is a para-aromatic carboxylic acid and / or a meta-aromatic carboxylic acid; further, the aminoaromatic carboxylic acid is m-aminobenzoic acid, p-aminobenzoic acid, m-aminophenylacetic acid, p-aminophenylacetic acid, m-aminophenylpropionic acid, p-aminophenylpropionic acid, or 6-amino-2-naphthoic acid.

[0017] In one embodiment of the present invention, the polytetrahydrofuran ether amine is amino-terminated polytetrahydrofuran diol diparaaminobenzoate.Amino-terminated polytetrahydrofuran diol diparaaminobenzoate possesses characteristics such as specific equivalent, low unsaturation and narrow molecular weight distribution (i.e. polydispersity) among the present invention.The chemical structural formula of amino-terminated polytetrahydrofuran diol diparaaminobenzoate of the present invention is as shown in formula (I):

[0018]

[0019] In the formula, R is tetramethylene, i.e. -(CH2)4-.

[0020] Furthermore, the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is selected from at least one of P1000 with an equivalent weight of 600-625, P650 with an equivalent weight of 395-415, and P250 with an equivalent weight of 220-250; further, the unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 0.007meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 1.30; further The unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 0.006meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 1.20; further, the unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is 0.004meq / g-0.006meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is 1.05-1.20. Compared with ordinary polyols or polyamines, polyols or polyamines with narrow molecular weight distribution can produce polyurethane or polyurea materials with higher elongation at break, higher strength, and wider application scenarios.

[0021] In one embodiment of the present invention, the diisocyanate having a symmetrical linear molecular structure is selected from the following materials: 2,4-toluene diisocyanate (2,4-TDI), hexamethylene diisocyanate (HDI), 1,4-cyclohexyl diisocyanate (CHDI), 1,4-phenyl diisocyanate (PPDI), meta-xylylene diisocyanate (m-XDI), 2,6-toluene diisocyanate (2,6-TDI) and mixtures thereof.

[0022] Some diisocyanates, such as modified 4,4'-methylenediphenyl diisocyanate (MDI), 1,5-NDI, TDI, and the aliphatic diisocyanate IPDI, are commonly used, but they do not necessarily have symmetrical linear structures. TDI has two isomers: 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Commercially available TDI comes in several grades: the pure 2,4-isomer, T-100; a mixture of 80% 2,4-isomer and 20% 2,6-isomer, T-80; and a mixture of 65% 2,4-isomer and 35% 2,6-isomer, T-65. Using T-100 with symmetrical diols or diamines can produce symmetrical linear polyurethanes or polyureas. Using T-80 or T-65 does not produce symmetrical polyurethanes or polyureas. In pure TDI, the 2,4- and 2,6-isomers have both isocyanate groups in the meta position, with the same relative positions. The 2,6-isomer is difficult to purchase commercially and is very expensive. The 2,4-isomer is mass-produced and is generally used. After the 2,4-isomer reacts with polyamines or polyols, it can form linear macromolecules through conformational rotation.

[0023]

[0024] In one embodiment of the present invention, component (B) may further include a symmetrical linear structure small molecule etheramine; preferably, the small molecule etheramine includes at least one of hydrogenated p-diphenylmethane diisobutylamine, 3,3'-dimethyl-4,4'-bis-sec-butylaminodicyclohexylmethane, ethylene glycol bis(3-aminopropyl) ether, diethylene glycol bis(3-aminopropyl) ether, and tetramethyl-m-xylylene diisocyanate (TMXDI).

[0025] In one embodiment of the present invention, the raw materials may further include: component (C) a reactive solvent, component (D) a catalyst, and component (E) an auxiliary agent.

[0026] The reaction rate can be increased by adding a catalyst. The catalyst is selected from organotin and amine catalysts or mixtures thereof; preferably, the catalyst is selected from stannous di(2-ethylhexanoate), stannous oleate, dibutyltin diacetate, dibutyltin dilaurate, dimethyltin dioctoate, dioctyltin dilaurate, 3-dimethylamino-N,N-dimethylpropionamide, N,N-dimethylcyclohexylamine, N,N',N',N',N'-pentamethyldiethylenetriamine, triethylenediamine and mixtures thereof;

[0027] The viscosity of the reactants can be adjusted by adding a reactive solvent, which is selected from propylene carbonate, polypropylene oxide diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, and mixtures thereof.

[0028] The auxiliary agents include 0-2wt% of a leveling agent, 0-2wt% of a defoaming agent, 0-1wt% of an anti-settling agent, 0.5-2wt% of a coupling agent, 0-1wt% of an ultraviolet light absorber, 0-1wt% of an antioxidant and 0-1wt% of a flame retardant; the colorant is selected from at least one of titanium dioxide, Sb2O3, carbon black, medium chrome yellow, phthalocyanine green and phthalocyanine blue.

