CN115594816A - Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof - Google Patents
Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof Download PDFInfo
- Publication number
- CN115594816A CN115594816A CN202211261942.6A CN202211261942A CN115594816A CN 115594816 A CN115594816 A CN 115594816A CN 202211261942 A CN202211261942 A CN 202211261942A CN 115594816 A CN115594816 A CN 115594816A
- Authority
- CN
- China
- Prior art keywords
- energy storage
- super
- tough
- dimensional network
- stirring
- 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
- 238000004146 energy storage Methods 0.000 title claims abstract description 49
- 229920001187 thermosetting polymer Polymers 0.000 title claims abstract description 25
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 8
- 238000003756 stirring Methods 0.000 claims description 47
- 238000006243 chemical reaction Methods 0.000 claims description 42
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 32
- 238000010438 heat treatment Methods 0.000 claims description 30
- DZCCLNYLUGNUKQ-UHFFFAOYSA-N n-(4-nitrosophenyl)hydroxylamine Chemical compound ONC1=CC=C(N=O)C=C1 DZCCLNYLUGNUKQ-UHFFFAOYSA-N 0.000 claims description 26
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 24
- -1 polytetrafluoroethylene Polymers 0.000 claims description 24
- 238000010992 reflux Methods 0.000 claims description 20
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 19
- 125000005442 diisocyanate group Chemical group 0.000 claims description 19
- 229920000642 polymer Polymers 0.000 claims description 18
- 239000007788 liquid Substances 0.000 claims description 17
- 229910052757 nitrogen Inorganic materials 0.000 claims description 16
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 16
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 16
- 239000002202 Polyethylene glycol Substances 0.000 claims description 15
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 15
- 229920001223 polyethylene glycol Polymers 0.000 claims description 15
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical group CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 14
- 230000008859 change Effects 0.000 claims description 12
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 11
- 150000002009 diols Chemical class 0.000 claims description 11
- 239000003960 organic solvent Substances 0.000 claims description 10
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 claims description 9
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 8
- 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 7
- 239000005057 Hexamethylene diisocyanate Substances 0.000 claims description 7
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 6
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 claims description 6
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical group CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 6
- 239000005058 Isophorone diisocyanate Substances 0.000 claims description 5
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims description 5
- KXBFLNPZHXDQLV-UHFFFAOYSA-N [cyclohexyl(diisocyanato)methyl]cyclohexane Chemical compound C1CCCCC1C(N=C=O)(N=C=O)C1CCCCC1 KXBFLNPZHXDQLV-UHFFFAOYSA-N 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 239000000178 monomer Substances 0.000 claims description 4
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 4
- 239000012948 isocyanate Substances 0.000 claims description 2
- 150000002923 oximes Chemical class 0.000 claims description 2
- 238000003303 reheating Methods 0.000 claims description 2
- 238000001291 vacuum drying Methods 0.000 claims description 2
- 150000002513 isocyanates Chemical class 0.000 claims 1
- 239000002861 polymer material Substances 0.000 abstract description 19
- 239000000463 material Substances 0.000 abstract description 12
- 238000004132 cross linking Methods 0.000 abstract description 4
- 230000008569 process Effects 0.000 abstract description 3
- 239000012071 phase Substances 0.000 description 9
- 239000002904 solvent Substances 0.000 description 9
- 125000000524 functional group Chemical group 0.000 description 7
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 4
- 238000005338 heat storage Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000008118 PEG 6000 Substances 0.000 description 2
- 229920001030 Polyethylene Glycol 4000 Polymers 0.000 description 2
- 229920002584 Polyethylene Glycol 6000 Polymers 0.000 description 2
- 229920002594 Polyethylene Glycol 8000 Polymers 0.000 description 2
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical compound ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 125000003544 oxime group Chemical group 0.000 description 2
- 239000012782 phase change material Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical group O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 239000012860 organic pigment Substances 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 229920002523 polyethylene Glycol 1000 Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
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
- C08G18/08—Processes
- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
- C08G18/12—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step using two or more compounds having active hydrogen in the first polymerisation step
-
- 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
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
- C08G18/4833—Polyethers containing oxyethylene units
-
- 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
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
- C08G18/4854—Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
-
- 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
- C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
- C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
- C08G18/6666—Compounds of group C08G18/48 or C08G18/52
- C08G18/667—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
- C08G18/6681—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/32 or C08G18/3271 and/or polyamines of C08G18/38
- C08G18/6688—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/32 or C08G18/3271 and/or polyamines of C08G18/38 with compounds of group C08G18/3271
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention discloses a super-tough photo-thermal energy storage three-dimensional network polymer and a preparation method thereof. The problem of relatively poor toughness of the material can be effectively solved due to the cross-linking stable structure of the material, the problems of structural damage and the like in the flexible wearing process are solved, the service life is long, the durability of the material is improved, the polymer material with better photo-thermal energy storage and super-toughness can be prepared, and the continuous energy supply and wearing comfort of intelligent wearing are realized.
