CN117089035A - Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof - Google Patents
Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof Download PDFInfo
- Publication number
- CN117089035A CN117089035A CN202311364049.0A CN202311364049A CN117089035A CN 117089035 A CN117089035 A CN 117089035A CN 202311364049 A CN202311364049 A CN 202311364049A CN 117089035 A CN117089035 A CN 117089035A
- Authority
- CN
- China
- Prior art keywords
- silicon dioxide
- nano silicon
- modified nano
- polyurethane
- polyurethane elastomer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 317
- 235000012239 silicon dioxide Nutrition 0.000 title claims abstract description 138
- 239000005543 nano-size silicon particle Substances 0.000 title claims abstract description 137
- 229920003225 polyurethane elastomer Polymers 0.000 title claims abstract description 57
- 238000002360 preparation method Methods 0.000 title claims abstract description 37
- 239000000203 mixture Substances 0.000 claims abstract description 51
- 238000003756 stirring Methods 0.000 claims abstract description 50
- 238000006243 chemical reaction Methods 0.000 claims abstract description 41
- 239000005056 polyisocyanate Substances 0.000 claims abstract description 31
- 229920001228 polyisocyanate Polymers 0.000 claims abstract description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000008367 deionised water Substances 0.000 claims abstract description 23
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 23
- 239000003960 organic solvent Substances 0.000 claims abstract description 22
- 239000013067 intermediate product Substances 0.000 claims abstract description 17
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 14
- 238000001035 drying Methods 0.000 claims abstract description 8
- 230000004048 modification Effects 0.000 claims abstract description 7
- 238000012986 modification Methods 0.000 claims abstract description 7
- 238000005576 amination reaction Methods 0.000 claims abstract description 6
- 229920002635 polyurethane Polymers 0.000 claims description 57
- 239000004814 polyurethane Substances 0.000 claims description 57
- 238000000034 method Methods 0.000 claims description 48
- 239000000377 silicon dioxide Substances 0.000 claims description 30
- 238000010438 heat treatment Methods 0.000 claims description 27
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 26
- 239000004970 Chain extender Substances 0.000 claims description 25
- 229920001730 Moisture cure polyurethane Polymers 0.000 claims description 23
- 239000002245 particle Substances 0.000 claims description 22
- 238000002156 mixing Methods 0.000 claims description 19
- 125000005442 diisocyanate group Chemical group 0.000 claims description 18
- 229920005862 polyol Polymers 0.000 claims description 15
- 150000003077 polyols Chemical class 0.000 claims description 15
- 238000001291 vacuum drying Methods 0.000 claims description 13
- 238000001816 cooling Methods 0.000 claims description 12
- 238000011417 postcuring Methods 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 11
- UPMLOUAZCHDJJD-UHFFFAOYSA-N 4,4'-Diphenylmethane Diisocyanate Chemical compound C1=CC(N=C=O)=CC=C1CC1=CC=C(N=C=O)C=C1 UPMLOUAZCHDJJD-UHFFFAOYSA-N 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 10
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 9
- 229920005906 polyester polyol Polymers 0.000 claims description 9
- 239000008096 xylene Substances 0.000 claims description 9
- ALQLPWJFHRMHIU-UHFFFAOYSA-N 1,4-diisocyanatobenzene Chemical compound O=C=NC1=CC=C(N=C=O)C=C1 ALQLPWJFHRMHIU-UHFFFAOYSA-N 0.000 claims description 8
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 8
- 229920000570 polyether Polymers 0.000 claims description 8
- 238000007711 solidification Methods 0.000 claims description 8
- 230000008023 solidification Effects 0.000 claims description 8
- QORUGOXNWQUALA-UHFFFAOYSA-N N=C=O.N=C=O.N=C=O.C1=CC=C(C(C2=CC=CC=C2)C2=CC=CC=C2)C=C1 Chemical compound N=C=O.N=C=O.N=C=O.C1=CC=C(C(C2=CC=CC=C2)C2=CC=CC=C2)C=C1 QORUGOXNWQUALA-UHFFFAOYSA-N 0.000 claims description 7
- 239000000178 monomer Substances 0.000 claims description 7
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 7
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 5
- 230000008018 melting Effects 0.000 claims description 5
- ZXHZWRZAWJVPIC-UHFFFAOYSA-N 1,2-diisocyanatonaphthalene Chemical compound C1=CC=CC2=C(N=C=O)C(N=C=O)=CC=C21 ZXHZWRZAWJVPIC-UHFFFAOYSA-N 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 3
- 239000002861 polymer material Substances 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 42
- 239000002105 nanoparticle Substances 0.000 description 21
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 14
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 12
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 12
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 11
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 125000003277 amino group Chemical group 0.000 description 6
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 6
- 239000004433 Thermoplastic polyurethane Substances 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 5
- 239000012298 atmosphere Substances 0.000 description 5
- 230000020169 heat generation Effects 0.000 description 5
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 5
- SBJCUZQNHOLYMD-UHFFFAOYSA-N 1,5-Naphthalene diisocyanate Chemical compound C1=CC=C2C(N=C=O)=CC=CC2=C1N=C=O SBJCUZQNHOLYMD-UHFFFAOYSA-N 0.000 description 4
- 239000006087 Silane Coupling Agent Substances 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 4
- 229920001971 elastomer Polymers 0.000 description 4
- 239000000806 elastomer Substances 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000002035 prolonged effect Effects 0.000 description 4
- 230000035484 reaction time Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000007822 coupling agent Substances 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 239000012948 isocyanate Substances 0.000 description 3
- 150000002513 isocyanates Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- XLJMAIOERFSOGZ-UHFFFAOYSA-M cyanate group Chemical group [O-]C#N XLJMAIOERFSOGZ-UHFFFAOYSA-M 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 2
- 238000013040 rubber vulcanization Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229920001875 Ebonite Polymers 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000010382 chemical cross-linking Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 238000010559 graft polymerization reaction Methods 0.000 description 1
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Chemical group 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000011256 inorganic filler Substances 0.000 description 1
- 229910003475 inorganic filler Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
- 230000000930 thermomechanical effect Effects 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N urethane group Chemical group NC(=O)OCC JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000004636 vulcanized rubber Substances 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/38—Low-molecular-weight compounds having heteroatoms other than oxygen
- C08G18/3893—Low-molecular-weight compounds having heteroatoms other than oxygen containing silicon
- C08G18/3895—Inorganic compounds, e.g. aqueous alkalimetalsilicate solutions; Organic derivatives thereof containing no direct silicon-carbon bonds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
- C08L75/04—Polyurethanes
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention discloses modified nano silicon dioxide, a preparation method thereof, a polyurethane elastomer and a preparation method thereof, which belong to the technical field of high polymer materials, wherein the modified nano silicon dioxide is subjected to surface amination modification, and the preparation method of the modified nano silicon dioxide comprises the following steps: adding polyisocyanate into an organic solvent, stirring and dissolving; adding nano silicon dioxide into a mixture of polyisocyanate and an organic solvent for reaction to obtain a reaction product; and separating a modified nano silicon dioxide intermediate product from the reaction product, transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide. The invention realizes the technical effect of prolonging the service life of the polyurethane elastomer for the tire by adding the nano silicon dioxide with the surface modified by amination in the preparation process of the polyurethane elastomer.