[0029] The second aspect of the present invention further provides a method for preparing polytetrahydrofuran ether amine polyurea with high elongation at break, wherein the preparation method is carried out under solvent-free conditions, and the specific preparation steps include the following steps:

[0030] Step 1: Preparation of anhydrous polytetrahydrofuran etheramine component B: Add 1 / 3-2 / 3 volume of polytetrahydrofuran etheramine having a symmetrical linear structure into a reaction vessel, raise the temperature to 90-100° C., evacuate to a vacuum degree of less than 0.01 MPa, heat and stir to react for 2 h-3 h, and then lower the temperature to room temperature (20-40° C.) under sealed conditions or under nitrogen protection to obtain anhydrous polytetrahydrofuran etheramine;

[0031] Step 2: The diisocyanate having a symmetrical linear molecular structure in component A is mixed evenly with the anhydrous polytetramethylene ether amine prepared in step 1 at 20-40° C., vacuum degassing, and curing for 40 seconds to 15 minutes to obtain the polytetramethylene ether amine polyurea with high elongation at break.

[0032] In one embodiment of the present invention, in step 2, after vacuum degassing, the coating is quickly applied to the object and cured to prepare an elastic material, or quickly poured into a mold and cured to prepare an elastic casting body.

[0033] The third aspect of the present invention further provides a use of a polytetramethylene ether amine polyurea with high elongation at break, wherein the polytetramethylene ether amine polyurea with high elongation at break is used for sealing and caulking high deformation areas.

[0034] Compared with the prior art, the present invention achieves the following technical effects:

[0035] (1) use the polyurea material of polytetrahydrofuran ether amine and isocyanate synthesis, polytetrahydrofuran ether amine is preferably amino-terminated polytetrahydrofuran diol diparaaminobenzoate, both contains ether segment and also contains ester segment in the raw material.

[0036] (2) The raw materials for polyurea products are all linear molecules with difunctional groups, and the synthetic polyurea materials are linear polymers. Polyurea materials can also be designed as linear polymers with slight three-dimensional crosslinking, high strength and toughness. Symmetrical diisocyanates are selected. The symmetry of diisocyanates plays an important role in the performance characteristics of polyurethanes. Symmetrical diisocyanates can better form dense hard segments and promote the formation of microphase separation structures. The molar ratio of the NCO functional group of the diisocyanate to the NH2 functional group of the polyamine is equal to 1.07-1.00, which can produce polyurea with super molecular weight.

[0037] (3) In the present invention, a terminal isocyanate reacts with a stoichiometric diamine to form a polyurea material. Because bidentate hydrogen bonds are stronger than monodentate hydrogen bonds, the urea segments produced by the polytetramethyleneimine ether amine reaction have stronger hard segments than the urethane segments produced by the diol reaction. Polyurea materials have a wider operating temperature window.

[0038] (4) The polyurea material of the present invention has good toughness and high elongation at break, exceeding 2150%. It is the highest known polyurea material with elongation at break. It also has high tensile strength, exceeding 6.3 MPa, and exhibits excellent mechanical properties.

[0039] (5) In the two-component polyurea material of the present invention, both component A and component B contain no volatile solvent, and the obtained polyurea product has a solid content of 100%.

[0040] (6) The polyurea product obtained by the present invention has a wide operating temperature range, can be folded in half without breaking at 120°C, and has good mechanical properties.

[0041] (7) Polyurea has a simple production process and is easy to apply. It can be applied manually or by machine. It is insensitive to temperature and moisture and is less affected by ambient temperature and humidity during application.

[0042] (8) Used for bonding, caulking, and sealing of high-deformation areas. It is used for caulking and sealing of high-speed railway ballastless tracks, airport runways, highways, bridges, and other projects. It can also be used to prepare solid tire injection materials, shock-absorbing materials, damping materials, and elastomers, etc., and has great economic significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a schematic flow chart of a method for preparing polytetramethylene etheramine polyurea with high elongation at break. DETAILED DESCRIPTION

[0044] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0045] The technical solutions of the present invention are described below by means of specific embodiments. It should be understood that one or more steps mentioned in the present invention do not exclude the presence of other methods and steps before and after the combination step, or other methods and steps may be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and does not limit the order of arrangement of each method or the scope of implementation of the present invention. Changes or adjustments in their relative relationships can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0046] The sources of the raw materials and instruments used in the examples are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0047] The invention provides a two-component polytetramethylene etheramine polyurea with high elongation at break. The raw materials of the two-component ...

[0048] The molecular structure of the high-elongation-at-break polytetramethylene ether amine polyurea is a microphase separation structure composed of hard segments and soft segments, and the weight percentage of the hard segments relative to the soft segments is greater than 20%.