Description
Technical Field
The invention relates to the technical field of photo-thermal energy storage polymer preparation, in particular to a super-tough photo-thermal energy storage three-dimensional network polymer and a preparation method thereof.
Background
With the improvement of living standard and quality, self-powered intelligence flexible wearing is a key development direction of future science and technology. Solar energy is used as clean energy, has the advantage of inexhaustible energy, becomes one of the solutions to global problems of global energy crisis, environmental pollution, greenhouse effect and the like, and is ideal energy for flexible wearing. However, the utilization rate of solar photo-thermal conversion is greatly limited due to the influence of low energy density of solar radiation, uncertain change of natural environment and the like. Therefore, an energy storage device for solving the problem of short solar energy mismatch in time and space and realizing stable energy supply needs to be found.
At present, the heat energy storage mainly comprises chemical heat storage, sensible heat storage and phase change heat storage, wherein the phase change refers to a reversible phenomenon that a material absorbs or releases a large amount of latent heat due to the change of a physical phase state when the temperature reaches the transition temperature of the solid phase-liquid phase, the liquid phase-gas phase and the solid phase-gas phase of the material, and the environmental temperature can be kept unchanged in the process for a period of time, so that the temperature is not further increased or reduced. Therefore, the phase-change material is also applied to solving the problem of solar energy space-time mismatch due to the advantages of high energy storage density, strong energy storage capacity, small temperature change, low price, environmental protection and the like, and the application of solar photo-thermal utilization is popularized.
However, in practical applications, only about 40% of the infrared band of solar radiation can directly generate thermal effect, while the visible light band occupying about 50% of the solar radiation has no thermal effect and is difficult to directly absorb and utilize, and the conversion of visible light and high-efficiency thermal utilization need to be realized by means of light trapping or photo-thermal conversion materials. In order to improve the photothermal conversion efficiency of the system, a light conversion material is added: selectively absorb carbon black, cobalt coating, metal oxide, metal sulfide, semiconductor, organic pigment, organic dye and the like in a photothermal conversion system of photothermal technology. Therefore, the performance of the composite material can be greatly affected when the photo-thermal energy storage system is constructed.
Therefore, there is a need for a photo-thermal energy storage polymer and a preparation process thereof, which can integrate the functions of photo-thermal conversion, thermal energy storage, flexibility and stretchability.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a super-tough photothermal energy storage three-dimensional network polymer and a preparation method thereof, the polymer is a polymer which is formed by blocking a phase-change group and storing energy through photothermal conversion, and a photothermal conversion functional group and a phase-change functional group are blocked on a molecular chain through molecular synthesis, so that the photothermal energy storage and super-tough dual functions are realized, a good photothermal energy storage and super-tough polymer material can be prepared, the continuous energy supply and wearing comfort of intelligent wearing are realized, and the problems in the background art are solved.