Description
Technical Field
The invention relates to the technical field of high polymer materials, in particular to modified nano silicon dioxide and a preparation method thereof, a polyurethane elastomer and a preparation method thereof.
Background
Polyurethane materials have excellent tear strength and tensile strength, excellent abrasion resistance and rebound resilience, and are applied as support materials to non-pneumatic tires.
However, because the urethane structure in the polyurethane main chain has higher polarity, the polyurethane has larger deformation hysteresis under the use condition of high speed and high load, has serious intramolecular friction and high internal heat generation, and because the polyurethane material has poorer heat conductivity and continuously accumulates heat, the high-temperature area inside the material generates local stress defects, so that the polyurethane material is easy to damage structural members due to fatigue, and the normal service life of the non-pneumatic tire is influenced. Therefore, the range of application of polyurethane materials in the field of tire materials is widened, and the problem of internal heat generation of polyurethane materials is required to be improved.
Disclosure of Invention
The invention mainly aims to provide modified nano silicon dioxide, a preparation method thereof, a polyurethane elastomer and a preparation method thereof, and aims to solve the problems of high internal heat generation and reduced service life of the polyurethane material for the existing tire.
In order to achieve the above object, the present invention provides a method for preparing modified nano-silica, wherein the modified nano-silica is modified by surface amination, and the method for preparing the modified nano-silica comprises the following steps:
adding polyisocyanate into an organic solvent, stirring and dissolving;
adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent for reaction to obtain a reaction product;
and separating a modified nano silicon dioxide intermediate product from the reaction product, transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide.
Optionally, the nano-silica has a particle size of 5-80nm.
Optionally, the polyisocyanate comprises at least one of diphenylmethane diisocyanate, toluene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, or triphenylmethane triisocyanate;
and/or the organic solvent comprises at least one of toluene, xylene, chlorobenzene or acetone.
Optionally, the step of adding nano silica to the mixture of polyisocyanate and organic solvent to react to obtain a reaction product comprises:
adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent, carrying out ultrasonic mixing for 10-60min, heating to 40-80 ℃, and stirring at a rotating speed of 50-5000rpm for reaction for 10-30min to obtain a reaction product;
the step of transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide comprises the following steps:
transferring the washed modified nano silicon dioxide intermediate product into deionized water, stirring for 5-60min at the constant temperature of 20-60 ℃, centrifugally separating, washing for 3-6 times, and vacuum drying for 12-14h to obtain the modified nano silicon dioxide.
In addition, in order to achieve the above object, the present invention also provides a method for preparing a polyurethane elastomer, wherein modified nano silica in the preparation raw material is prepared by the method for preparing modified nano silica as described above, and the method for preparing a polyurethane elastomer comprises the following steps:
reacting polyester polyol or polyether polyol with diisocyanate at 60-80 ℃ for 1-4h to obtain polyurethane prepolymer;
adding the modified nano silicon dioxide into a preheated chain extender, stirring and mixing for 5-20min, adding the polyurethane prepolymer, stirring, performing vacuum defoaming treatment, and injecting into a die;
and heating and pre-curing the mixture in the mold for 2-4 hours, and cooling and post-curing for at least 16 hours to obtain the polyurethane elastomer.
Optionally, the mass ratio of the modified nano silicon dioxide in the total mass of the preparation raw materials is 0.1-4.0%.
Alternatively, the molecular weight of the polyester polyol is 800-3000 and the molecular weight of the polyether polyol is 800-3000.
In addition, in order to achieve the above object, the present invention also provides a method for preparing a polyurethane elastomer, wherein modified nano silica in the preparation raw material is prepared by the method for preparing modified nano silica as described above, and the method for preparing a polyurethane elastomer comprises the following steps:
stirring and mixing the modified nano silicon dioxide and a chain extender for 5-20min, and preheating to 40-80 ℃;
adding the preheated diisocyanate monomer, stirring for 2-10min at the rotating speed of 100-5000rpm, and heating to 80 ℃ for reaction and solidification;
crushing polyurethane obtained by solidification, adding the crushed polyurethane into an extruder, heating to 200-240 ℃, and carrying out melting and granulating to obtain the polyurethane elastomer.