[0049] Component (A) diisocyanate having a symmetrical linear molecular structure is selected from 2,4-toluene diisocyanate (2,4-TDI), hexamethylene diisocyanate (HDI), 1,4-cyclohexyl diisocyanate (CHDI), 1,4-phenyl diisocyanate (PPDI), meta-xylylene diisocyanate (m-XDI), 2,6-toluene diisocyanate (2,6-TDI) and mixtures thereof.

[0050] Component (B) is a polytetrahydrofuran ether amine having a symmetrical linear structure obtained by esterification of polytetrahydrofuran ether glycol with an aminoaromatic carboxylic acid. The polytetrahydrofuran ether amine has a degree of unsaturation of less than 0.007 meq / g and a molecular weight distribution (i.e., polydispersity) of less than 1.30. Compared with conventional polyols or polyamines, polyols or polyamines with narrow molecular weight distributions produce polyurethane or polyurea materials with higher elongation at break, higher strength, and a wider range of applications. Molecular weight distribution is the ratio of weight-average molecular weight to number-average molecular weight. It is determined by gel permeation chromatography (GPC). The aminoaromatic carboxylic acid is selected from para-aromatic carboxylic acids and / or meta-aromatic carboxylic acids. Specifically, the aminoaromatic carboxylic acid is m-aminobenzoic acid, p-aminobenzoic acid, m-aminophenylacetic acid, p-aminophenylacetic acid, m-aminophenylpropionic acid, p-aminophenylpropionic acid, and / or 6-amino-2-naphthoic acid.

[0051] More specifically, the polytetrahydrofuran ether amine is amino-terminated polytetrahydrofuran diol diparaaminobenzoate.Amino-terminated polytetrahydrofuran diol diparaaminobenzoate possesses characteristics such as specific equivalent, low unsaturation and narrow molecular weight distribution (i.e. polydispersity) among the present invention.The chemical structural formula of amino-terminated polytetrahydrofuran diol diparaaminobenzoate of the present invention is as shown in formula (I):

[0052]

[0053] In the formula, R is tetramethylene, i.e. -(CH2)4-.

[0054] The amino-terminated polytetrahydrofuran diol diparaaminobenzoate is selected from P1000 (equivalent weight 600-625, average weight 613), P650 (equivalent weight 395-415, average weight 405), and P250 (equivalent weight 220-250, average weight 213).

[0055] The hard segments are regularly arranged within the soft segments. Crystallinity, hydrogen bonding, and van der Waals interactions within the hard segments all contribute to microphase separation, thus affecting elongation at break. Urethane and urea bonds are desirable, as they are chemically stable and provide crystalline domains within the hard segments. The hard segments (crystalline domains) are immiscible with the soft segments (polyether, etc.). The elongation at break of the resulting polymer is directly related to the degree of microphase separation.

[0056] Thermodynamic incompatibility causes the hard segments to be insoluble in the soft segments, resulting in microphase separation. The soft segments are usually composed of relatively long flexible polyesters or polyether diols. The soft segments are non-crystalline at the use temperature, giving the material softness and flexibility. The hard segments are usually urethane groups, urea groups and small molecule segments. The hard segments help to increase hydrogen bonds, resulting in higher elongation, tensile strength and hardness, but lower recovery rate. The hard segments are characterized by polarity because they contain urethane groups and urea groups, which can form intramolecular and intermolecular hydrogen bonds with ether or ester soft segments and with other urethane groups / urea groups; when bonded with other urethane groups / urea groups, they can separate themselves into structural regions rich in hard segments, and the size of the microphase separation region is small. In addition to the microphase separation caused by the incompatibility between hard and soft segments, the crystallization of the hard segment can also be the driving force for microphase separation.

[0057] Polyurethane or polyurea hard segments segregate into isolated microdomains that are randomly dispersed within the continuous matrix of the soft segment phase. As the hard segment content increases, long-range interactions of the hard segments are expected to increase, which in turn facilitates their interaction through the soft segments. The hard segment regions act as physical crosslinking sites and reinforce the soft segments, allowing the polyurea or polyurethane to exhibit controllable structural properties within its intended application range. In addition to the hard segment content, the extent of hard segment interaction and its potential crystallization also significantly influence the mechanical and thermal properties of the material. In polyurea materials, the ability of the hard segments to establish hydrogen bonding networks further enhances their cohesion, particularly within the hard segment phase.