In order to achieve the purpose, the invention provides the following technical scheme: a super-tough three-dimensional network polymer with photo-thermal energy storage function is prepared through the reaction between diisocyanate and flexible long-chain diol to prepare the prepolymer sealed by isocyanate bond, the reaction between said prepolymer and binary oxime monomer to prepare the linear low-molecular polymer with photo-thermal conversion function and phase-change group block, and solidifying said linear low-molecular polymer by the use of trifunctional triol to form said three-dimensional network polymer
In addition, in order to achieve the purpose, the invention also provides the following technical scheme: a preparation method of a super-tough photo-thermal energy storage three-dimensional network polymer comprises the following steps:
s1, under the protection of high-purity nitrogen, carrying out vacuum drying treatment on flexible long-chain dihydric alcohol for 2-12 h, adding diisocyanate, and reacting under the condition of uniform stirring to obtain a-NCO-terminated prepolymer;
s2, adding the p-benzoquinone dioxime into an organic solvent, stirring and dissolving to obtain a p-benzoquinone dioxime organic solution, dropwise adding the p-benzoquinone dioxime organic solution into a-NCO-terminated prepolymer, heating, refluxing and stirring to react to obtain a linear oligomer polymer with a photo-thermal conversion function and a phase-change group block;
s3, adding triethanolamine into an organic solvent, stirring and dissolving to obtain a triethanolamine organic solution, adding the triethanolamine organic solution into a linear oligomer polymer, and stirring to obtain a uniform dark brown liquid;
and S4, pouring the uniform dark brown liquid into a polytetrafluoroethylene mold, heating the polytetrafluoroethylene mold in a vacuum oven at the temperature of 30-50 ℃ for 2-4 hours, and then heating and curing to obtain the super-tough photo-thermal energy storage three-dimensional network polymer.
Preferably, the molecular weight of the flexible long-chain diol is 4000-10000, and the flexible long-chain diol is polyethylene glycol (PEG), polytetramethylene glycol (PTMG) or a mixture of the PEG and the PTMG.
Preferably, in step S1, the reaction under the condition of uniform stirring is specifically: reflux reaction is carried out for 3 to 12 hours at the temperature of between 40 and 100 ℃.
Preferably, the molar ratio of the flexible long-chain diol to the diisocyanate is 1:2.
preferably, the diisocyanate is toluene diisocyanate TDI, isophorone diisocyanate IPDI, diphenylmethane diisocyanate MDI, dicyclohexylmethane diisocyanate HMDI or hexamethylene diisocyanate HDI; the organic solvent is N, N-dimethylformamide, tetrahydrofuran, N-dimethylacetamide or dimethyl sulfoxide.
Preferably, in step S2, the heating and reflux stirring reaction specifically comprises: and refluxing and stirring at 40-120 deg.c for 2-6 hr under the protection of high purity nitrogen.
Preferably, the molar ratio of the flexible long-chain diol to the p-benzoquinone dioxime is 1:1.
preferably, in step S3, the molar ratio of the added triethanolamine to the flexible long-chain diol is 1 to 2, and the stirring time is 10 to 30min.
Preferably, in step S4, the reheating curing specifically includes: then the temperature is raised to 60 to 120 ℃ for curing treatment for 2 to 4 hours.
The beneficial effects of the invention are:
1) The invention prepares the phase-change functional group block skeleton chain structure with a flexible molecular chain structure through molecular structure design, and endows the polymer material with the phase-change energy storage function.
2) The p-benzoquinone structure with the light absorption function and the photothermal conversion function is introduced onto a polymer molecular chain through the action of a chemical covalent bond, and the problems of material migration, interface defects and the like of the composite material caused by phase separation can be effectively solved due to the limitation of the molecular chain structure and the chemical covalent bond. The organic combination of the photo-thermal conversion functional group, the phase change functional group and the three-dimensional cross-linked network endows the polymer material with the capacity of absorbing about 90% of energy of infrared light and visible light in solar radiation, the capacity of storing the light energy into heat energy by the polymer material, the strength of the polymer in ultra-long breaking and stretching and the like.
3) According to the preparation method of the super-tough photo-thermal energy storage polymer, the problem of poor toughness of the material can be effectively solved due to the self cross-linking stable structure, the problems of structural damage and the like in the flexible wearing process are solved, the service life is long, and the durability of the material is improved.
Drawings
FIG. 1 is a schematic diagram of the synthesis reaction of a sample of Y1 in example;
FIG. 2 is a schematic view of a sample of Y1 in example;
FIG. 3 is a schematic infrared spectrum of a Y1 sample in example;
FIG. 4 is an XRD plot of a Y1 sample from example;
FIG. 5 is a DSC temperature increase and decrease cycle curve of the Y1 sample in the example;
FIG. 6 is a stress-strain curve of the Y1 sample of the example;
FIG. 7 is a photothermal conversion curve of the Y1 sample in example;
FIG. 8 is the energy storage curve of the Y1 sample in the example.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention adopts solution polycondensation reaction, prepares a final product by a one-pot method, and is a polyurethane synthesis method which realizes the functions of storing and releasing heat by absorbing light and generating heat through an oxime group and then realizing the functions of photo-thermal conversion and phase change.