In addition, in order to achieve the above object, the present invention also provides a modified nano-silica prepared by the preparation method of the modified nano-silica as described above.
In addition, in order to achieve the above purpose, the present invention also provides a polyurethane elastomer prepared by the preparation method of the polyurethane elastomer.
The preparation method of the modified nano silicon dioxide provided by the invention comprises the following steps of: adding polyisocyanate into an organic solvent, stirring and dissolving; adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent for reaction to obtain a reaction product; and separating a modified nano silicon dioxide intermediate product from the reaction product, transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide. Through the steps, the hydroxyl groups on the surface of the nano silicon dioxide react with partial cyanate functional groups in the polyisocyanate, so that the surface of the nano silicon dioxide is converted from hydroxyl groups to unreacted isocyanate functional groups, the unreacted isocyanate functional groups react with water fully, the isocyanate groups are converted into amino groups, and the modified nano silicon dioxide with the surface aminated is obtained, and further, the modified nano silicon dioxide can be used as a raw material capable of reacting with the isocyanate groups to prepare the polyurethane elastomer, covalent bonds are formed between the modified nano silicon dioxide and polyurethane molecules in the preparation process, the loss factor of the material at a certain temperature can be effectively reduced, the endophytic heat condition of the polyurethane elastomer is improved, and the service life is prolonged.
Drawings
FIG. 1 is a schematic view of a surface amination modification process of nanosilica according to an embodiment of the present invention;
fig. 2 is a schematic structural view of a polyurethane elastic supporting wheel according to an embodiment of the present invention.
The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Polyurethane materials are widely applied to the fields of automobiles, buildings, aviation and the like because of excellent mechanical properties, corrosion resistance and rebound resilience, but the problem of internal heat generation greatly influences the wide application of the materials.
Two improved methods are provided for solving the problem of polyurethane internal heat, namely a chemical method, namely diisocyanate with higher rigidity such as naphthalene 1, 5-diisocyanate (NDI) or p-phenylene diisocyanate (PPDI) is selected, and compared with common diphenylmethane diisocyanate (MDI) and Toluene Diisocyanate (TDI), the heat resistance of a polyurethane material can be obviously improved, so that the material can still be normally used under the condition of internal heat; secondly, a physical method is adopted, a fiber material with good heat conductivity is mixed into the polyurethane material, so that the heat conductivity is improved, the endophytic heat condition is relieved, and the normal use of the material is facilitated.
However, the above improvement method still has some practical problems, such as: NDI and PPDI type diisocyanate are expensive in cost, are only used in some extreme temperature resistant environments, and are not commonly used in popular tire materials; fibers with good thermal conductivity need to be imported and the price still limits the large-scale application of the fibers, so that the addition of some inorganic fillers is a method for improving the internal heat generation of polyurethane materials, which is economical and environment-friendly.
The polyurethane composite material is prepared by a method of adding nano particles, so that the endophytic heat of the material can be reduced to a certain extent. Among known inorganic nanoparticles, silica nanoparticles are widely used for improving optical, thermal and mechanical properties of polymers due to low thermal expansion, excellent thermal properties, high modulus, etc., however, they are not easily uniformly dispersed in polymer systems, and if they are directly added into polyurethane materials, agglomeration phenomenon occurs, so that the tensile strength of polyurethane materials is reduced and the elongation at break is reduced, and thus modification of the surfaces of the silica nanoparticles is required to improve their interfacial affinity with polyurethane. The current common modification method is to modify the surface of nano silicon dioxide by adopting a silane coupling agent, the modification reaction time is longer, the toughness of the material is reduced, and the elongation at break is reduced. The method carries out surface modification on the nano silicon dioxide in a non-coupling agent mode, uses isocyanate monomer to react with hydroxyl on the surface of the nano silicon dioxide, hydrolyzes to generate amino, shortens the time required by the whole process, ensures that the silicon dioxide is reserved on a polyurethane main chain, achieves molecular level dispersion, can form a structure similar to a rubber vulcanization crosslinking point, can effectively improve the thermodynamic performance of a polyurethane material, and maintains the rebound performance and tensile elongation at break of the polyurethane material.
The nano silicon dioxide particles are often used for improving the thermal performance and mechanical performance of polymer materials, and the compatibility of the nano silicon dioxide particles and polyurethane is good because the surface of the nano silicon dioxide particles has a plurality of polar hydroxyl groups, so that the nano silicon dioxide particles are easy to disperse in polyurethane, but because of the existence of the hydroxyl groups, hydrogen bonding effect exists between adjacent nano particles, and agglomeration phenomenon is easy to occur in the polyurethane materials, so that defects occur.
The current method for modifying the surface of the nano silicon dioxide particles comprises an alcohol esterification method, a coupling agent method, a surfactant method, a graft polymerization method, a high-energy method and the like, wherein the most commonly used method is the coupling agent method, and the specific steps are that silane coupling agent and nano silicon dioxide particles are mixed in an organic solvent by ultrasonic waves, then react for at least 6 hours at the constant temperature of 90 ℃, the modified nano silicon dioxide is obtained after centrifugal separation, and then methanol or acetone is used for repeatedly cleaning, and then the modified nano silicon dioxide powder is obtained after drying. The chemical structure of the silane coupling agent is greatly different from that of polyurethane, so that the interface compatibility of the nano silicon dioxide modified by the silane coupling agent and the polyurethane is poor.