[0058] The polyether units in the polyurea soft segment have a glass transition temperature (Tg) well below room temperature. The hard segments of polyurea materials are urea-based, increasing the length of the hard segments and, consequently, their mass. Generally, chemical incompatibility between the soft and hard segments increases with soft segment length. This incompatibility drives microphase separation, with the soft segment Tg and the high-temperature softening point of the hard segment determining the operating temperature range. This operating temperature range is typically above the soft segment Tg but below the softening point or degradation temperature of the hard segment.

[0059] A hydrogen bond is the attraction between the lone pair of electrons of an electronegative atom (such as N or O) and the hydrogen atom directly connected to the N or O. The hydrogen bond between an electronegative O atom and a single H connected to the N is called a monodentate hydrogen bond. The hydrogen bond between an electronegative O atom and H atoms connected to two different N atoms is called a bidentate hydrogen bond. The strength of the hydrogen bonds in a polyurethane chain or polyurea chain directly affects the final properties of these materials. The hydrogen bonds in a urethane bond are monodentate, while the hydrogen bonds in a polyurea bond are bidentate. Compared to polyurea, the hydrogen bond strength of polyurethane is weaker. Polyetheramine and diisocyanate react directly to form polyurea, and the urea group has a greater hydrogen bond strength, which improves the physical properties of the material.

[0060] The present invention provides a method for dehydrating a polytetrahydrofuran etheramine component. The method comprises: purging nitrogen through a reactor and heating the polytetrahydrofuran etheramine component under vacuum to remove moisture and prevent side reactions caused by the water. The polyetheramine component is then cooled to room temperature, and then a diisocyanate component and the dehydrated polyetheramine component are rapidly stirred. The molar ratio of the NCO functional groups of the diisocyanate to the NH2 functional groups of the polyetheramine is preferably between 1.07 and 1.00.

[0061] The present invention also provides a method for preparing polytetrahydrofuran ether amine polyurea with high elongation at break, as shown in the attached specification. Figure 1 As shown, the preparation method is carried out under solvent-free conditions, and the specific preparation steps include the following steps:

[0062] Step 1: Preparation of anhydrous polytetrahydrofuran etheramine component B: Add 1 / 3-2 / 3 volume of polytetrahydrofuran etheramine having a symmetrical linear structure into a reaction vessel, raise the temperature to 90-100° C., evacuate to a vacuum degree of less than 0.01 MPa, heat and stir to react for 2 h-3 h, and then lower the temperature to room temperature (20-40° C.) under sealed conditions or under nitrogen protection to obtain anhydrous polytetrahydrofuran etheramine;

[0063] Step 2: The diisocyanate having a symmetrical linear molecular structure in component A is mixed evenly with the anhydrous polytetramethylene ether amine prepared in step 1 at 20-40° C., vacuum degassing, and curing for 40 seconds to 15 minutes to obtain the polytetramethylene ether amine polyurea with high elongation at break.

[0064] The temperature for mixing two components should not be too high or too low. If the temperature is too low, the mixing will be uneven; if the temperature is too high, the reaction will be too fast and the operation period will be too short.

[0065] In a specific embodiment of the present invention, in step 2, after vacuum degassing, the coating is quickly coated on the object and cured to prepare an elastic material, or quickly poured into a mold and cured to prepare an elastic casting body.

[0066] The test method for the pressure sealing of plugs and sockets using polytetramethylene etheramine polyurea is as follows:

[0067] Plug socket construction: The metal pins of the plug socket are inserted into a phenolic fiberglass circular plate. The circular plate and the inner wall of the plug socket housing are tightly fitted. After the phenolic fiberglass plate with the pins is assembled, a layer of polytetramethylene ether amine polyurea approximately 4mm thick is potted. Technical requirements: The sealed plug socket is subjected to 10 temperature cycles from -50°C to 120°C, with each temperature point lasting 2 hours, followed by a room temperature leak test at 2MPa. One end of the plug socket is sealed and pressurized with argon gas, while the other end is immersed in water and left for 10 minutes without generating bubbles.

[0068] Sealing design considerations: a. Primer. The metal shell of the plug socket is coated with epoxy primer to eliminate the influence of water and pollutants. b. Toughness. If the casting material is too hard and brittle, it will fail the temperature cycle test and crack after the temperature cycle. Select polytetrahydrofuran ether amine polyurea material with high elongation and good toughness. c. Strength. The plug socket needs to be leak-proof under a pressure of 2MPa. The strength of the casting material is too low to withstand the pressure requirement, so it must be both tough and pressure-resistant. d. Material selection. The polytetrahydrofuran ether amine polyurea material of Example 1.