A super-tough photo-thermal energy storage three-dimensional network polymer is prepared by reacting diisocyanate with flexible long-chain dihydric alcohol to prepare an isocyanate-bond end-capped prepolymer, reacting the prepolymer with a binary oxime-group monomer to prepare a linear oligomer polymer with a photo-thermal conversion function and a phase change group block, and finally curing the linear oligomer polymer by using trifunctional trihydric alcohol as a cross-linking agent to form the three-dimensional network polymer.
The three-dimensional network established by the invention is a three-dimensional network structure with adjustable crosslinking density formed by reacting excess difunctional diisocyanate, long-chain dihydric alcohol and a dioxime-based monomer into a linear prepolymer and then adding trifunctional triol to react with the residual isocyanate functional group on the excess diisocyanate. And the material is endowed with better mechanical property due to the existence of a three-dimensional structure.
The three-dimensional network polymer has the molecular structure as follows:
a preparation method of a super-tough photo-thermal energy storage three-dimensional network polymer comprises the following steps:
1) Under the protection of high-purity nitrogen, 40.0-100.0g of flexible long-chain dihydric alcohol with different molecular weights (the molecular weight is 4000-10000) is dried in a vacuum oven for 2-12 hours, then 2.50-8.90g of diisocyanate is added to be dissolved in a three-neck flask filled with an organic solvent, and the molar ratio of the flexible long-chain dihydric alcohol to the diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 3 to 12 hours at the temperature of 40 to 100 ℃ under the condition of uniform stirring, and then the-NCO end-capped prepolymer is obtained.
2) Adding 1.38g of p-benzoquinone dioxime into 20-50ml of organic solvent, stirring and dissolving to obtain a p-benzoquinone dioxime organic solution, dropwise adding the solution into the prepolymer of the step 1), and controlling the molar ratio of the flexible long-chain diol to the p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction at 40-120 deg.c under the protection of high purity nitrogen for 2-6 hr.
3) Adding 1.49-2.98g of triethanolamine into 20-50ml of organic solvent, stirring and dissolving to obtain triethanolamine organic solution, then adding the obtained solution into 2), controlling the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine to be 1-2, and stirring for 10-30 minutes to obtain uniform dark brown liquid.
Pouring the liquid obtained in the step 3) into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a vacuum oven at the temperature of 30-50 ℃, heating for 2-4 hours, and then increasing the temperature to 60-120 ℃ for curing treatment for 2-4 hours to obtain the super-tough photothermal energy storage polymer material.
Further, the flexible long-chain diol is polyethylene glycol (PEG), polytetramethylene glycol (PTMG) or a mixture of the two.
Further, the organic solvent is N, N dimethylformamide, tetrahydrofuran, N dimethylacetamide, dimethylsulfoxide, or the like.
Further, the diisocyanate is Toluene Diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene Diisocyanate (HDI), or the like.
Example 1
Under the protection of high-purity nitrogen, 60.0g of polyethylene glycol (PEG 6000,0.01 mol) with the molecular weight of 6000 is dried in a vacuum oven at 110 ℃ for 2 hours, then 4.44g of isophorone diisocyanate (0.02 mol) is added and dissolved in a three-neck flask filled with an ultra-dry tetrahydrofuran solvent, and the molar ratio of PEG6000 to diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 2 hours at the temperature of 50 ℃ under the condition of uniform stirring to obtain the-NCO terminated prepolymer. Then adding 1.38g of p-benzoquinone dioxime into 20ml of tetrahydrofuran solvent, stirring and dissolving to obtain an organic solution of p-benzoquinone dioxime, dropwise adding the solution into the-NCO-terminated prepolymer, and controlling the molar ratio of PEG6000 to p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction are carried out for 6 hours at the temperature of 40 ℃ under the protection of high-purity nitrogen.