The embodiment of the invention provides a preparation method of modified nano silicon dioxide, which comprises the following steps of:
step S10, adding polyisocyanate into an organic solvent, and stirring for dissolution;
polyisocyanates refer to compounds having at least two isocyanate groups in the structure. The present embodiment modifies nano-silica using a polyisocyanate as a starting modifying material, and the selected polyisocyanate may include at least one of diphenylmethane diisocyanate (MDI), toluene Diisocyanate (TDI), naphthalene Diisocyanate (NDI), p-phenylene diisocyanate (PPDI), or triphenylmethane triisocyanate. The organic solvent that dissolves the isocyanate may include at least one of toluene, xylene, chlorobenzene, or acetone. The polyisocyanate is added to the organic solvent and the stirring and dissolving process can be performed under an inert gas environment to prevent the isocyanate from reacting with water to hydrolyze, and the inert gas can be nitrogen. The polyisocyanate may be added in an amount of 0.2 to 20.0g, and is adapted to the amount of deionized water added to react sufficiently with the deionized water, for example, 0.2g, 1.0g, 2.0g, 5.0g, 8.0g, 10.0g, 12.0g, 15.0g, 18.0g, 20.0g.
Step S20, adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent for reaction to obtain a reaction product;
FIG. 1 is a schematic diagram showing an amino modification process of nanosilica, wherein hydrophilic nanosilica having hydroxyl groups on the surface is reacted with a part of isocyanate groups in polyisocyanate, as shown in FIG. 1, and after nanosilica is added into a mixture of triphenylmethane triisocyanate and an organic solvent, the nanosilica is uniformly dispersed under ultrasonic treatment, reacts with one of the isocyanate groups in the triphenylmethane triisocyanate under heating and stirring conditions, and links the nanosilica and the triphenylmethane triisocyanate, so that the surface of the nanosilica is converted from the original hydroxyl groups into unreacted isocyanate groups. The nano-silica selected in this example has a particle size in the range of 5-80nm, for example, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm. The particle size of the nano silicon dioxide is not too large, and if the particle size is too large, the mechanical properties of the finally prepared polyurethane elastomer can be affected.
In the reaction process of the nano silicon dioxide and the polyisocyanate, the time of ultrasonic mixing at room temperature can be set within the range of 10-60min, and the ultrasonic mixing can enable the nano silicon dioxide to be uniformly dispersed in a reaction system, for example, 10min, 20min, 30min, 40min, 50min and 60min. The heating temperature is in the range of 40-80℃and a suitable reaction temperature may facilitate the reaction, for example, 40℃50℃60℃70℃80 ℃. The stirring speed is in the range of 50-5000rpm, for example, 50rpm, 100rpm, 500rpm, 1000rpm, 2000rpm, 2500rpm, 3000rpm, 4000rpm, 5000rpm. The reaction time is in the range of 10-30min, for example, 10min, 15min, 20min, 25min, 30min.
And S30, separating a modified nano silicon dioxide intermediate product from the reaction product, transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide.
Under the above reaction conditions, the reaction between the polyisocyanate and the nano-silica may not be complete, and the desired modified nano-silica intermediate product may be separated by cooling and centrifugation, and then washed 3 to 6 times with anhydrous acetone to remove the unreacted polyisocyanate physically adsorbed on the surface of the nano-particles.
The modified nano silicon dioxide intermediate product contains unreacted isocyanate groups, and after the unreacted isocyanate groups are transferred into deionized water, the isocyanate groups react with the deionized water, and the isocyanate groups are converted into amino groups. Referring to fig. 1, the other two isocyanate groups in triphenylmethane triisocyanate that do not react with the hydroxyl groups of the nanosilica are converted to amino groups, resulting in surface amination modified nanosilica.
In the reaction process of the modified nano silica intermediate product and deionized water, isocyanate groups are easy to react with water, and proper heating can promote the reaction, and the reaction temperature can be set to 20-60 ℃, such as 20 ℃, 30 ℃,40 ℃,50 ℃ and 60 ℃. The stirring time is in the range of 5-60min, for example, 5min, 10min, 20min, 30min, 40min, 50min, 55min, 60min. The adding amount of deionized water can be 50-500mL, and is matched with the adding amount of polyisocyanate, so that the polyisocyanate can be reacted completely as much as possible. After the reaction is completed, centrifugal separation can be performed, the required product is centrifugally separated, the product is washed for 3-6 times by absolute ethyl alcohol, then vacuum drying is performed, the absolute ethyl alcohol and the water are removed, and the time of vacuum drying can be 12 hours, 13 hours and 14 hours. The vacuum drying process may be performed in an oven, and the temperature of the oven may be set to 80-120 ℃.
In the embodiment, the hydroxyl groups on the surface of the nano silicon dioxide react with partial cyanate functional groups in the polyisocyanate, so that the surface of the nano silicon dioxide is converted from hydroxyl groups to unreacted isocyanate functional groups, the unreacted isocyanate functional groups react with water fully, and the isocyanate groups are converted into amino groups, so that the modified nano silicon dioxide with the aminated surface is obtained, and further the modified nano silicon dioxide can be used as a raw material capable of reacting with the isocyanate groups to prepare the polyurethane elastomer, covalent bonds are formed between the modified nano silicon dioxide and polyurethane molecules in the preparation process, the loss factor of the material at a certain temperature can be effectively reduced, the endophytic heat condition of the polyurethane elastomer is improved, and the service life is prolonged.