[0069] Sealing Process: a. Plug and socket surface treatment: Apply epoxy primer to aluminum and steel housings (where the housing contains two metal materials) and allow to cure. b. Heat and evacuate the polytetramethylene ether amine component of the sealing material to remove water. c. Remove all water from all tools. d. Preheat the plug and socket to 80°C to achieve thermal equilibrium and remove any bubbles adsorbed by the metal. e. Two-component mixing temperature: 40±5°C. Mix according to the proper ratio and evacuate to remove any bubbles. Seal. Apply multiple seals, approximately 1-2 mm thick each time, to eliminate thermal stress. f. Curing. Performance testing.

[0070] Example 1

[0071] Preparation of anhydrous polytetrahydrofuran ether amine component B: A reaction vessel is equipped with a thermometer and an agitator at a speed of 1-200 rpm. The reaction vessel is also equipped with a heating jacket containing a heating tube and thermal oil, and the temperature is controllable between room temperature and 150°C. 1 / 3-2 / 3 of the volume of P650 (polytetrahydrofuran ether amine, Suzhou Xiangyuan New Materials Co., Ltd., equivalent N=405) is added to the reaction vessel. The temperature is raised to 90-100°C, and the reaction is evacuated to a vacuum of less than 0.01 MPa. The reaction is heated and stirred for 2-3 hours to obtain anhydrous P650. Subsequently, the temperature is lowered to room temperature (20-40°C) in a sealed container or under nitrogen.

[0072] Component A uses 2,4-TDI and can be used directly.

[0073] Control the temperature of components A and B at 20-40°C, weigh 405 parts by weight of P650 and 87 parts by weight of 2,4-TDI, place them in an iron or plastic container, and quickly stir and mix them evenly with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), quickly apply them to the coated object to prepare an elastic material, or pour them into a mold to prepare a casting body. 100g of the mixture of components A and B is cured for 10-15 minutes.

[0074] You can use Feilong's CPU20F-HG1 programmable ratio pouring equipment to perform pouring according to the above method.

[0075] Cure at 100°C for 3 hours or at room temperature not lower than 30°C for 7 days. After 7 days, perform performance testing. The test results are shown in Table 1.

[0076] The measured tensile strength of the polytetramethyleneimine urea material is 8.5-9.2 MPa, the elongation at break is 2180%-2320%, it does not break when folded in half at 120°C, has good thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0077] The polytetrahydrofuran etheramine polyurea obtained in Example 1 can pass the plug socket pressure sealing test.

[0078] Example 2

[0079] Preparation of anhydrous polytetrahydrofuran ether amine component B: A reaction vessel is equipped with a thermometer and an agitator at a speed of 1-200 rpm. The reaction vessel is also equipped with a heating jacket containing a heating tube and thermal oil, and the temperature is controllable between room temperature and 150°C. To the reaction vessel, 613.0 parts by weight of P1000 (polytetrahydrofuran ether amine, Suzhou Xiangyuan New Materials Co., Ltd., equivalent weight N=613) and 50.0 parts by weight of tetramethyl-m-xylylene diisocyanate (TMXDI) (Yantai Wanhua, N=122) are added. The temperature is raised to 90-100°C, and the mixture is evacuated to a vacuum of less than 0.01 MPa. The reaction is heated and stirred for 2-3 hours to obtain anhydrous component B. Subsequently, the temperature is lowered to room temperature (20-40°C) in a sealed container or under nitrogen.

[0080] Component A uses HDI and can be used directly.

[0081] The catalyst used was dibutyltin dilaurate.

[0082] The temperature of the two components is controlled at 20-40°C, and they are weighed in a weight ratio of A:B = 194.5:663.5. They are placed in an iron or plastic container and quickly stirred and mixed with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), they are quickly applied to the coated object to prepare an elastic material, or poured into a mold to prepare a casting body. 100g of the mixture of components A and B is cured for 10-15 minutes.

[0083] The above method can be used to cast the material using Feilong's CPU20F-HG1 programmable pouring equipment. Curing should be performed at 100°C for 3 hours or at room temperature of at least 30°C for 7 days. Performance testing should be performed after 7 days. The test results are shown in Table 1.

[0084] The polyurea material has a tensile strength of 8.9-9.8 MPa and an elongation at break of 2210%-2350%. The polytetrahydrofuran ether amine polyurea material remains unbroken when folded in half at 100°C, exhibiting excellent thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0085] The polytetrahydrofuran etheramine polyurea obtained in Example 2 can pass the plug socket pressure sealing test.

[0086] Example 3

[0087] 100g of polytetrahydrofuran ether amine B component P650 (polytetrahydrofuran ether amine, Suzhou Xiangyuan New Materials Co., Ltd., equivalent weight N=405), containing a small amount of water, was placed in a plastic or glass beaker and heated in a vacuum drying oven at 100°C and a vacuum of less than 0.01 MPa for 2 hours. The polytetrahydrofuran ether amine component was weighed on an analytical balance before and after heating and vacuuming to calculate the weight percentage of water. In this example, the polytetrahydrofuran ether amine component P650 contained 0.2% (w) water.