Adding 1.49g of triethanolamine into 20ml of tetrahydrofuran solvent, stirring and dissolving to obtain a triethanolamine tetrahydrofuran solvent solution, then adding the obtained solution into the solution, and controlling the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine to be 1: after stirring for 10 minutes, a homogeneous dark brown liquid was obtained. And pouring the obtained liquid into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a vacuum oven at 30 ℃ for heating for 2 hours, and then increasing the temperature to 60 ℃ for curing treatment for 2 hours to obtain the super-tough photothermal energy storage polymer material. The super-tough photothermal energy storage polymer material is named as Y1, and the molecular structure of the material is as follows:
the specific reaction equation of the synthesis is shown in figure 1, and the Y1 sample is shown in figure 2. The peak of the chemical structure characteristic of the Y1 sample is tested by Fourier infrared, the curve is shown in figure 3, and the successful synthesis of Y1 can be seen from figure 3. And the crystallization performance of Y1 is tested by X-ray diffraction, and as can be seen from figure 4, Y1 has good crystallization ability. The endothermic heat evolution of Y1 under temperature rising and falling conditions was tested using a Differential Scanning Calorimeter (DSC). The test conditions used in the present invention are: after the thermal history is eliminated by heating at 40K/min in the early stage, cooling and heating are circulated at 10K/min. From FIG. 5, it can be seen that Y1 has endothermic and exothermic peaks, indicating its own heat absorbing and releasing ability of the phase change material. Mechanical property testing was performed on Y, and as can be seen in fig. 6, the elongation at break of the sample reached 900%. Then the temperature change curve of the sample is tested by irradiating the sample through a near infrared lamp and heating the sample through a 70 ℃ heating table, as shown in figures 7 and 8, the sample can be seen to have the capabilities of light absorption, heat storage and photo-thermal conversion.
Example 2
Under the protection of high-purity nitrogen, 40.0g of polyethylene glycol with the molecular weight of 4000 (PEG 4000,0.01 mol) is dried in a vacuum oven at 120 ℃ for 4 hours, then 3.36g of hexamethylene diisocyanate (0.02 mol) is added and dissolved in a three-neck flask filled with an ultra-dry tetrahydrofuran solvent, and the molar ratio of the PEG4000 to the diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 6 hours at the temperature of 60 ℃ under the condition of uniform stirring, and then a prepolymer with-NCO end capping is obtained. Then adding 1.38g of p-benzoquinone dioxime into 50ml of tetrahydrofuran solvent, stirring and dissolving to obtain an organic solution of p-benzoquinone dioxime, dropwise adding the solution into the-NCO-terminated prepolymer, and controlling the molar ratio of PEG4000 to p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction are carried out for 5 hours at the temperature of 50 ℃ under the protection of high-purity nitrogen.
Adding 1.98g of triethanolamine into 30ml of tetrahydrofuran solvent, stirring and dissolving to obtain triethanolamine tetrahydrofuran solvent solution, wherein the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine is controlled to be 1:1.3, then adding the obtained solution into the solution, and stirring for 30 minutes to obtain uniform black brown liquid. Pouring the obtained liquid into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a vacuum oven at 40 ℃ for heating for 2 hours, then increasing the temperature to 70 ℃ for curing for 1 hour to obtain the super-tough photothermal energy storage polymer material, wherein the super-tough photothermal energy storage polymer material is named as Y2, and the molecular structure of the super-tough photothermal energy storage polymer material is as follows:
example 3
Under the protection of high-purity nitrogen, 80.0g of polyethylene glycol with molecular weight of 8000 (PEG 8000,0.01 mol) is dried in a vacuum oven at 100 ℃ for 4 hours, then 3.48g of toluene diisocyanate (0.02 mol) is added and dissolved in a three-neck flask filled with an ultra-dry N, N dimethylformamide solvent, and the molar ratio of the PEG8000 to the diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 4 hours at the temperature of 80 ℃ under the condition of uniform stirring, and then a prepolymer with-NCO end capping is obtained. Then adding 1.38g of p-benzoquinone dioxime into 50mlN, N dimethylformamide solvent, stirring and dissolving to obtain a p-benzoquinone dioxime organic solution, dropwise adding the solution into the-NCO-terminated prepolymer, and controlling the molar ratio of PEG8000 to p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction is carried out for 4 hours at the temperature of 100 ℃ under the protection of high-purity nitrogen.