The embodiment of the invention also provides a preparation method of the polyurethane elastomer, which is used for preparing the casting polyurethane elastomer and comprises the following steps:
step A10, reacting polyester polyol or polyether polyol with diisocyanate at 60-80 ℃ for 1-4 hours to obtain polyurethane prepolymer;
the reaction of the polyester polyol and the diisocyanate is a prepolymerization reaction, and the polyester polyol can be replaced by polyether polyol, so that the polyurethane elastomer prepared by the polyester polyol and the diisocyanate has a slight difference in properties. The polyester material has high mechanical strength and the polyether material has better low-temperature flexibility. The polyester polyols may be selected to have molecular weights of 800 to 3000 and the polyether polyols 800 to 3000. The reaction temperature is in the range of 60-80 ℃, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃. The reaction time is in the range of 1 to 4 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours.
Step A20, adding the modified nano silicon dioxide into a preheated chain extender, stirring and mixing for 5-20min, adding the polyurethane prepolymer, stirring, performing vacuum defoaming treatment, and injecting into a die;
the polyurethane prepolymer and the chain extender prepared by the method can be dried in vacuum in an oven at 120 ℃ for 2 hours before being used. The chain extender may be selected from glycols. Preheating a chain extender for 10min at 80 ℃, adding modified nano silicon dioxide into the chain extender, stirring and mixing for 5-20min, for example, 5min, 10min, 15min and 20min, adding a polyurethane prepolymer, and then enabling amino groups of the modified nano silicon dioxide to participate in polymerization reaction of the polyurethane prepolymer, wherein covalent bonds are formed between the modified nano silicon dioxide and polyurethane molecules. The vacuum defoaming treatment is to discharge the gas in the mixture, and the treatment time for the vacuum defoaming can be 5min. The mixture after the prepolymerization is injected into a mold for subsequent curing.
And step A30, heating and pre-curing the mixture in the mold for 2-4 hours, and cooling and post-curing for at least 16 hours to obtain the polyurethane elastomer.
The curing process may include two stages, pre-curing and post-curing. For example, the mixture in the mold is pre-cured by heating for 1 to 2 hours, for example, 1 hour, 1.5 hours, 2 hours, and then post-cured by cooling for at least 16 hours to obtain the molded cast polyurethane elastomer. The pre-curing process initiates the expansion of polyurethane prepolymer molecular chains by heating, promotes the connection between the modified nano silicon dioxide and polyurethane molecules, and after the initiation, the post-curing process can utilize the waste heat generated in the pre-curing process without heating.
In the embodiment, the polyurethane elastomer is prepared by adopting a casting method, has the characteristic of high strength, and is suitable for application scenes with high strength requirements.
The embodiment of the invention also provides a preparation method of another polyurethane elastomer, which is used for preparing a thermoplastic polyurethane elastomer, and comprises the following steps:
step B10, stirring and mixing the modified nano silicon dioxide and a chain extender for 5-20min, and preheating to 40-80 ℃;
the chain extender selected in this embodiment may be a polyol. The stirring and mixing time of the modified nano silicon dioxide and the chain extender is in the range of 5-20min, so that the dispersion of the nano silicon dioxide in the chain extender is promoted, for example, 5min, 10min, 15min and 20min. The mixture of the modified nano silicon dioxide and the chain extender is preheated to 40-80 ℃, a certain initial temperature is provided for the polymerization reaction, and the reaction is accelerated, for example, 40 ℃,50 ℃,60 ℃, 70 ℃ and 80 ℃.
Step B20, adding a preheated diisocyanate monomer, stirring for 2-10min at a rotating speed of 100-5000rpm, and heating to 80 ℃ for reaction and solidification;
the diisocyanate monomer is also preheated, and the preheating temperature of the mixture of the modified nano silicon dioxide and the chain extender is the same as that of the mixture of the modified nano silicon dioxide and the chain extender, and the preheating temperature is in the range of 40-80 ℃. And (3) stirring a mixture of diisocyanate monomer, chain extender and modified nano silicon dioxide, and reacting and curing after heating. The rotation speed may be set in the range of 100-5000rpm, for example, 100rpm, 500rpm, 1000rpm, 2000rpm, 3000rpm, 4000rpm, 4500rpm, 5000rpm. The stirring time is in the range of 2-10min, for example, 2min, 4min, 6min, 8min, 10min.
And step B30, crushing the polyurethane obtained by solidification, then adding the crushed polyurethane into an extruder, heating to 200-240 ℃, and carrying out melting and granulating to obtain the polyurethane elastomer.
After solidification, polyurethane particles can be obtained, the polyurethane particles are crushed and placed in an extruder for melting and granulating treatment, and then the thermoplastic polyurethane elastomer can be obtained. The temperature in the extruder may be set in the range of 200-240 ℃, e.g., 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃. The preparation process can be used for being melt mixed with conventional thermoplastic polyurethane particles at the temperature of 200-240 ℃ and then injection molded into polyurethane products or directly injection molded into polyurethane products.
In the embodiment, the preparation raw materials are directly solidified by adopting a one-step method, and then the thermoplastic polyurethane elastomer is prepared in an extruder, so that the material has good elasticity and high elongation at break, and is suitable for scenes with high requirements on elasticity and elongation at break.
The embodiment of the invention also provides a polyurethane elastomer, which is prepared by adopting the preparation method of the polyurethane elastomer. The polyurethane elastomer provided by the embodiment of the invention is mainly used on the polyurethane elastic supporting wheel shown in fig. 2, is used as a polyurethane material tire support or a polyurethane tread, is matched with a metal hub area, and can carry out reciprocating pulling and pressing movement under a certain strain when in use.
Example 1
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) 5g of MDI was added to the organic solvent xylene under inert gas (nitrogen) and stirred until completely dissolved.
(3) The nano silicon dioxide is put into the mixture, ultrasonic mixed for 10min at room temperature, heated to 40 ℃ and stirred for reaction for 10min at the rotating speed of 50 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100mL of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The Langsheng C525 prepolymer was dried in vacuo at 120℃for 2h to remove water.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 2
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) Under an inert atmosphere (nitrogen), 0.2g of MDI was added to the xylene and stirred until completely dissolved.