[0088] Component A uses 2,4-TDI and can be used directly.

[0089] The temperature of the two components is controlled at 20-40°C, and the weight ratio of P650:2,4-TDI = 405:90.9 is weighed. The components are placed in an iron container and quickly stirred and mixed with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), the mixture is quickly coated on a polyethylene flat plate to prepare an elastic material, or poured into a mold to prepare a casting body. 100g of the mixture of components A and B is cured for 10-15 minutes.

[0090] You can use Feilong's CPU20F-HG1 programmable ratio pouring equipment to perform pouring according to the above method.

[0091] Cure at 100°C for 3 hours or at room temperature not lower than 30°C for 7 days. After 7 days, perform performance testing. The test results are shown in Table 1.

[0092] The obtained polyurea material has a small amount of uniform bubbles.

[0093] The polyurea material has a tensile strength of 6.8-7.5 MPa and an elongation at break of 2070%-2180%. The polytetramethylene ether amine polyurea material remains unbroken when folded in half at 120°C, exhibiting excellent thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0094] The polytetrahydrofuran etheramine polyurea obtained in Example 3 can pass the plug socket pressure sealing test.

[0095] Example 4

[0096] Preparation of polytetramethylene ether amine component B: 100 parts by weight of polytetramethylene ether amine (Suzhou Xiangyuan New Materials Co., Ltd., equivalent N=405; water content 0.2% by weight), 0.50 parts by weight of a leveling agent (modified polysiloxane leveling agent, Levaslip 432, Elementis, UK), 0.50 parts by weight of a defoaming agent (a defoaming agent composed of a defoaming polymer and a polysiloxane solution, BYK-060N, BYK, Germany), 0.50 parts by weight of an anti-settling agent (modified urea solution, BYK-D410, BYK, Germany), 0.50 parts by weight of a coupling agent (γ-glycidyloxypropyltrimethoxysilane coupling agent, GF80, Wacker Chemical Company, Germany), 0.26 parts by weight of a UV absorber (2-(5-chloro-2H-benzotriazol-2)-6-yl)-1,2-dimethyl-1-thiazolyl-1-ol -tert-Butyltetramethylphenol, 3326, Clariant, Germany), 0.10 parts by weight of an antioxidant (triethylene glycol bis-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)] propionate, 245, BASF, Germany), 0.50 parts by weight of a flame retardant (dimethyl methylphosphonate, Qingdao Lianmei Chemical Co., Ltd.), and 5.5 parts by weight of a white Sb2O3 pigment were mixed uniformly, stirred in a high-speed blender (1000 rpm) for 1 h, and ground in a sand mill to a fineness of less than 50 μm. The discharged material was sealed and stored.

[0097] Component A consists of 2,4-TDI and is used directly.

[0098] The temperature of the two components is controlled at 20-40°C, and the B:A components are weighed in a weight ratio of 439:87. The components are placed in an iron or plastic container and quickly stirred and mixed with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), the mixture is quickly applied to the coated object to prepare an elastic material, or poured into a mold to prepare a casting body. 100g of the mixture of components A and B is cured for 10-15 minutes.

[0099] You can use Feilong's CPU20F-HG1 programmable ratio pouring equipment to perform pouring according to the above method.

[0100] Cure at 100°C for 3 hours or at room temperature not lower than 30°C for 7 days. After 7 days, perform performance testing. The test results are shown in Table 1.

[0101] The polyurea material produced is bubble-free.

[0102] The polyurea material has a tensile strength of 7.5-8.8 MPa and an elongation at break of 2250%-2420%. The polytetramethylene ether amine polyurea material remains unbroken when folded in half at 120°C, exhibiting excellent thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0103] The polytetrahydrofuran etheramine polyurea obtained in Example 4 can pass the plug socket pressure sealing test.

[0104] Example 5

[0105] Preparation of anhydrous polytetrahydrofuran ether amine component B: A reaction vessel is equipped with a thermometer and an agitator at a speed of 1-200 rpm. The reaction vessel is also equipped with a heating jacket containing a heating tube and thermal oil, and the temperature is controllable between room temperature and 150°C. 272 ​​parts by weight of P250 (polytetrahydrofuran ether amine, Suzhou Xiangyuan New Materials Co., Ltd., equivalent weight N=235) is added to the reaction vessel. The temperature is raised to 90-100°C, and the mixture is evacuated to a vacuum of less than 0.01 MPa. The reaction is heated and stirred for 2-3 hours to obtain anhydrous P250. Subsequently, the temperature is lowered to 80-85°C in a sealed container or under nitrogen.

[0106] Component A consists of 2,4-TDI and is used directly.