Adding 2.98g of triethanolamine into 30mlN, N dimethylformamide solvent, stirring and dissolving to obtain triethanolamine solution, wherein the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine is controlled to be 1:2, the resulting solution was then added to the above solution and stirred for 10 minutes to give a uniform dark brown liquid. Pouring the obtained liquid into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a vacuum oven at 50 ℃ for heating for 2 hours, then increasing the temperature to 100 ℃ for curing for 1 hour to obtain the super-tough photothermal energy storage polymer material, wherein the super-tough photothermal energy storage polymer material is named as Y3 and has the following molecular structure:
example 4
Under the protection of high-purity nitrogen, 100.0g of polytetramethylene glycol (PTMG 10000,0.01 mol) with the molecular weight of 10000 is dried in a vacuum oven at 100 ℃ for 12 hours, then 5.00g of diphenylmethane diisocyanate (0.02 mol) is added and dissolved in a three-neck flask filled with super-dry N, N-dimethylacetamide solvent, and the molar ratio of the PTMG10000 to the diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 12 hours at the temperature of 100 ℃ under the condition of uniform stirring to obtain the-NCO terminated prepolymer. Then adding 1.38g of p-benzoquinone dioxime into 50mlN, stirring and dissolving in N-dimethylacetamide solvent to obtain a p-benzoquinone dioxime organic solution, dropwise adding the solution into-NCO end-capped prepolymer, and controlling the molar ratio of PTMG10000 to p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction is carried out for 2 hours at the temperature of 120 ℃ under the protection of high-purity nitrogen.
Adding 2.24g of triethanolamine into 30mlN, N-dimethylacetamide solvent, stirring and dissolving to obtain triethanolamine solution, wherein the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine is controlled to be 1:1.5, then adding the obtained solution into the solution, and stirring for 30 minutes to obtain uniform black brown liquid. Pouring the obtained liquid into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a vacuum oven at 50 ℃ for heating for 4 hours, then increasing the temperature to 120 ℃ for curing treatment for 4 hours to obtain the super-tough photothermal energy storage polymer material, wherein the super-tough photothermal energy storage polymer material is named as Y4 and has the following molecular structure:
example 5
Under the protection of high-purity nitrogen, 100.0g of polytetramethylene glycol and polyethylene glycol (PTMG 10000, PEG1000, the proportion of the two is 1, 0.01mol) with the molecular weight of 10000 are dried in a vacuum oven at 100 ℃ for 12 hours, then 5.25g of dicyclohexylmethane diisocyanate (0.02 mol) are added and dissolved in a three-neck flask filled with ultra-dry dimethyl sulfoxide solvent, and the molar ratio of the PTMG10000 to the diisocyanate is controlled to be 1:2. heating reflux reaction is carried out for 10 hours at the temperature of 100 ℃ under the condition of uniform stirring to obtain the-NCO terminated prepolymer. Then adding 1.38g of p-benzoquinone dioxime into 40ml of tetrahydrofuran, stirring and dissolving to obtain a p-benzoquinone dioxime organic solution, dropwise adding the solution into a-NCO-terminated prepolymer, and controlling the molar ratio of long-chain diol to p-benzoquinone dioxime to be 1:1. heating and reflux stirring reaction is carried out for 2 hours at the temperature of 120 ℃ under the protection of high-purity nitrogen.
Adding 2.53g of triethanolamine into 30ml of tetrahydrofuran solvent, stirring and dissolving to obtain a triethanolamine solution, wherein the molar ratio of the flexible long-chain dihydric alcohol to the triethanolamine is controlled to be 1:1.7, the solution obtained is then added to the above solution and, after stirring for 20 minutes, a uniform dark brown liquid is obtained. Pouring the obtained liquid into a polytetrafluoroethylene mould, placing the polytetrafluoroethylene mould in a vacuum oven at 50 ℃ for heating for 4 hours, then increasing the temperature to 120 ℃ for curing for 4 hours to obtain the super-tough photo-thermal energy storage polymer material, wherein the super-tough photo-thermal energy storage polymer material is named as Y5, and the molecular structure of the super-tough photo-thermal energy storage polymer material is as follows:
according to the invention, photo-thermal functional groups and phase change functional groups are blocked on a molecular chain through covalent bonds, and a three-dimensional network structure is formed through curing and crosslinking of trihydric alcohol, so that the problem of a composite material interface is avoided, the dual functions of photo-thermal energy storage and super toughness are realized, and the performances of the polymer material such as wear resistance, water washing resistance, strain resistance and the like are ensured.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.