(3) The nano silicon dioxide is put into the mixture, ultrasonic mixed for 10min at room temperature, heated to 40 ℃ and stirred for reaction for 10min at the rotating speed of 50 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 3
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) Under an inert atmosphere (nitrogen), 0.2g of MDI was added to the xylene and stirred until completely dissolved.
(3) The hydrophilic nanoscale silica nanoparticles were placed in the mixture, ultrasonically mixed at room temperature for 10min, heated to 40 ℃ and stirred at 50rpm for reaction for 10min. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) The polyurethane prepolymer is preheated at 80 ℃ for 30min, modified nano silicon dioxide particles (mass fraction of 0.5 wt%) are added, the mixture is mechanically stirred and mixed for 20min, the chain extender is added, then the mixture is stirred at a high speed, the vacuum is defoamed for 5min, and the mixture is injected into a die.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 4
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) Under an inert gas atmosphere (nitrogen), 1g of MDI was added to the xylene and stirred until completely dissolved.
(3) The nano silicon dioxide is put into the mixture, ultrasonic mixed for 10min at room temperature, heated to 40 ℃ and stirred for reaction for 10min at the rotating speed of 50 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 5
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) Selecting H15 series nano silicon dioxide with the particle size of 20nm and produced by HDK.
(2) Under an inert atmosphere (nitrogen), 1g of ndi was added to xylene and stirred until completely dissolved.
(3) The nano silicon dioxide is put into the mixture, ultrasonic mixed for 10min at room temperature, heated to 40 ℃ and stirred for reaction for 10min at the rotating speed of 50 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 6
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) The nano silicon dioxide is put into TDI, ultrasonic mixed for 10min at room temperature, heated to 40 ℃ and stirred for reaction for 10min at the rotating speed of 50 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 5min at a constant temperature of 20 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 7
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) Under an inert atmosphere (nitrogen), 1g of PPDI was added to xylene and stirred until completely dissolved.
(3) The nano silicon dioxide is put into the mixture, ultrasonic mixed for 15min at room temperature, heated to 70 ℃ and stirred for reaction for 30min at the rotating speed of 200 rpm. The mixture was then cooled, centrifuged and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 20min at a constant temperature of 40 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) The polyol and diisocyanate are reacted for 2 hours at 80 ℃ to obtain polyurethane prepolymer.
(2) Preheating chain extender glycol at 80 ℃ for 10min, adding modified nano silicon dioxide particles (mass fraction is 0.1-4wt%) and mechanically stirring and mixing for 5-20min, adding polyurethane prepolymer and stirring at high speed, vacuum defoaming for 5min, and injecting the mixture into a mold.
(3) And heating and pre-curing the mixture for 2 hours, cooling and post-curing for at least 16 hours to obtain the formed polyurethane elastomer.
Example 8
1. The preparation method of the modified nano silicon dioxide comprises the following steps:
(1) The H15 series nano silicon dioxide produced by HDK with the grain diameter of 10nm is selected.
(2) The nanosilica was placed in HMDI, sonicated at room temperature for 15min, heated to 70 ℃, and stirred at 2000rpm for 30min.
(3) The mixture was cooled, centrifuged, and washed 3-6 times with anhydrous acetone.
(4) Transferring the nano particles into 100ml of deionized water, mechanically stirring for about 20min at a constant temperature of 40 ℃, centrifugally separating, washing with absolute ethyl alcohol for 3 times, and vacuum drying in an oven at 80 ℃ for 1h to obtain the modified nano silicon dioxide.
2. Preparing a polyurethane elastomer by using modified nano silicon dioxide:
(1) Stirring and mixing the modified nano silicon dioxide and the chain extender polyol for 15min at normal temperature, and preheating to 40-80 ℃.
(2) The polyisocyanate monomer compound preheated for 15min at 70 ℃ is added, and the mixture is mechanically stirred for 2min at 500rpm, and the temperature is raised to 80 ℃ for reaction curing.
(3) And after the polyurethane obtained by solidification is crushed, adding the crushed polyurethane into an extruder, heating to 200-240 ℃, and carrying out melting and granulating to obtain the nano silicon dioxide modified thermoplastic polyurethane elastomer.
Test results and analysis
(1) The tensile test of polyurethane articles was carried out according to the standard GB/T1701-2001 determination of tensile strength and elongation at break of hard rubber, for characterizing the tensile mechanical properties of the materials.
(2) The loss tangent at-10℃to 110℃was determined by dynamic thermomechanical analysis according to DIN 53513-1990 and used to characterize the intrinsic thermal properties of the materials.
(3) And carrying out chemical structure analysis on the nano silicon dioxide by adopting infrared spectrum.
(4) The flex life test was performed on polyurethane articles according to the standard GB/T13934-92 determination of flex cracking of vulcanized rubber. And (3) testing under normal temperature according to the standard conditions, setting the maximum stretching, unifying the bending strain to 100%, finishing the test when the sample breaks at the reciprocating motion frequency of 5Hz, and recording the number of times of breaking test to obtain the flexural life of the corresponding material (taking the average value of five test bars).
The test results are shown in Table 1 below.
TABLE 1
The unmodified polyurethane material (polyurethane blank) had a tensile strength of 30MPa, an elongation at break of 310% and a loss tangent of 0.18. The polyurethane material (silica blank) to which 1wt% of unmodified nanoparticles was added had a tensile strength of 32MPa, an elongation at break of 290% and a loss factor of 0.19. It was found that the polyurethane elastomer exhibited different tensile strength, modulus and loss tangent values under the same addition amount conditions by changing the kind of polyisocyanate used for the nano silica modification. The content of nano silicon dioxide in the polyurethane material is changed, so that the polyurethane elastomer presents different tensile strength, modulus and loss factor. The maximum tensile strength and minimum loss tangent of example 5 indicate high strength and good thermodynamic properties.