[0107] Components A and B are weighed at a weight ratio of P250:2,4-TDI:propylene carbonate = 272 (85°C):101:16, placed in an iron or plastic container, and rapidly stirred and mixed with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), quickly apply to the coated object to prepare an elastic material, or pour into a mold to prepare a casting. 100g of the mixture of components A and B cures within 10-15 minutes.

[0108] The above method can be used to cast using Feilong's CPU20F-HG1 adjustable ratio casting equipment. P250 and propylene carbonate components are first mixed evenly and heated to 80-85℃.

[0109] Cure at 100°C for 3 hours or at room temperature not lower than 30°C for 7 days. After 7 days, perform performance testing. The test results are shown in Table 1.

[0110] The polyurea material has a tensile strength of 6.3-7.5 MPa and an elongation at break of 2100%-2320%. The polytetramethylene ether amine polyurea material remains unbroken when folded in half at 120°C, exhibiting excellent thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0111] The polytetramethylene etheramine polyurea obtained in Example 5 can pass the plug socket pressure sealing test.

[0112] Comparative Example 1

[0113] Preparation of anhydrous polytetrahydrofuran ether amine component B: A reaction vessel is equipped with a thermometer and an agitator at a speed of 1-200 rpm. The reaction vessel is also equipped with a heating jacket containing a heating tube and thermal oil, and the temperature is controllable between room temperature and 150°C. 1 / 3-2 / 3 of the volume of P650 (polytetrahydrofuran ether amine, Suzhou Xiangyuan New Materials Co., Ltd., equivalent N=405) is added to the reaction vessel. The temperature is raised to 90-100°C, and the reaction is evacuated to a vacuum of less than 0.01 MPa. The reaction is heated and stirred for 2-3 hours to obtain anhydrous P650. Subsequently, the temperature is lowered to room temperature (20-40°C) in a sealed container or under nitrogen.

[0114] Component A is modified liquefied MDI and can be used directly.

[0115] The temperature of the two components is controlled at 20-40°C. P650 and modified liquefied MDI are weighed at 405 and 125 parts by weight, respectively. The mixture is placed in an iron or plastic container and quickly stirred and mixed with a stirrer at 100-1000 rpm. After vacuum degassing (in a vacuum drying oven or other vacuum equipment), the mixture is quickly applied to the substrate to prepare an elastic material, or poured into a mold to prepare a casting body. 100g of the mixture of components A and B is cured for 30-40 minutes.

[0116] You can use Feilong's CPU20F-HG1 programmable ratio pouring equipment to perform pouring according to the above method.

[0117] Cure at 100°C for 3 hours or at room temperature not lower than 30°C for 7 days. After 7 days, perform performance testing. The test results are shown in Table 1.

[0118] The polyurea material has a tensile strength of 11.0 MPa and an elongation at break of 175%. The polytetramethylene ether amine polyurea material remains unbroken when folded in half at 120°C, exhibiting excellent thermal stability and toughness, and does not crack when immersed in liquid nitrogen.

[0119] The polytetramethylene ether amine polyurea obtained in Comparative Example 1 cannot pass the plug socket pressure sealing test.

[0120] The asymmetric structure leads to a significant decrease in the elongation at break.

[0121] Table 1 Comparison of properties of polyurea materials obtained in Examples and Comparative Examples

[0122]

[0123] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to make and utilize a variety of exemplary embodiments of the invention and various options and variations. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A polytetramethyleneimine polyurea with high elongation at break, characterized in that: The raw materials include: component (A) is a diisocyanate with a symmetrical linear molecular structure; component (B) is a polytetramethylenetetrahydrofuran ether amine with a symmetrical linear structure, wherein: The molar ratio of the NCO functional group of the diisocyanate having a symmetrical linear molecular structure to the NH2 functional group of the polytetramethylene ether amine having a symmetrical linear structure is between 1.07 and 1.00; The molecular structure of the high-elongation-at-break polytetramethylene ether amine polyurea is a microphase separation structure consisting of hard segments and soft segments, and the weight percentage of the hard segments relative to the soft segments is greater than 20%; The diisocyanate having a symmetrical linear molecular structure is selected from the following materials: 2,4-toluene diisocyanate (2,4-TDI), hexamethylene diisocyanate (HDI), 1,4-cyclohexyl diisocyanate (CHDI), 1,4-phenyl diisocyanate (PPDI), meta-xylylene diisocyanate (m-XDI), 2,6-toluene diisocyanate (2,6-TDI) and mixtures thereof; The polytetrahydrofuran ether amine is amino-terminated polytetrahydrofuran diol diparaaminobenzoate; the unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 0.007meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 1.30; The high-elongation-at-break polytetramethylene ether amine polyurea has an elongation at break greater than 1500%.

2. The high elongation at break polytetramethylene ether amine polyurea according to claim 1, characterized in that: The elongation at break is greater than 1800%.

3. The high elongation at break polytetramethylene ether amine polyurea according to claim 2, characterized in that: The elongation at break is greater than 2000%.

4. The high elongation at break polytetramethylene ether amine polyurea according to claim 3, characterized in that: The elongation at break is greater than 2150%.

5. The high elongation at break polytetramethylene ether amine polyurea according to claim 4, characterized in that: The elongation at break is greater than 2300%.

6. The polytetramethylene ether amine polyurea with high elongation at break according to claim 5, characterized in that: The elongation at break is 2300%-2500%.

7. The polytetramethylene ether amine polyurea with high elongation at break according to claim 1, characterized in that: The amino-terminated polytetrahydrofuran diol diparaaminobenzoate is obtained by esterification of polytetrahydrofuran ether diol and paraaminobenzoic acid.

8. The polytetramethylene ether amine polyurea with high elongation at break according to claim 7, characterized in that: The amino-terminated polytetrahydrofuran diol diparaaminobenzoate is selected from at least one of P1000 with an equivalent weight of 600-625, P650 with an equivalent weight of 395-415, and P250 with an equivalent weight of 220-250.

9. The polytetramethylene ether amine polyurea with high elongation at break according to claim 7, characterized in that: The unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 0.006meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is less than 1.

20.

10. The polytetramethylene ether amine polyurea with high elongation at break according to claim 9, characterized in that: The unsaturation of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is 0.004meq / g-0.006meq / g, and the molecular weight distribution of the amino-terminated polytetrahydrofuran diol diparaaminobenzoate is 1.05-1.

20.

11. The polytetramethylene ether amine polyurea with high elongation at break according to claim 1, characterized in that: Component (B) may also contain symmetrical linear small molecule etheramine.

12. The polytetramethylene ether amine polyurea with high elongation at break according to claim 11, characterized in that: The symmetrical linear structure small molecule amine includes at least one of hydrogenated p-diphenylmethane diisobutylamine, 3,3'-dimethyl-4,4'-bis-sec-butylaminodicyclohexylmethane, ethylene glycol bis(3-aminopropyl) ether, and diethylene glycol bis(3-aminopropyl) ether.

13. The polytetramethylene ether amine polyurea with high elongation at break according to claim 1, characterized in that: The raw materials may further include: component (C) reactive solvent, component (D) catalyst, component (E) auxiliary agent; Wherein, the catalyst is selected from organotin and amine catalysts or mixtures thereof; The reactive solvent is selected from the group consisting of propylene carbonate, polypropylene oxide diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, and mixtures thereof.

14. The polytetramethylene ether amine polyurea with high elongation at break according to claim 13, characterized in that: The catalyst is selected from stannous (2-ethylhexanoate), stannous oleate, dibutyltin diacetate, dibutyltin dilaurate, dimethyltin dioctoate, dioctyltin dilaurate, 3-dimethylamino-N,N-dimethylpropionamide, N,N-dimethylcyclohexylamine, N,N',N',N',N'-pentamethyldiethylenetriamine, triethylenediamine and mixtures thereof.

15. The method for preparing polytetramethylene ether amine polyurea with high elongation at break according to claim 1, characterized in that: The preparation method is carried out under solvent-free conditions, and the specific preparation steps include the following steps: Step 1: Preparation of anhydrous polytetrahydrofuran etheramine component B: Add 1 / 3-2 / 3 volume of polytetrahydrofuran etheramine having a symmetrical linear structure into a reaction vessel, raise the temperature to 90-100° C., evacuate to a vacuum degree of less than 0.01 MPa, heat and stir to react for 2 h-3 h, and then lower the temperature to room temperature (20-40° C.) under sealed conditions or under nitrogen protection to obtain anhydrous polytetrahydrofuran etheramine; Step 2: The diisocyanate having a symmetrical linear molecular structure in component A is mixed evenly with the anhydrous polytetramethylene ether amine prepared in step 1 at 20-40° C., vacuum degassing, and curing for 40 seconds to 15 minutes to obtain the polytetramethylene ether amine polyurea with high elongation at break.

16. The method for preparing polytetramethylene ether amine polyurea with high elongation at break according to claim 15, characterized in that: In the second step, after vacuum degassing, the coating is quickly coated on the object to be coated and then solidified to prepare an elastic material, or quickly poured into a mold and then solidified to prepare an elastic casting body.

17. Use of the polytetramethylene ether amine polyurea with high elongation at break according to claim 1, wherein the polytetramethylene ether amine polyurea with high elongation at break is used for sealing and caulking high deformation areas.

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