Claims (10)
1. A super-tough photo-thermal energy storage three-dimensional network polymer is characterized in that diisocyanate and flexible long-chain dihydric alcohol react to prepare an isocyanate-linked end-capped prepolymer, the prepolymer reacts with a binary oxime-based monomer to prepare a linear oligomer polymer with a photo-thermal conversion function and a phase change group block, and finally the linear oligomer polymer is cured by trifunctional trihydric alcohol to form the three-dimensional network polymer, wherein the molecular structure of the polymer is that
2. A method for preparing the super-tough photothermal energy storage three-dimensional network polymer according to claim 1, wherein: the method comprises the following steps:
s1, under the protection of high-purity nitrogen, carrying out vacuum drying treatment on flexible long-chain dihydric alcohol for 2-12 h, adding diisocyanate, and reacting under the condition of uniform stirring to obtain an-NCO-terminated prepolymer;
s2, adding the p-benzoquinone dioxime into an organic solvent, stirring and dissolving to obtain a p-benzoquinone dioxime organic solution, dropwise adding the p-benzoquinone dioxime organic solution into a-NCO-terminated prepolymer, heating, refluxing and stirring for reaction to obtain a linear oligomer polymer with a photo-thermal conversion function and a phase change group block;
s3, adding triethanolamine into an organic solvent, stirring and dissolving to obtain a triethanolamine organic solution, adding the triethanolamine organic solution into a linear oligomer polymer, and stirring to obtain a uniform dark brown liquid;
and S4, pouring the uniform dark brown liquid into a polytetrafluoroethylene mold, heating the polytetrafluoroethylene mold in a vacuum oven at the temperature of 30-50 ℃ for 2-4 hours, and then heating and curing to obtain the super-tough photo-thermal energy storage three-dimensional network polymer.
3. The preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: the molecular weight of the flexible long-chain dihydric alcohol is 4000-10000, and the flexible long-chain dihydric alcohol is polyethylene glycol (PEG), polytetramethylene glycol (PTMG) or a mixture of the PEG and the PTMG.
4. The preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: in step S1, the reaction under the condition of uniform stirring is specifically: reflux reaction is carried out for 3 to 12 hours at the temperature of between 40 and 100 ℃.
5. The preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: the molar ratio of the flexible long-chain dihydric alcohol to the diisocyanate is 1:2.
6. the preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: the diisocyanate is toluene diisocyanate TDI, isophorone diisocyanate IPDI, diphenylmethane diisocyanate MDI, dicyclohexylmethane diisocyanate HMDI or hexamethylene diisocyanate HDI; the organic solvent is N, N-dimethylformamide, tetrahydrofuran, N-dimethylacetamide or dimethyl sulfoxide.
7. The method for preparing the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: in step S2, the heating and reflux stirring reaction specifically comprises: and refluxing and stirring the mixture for reaction for 2 to 6 hours at the temperature of between 40 and 120 ℃ under the protection of high-purity nitrogen.
8. The method for preparing the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: the molar ratio of the flexible long-chain diol to the p-benzoquinone dioxime is 1:1.
9. the preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: in the step S3, the molar ratio of the added triethanolamine to the flexible long-chain diol is 1-2, and the stirring time is 10-30 min.
10. The preparation method of the super-tough photothermal energy storage three-dimensional network polymer according to claim 2, wherein: in step S4, the reheating curing specifically includes: then the temperature is raised to 60 to 120 ℃ for curing treatment for 2 to 4 hours.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211261942.6A CN115594816A (en) | 2022-10-14 | 2022-10-14 | Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211261942.6A CN115594816A (en) | 2022-10-14 | 2022-10-14 | Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof |
Publications (1)
Publication Number | Publication Date |
---|---|
CN115594816A true CN115594816A (en) | 2023-01-13 |
Family
ID=84846436
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202211261942.6A Pending CN115594816A (en) | 2022-10-14 | 2022-10-14 | Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN115594816A (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108467469A (en) * | 2018-01-24 | 2018-08-31 | 北京服装学院 | A kind of photothermal conversion polyurethane energy storage thin-film material and preparation method thereof and film |
CN109705300A (en) * | 2018-12-24 | 2019-05-03 | 东华大学 | A kind of selfreparing polyurethane and preparation method thereof |
CN112062930A (en) * | 2020-08-24 | 2020-12-11 | 郑州大学 | Transparent, yellowing-resistant, high-toughness and rapid self-repairing polyurethane elastomer |
CN112521574A (en) * | 2020-12-07 | 2021-03-19 | 西安交通大学 | Intrinsic black polyurethane with near-infrared thermal effect and preparation and application thereof |
-
2022
- 2022-10-14 CN CN202211261942.6A patent/CN115594816A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108467469A (en) * | 2018-01-24 | 2018-08-31 | 北京服装学院 | A kind of photothermal conversion polyurethane energy storage thin-film material and preparation method thereof and film |
CN109705300A (en) * | 2018-12-24 | 2019-05-03 | 东华大学 | A kind of selfreparing polyurethane and preparation method thereof |
CN112062930A (en) * | 2020-08-24 | 2020-12-11 | 郑州大学 | Transparent, yellowing-resistant, high-toughness and rapid self-repairing polyurethane elastomer |
CN112521574A (en) * | 2020-12-07 | 2021-03-19 | 西安交通大学 | Intrinsic black polyurethane with near-infrared thermal effect and preparation and application thereof |
Non-Patent Citations (2)
Title |
---|
TIANREN LIU等: ""Catalyst-free, reprocessable, intrinsic photothermal phase change materials networks based on conjugated oxime structure"", 《CHEMICAL ENGINEERING JOURNAL》, 16 July 2022 (2022-07-16), pages 138144 * |
XINGXING CHEN等,: ""NIR-triggered dynamic exchange and intrinsic photothermal-responsive covalent adaptable networks"", 《CHEMICAL ENGINEERING JOURNAL》, 21 July 2021 (2021-07-21), pages 131212 * |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Shi et al. | Tuning the flexibility and thermal storage capacity of solid–solid phase change materials towards wearable applications | |
Yang et al. | Recyclable and self-healing polyurethane composites based on Diels-Alder reaction for efficient solar-to-thermal energy storage | |
Wang et al. | A solid-solid phase change material based on dynamic ion cross-linking with reprocessability at room temperature | |
Fang et al. | Light-and heat-triggered polyurethane based on dihydroxyl anthracene derivatives for self-healing applications | |
Wang et al. | UV-triggered self-healing polyurethane with enhanced stretchability and elasticity | |
Lu et al. | Enhanced thermal conductivity of polyurethane/wood powder composite phase change materials via incorporating low loading of graphene oxide nanosheets for solar thermal energy storage | |
CN110591542A (en) | Disulfide bond and hydrogen bond containing dual self-repairing polyurethane coating for invisible car cover and preparation method thereof | |
CN103524707B (en) | Preparation method of phase-transition temperature adjustable comb-like copolymer solid-solid phase change material | |
CN108503783B (en) | Thermoplastic polyurethane elastomer and preparation method thereof | |
Wu et al. | A robust self-healing polyurethane elastomer enabled by tuning the molecular mobility and phase morphology through disulfide bonds | |
US11091583B2 (en) | Preparation method of shape memory polyurethane | |
CN109679103B (en) | Dynamic thermoreversible and remodelable polysiloxane elastomer material and preparation method thereof | |
Sundararajan et al. | Thermal energy storage using poly (ethylene glycol) incorporated hyperbranched polyurethane as solid–solid phase change material | |
CN108467469A (en) | A kind of photothermal conversion polyurethane energy storage thin-film material and preparation method thereof and film | |
CN107418420A (en) | A kind of hydrophobic polyurethane hybrid coating and preparation method thereof | |
Li et al. | NIR-induced self-healing and recyclable polyurethane composites based on thermally reversible cross-linking for efficient solar-to-thermal energy storage | |
Zhao et al. | Preparation of mechanically robust and thermochromic phase change materials for thermal energy storage and temperature indicator | |
CN111269384B (en) | Photochromic shape memory polymer containing spiropyran and preparation method thereof | |
Xie et al. | Thermally healable polyurethane with tailored mechanical performance using dynamic crosslinking motifs | |
CN106832172A (en) | A kind of light heat response at different level shape-memory polymer and its preparation method and application | |
CN113896854B (en) | Castor oil-based shape memory polymer and preparation method thereof | |
Chen et al. | A comparative study of linear polyurea and crosslinked polyurea as supports to stabilize polyethylene glycol for thermal energy storage | |
CN115594816A (en) | Super-tough photo-thermal energy storage three-dimensional network polymer and preparation method thereof | |
Wu et al. | Recyclable Solid–Solid Phase Change Materials with Superior Latent Heat via Reversible Anhydride‐Alcohol Crosslinking for Efficient Thermal Storage | |
CN113621127A (en) | Preparation method of solvent-free graphene-polyurethane self-repairing material |
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 |