The method for modifying the nano silicon dioxide provided by the embodiment of the invention can reduce the use of an organic solvent and the heating reaction time, thereby achieving the effects of energy conservation and environmental protection. The hydroxyl groups on the surfaces of the nano particles are firstly converted into isocyanate groups and then into amino groups, so that the phenomenon of agglomeration and agglomeration of the modified nano particles due to environmental moisture during storage can be effectively avoided, and the storage life is prolonged. The polyurethane pouring material prepared from the modified nano particles and the polyurethane raw material can be effectively connected into polyurethane molecular chain segments due to the reaction of the modified nano particles and NCO groups in the system, so that the nano silicon dioxide is promoted to realize molecular-level dispersion, the polyurethane material is ideally enhanced, and the risk of weakening the performance of the polyurethane composite material due to filler aggregation is reduced. As a large number of hydroxyl groups exist on the surfaces of the nano particles, namely the modified nano silicon dioxide surface is a multi-functional branched structure, a reticular structure similar to rubber vulcanization chemical crosslinking can appear after the modified nano silicon dioxide surface reacts with NCO groups in polyurethane, the deformation hysteresis of the material under the use condition of high speed and high load is reduced, the endophytic heat of the material is further reduced, and the service life of the material is prolonged.
The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.
Claims (10)
1. The preparation method of the modified nano silicon dioxide is characterized in that the modified nano silicon dioxide is subjected to surface amination modification, and comprises the following steps:
adding polyisocyanate into an organic solvent, stirring and dissolving;
adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent for reaction to obtain a reaction product;
and separating a modified nano silicon dioxide intermediate product from the reaction product, transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide.
2. The method for preparing modified nano-silica according to claim 1, wherein the particle size of the nano-silica is 5 to 80nm.
3. The method of preparing modified nanosilica of claim 1, wherein the polyisocyanate comprises at least one of diphenylmethane diisocyanate, toluene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, or triphenylmethane triisocyanate;
and/or the organic solvent comprises at least one of toluene, xylene, chlorobenzene or acetone.
4. The method of preparing modified nanosilica of claim 1, wherein the step of adding nanosilica to the mixture of polyisocyanate and organic solvent for reaction to obtain the reaction product comprises:
adding nano silicon dioxide into the mixture of the polyisocyanate and the organic solvent, carrying out ultrasonic mixing for 10-60min, heating to 40-80 ℃, and stirring at a rotating speed of 50-5000rpm for reaction for 10-30min to obtain a reaction product;
the step of transferring the modified nano silicon dioxide intermediate product into deionized water for reaction, and drying to obtain the modified nano silicon dioxide comprises the following steps:
transferring the washed modified nano silicon dioxide intermediate product into deionized water, stirring for 5-60min at the constant temperature of 20-60 ℃, centrifugally separating, washing for 3-6 times, and vacuum drying for 12-14h to obtain the modified nano silicon dioxide.
5. A method for preparing a polyurethane elastomer, wherein modified nano-silica in a preparation raw material is prepared by the method for preparing modified nano-silica according to any one of claims 1 to 4, and the method for preparing the polyurethane elastomer comprises the following steps:
reacting polyester polyol or polyether polyol with diisocyanate at 60-80 ℃ for 1-4h to obtain polyurethane prepolymer;
adding the modified nano silicon dioxide into a preheated chain extender, stirring and mixing for 5-20min, adding the polyurethane prepolymer, stirring, performing vacuum defoaming treatment, and injecting into a die;
and heating and pre-curing the mixture in the mold for 2-4 hours, and cooling and post-curing for at least 16 hours to obtain the polyurethane elastomer.
6. The method for producing a polyurethane elastomer according to claim 5, wherein the mass ratio of the modified nano-silica in the total mass of the production raw materials is 0.1 to 4.0%.
7. The process for producing a polyurethane elastomer according to claim 5, wherein the molecular weight of the polyester polyol is 800 to 3000 and the molecular weight of the polyether polyol is 800 to 3000.
8. A method for preparing a polyurethane elastomer, wherein modified nano-silica in a preparation raw material is prepared by the method for preparing modified nano-silica according to any one of claims 1 to 4, and the method for preparing the polyurethane elastomer comprises the following steps:
stirring and mixing the modified nano silicon dioxide and a chain extender for 5-20min, and preheating to 40-80 ℃;
adding the preheated diisocyanate monomer, stirring for 2-10min at the rotating speed of 100-5000rpm, and heating to 80 ℃ for reaction and solidification;
crushing polyurethane obtained by solidification, adding the crushed polyurethane into an extruder, heating to 200-240 ℃, and carrying out melting and granulating to obtain the polyurethane elastomer.
9. A modified nano-silica prepared by the method of any one of claims 1 to 4.
10. A polyurethane elastomer prepared by the method of any one of claims 5 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311364049.0A CN117089035A (en) | 2023-10-20 | 2023-10-20 | Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311364049.0A CN117089035A (en) | 2023-10-20 | 2023-10-20 | Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117089035A true CN117089035A (en) | 2023-11-21 |
Family
ID=88772004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311364049.0A Pending CN117089035A (en) | 2023-10-20 | 2023-10-20 | Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117089035A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102558828A (en) * | 2011-12-29 | 2012-07-11 | 华南理工大学 | Method for preparing polyurethane hybridization material for hydroxyl-containing filler |
| CN106739827A (en) * | 2016-12-21 | 2017-05-31 | 青岛双星轮胎工业有限公司 | Non-inflatable tyre |
| CN110682741A (en) * | 2019-11-14 | 2020-01-14 | 山东理工大学 | Bionic non-pneumatic tire |
| CN112375448A (en) * | 2020-12-02 | 2021-02-19 | 周菊青 | High-hardness carbon nanotube modified acrylic resin composite coating and preparation method thereof |
| CN112694759A (en) * | 2020-12-21 | 2021-04-23 | 上饶市泰士特科技有限公司 | Nano silicon dioxide modified low-density polyethylene composite material and preparation method thereof |
| CN114801591A (en) * | 2022-04-20 | 2022-07-29 | 山东玲珑轮胎股份有限公司 | Non-pneumatic tire |
| CN217435414U (en) * | 2022-01-12 | 2022-09-16 | 广西玲珑轮胎有限公司 | Bionic non-pneumatic tire |
| CN115260630A (en) * | 2022-08-03 | 2022-11-01 | 江苏惠升管业集团有限公司 | High-strength HDPE/PA alloy antibacterial and anticorrosive pipe and preparation method thereof |
-
2023
- 2023-10-20 CN CN202311364049.0A patent/CN117089035A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102558828A (en) * | 2011-12-29 | 2012-07-11 | 华南理工大学 | Method for preparing polyurethane hybridization material for hydroxyl-containing filler |
| CN106739827A (en) * | 2016-12-21 | 2017-05-31 | 青岛双星轮胎工业有限公司 | Non-inflatable tyre |
| CN110682741A (en) * | 2019-11-14 | 2020-01-14 | 山东理工大学 | Bionic non-pneumatic tire |
| CN112375448A (en) * | 2020-12-02 | 2021-02-19 | 周菊青 | High-hardness carbon nanotube modified acrylic resin composite coating and preparation method thereof |
| CN112694759A (en) * | 2020-12-21 | 2021-04-23 | 上饶市泰士特科技有限公司 | Nano silicon dioxide modified low-density polyethylene composite material and preparation method thereof |
| CN217435414U (en) * | 2022-01-12 | 2022-09-16 | 广西玲珑轮胎有限公司 | Bionic non-pneumatic tire |
| CN114801591A (en) * | 2022-04-20 | 2022-07-29 | 山东玲珑轮胎股份有限公司 | Non-pneumatic tire |
| CN115260630A (en) * | 2022-08-03 | 2022-11-01 | 江苏惠升管业集团有限公司 | High-strength HDPE/PA alloy antibacterial and anticorrosive pipe and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 周鑫 等: "《气相二氧化硅的异氰酸酯改性及其对浇注型聚氨酯弹性体力学性能的影响》", 《复合材料学报》, vol. 40, no. 2, pages 852 - 859 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110511344B (en) | Self-repairing polyurethane elastomer based on multiple dynamic reversible effects and preparation method thereof | |
| CN111234175B (en) | Preparation method of self-repairing waterproof material, self-repairing waterproof material and application of self-repairing waterproof material | |
| CN108003317A (en) | A kind of silicone elastomer and its preparation method and application | |
| Zhao et al. | Formation of POSS-POSS interactions in polyurethanes: From synthesis, morphologies to shape memory properties of materials | |
| CN101698695B (en) | Method for synthesizing heat-resistance epoxy resin modified thermoplastic linear polyurethane elastomer | |
| CN109608606B (en) | Preparation method of polyurethane solid tire for mining vehicle | |
| CN110452354B (en) | Reversible crosslinking type thermoplastic polyurethane elastomer and preparation method thereof | |
| WO2011125540A1 (en) | Thermoplastic polyurethane resin and molded article | |
| US20210237511A1 (en) | Non-pneumatic wheel having a moldable reinforced thermoplastic polyurethane spoke and a process for preparing the same | |
| CN110511390B (en) | Graphene end-crosslinked elastomer material and preparation method thereof | |
| CN117089035A (en) | Modified nano silicon dioxide and preparation method thereof, polyurethane elastomer and preparation method thereof | |
| KR101642415B1 (en) | Heterogeneous polyurethane prepolymer for nonpneumatic-type tire and method for manufacturing the same | |
| Ding et al. | Thermally reversible, self-healing polyurethane based on propyl gallate and polyurethane prepolymers with varied isocyanate content | |
| CN114426805B (en) | Preparation method of hydrolysis-resistant polyurethane hot melt adhesive | |
| CN112266603A (en) | Manufacturing method of composition for load-bearing forklift tires | |
| CN115322324A (en) | Preparation method, regeneration method and application of linear boron ester bond polyurethane elastomer composite material | |
| CN113999430B (en) | Internal mold release agent, preparation method thereof, polyurethane composition and method for preparing polyurethane interlayer part by using same | |
| CN109929084B (en) | Novel polyether ester elastomer and preparation method thereof | |
| CN115850642A (en) | Preparation method of high-performance polyurethane elastomer | |
| CN112851980B (en) | Recycled carbon fiber reinforced thermoplastic polyurethane elastomer and preparation method thereof | |
| CN115216138B (en) | Preparation method of high-permeability and easy-to-process molding thermoplastic polyurethane elastomer | |
| CN116789932A (en) | Recyclable polyurethane elastomer containing multiple hydrogen bonds and obtained through chain extension of aldehyde groups and preparation method of recyclable polyurethane elastomer | |
| CN114163809B (en) | Preparation method and application of kaolin grafted polyphenyl ether modified polyurethane resin | |
| JPS6018514A (en) | Elastomer-forming composition | |
| JP2003055548A (en) | Thermoplastic polyurethane resin composition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |