Ultrasonic-assisted front-end metathesis reaction, and reaction product and reaction device thereof

Abstract

The present application provides a method of performing a metathesis reaction, the method comprising: providing a reaction solution comprising at least one olefin substrate and a metathesis catalyst; and initiating the reaction solution to perform a metathesis reaction using ultrasonic waves. The invention also provides a product of the metathesis reaction; and a device for performing the metathesis reaction.

Description

[0001] References to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 617,425, filed on January 4, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates generally to the field of metathesis chemistry and, more particularly, to methods for ring-opening metathesis polymerization for scalable and energy-efficient high-performance polymers and composites. Background Art

[0004] The increasing demand for high-performance polymers and composites for various applications has prompted researchers to investigate innovative curing methods that are both energy-efficient and efficient compared to traditional autoclave or oven curing methods, which require long curing times and expensive equipment. Ideally, the curing method should also be eco-friendly and cost-effective. Frontal ring-opening metathesis polymerization (FROMP) is one such technology, characterized by a self-sustaining chemical reaction initiated by an external stimulus, such as heat, to produce a self-sustaining reaction region known as the "polymerization front." The development of FROMP has the potential to revolutionize the curing of thermosetting polymers such as dicyclopentadiene (DCPD) as it is considered a zero-energy curing method and is very fast, meaning that production rates can be increased by several orders of magnitude. However, it has several limitations, such as lower mechanical properties compared to oven-cured polymers and composites, and scalability issues, as the front may quench due to thermal energy loss after traveling a certain distance, which has hindered its use in industrial applications.

[0005] The main issue hindering the incorporation of FROMP into existing technologies is scalability. Since the polymerization front may be quenched due to heat energy loss after traveling a certain distance, this limits the size of polymers that can be cured using FROMP, making it unsuitable for large-scale production. Moreover, the lower mechanical properties (such as tensile strength and toughness) compared to oven-cured polymers are due to the rapid heating and cooling that occurs during the FROMP process, which can lead to incomplete cross-linking, polymer degradation and defect formation. On the other hand, the exothermic nature of FROMP may raise safety issues, as the high temperatures generated during the reaction may create a risk of thermal runaway or ignition of nearby flammable materials. Reducing the front temperature while maintaining the same front speed may address the safety issues.

[0006] So far, several strategies have been explored to address the above challenges. One potential solution to the challenges of front-end polymerization involves the use of embedded conductive fibers (such as copper or stainless steel wire and carbon fiber) to assist in heat transfer in the reaction medium. These fibers can act as heat pipes to increase heat transfer and reduce reaction time. The use of embedded conductive fibers can also improve the safety of front-end polymerization by reducing the risk of thermal runaway and explosion. However, this approach changes the shape of the front end, and this cannot be used to make pure polymer products. Another strategy to address the challenges of front-end polymerization is multi-point ignition, whereby multiple sites undergo initiation and propagation simultaneously. Multi-point ignition can improve the scalability of front-end polymerization by reducing reaction time and increasing the amount of polymer that can be synthesized. However, the interface between multiple propagation sites may introduce structural defects. When two high-temperature front ends fuse, the temperature peak in the boundary can cause polymer degradation, resulting in defects that affect use.

[0007] Therefore, there is a need for an improved FROMP process that addresses or overcomes at least some of the shortcomings of the prior art to produce polymers and composites having one or more of the following desirable properties: low energy consumption, high tensile strength, high tensile ductility, high toughness, and high production efficiency compared to oven-cured polymers. Summary of the Invention

[0008] While FROMP is typically initiated by heat or light, we propose using ultrasonic mechanical waves to initiate FROMP. We propose that the nature of the input energy may directly influence the FROMP process and the subsequent polymer structure. While heat affects only the point of excitation, the mechanical waves during initiation affect the entire reaction solution, including Grubbs' catalyst and monomers. The key difference between heat and ultrasound as energy lies in their transfer mechanisms and their effects on materials. The energy transfer mechanisms for thermal and ultrasonic FROMP differ. Thermal energy is transferred to the medium via conduction. The heat source raises the temperature of molecules in direct contact with it. These heated molecules then transfer their energy to neighboring molecules, resulting in a gradual temperature increase throughout the front movement and exothermic reaction.

[0009] In contrast, ultrasound waves are mechanical waves that propagate through a medium by causing particle oscillations. When ultrasound waves are applied to one side of the mold body, they create regions of compression and rarefaction in the reaction solution. These oscillations induce mechanical vibrations in the molecules, leading to localized heating and producing acoustic streaming and microfluidic effects. Ultrasonic waves with frequencies between 20 kHz and 1 MHz have shown potential in various synthetic chemistry applications, including polymer degradation and synthesis. Leveraging ultrasonic cavitation, sonochemical initiation offers an energy-efficient and sustainable approach to polymer curing. Sonochemistry has been reported to exhibit numerous effects on chemical reactions, such as increasing reaction rates, reducing reaction times, and improving yields by favoring specific reaction pathways that are inaccessible to conventional heating methods. These findings can be attributed to simultaneous reactions. Therefore, in the method described herein, polymer production is achieved by leveraging the power of ultrasound to initiate the front and exploiting the advantages of ultrasound over focused heating. Consequently, ultrasound and acoustic cavitation provide hotspots capable of initiating FROMP, which propagates at low temperatures and simultaneously produces fully cured polymers with superior tensile properties compared to thermal FROMP and oven-cured samples. Ultrasonic FROMP allows us to tune mechanical properties by varying ultrasound parameters (such as amplitude). The reduction in front-end temperature also contributes to safety, as FROMP releases less heat while still producing high-performance polymer.

[0010] In a first aspect, provided herein is a method for performing a metathesis reaction, the method comprising: providing a reaction solution comprising at least one olefin substrate and a metathesis catalyst; and inducing the reaction solution to perform a metathesis reaction using ultrasound, with the proviso that the metathesis catalyst is not an oxyhalide, halide, oxide, or organic ammonium salt of tungsten, molybdenum, tantalum, ruthenium, or rhenium, a vinylidene, propadienyl, or higher cumulanylene complex containing ruthenium or osmium, (p-methylisopropylphenyl)RuCl(PCy3)(═C═C═CPh2), or a mixture thereof. + 、WCl6 / Me4Sn or

[0011]

[0012] where R 1 It is methoxypoly(butylene oxide)butyl.

[0013] In certain embodiments, the metathesis catalyst is a ruthenium metathesis catalyst, a molybdenum metathesis catalyst, an osmium metathesis catalyst, or a tungsten metathesis catalyst.

[0014] In certain embodiments, the metathesis catalyst has Formula 1:

[0015]

[0016] where L is PR 3 3;

[0017] X 1 is independently in each case an anionic ligand;

[0018] Ar is optionally substituted phenyl;

[0019] R 2 is independently at each occurrence alkyl, cycloalkyl, or aryl; and

[0020] R 3 Each occurrence is independently alkyl, cycloalkyl or aryl.

[0021] In certain embodiments, the CAS number of the metathesis catalyst is selected from the group consisting of the following CAS numbers: CAS No. 250220-36-1, CAS No. 172222-30-9, CAS No. 340810-50-6, CAS No. 1307233-23-3, CAS No. 536724-67-1, CAS No. 254972-49-1, CAS No. 246047-72-3, CAS No. 927429-60-5, CAS No. 373640-75-6, CAS No. 253688-91-4, CAS No. 1190427-50-9, CAS No. 1190427-49-6, CAS No. 1255536-61-8, CAS No. 1031262-76-6, CAS No. 934538-12-2, CAS No. 203714-71-0, CAS No. 1025728-56-6, CAS No. 1212008-99-5, CAS No. 301224-40-8, CAS No. 927429-61-6, CAS No. 635679-24-2, CAS No. 1025728-57-7, CAS No. 1212009-05-6, CAS No. 1383684-54-5, CAS No. 1632041-02-1, and CAS No. 1352916-84-7.

[0022] In certain embodiments, the metathesis catalyst has a CAS number of 246047-72-3.

[0023] In certain embodiments, the at least one olefin substrate comprises a cyclic olefin.

[0024] In certain embodiments, the at least one olefin substrate comprises a cyclic olefin selected from the group consisting of norbornene, dicyclopentadiene, tricyclopentadiene, cyclooctene, cyclooctadiene, cyclobutene, cyclopropene, and oxanorbornene.

[0025] In certain embodiments, the metathesis reaction is carried out at -20°C to -10°C.

[0026] In certain embodiments, the frequency of the ultrasound waves is 20-100 kHz.

[0027] In certain embodiments, the reaction solution further comprises P(OR 5 )3, where R 5 In each case, independently C1-C 12 alkyl.

[0028] In certain embodiments, the reaction solution further comprises nanoparticles selected from the group consisting of metal oxide nanoparticles and carbon-based nanoparticles.

[0029] In a second aspect, provided herein is a method for performing a ring-opening metathesis polymerization reaction, the method comprising: providing a reaction solution comprising at least one olefin substrate, tributyl phosphite, and a metathesis catalyst; and initiating the ring-opening metathesis polymerization reaction in the reaction solution using ultrasound; wherein the metathesis catalyst has a CAS number of 246047-72-3, the at least one olefin substrate comprises a cycloolefin selected from the group consisting of norbornene, dicyclopentadiene, tricyclopentadiene, cyclooctene, cyclooctadiene, cyclobutene, cyclopropene, and oxa-norbornene, and optionally methyl methacrylate, N-hydroxymethyl acrylamide, or methacrylate, and the frequency of the ultrasound is 20-100 kHz.

[0030] In certain embodiments, the at least one olefin substrate comprises dicyclopentadiene.

[0031] In a third aspect, provided herein are polymers prepared according to the methods described herein.

[0032] In certain embodiments, the polymer further comprises metal oxide nanoparticles or carbon-based nanoparticles.

[0033] In certain embodiments, the polymer comprises polydicyclopentadiene, dicyclopentadiene-co-methacrylate, or dicyclopentadiene-co-methyl methacrylate.

[0034] In certain embodiments, the polymer further comprises carbon nanotubes.

[0035] In a fourth aspect, the present invention provides an apparatus for performing the metathesis reaction described herein, the apparatus comprising: a mold body for receiving a reaction solution; a first ultrasonic probe; and a cover plate arranged on the mold body to form a reaction surface for the reaction solution to undergo a metathesis reaction, wherein the mold body is provided with a first opening for receiving the first ultrasonic probe.

[0036] In some embodiments, the device further comprises a second ultrasonic probe, and the mold body is provided with a second opening for receiving the second ultrasonic probe, wherein the first ultrasonic probe and the second ultrasonic probe are arranged at opposite ends of the mold body.

[0037] In certain embodiments, the mold body comprises polytetrafluoroethylene.

[0038] In certain embodiments, the apparatus further comprises one or more thermocouples for measuring the temperature of the reaction solution.

[0039] This paper presents a method and system for rapid, energy-efficient polymerization at low temperatures, suitable for harsh environments where in-situ curing strategies are required to produce high-performance polymers. Combining the freezing effect of the reaction solution with ultrasound enables the production of uniform polymers via multi-point ignition, a cutting-edge approach to address the scalability challenges of FROMP. Overall, the potential for mass production of thermoset polymers could overcome long-standing and pressing production challenges.

[0040] In another aspect, this article provides a high-production capacity system for producing polydicyclopentadiene (pDCPD) polymers with adjustable tensile strength, ductility, and toughness by optimizing ultrasonic parameters. The mechanical, thermomechanical, and thermal properties were systematically studied, and the effectiveness of the method described herein for producing pDCPD polymers through a three-dimensional spherical front end was demonstrated. In addition, the versatility of this method was revealed by performing FROMP at a temperature of -20°C to obtain a tough and ductile polymer, and it was also able to address scalability and safety issues. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The foregoing aspects of the present invention and many of its attendant advantages will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

[0042] Figure 1 Figure a shows an exemplary ultrasonic FROMP system; Figure b shows the ultrasonic front propagation of a 10 cm×10 cm rectangular plate.

[0043] Figure 2 The variation of tensile strength and ductility with changes in ultrasonic acoustic power is shown.

[0044] Figure 3 The bar graph shows the comparison of energy consumption, cure time and CO2 emissions between ultrasonic FROMP, thermal FROMP and conventional oven cured samples.

[0045] Figure 4 The bar graph shows the improved tensile strength and toughness values for ultrasonic FROMP compared with thermal FROMP and conventional oven cured samples.

[0046] Figure 5 The photograph shows the real-time monitoring of the polymerization front using a two-dimensional infrared thermography camera during the curing process of the low-temperature-FROMP method.

[0047] Figure 6 The bar graph shows the improved toughness, ductility, and tensile strength of the low-temperature-FROMP samples compared to the conventional oven-cured samples.

[0048] Figure 7 Shown are photographs taken by a two-dimensional infrared camera, which show two front ends approaching each other during two-point initiation using ultrasonic cryo-FROMP.

[0049] Figure 8 The photograph shows the carbon nanotube polydicyclopentadiene (CNT-pDCPD) composite produced using the ultrasonic FROMP method.

[0050] Figure 9 A schematic diagram of an exemplary apparatus for remote ultrasonic FROMP is shown, which includes an ultrasonic probe, a reaction solution, water, and cavitation bubbles.

[0051] Figure 10 The photograph shows the three-dimensional front propagation of long-range ultrasound from the reaction solution.

[0052] Figure 11 The graph shows the temperature profile during remote ultrasonic FROMP.

[0053] Figure 12 Figure a shows an exemplary apparatus (100) for performing the metathesis reaction described herein, comprising a mold body (101) for receiving a reaction solution (107), a first ultrasonic probe (102), and a cover plate (103) arranged on the mold body (101), wherein the mold body is provided with a first opening (106) for receiving the first ultrasonic probe (102); b shows a schematic diagram of sound waves and bubble implosion caused by negative pressure caused by ultrasonic radiation passing through a liquid reaction solution; c shows U-FROMP front propagation of a 100 mm × 100 mm rectangular plate.

[0054] Figure 13 Shown is a side view of an exemplary apparatus for FROMP of CFRP composites using the new VARI design strategy.

[0055] Figure 14 Shown is the dynamic DSC of the DCPD reaction solution after sonication for several seconds with different ultrasonic intensities. The polymerization is highly exothermic due to the high ring strain stored in the norbornene moiety of DCPD.

[0056] Figure 15 Figure 3. Energy efficiency of U-FROMP and its potential for NMR studies and scalability. a. Comparison of energy consumption versus cure time for various sonication powers, thermal-FROMP, and conventional oven curing. b. For a mixture of G2 catalyst and tributyl phosphite (TBP) inhibitor, free PCy3 species and new ruthenium species are observable in 31P NMR after sonication at optimized power for a few seconds. c. Extension of U-FROMP via two-site initiation, showing the energy consumption of 1-10 J·cm -3 Energy and 0.02-0.04 min·cm -3 The curing time of 1000 nm was 200 nm, and the size of the sample was 70–100 cm × 5–10 cm. This near-zero energy consumption and reliable mechanical properties demonstrate the scalability potential of the U-FROMP method.

[0057] Figure 16 Characterization of p-COD is shown, where a: p-COD measured in CDCl3 at 400 MHz 1 H NMR spectrum. Key peaks include those corresponding to A 顺式 δ5.3 and attributed to A 反式 δ 5.5. b: The first heating cycle of the DSC run for p-COD reveals the endothermic peak associated with the crystalline domains of the US-extended sonicated sample. c: GPC analysis of p-COD performed in dimethylformamide (DMF) as the eluent. The chromatogram shows the molecular weight distribution of p-COD, indicating key parameters including the number average molecular weight (M n ), weight average molecular weight (M w ) and polydispersity index (PDI=M w / M n ). Calibration was performed using polystyrene standards to correlate elution volume with molecular weight.

[0058] Figure 17 A comparison of the tensile properties of p-DCPD polyolefins cured by remote U-FROMP using water or air medium versus cure time is shown, indicating that remote water (RW) and remote air (RA) have comparable mechanical properties to oven-cured samples while saving time, which represents a huge improvement in production efficiency.

[0059] Figure 18The energy efficiency and mechanical properties of CFRP produced by the U-FROMP method are shown. a: Image captured by an infrared camera during reaction wave propagation; b: Actual photograph of front-end propagation; c: Comparison of energy consumption and curing time between direct U-FROMP and conventional curing methods, demonstrating significant energy and production time savings. d and e show the tensile and flexural properties of CFRP produced by the U-FROMP method compared to conventional oven curing, demonstrating improved mechanical properties of CFRP produced by the U-FROMP method compared to oven curing. This suggests that the present invention can save energy and time while producing CFRP with better mechanical properties.

[0060] Figure 19 Figures a and b show photographs of copolymers with different amounts of methacrylate produced by remote U-FROMP and thermal FROMP, showing the uniform structure of the copolymer formed by U-FROMP, while the copolymer formed by thermal FROMP exhibits a large number of patterns caused by the instability of the polymerization front, and for a high proportion of MMA, severe phase separation occurs; c and d show SEM micrographs of olefin-methacrylate copolymers, showing obvious structural differences, and the structure of U-FROMP is more uniform.

[0061] Figure 20 Figure a shows an infrared captured image of the propagation of reaction waves at low temperatures triggered by ultrasound; b shows the 2-point initiation of cryogenic-FROMP; c shows an infrared camera captured image; d shows the improved ductility of the 2-point initiation using cryogenic-FROMP, which paves the way for better scalability because the joint at the converging front will not become a poor quality part due to temperature fluctuations.

[0062] Figure 21 The cure rates of direct U-FROMP, remote U-FROMP, and oven-cured CFRP are shown. DETAILED DESCRIPTION

[0063] definition

[0064] The following terms will be used to describe the present invention. Unless specifically defined herein, the terms used to describe the present invention should be given the ordinary meanings understood by those of ordinary skill in the art.

[0065] In this application, when a composition is described as having, containing, or comprising specific components, or when a process is described as having, containing, or comprising specific process steps, it should be understood that the composition of the present application may also essentially consist of or consist of the described components, and the process of the present application may also essentially consist of or consist of the described process steps.

[0066] The following terms will be used to describe the present invention. Unless specifically defined herein, the terms used to describe the present invention should be given the ordinary meanings understood by those of ordinary skill in the art.

[0067] In the present disclosure, unless the context requires otherwise, the word "comprise" or its grammatical variations should be understood to mean the inclusion of the stated integers or groups of integers, but not the exclusion of any other integers or groups of integers. It should also be noted that in the present disclosure, especially in the claims and / or paragraphs, terms such as "comprise" may have the meanings assigned to them by Chinese Patent Law; for example, they may mean "including" and the like; and terms such as "essentially consisting of..." have the meanings assigned to them by Chinese Patent Law, for example, they allow elements not explicitly listed, but exclude elements found in the prior art or that affect the basic or novel characteristics of the invention.

[0068] Furthermore, in this specification and claims, unless the context requires otherwise, the word "comprise" or "comprising" or its grammatical variations will be understood to imply the inclusion of a stated integer or groups of integers but not the exclusion of any other integer or groups of integers.

[0069] The order of steps or the order in which certain actions are performed is not important, as long as the application is operable. In addition, two or more steps or actions can be performed simultaneously.

[0070] Unless expressly stated otherwise, the use of the singular in this application includes the plural (and vice versa). Furthermore, unless expressly stated otherwise, when the term "about" is used before a quantitative value, this application also includes the specific quantitative value itself. Unless otherwise indicated or inferred, the term "about" as used herein refers to a difference of ±10%, ±7%, ±5%, ±3%, ±1%, or ±0% from the nominal value.

[0071] As used herein, the term "alkyl" refers to a straight or branched saturated hydrocarbon group. Examples of alkyl groups include methyl, ethyl, propyl (e.g., n-propyl and isopropyl), butyl (e.g., n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (e.g., 1-methylbutyl, 2-methylbutyl, isopentyl, tert-pentyl, 1,2-dimethylpropyl, neopentyl, and 1-ethylpropyl), hexyl, and the like. In various embodiments, the alkyl group may have 1 to 40 carbon atoms (i.e., C1-C 40 Alkyl), for example, 1 to 30 carbon atoms (i.e., C1-C 30In some embodiments, an alkyl group may have 1 to 6 carbon atoms and may be referred to as a "lower alkyl group". Examples of lower alkyl groups include methyl, ethyl, propyl (e.g., n-propyl and isopropyl), and butyl (e.g., n-butyl, isobutyl, sec-butyl, tert-butyl). In some embodiments, an alkyl group may be optionally substituted, as described herein. Typically, an alkyl group is not substituted by another alkyl group, alkenyl group, or alkynyl group.

[0072] Unless otherwise indicated, the term "cycloalkyl" as used herein, by itself or as part of another substituent, refers to a monocyclic hydrocarbon having 3 to 12 carbon atoms in the ring system, including hydrogen, straight chain, branched chain and / or cyclic substituents. Exemplary cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.

[0073] As used herein, the term "aryl" refers to an aromatic monocyclic hydrocarbon ring system or a polycyclic hydrocarbon ring system in which two or more aromatic hydrocarbon rings are fused together (i.e., have a common bond) or at least one aromatic monocyclic hydrocarbon ring is fused to one or more cycloalkyl and / or cycloheteroalkyl rings. Aryl groups can have from 6 to 24 carbon atoms (e.g., C6-C8) in their ring system. 24 In some embodiments, the polycyclic aryl group may have 8 to 24 carbon atoms. Any suitable ring position of the aryl group may be covalently linked to a specific chemical structure. Examples of aryl groups having only aromatic carbocyclic rings include phenyl, 1-naphthyl (bicyclic), 2-naphthyl (bicyclic), anthracenyl (tricyclic), phenanthrenyl (tricyclic), condensed pentaphenyl (pentacyclic) and other groups. Examples of polycyclic ring systems in which at least one aromatic carbocyclic ring is fused to one or more cycloalkyl and / or cycloheteroalkyl rings include benzo derivatives of cyclopentane (i.e., indanyl, which is a 5,6-bicyclic cycloalkyl / aromatic ring system), benzo derivatives of cyclohexane (i.e., tetrahydronaphthyl, which is a 6,6-bicyclic cycloalkyl / aromatic ring system), benzo derivatives of imidazoline (i.e., benzimidazolinyl, which is a 5,6-bicyclic cycloheteroalkyl / aromatic ring system), and benzo derivatives of pyran (i.e., chromenyl, which is a 6,6-bicyclic heterocycloalkyl / aromatic ring system). Other examples of aryl groups include benzodioxanyl, benzodioxolyl, chromanyl, indolinyl, and the like. In certain embodiments, aryl groups may be optionally substituted. In certain embodiments, aryl groups may have one or more halogen substituents and may be referred to as "haloaryl" groups. Perhaloaryl groups (i.e., aryl groups in which all hydrogen atoms are replaced by halogen atoms, such as -C6F5) are included in the definition of "haloaryl". In certain embodiments, one aryl group is substituted by another aryl group and can be referred to as a biaryl group. Each aryl group in the biaryl group can be optionally substituted.

[0074] As used herein, term " cycloolefin " refers to the compound comprising one, two, three or more non-aromatic rings (condensed rings and / or non-condensed rings), and the non-aromatic ring comprises at least one pair of adjacent carbon atoms mutually bound by unsaturated bonds in the ring.Ring can be optionally substituted or unsubstituted, and cycloolefin can optionally include one unsaturated bond (" monounsaturated "), two unsaturated bonds (" diunsaturated "), three unsaturated bonds (" triunsaturated "), or more than three unsaturated bonds.In some embodiments, cycloolefin is optionally substituted.

[0075] The term "optionally substituted" means that one or more hydrogen atoms in a chemical group (e.g., a cycloalkene) may be replaced with a substituent as described herein (e.g., a halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxy, alkoxy, amino, nitro, thiol, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, sulfonamido, ketone, aldehyde, ester, heterocyclic, aromatic or heteroaromatic moiety, -CF3 or -CN, etc.).

[0076] The present application provides a method for performing a metathesis reaction, the method comprising: providing a reaction solution comprising at least one olefin substrate and a metathesis catalyst; and initiating the metathesis reaction in the reaction solution using ultrasound. The metathesis reaction can be a cross metathesis reaction, a ring-closing metathesis reaction, a ring-opening metathesis reaction, or a ring-opening polymerization reaction.

[0077] In certain embodiments, the metathesis catalyst is not an oxyhalide, halide, oxide or organic ammonium salt of tungsten, molybdenum, tantalum, ruthenium or rhenium, a vinylidene, propadienylene or higher cumulative olefine complex containing ruthenium or osmium (p-methylisopropylphenyl)RuCl(PCy3)(=C=C=CPh2) + , WCl6 / Me4Sn or

[0078]

[0079] where R 1 It is methoxypoly(butylene oxide)butyl.

[0080] In certain embodiments, the metathesis catalyst is not a vinylene, propadienylene, or higher order cumene complex of the formula:

[0081]

[0082] wherein M is ruthenium or osmium;

[0083] X is an anionic ligand;

[0084] L 2Selected from the group consisting of phosphines, sulfonated phosphines, fluorinated phosphines, functionalized phosphines with up to three aminoalkyl, ammoniumalkyl, alkoxyalkyl, alkoxycarbonylalkyl, hydroxycarbonylalkyl, hydroxyalkyl, ketoalkyl groups, phosphites, phosphinates, arsine and antimony;

[0085] L 1 It is a neutral π-bond ligand;

[0086] A and B are independently selected from hydrogen or C1-C 20 Alkyl, aryl, C2-C 20 Alkenyl, alkynyl, C1-C 20 Alkoxy, carboxylate, carbamate, C2-C 20 Alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, C1-C 20 The group consisting of alkylthio, alkylsulfonyl, alkylsulfinyl, arylthio, arylsulfonyl, arylsulfinyl, alkylamide, and alkylamino, each of which is optionally substituted by C1-C 10 Alkyl, perfluoroalkyl, aryl, alkoxy or halogen substituted;

[0087] Y - is a non-coordinating anion; and

[0088] n is 0-5.

[0089] There are no particular limitations on the metathesis catalyst, and the present disclosure contemplates the use of all known metathesis catalysts. In certain embodiments, the metathesis catalyst is a ruthenium metathesis catalyst, a molybdenum metathesis catalyst, an osmium metathesis catalyst, or a tungsten metathesis catalyst.

[0090] Metathesis catalysts are disclosed in PCT / US95 / 09655, PCT / US96 / 12654, PCT / US02 / 12165, and US Patent No. 6,211,391, which are incorporated herein by reference in their entirety.

[0091] In certain embodiments, the metathesis catalyst has Formula 1:

[0092]

[0093] where L is PR 3 3;

[0094] X 1 is independently in each case an anionic ligand;

[0095] Ar is phenyl, optionally substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl, heterocycloalkyl, heteroaryl, halide, nitro, cyano, ether, aldehyde, ketone, ester, carboxyl, amine, amide, acylamide, sulfone, and sulfonamide;

[0096] R 2 is independently at each occurrence alkyl, cycloalkyl, or aryl; and

[0097] R 3 Each occurrence is independently alkyl, cycloalkyl or aryl.

[0098] In certain embodiments, X 1 is independently in each case a chloride, a bromide, a C1-C6 carboxylate, a C1-C6 alkoxide, a benzoate or a C1-C6 alkylsulfonate.

[0099] In certain embodiments of the metathesis catalyst of Formula 1, X 1 is chloride, Ar is phenyl; R 2 is optionally substituted phenyl; and R 3 In certain embodiments, X1 is chloride, Ar is phenyl; R 2 is 2-methyl-phenyl, 2,4,6-trimethyl-phenyl or 2,6-diisopropyl-phenyl; and R 3 is isopropyl or cyclohexyl.

[0100] Exemplary metathesis catalysts include, but are not limited to, CAS No. 250220-36-1 (Grubbs M101), CAS No. 172222-30-9 Grubbs M102), CAS number 340810-50-6 (Grubbs M200), CAS No. 1307233-23-3 (Grubbs M201), CAS No. 536724-67-1 (Grubbs M202), CAS No. 254972-49-1 (Grubbs M203), CAS No. 246047-72-3 (Grubbs M204), CAS No. 927429-60-5 (Grubbs M205), CAS number 373640-75-6 (Grubbs M206), CAS No. 253688-91-4 (Grubbs M207), CAS No. 1190427-50-9 (Grubbs M208), CAS number 1190427-49-6 (Grubbs M209), CAS No. 1255536-61-8 (Grubbs M220), CAS No. 1031262-76-6 (Grubbs M310), CAS No. 934538-12-2 (Grubbs M350), CAS number 203714-71-0 (Hoveyda Grubbs M700), CAS number 1025728-56-6 (Hoveyda Grubbs M710), CAS number 1212008-99-5 (Hoveyda Grubbs M711), CAS number 301224-40-8 (Hoveyda Grubbs M720), CAS number 927429-61-6 (Hoveyda Grubbs M721), CAS number 635679-24-2 (Hoveyda Grubbs M722), CAS number 1025728-57-7 (Hoveyda Grubbs M730), CAS number 1212009-05-6 (HoveydaGrubbs M731), CAS No. 1383684-54-5 (Grubbs M800), CAS number 1632041-02-1 (Hoveyda Grubbs M1001) and CAS No. 1352916-84-7 (Hoveyda Grubbs M2001).

[0101] In certain embodiments, at least one olefin substrate is a cyclic olefin, an acyclic olefin, or a mixture thereof. In certain embodiments, at least one olefin substrate comprises one or more functional groups selected from the group consisting of alkyl, aralkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, perhaloalkyl, nitro, nitrile, halide (e.g., fluorine, chlorine, bromine, or iodine), hydroxyl, ether, thioether, tertiary amine, aldehyde, ketone, ester, amide, carbonate, phosphite, phosphonate, phosphate, carbamate, urea, and sulfonamide.

[0102] In certain embodiments, the cycloolefin comprises 3 to 24 carbon atoms. In certain embodiments, the cycloolefin comprises one or more (e.g., 1, 2, 3, 4, or 5) heteroatoms selected from the group consisting of oxygen, nitrogen, sulfur, and phosphorus in the ring system. The cycloolefin can be a strained cycloolefin or an unstrained cycloolefin.

[0103] In certain embodiments, the cyclic olefin has Formula 2:

[0104]

[0105] Each R 4 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, halogen, ester, ketone, and amido; and

[0106] A is a saturated or unsaturated optionally substituted hydrocarbon, wherein the hydrocarbon optionally contains one or more heteroatoms selected from the group consisting of oxygen, nitrogen, sulfur and phosphorus between its carbon atoms, and two or more substituents attached to the hydrocarbon are optionally linked to form a bicyclic olefin or a polycyclic olefin.

[0107] Examples of cycloolefins include, but are not limited to, cyclobutene, cyclopropene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclononene, cyclodecene, cycloundecene, cyclododecene, tricyclodecene, tetracyclodecene, octacyclodecene, and cycloeicosene, and substituted forms thereof, such as methylcyclopentene (e.g., 1-methylcyclopentene, 4-methylcyclopentene), ethylcyclopentene (e.g., 1-ethylcyclopentene), isopropylcyclohexene (e.g., 1-isopropylcyclohexene), chlorocyclopentene (e.g., 1-chlorocyclopentene), fluorocyclopentene (e.g., 1-fluorocyclopentene), methoxycyclopentene (e.g., 4-methoxycyclopentene), ethoxycyclopentene (e.g., 4-ethoxycyclopentene), cyclopentene, ... Pentenethiols (e.g., cyclopentene-3-thiol), methylthiolcyclopentenes (e.g., 4-methylthiol-cyclopentene), methylcyclohexenes (e.g., 3-methylcyclohexene), methylcyclooctenes (e.g., 1-methylcyclooctene), dimethylcyclooctenes (e.g., 1,5-dimethylcyclooctene), 1,3-cyclopentadiene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, heptadienes (e.g., 1,3-cycloheptadiene), octadiene (e.g., 1,5-cyclooctadiene, 1,3-cyclooctadiene), norbornenes (e.g., bicyclo[2.2.1]hept-2-ene) and substituted forms thereof, norbornadiene (bicyclo[2.2.1]hept-2,5-diene) and substituted forms thereof forms, polycyclic norbornenes and substituted forms thereof, bicyclic and polycyclic olefins (e.g., dicyclopentadiene (DCPD)); trimers and higher oligomers of cyclopentadiene (e.g., cyclopentadiene tetramer, cyclopentadiene pentamer); ethylidene norbornene; dicyclohexadiene; norbornene; 5-methyl-2-norbornene; 5-ethyl-2-norbornene; 5-isobutyl-2-norbornene; 5,6-dimethyl-2-norbornene; 5-phenyl norbornene; 5-benzyl norbornene; 5-acetyl norbornene; 5-methoxycarbonyl norbornene; 5-ethoxycarbonyl-1-norbornene; 5-methyl-5-methoxy-carbonyl norbornene; 5 -cyano norbornene; 5,5,6-trimethyl-2-norbornene; cyclohexenyl norbornene; endo,exo-5,6-dimethoxynorbornene; endo,exo-5,6-dimethoxycarbonyl norbornene; endo,endo-5,6-dimethoxycarbonyl norbornene; 2,3-dimethoxynorbornene; norbornadiene; tricyclodecene; tetracyclododecene; 8-methyltetracyclododecene; 8-ethyltetracyclododecene; 8-methoxycarbonyltetracyclododecene; 8-methyl-8-tetracyclododecene; 8-cyanotetracyclododecene; pentacyclopentadecene; pentacyclohexadecene, etc.; and oxa-norbornene.

[0108] In cases where the one or more olefin substrates comprise cyclic olefins, when the reaction solution is irradiated with ultrasonic waves sufficient to trigger FROMP at one or more initiation sites in the reaction solution, the ultrasonic waves are selectively interrupted, allowing FROMP to propagate through the reaction solution starting from the one or more initiation sites, thereby forming a metathesis product.

[0109] There are no particular limitations on the acyclic olefins that can be used in conjunction with the methods described herein, and any acyclic olefin can be used. In certain embodiments, the acyclic olefin is an acrylate, a methacrylate, an alkyl acrylate, an alkyl methacrylate, an olefin, a styrene, a diene, a vinyl halide, a vinyl nitrile, a vinyl ester, or a vinyl amide. In the case where the reaction solution further comprises a non-cyclic olefin, the non-cyclic olefin may be present in an amount of 0.5-60 wt%, 2.5-60 wt%, 5-60 wt%, 7.5-60 wt%, 10-60 wt%, 15-60 wt%, 20-60 wt%, 25-60 wt%, 30-60 wt%, 40-60 wt%, 50-60 wt%, 0.5-50 wt%, 0.5-40 wt%, 0.5-30 wt%, 0.5-25 wt%, 0.5-20 wt%, 0.5-15 wt%, 0.5-10 wt%, 0.5-7.5 wt%, 0.5-5 wt%, 0.5-2.5 wt%, 20-50 wt% or 30-40 wt%, relative to the total weight of the non-cyclic olefin and the cyclic olefin.

[0110] In certain embodiments, the at least one olefin substrate comprises a cyclic olefin, and optionally comprises an acyclic olefin. In certain embodiments, the at least one olefin substrate comprises DCPD, 5-ethylidene-2-norbornene, or 1,5-cyclooctadiene, and optionally comprises an acrylate, methacrylate, methacrylate, N-hydroxymethyl acrylamide, or methyl methacrylate.

[0111] In certain embodiments, the reaction solution further comprises a compound selected from P(OR 5 )3 inhibitor, used to extend the activation life of the metathesis reaction, wherein R 5 In each case, independently C1-C 12 Alkyl phosphites, C1-C9 alkyl phosphites, C1-C6 alkyl phosphites, C3-C6 alkyl phosphites, triphenyl phosphites, 4-dimethylaminopyridine (DMAP), triphenylphosphine, tricyclohexylphosphine and limonene. Exemplary trialkyl phosphites include, but are not limited to, trimethyl phosphite, triethyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, tri-sec-butyl phosphite, triisobutyl phosphite, tri-tert-butyl phosphite, tri-n-pentyl phosphite and trihexyl phosphite.

[0112] The inhibitor may be present in the reaction solution in an amount of 10-200 mol%, 50-200 mol%, 100-200 mol%, 150-200 mol%, 50-150 mol%, or 50-100 mol% relative to the metathesis catalyst.

[0113] The reaction solution may also contain nanoparticles selected from the group consisting of metal oxide nanoparticles, carbon-based nanoparticles, and metal foam nanoparticles. The metal oxide nanoparticles may be oxides of Groups 3-15 of the periodic table. Exemplary metal oxide nanoparticles include, but are not limited to, oxides of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The carbon-based nanoparticles may be graphite nanoparticles, graphene nanoparticles, graphene oxide nanoparticles, reduced graphene oxide nanoparticles, carbon nanotube nanoparticles, carbon black nanoparticles, carbon nanofiber nanoparticles, and combinations thereof. The metal foam nanoparticles may include one or more of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The metal foam nanoparticles may have irregular pores or regular pores.

[0114] The reaction solution may comprise any inert solvent in which the metathesis catalyst and the at least one olefin substrate are at least partially soluble. Suitable solvents include, but are not limited to, aromatic solvents, aliphatic solvents, halogenated alkanes, esters, ethers, alcohols, water, and combinations thereof. Exemplary solvents that can be used in the methods described herein include toluene, xylene, mesitylene, chlorobenzene, phenylcyclohexane, heptane, hexane, dichloromethane, dichloroethane, ethyl acetate, isopropyl acetate, tert-butyl methyl ether, 2-methyltetrahydrofuran, methanol, ethanol, butanol, tetrahydrofuran, diethyl ether, or mixtures thereof.

[0115] The metathesis catalyst can be present in the reaction solution in an amount of 0.001-10 mol%, 0.001-5 mol%, 0.001-4 mol%, 0.001-3 mol%, 0.001-2 mol%, 0.001-1 mol%, 0.01-1 mol%, 0.01-0.9 mol%, 0.01-0.8 mol%, 0.01-0.7 mol%, 0.01-0.6 mol%, 0.01-0.5 mol%, 0.01-0.4 mol%, 0.01-0.3 mol%, 0.01-0.2 mol%, or 0.01-0.1 mol%, relative to the at least one olefin substrate.

[0116] Irradiating the reaction solution can initiate the metathesis reaction, accelerate the propagation of the metathesis reaction, or a combination thereof.

[0117] Ultrasonic waves can be applied directly to the reaction solution, for example, by directly contacting the reaction solution with an ultrasonic probe; or they can be applied indirectly to the reaction solution, for example, by subjecting a reaction vessel (e.g., a mold body) to ultrasonic waves. Ultrasonic waves can also be transmitted through a medium, such as a solvent (e.g., water or oil) or air.

[0118] The frequency of the ultrasonic wave can be 10-100kHz, 10-90kHz, 10-80kHz, 10-70kHz, 10-60kHz, 10-50kHz, 10-40kHz, 10-30kHz, 10-20kHz, 15-25kHz or 20-40kHz. The power of the ultrasonic wave can be 6.6-750W, 10-750W, 25-750W, 50-750W, 100-750W, 100-700W, 100-650W, 100-600W, 100-550W, 100-500W, 100-400W, 100-300W, 100-250W, 150-250W, 100-200W or 150-200W.

[0119] like Figure 17 As shown, the duration of ultrasonic irradiation can be used to increase the trans / cis ratio of the olefins present in the metathesis product. Thus, the methods described herein can produce metathesis products having more than 50%, more than 60%, more than 70%, more than 80%, or more than 90% trans isomers. In certain embodiments, the methods described herein produce metathesis products having 50-90%, 60-90%, 70-90%, 80-90%, 50-80%, 50-70%, 50-60%, 60-80%, 60-70%, or 70-80% trans isomers. In certain embodiments, the methods described herein provide metathesis products having a higher trans isomer ratio than methods performed under thermal initiation conditions and in the absence of ultrasonic irradiation.

[0120] Advantageously, the metathesis reaction can be initiated at a reduced temperature. In certain embodiments, the metathesis reaction is initiated at -50°C to 50°C, -40°C to 50°C, -30°C to 50°C, -20°C to 50°C, -20°C to 40°C, -20°C to 30°C, -20°C to 20°C, -20°C to 10°C, -20°C to 0°C, -20°C to -10°C, -20°C to -15°C, -50°C to -10°C, -40°C to -10°C or -30°C to -10°C with ultrasound.

[0121] Provided herein is a method for front-end polymerization in a low-temperature environment (e.g., at -20°C). The method can include placing the reaction solution in a refrigerator, freezing it, and then initiating ultrasound-induced FROMP by inserting an ultrasound probe into the frozen reaction solution. The front starts and propagates at a low temperature of approximately 70-120°C while maintaining an acceptable speed. The resulting polymer exhibits enhanced mechanical properties, especially ductility and toughness, that exceed those of oven-cured pDCPD. This method enables the manufacture of high-performance polymers in harsh environmental conditions (e.g., open areas with temperatures as low as -20°C) without the need for expensive oven curing. Although the ability to cure polymers at such temperatures is unconventional, our findings demonstrate the feasibility and advantages of this method.

[0122] Also provided herein are polymers prepared according to the methods described herein.

[0123] The polymer can be prepared from one or more of at least one olefin substrate described herein. In certain embodiments, the polymer comprises polydicyclopentadiene, dicyclopentadiene-methacrylate copolymer, dicyclopentadiene-methyl methacrylate copolymer, dicyclopentadiene-N-hydroxymethyl acrylamide copolymer, polynorbornene, norbornene-methacrylate copolymer, norbornene-methyl methacrylate copolymer, norbornene-N-hydroxymethyl acrylamide copolymer, polytricyclopentadiene, tricyclopentadiene-methacrylate copolymer, tricyclopentadiene-methyl methacrylate copolymer, tricyclopentadiene-N-hydroxymethyl acrylamide copolymer, polycyclooctene, cyclooctene-methacrylate copolymer, cyclooctene-methyl methacrylate copolymer, cyclooctene-N-hydroxymethyl acrylamide copolymer, Methacrylamide copolymer, polycyclooctadiene, cyclooctadiene-methacrylate copolymer, cyclooctadiene-methyl methacrylate copolymer, cyclooctadiene-N-hydroxymethyl acrylamide copolymer, polycyclobutene, cyclobutene-methacrylate copolymer, cyclobutene-methyl methacrylate copolymer, cyclobutene-N-hydroxymethyl acrylamide copolymer, polycyclopropylene, cyclopropylene-methacrylate copolymer, cyclopropylene-methyl methacrylate copolymer, cyclopropylene-N-hydroxymethyl acrylamide copolymer, polyoxanorbornene, oxanorbornene-methacrylate copolymer, oxanorbornene-methyl methacrylate copolymer or oxanorbornene-N-hydroxymethyl acrylamide copolymer.

[0124] In cases where the polymer is prepared from cyclic olefins and non-cyclic olefins, the non-cyclic olefin may be present in the polymer in an amount of 0.5-60 wt%, 2.5-60 wt%, 5-60 wt%, 7.5-60 wt%, 10-60 wt%, 15-60 wt%, 20-60 wt%, 25-60 wt%, 30-60 wt%, 40-60 wt%, 50-60 wt%, 0.5-50 wt%, 0.5-40 wt%, 0.5-30 wt%, 0.5-25 wt%, 0.5-20 wt%, 0.5-15 wt%, 0.5-10 wt%, 0.5-7.5 wt%, 0.5-5 wt%, 0.5-2.5 wt%, 20-50 wt% or 30-40 wt% relative to the total weight of the non-cyclic olefin and cyclic olefin in the polymer.

[0125] In certain embodiments, the polymer further comprises one or more types of nanoparticles selected from the group consisting of metal oxide nanoparticles and carbon-based nanoparticles. The metal oxide nanoparticles may be oxides of Groups 3-15 of the periodic table. Exemplary metal oxide nanoparticles include, but are not limited to, oxides of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The carbon-based nanoparticles may be graphite nanoparticles, graphene nanoparticles, graphene oxide nanoparticles, reduced graphene oxide nanoparticles, carbon nanotube nanoparticles, carbon black nanoparticles, carbon nanofiber nanoparticles, and combinations thereof. The metal foam nanoparticles may comprise one or more of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The metal mesh may have irregular pores or regular pores.

[0126] The present disclosure also provides a composite material comprising a polymer prepared according to the methods described herein and one or more nanoparticles and / or one or more fabrics. The nanoparticles can be selected from the group consisting of metal oxide nanoparticles, carbon-based nanoparticles, and metal foam nanoparticles. The metal oxide nanoparticles can be oxides of Groups 3-15 of the periodic table. Exemplary metal oxide nanoparticles include, but are not limited to, oxides of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The carbon-based nanoparticles can be graphite nanoparticles, graphene nanoparticles, graphene oxide nanoparticles, reduced graphene oxide nanoparticles, carbon nanotube nanoparticles, carbon black nanoparticles, carbon nanofiber nanoparticles, and combinations thereof. The metal foam nanoparticles may include one or more of titanium, zirconium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, iridium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, and bismuth. The metal foam nanoparticles may have irregular pores or regular pores.

[0127] The one or more fabrics can include carbon fibers, glass fibers, carbon fiber bundles, wire mesh, aromatic polyamide fibers, ultra-high molecular weight polyethylene, ceramic fibers, steel fibers, copper fibers, or combinations thereof. The fabric can be woven (e.g., plain or twill), nonwoven, or combinations thereof.

[0128] In certain embodiments, the composite material comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more layers of fabric. Advantageously, the methods described herein can produce composite materials comprising one or more layers of fabric that are more highly cured than conventional curing methods (e.g., thermally initiated FROMP and oven curing). Figure 21 shown.

[0129] The composite material can include up to 20 wt%, up to 30 wt%, up to 40 wt%, up to 50 wt%, up to 60 wt% or up to 70 wt% of the one or more nanoparticles and / or the one or more fabrics. In some embodiments, the composite material includes 1-70 wt%, 5-70 wt%, 10-70 wt%, 20-70 wt%, 30-70 wt%, 40-70 wt%, 50-70 wt%, 60-70 wt% or 65-70 wt% of the one or more nanoparticles and / or the one or more fabrics relative to the total weight of the polymer and the one or more nanoparticles and / or the one or more fabrics.

[0130] In certain embodiments, the method further comprises stacking one or more layers of fabric, distributing the reaction solution throughout the fabric (e.g., dispersing the reaction solution into and / or spreading it on the fabric such that the reaction solution substantially penetrates the fabric) to form an impregnated fabric, and irradiating the impregnated fabric with ultrasonic waves sufficient to trigger FROMP at one or more initiation locations, selectively interrupting the ultrasonic waves, and allowing FROMP to propagate through the impregnated fabric from the one or more initiation locations.

[0131] Polymers and composites prepared according to the methods described herein can exhibit enhanced mechanical properties over those of oven-cured pDCPD, particularly in terms of ductility and toughness. Figure 6 The superior mechanical properties of the final polymer compared to oven-cured samples are highlighted. The method described in this patent offers significant advantages, especially in harsh environmental conditions. By enabling polymers to cure at -20°C, it opens up the possibility of manufacturing high-performance polymers in open areas where temperatures can drop as low as -20°C. This eliminates the need for expensive oven-curing equipment and provides a cost-effective option for in-situ polymer manufacturing.

[0132] The polymers and composite materials prepared according to the methods described herein can exhibit improved physical properties relative to polymers prepared using thermal curing (i.e., polymerization using thermal initiation or oven curing under the same conditions without ultrasound). In certain embodiments, the composite material is a carbon fiber reinforced plastic (CFRP) comprising a polymer prepared according to the methods described herein and woven carbon fibers. In certain embodiments, the composite CFRP prepared according to the methods described herein has improved tensile strength, tensile modulus, flexural strength, and flexural modulus. The CFRP prepared according to the methods described herein may have a tensile strength of 430-500 MPa, 440-500 MPa, 450-500 MPa, 460-500 MPa, 470-500 MPa, 480-500 MPa, 490-500 MPa, 495-500 MPa, 496-500 MPa, 497-500 MPa, 498-500 MPa, or 499-500 MPa. The polymers prepared according to the methods described herein can have a tensile modulus of 42-70 GPa, 42-60 GPa, 42-50 GPa, 43-50 GPa, 44-50 GPa, 45-50 GPa, 46-50 GPa, 47-50 GPa, 48-50 GPa, 49-50 GPa, 50-70 GPa, 55-70 GPa, 60-70 GPa, 65-70 GPa, 66-70 GPa, 67-70 GPa, 68-70 GPa, or 69-70 GPa. The polymers prepared according to the methods described herein can have a flexural strength of 250-300 MPa, 260-300 MPa, 270-300 MPa, 280-300 MPa, 290-300 MPa, 295-300 MPa, 296-300 MPa, 297-300 MPa, 298-300 MPa, or 299-300 MPa. The polymers prepared according to the methods described herein can have a flexural modulus of 30-40 GPa, 31-40 GPa, 32-40 GPa, 33-40 GPa, 34-40 GPa, 35-40 GPa, 36-40 GPa, 37-40 GPa, 38-40 GPa, or 39-40 GPa.

[0133] The present disclosure also provides an apparatus for performing the metathesis reactions described herein. Figure 13 The device (100) for performing a metathesis reaction includes: a mold body (101) for receiving a reaction solution (107), a first ultrasonic probe (102) and a cover plate (103) arranged on the mold body (101), wherein the mold body is provided with a first opening (106) for receiving the first ultrasonic probe (102); in some embodiments, the device further includes a sealing tape (105).

[0134] The mold body (101) can be made of or lined with a release material to facilitate removal of the polymer product from the mold body. In certain embodiments, the mold body (101) comprises perfluoroalkoxyalkane (PFA), perfluoropolyether, or perfluoroalkane, such as PTFE.

[0135] In some embodiments, the device further comprises one or more additional ultrasound probes, and the mold body is provided with one or more additional openings for receiving the one or more additional ultrasound probes. In some embodiments, the device further comprises a second ultrasound probe, and the mold body is provided with a second opening for receiving the second ultrasound probe. In some embodiments, the device comprises 1, 2, 3, 4, or more ultrasound probes.

[0136] The cover plate (103) can be made of any material. In some embodiments, the cover plate (103) is made of a transparent material (eg, glass).

[0137] There is no particular limitation on the size of the first ultrasonic probe (102), and any ultrasonic probe may be used in conjunction with the apparatus described herein. In some embodiments, the size of the first ultrasonic probe (102) may be in the range of 1.6 mm to 26 mm.

[0138] The first opening (106) and any additional openings on the mold body can have any shape. In certain embodiments, the openings are polygonal, or can be a shape with curvature, such as a circle or an ellipse.

[0139] The present disclosure provides a polymerization apparatus for controlling FROMP using ultrasound. Figure 1 The components of the device are shown, including a mold body (e.g. made of PTFE or coated with PTFE) with a cover plate (e.g. made of glass), the mold body having an opening for inserting an ultrasonic probe. The reaction solution can be injected through a tube or poured directly into the mold body.

[0140] The polymerization process consists of two main steps. In step I, the ultrasonic machine is turned on to initiate the front through acoustic cavitation. The timing of front initiation is crucial for controlling the polymerization process. In step II, the front propagates while the ultrasonic probe is turned off. The probe position and ultrasonic amplitude are key factors affecting the final polymer structure and homogeneity. The polymerization process can be precisely monitored by measuring the front temperature and velocity using an embedded thermocouple and a glass scale.

[0141] A key advantage of this design is the ability to control the front temperature and speed by adjusting the ultrasonic amplitude. This control directly affects the polymer structure and mechanical properties, such as Figure 2The ultrasound-induced FROMP method allows for a wide range of tensile strength and ductility without changing the chemical properties of the reaction solution or adding new monomers or nanoparticles. By harnessing the energy of ultrasonic mechanical waves, the potential capacity of the reaction solution system can be fully utilized.

[0142] The proposed ultrasound-induced FROMP method offers several advantages over thermal FROMP. Optimized ultrasound parameters produce polymers with superior mechanical properties compared to conventional oven-cured pDCPD, which typically requires approximately 27 hours of curing at elevated temperatures ( Figure 3 This method is not only fast and energy-efficient, but also has mechanical properties superior to conventional oven-cured samples ( Figure 4 ).

[0143] The ultrasonic cryogenic-FROMP method operates at a reduced temperature, achieving a front temperature of approximately 70-120°C. This temperature reduction minimizes the temperature peak that occurs when the two fronts fuse, compared to the temperature of a thermally initiated front that typically reaches 176°C. The frozen reaction solution between the fusing fronts acts as a heat sink, further reducing the front temperature. As a result, the produced polymer exhibits a uniform structure that exceeds the quality of oven-cured samples. The ultrasonic cryogenic-FROMP technology facilitates the manufacture of large-area polymer sheets with multiple ignition points, thus breaking through previous system limitations. The present invention proposes an ultrasonic cryogenic-FROMP system that provides an innovative method for front polymerization at lower temperatures. The system achieves a front temperature of approximately 70-120°C, which significantly reduces the temperature peak during the fusion of the two fronts, compared to conventional hot fronts that reach a temperature of 176°C.

[0144] In the ultrasonic cryo-FROMP system, the frozen reaction solution between the two fusing fronts acts as a heat sink, effectively reducing the front temperature. This temperature reduction offers several benefits. First, the lower temperature rise during front fusion ensures that it remains below the polymer's degradation temperature, preventing any adverse effects on the final polymer structure. Second, the resulting polymer exhibits a uniform structure, superior to oven-cured samples. Measurements and observations demonstrate that the ultrasonic cryo-FROMP system provides results superior to those of traditional methods. Figure 7 The temperature in the system is shown to drop to approximately 70-120°C, highlighting the reduction in temperature peaks during front fusion. This temperature reduction is attributed to the frozen reaction solution acting as a heat sink. Figure 6The mechanical properties of the final polymer were shown to be superior to those of oven-cured samples. The advantages of the ultrasonic cryogenic-FROMP method are not limited to temperature control and improved polymer structure. This method enables the fabrication of large-scale polymer plates with multiple ignition points, overcoming previous system limitations. The ability to fabricate large-scale polymer structures without compromising quality and uniformity opens up new possibilities for a variety of applications.

[0145] In certain embodiments, the methods described herein utilize nanoparticles, such as carbon nanotubes (CNTs), to enhance thermal conductivity. Due to their excellent thermal properties, carbon nanotubes are able to initiate FROMP within 10 seconds. The rapid initiation of the polymerization process ensures that the nanoparticles are evenly dispersed before any deposition or agglomeration occurs. Another advantage of this method is reduced energy consumption compared to pure pDCPD polymer. The energy required to manufacture nanocomposites using this accelerated curing process is approximately one-third of the energy required for pure pDCPD polymer. This energy efficiency makes the method not only time-saving but also cost-effective. After manufacturing is complete, samples are cut for further mechanical property analysis ( Figure 8 Applications of this method include the production of high-performance nanocomposites with enhanced mechanical, thermal, and electrical properties. The uniform distribution of nanoparticles achieved through rapid curing improves the overall performance and functionality of the resulting material. These nanocomposites are used in a variety of industries, including aerospace, automotive, electronics, and construction.

[0146] like Figure 9 As shown, the present invention proposes a new method of inducing a three-dimensional (3D) front in FROMP using remote ultrasonic excitation. Conventional FROMP methods require the probe to be in the reaction solution. However, we also propose a remote ultrasonic FROMP method in which the front can be initiated even when the probe is not in direct contact with the reaction solution. In the remote ultrasonic FROMP method, the three-dimensional front starts from the center of the reaction solution and propagates until complete polymerization occurs. This three-dimensional front is different from the vertical two-dimensional thermal front in that its solidification time is approximately half that of the latter for the same volume of reaction solution ( Figure 10 ). Compared with the conventional FROMP method, the initiation time of remote ultrasonic FROMP is prolonged. This is because cavitation bubbles are generated in the water surrounding the reaction solution rather than in the reaction solution itself. Therefore, a longer time is required to initiate the front. Depending on the specific situation, the initiation time varies from 30 seconds to 11 minutes. Measurements show that the front temperature of remote ultrasonic FROMP reaches 116°C ( Figure 11 However, it should be noted that there is currently no theoretical analysis to explain this phenomenon. One hypothesis proposed is that the lower heat loss in the center of the reactor allows the central part to reach the critical point necessary to break the activation barrier and initiate the front.

[0147] Example

[0148] Material

[0149] The following chemicals are used in the present invention: bicyclic olefins such as dicyclopentadiene (DCPD), 5-ethylidene-2-norbornene (ENB) and monocyclic olefins: 1,5-cyclooctadiene (COD). Other chemicals include methyl methacrylate (MMA), N-methylolacrylamide (NMA) and phenylcyclohexane, (1,3-bis(2,4,6-trimethylphenyl)-2-imidazolylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium, benzyl[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolylidene]dichloro(tricyclohexylphosphine)ruthenium, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolylidene](benzylidene)(tricyclohexylphosphine)ruthenium(II) second generation Grubbs (G2) and tributyl phosphite (TBP) inhibitor.

[0150] Ultrasonic-induced frontal ring-opening metathesis polymerization (U-FROMP) process for developing polymers

[0151] For each experiment, a sufficient amount of G2 was weighed and dissolved in phenylcyclohexane (1-4 mL). Next, TBP (20-140 μL) was added to the solution. The catalyst / inhibitor solution was then added to the DCPD / ENB solution (9,000-10,000 molar equivalents relative to G2) or COD (10,000 molar equivalents relative to G2), and the mixture was thoroughly mixed using a magnetic stirrer. It is important to note that the reaction solution was used immediately after mixing to initiate FROMP polymerization, either directly or remotely.

[0152] Direct U-FROMP

[0153] A 13 mm diameter probe connected to a sonicator (500-750 W, 20 kHz) was used at various amplitudes in the range of 100-500 W. The probe was placed on the left side of the planar reactor and immersed 2-5 mm into the reaction solution (see Figure 12 a) For multi-point initiation, two or more ultrasonic probes are used to initiate U-FROMP.

[0154] Remote U-FROMP

[0155] For remote water initiation, the reactor containing the reaction solution was transferred to an ultrasonic bath operating at a frequency of 40-45 kHz and a power of 6.6-120 W. The initiation time for remote U-FROMP depends on the water height and temperature within the ultrasonic bath. The water temperature was varied from 20°C to 60°C, and the water height was varied from 2.5 cm to 7.5 cm. The dependence of initiation time, front characteristics, and polymer properties on water temperature and height was observed. For remote air initiation, an ultrasonic probe was placed at a distance of 1 mm on top of the glass portion of the reactor. The power was varied from 100 W to 500 W, and the frequency was 20 kHz.

[0156] For both direct and remote U-FROMP, to effectively monitor the front temperature during FP (front polymerization), a T-type thermocouple was placed within the reaction solution before initiating U-FROMP. The thermocouple was used to measure the peak temperature during the process. Front propagation was then observed using a camera and a FLIR E8xt thermal infrared camera. Recorded movies were used to determine changes in front position. Front velocity was calculated using the best trendline correlating front position with time.

[0157] Manufacturing carbon fiber reinforced plastics by U-FROMP

[0158] This novel composite system is inspired by the cost-effective vacuum-assisted resin infusion (VARI) method, and this novel design allows us to achieve near-zero energy consumption (6-10 J·cm) through front-end polymerization. -3 ) to cure 12 layers of high fabric percentage (60-70 wt%) carbon fiber fabric. The kit for the VARI process consists of a PTFE mold body, a vacuum pump, a pressure tank, inlet and outlet hoses for injecting resin, a peel ply, a mesh, an acrylic plate on top, acrylic spacers, spiral tubing, and a vacuum bag, such as Figure 13 As shown. After the reinforcement layer is placed on the PTFE mold body and covered with a vacuum bag, the resin inlet is locked with a clamp and the resin outlet is connected to the pressure tank of the vacuum pump. The assembly is then placed under maximum vacuum pressure (0.1mbar) using a vacuum pump to remove the air trapped between the layers of the laminate. The reaction solution is then injected. After the injection is complete, the inlet hose is clamped and the composite material is cured based on direct or remote U-FROMP. Compared to the previously proposed VARI system, this VARI design has two specifications: (a) an acrylic plate is used on the top and (b) a resin pool is used to start acoustic cavitation from the resin pool and then propagate into the VARI stack until curing is completed. For direct U-FROMP, a hole is set to immerse the ultrasonic probe in the resin pool to induce acoustic cavitation. For remote U-FROMP, after injection, the stack is transferred to an ultrasonic bath and U-FROMP is activated remotely.

[0159] Remote U-FROMP for the development of copolymers

[0160] For the copolymer, G2 was dissolved in phenylcyclohexane. Next, TBP (20-140 μL) was added to the solution. The catalyst / inhibitor solution was then added to the DCPD / ENB solution (10,000 molar equivalents relative to G2). Methyl methacrylate was mixed with benzoyl peroxide (BPO) as a thermal initiator. After adding an appropriate amount of DCPD and MMA reaction solution, the solution was cured by remote U-FROMP. The amount of MMA varied in the range of 0.5-60 wt% relative to the total weight of DCPD and MMA. For all these compositions, complete curing occurred by front-end polymerization. For these experiments, the reactor was transferred to an ultrasonic bath with a frequency of 40-45 kHz and a power of 6-120 W.

[0161] Low-Temperature-FROMP for the Development of High-Performance Polymers

[0162] For each experiment, G2 was measured and dissolved in phenylcyclohexane. Next, TBP (20-140 μL) was added to the solution. The catalyst / inhibitor solution was then added to a DCPD / ENB solution (9000-10000 molar equivalents relative to G2) or COD (10000 molar equivalents relative to G2), and the mixture was thoroughly mixed with a magnetic stirrer. The reaction solution was then injected into the reactor and transferred to a refrigerator at a temperature of -20°C. After 15-30 minutes (depending on the geometry of the reactor), the reaction solution temperature dropped to -20°C to -10°C. A horn probe connected to an ultrasonicator (500-750W, 20kHz) was then used. The probe was placed on the left side of the planar reactor and immersed 2-5mm into the frozen reaction solution. Acoustic cavitation caused the initiation front to propagate until the sample was fully cured. For multi-point initiation, two or more ultrasonic probes were used to initiate U-FROMP. Other energy sources (e.g., using heat or ultraviolet irradiation) for curing polymers by low-temperature-FROMP were used as comparative examples.

[0163] Product Characteristics

[0164] Polyolefins developed via direct U-FROMP

[0165] To induce acoustic cavitation for polymer synthesis, a high-power ultrasonic probe is immersed in a liquid reaction solution containing monomers, catalysts, and inhibitors ( Figure 12a). The ultrasonic probe was activated until acoustic cavitation occurred in samples of varying sizes and geometries. This triggered a radial front propagation of 1 cm. The probe was then closed and the reaction continued to completion without further sonication. The activation of sonication produced an acoustic wave with alternating compression and rarefaction phases ( Figure 12 b). During the rarefaction phase, negative pressure induces the liquid to expand, causing the dissolved gas to form tiny bubbles near the probe tip ( Figure 12 a). These bubbles promote acoustic cavitation because they undergo violent collapse during the compression phase, sending shock waves into the liquid. As explained by the hot spot theory, this collapse generates high pressure and intense local heating, effectively initiating the polymerization front (e.g. Figure 12 c). Acoustic cavitation exhibits a different mechanism from thermal boiling because it is driven by negative pressure rather than thermal energy, which leads to the violent collapse of bubbles, producing unique effects not observed in conventional boiling processes. As demonstrated in previous studies, this phenomenon is crucial in influencing the properties of polymers subjected to ultrasonic treatment. Due to the small diameter of the probe compared to the width of the mold body and the circular shape of the probe, the initiation type is characterized by a point shape, resulting in a concave shape of the rapidly propagating front ( Figure 12 c).

[0166] Mechanism of U-FROMP

[0167] From a mechanistic perspective, U-FROMP demonstrates the ability to achieve rapid and controlled DCPD polymerization using the second-generation Grubbs catalyst due to the high ring strain energy (RSE) stored in the norbornene moiety of DCPD. The DCPD ring strain energy is 90 kJ·mol -1 , for 1,5-cyclooctadiene (COD), it is 56 kJ·mol -1 Due to the high ring strain stored in the norbornene moiety of DCPD, the polymerization reaction is highly exothermic, as Figure 14 As shown, and depending on the ultrasonic power, the polymerization reaction enthalpy is approximately 240-400 J·g -1 .

[0168] Varying the ultrasonic power from 100 W to 500 W changes the acoustic cavitation, bubble dynamics, and front characteristics, affecting the polymer properties. For an acoustic power of 100 W, the polymer properties are very similar to those obtained by thermal induction. At lower acoustic intensities, cavitation is controlled, resulting in uniform polymerization and properties similar to those obtained by thermal induction. When the power is increased to 150 W, enhanced tensile strength and ductility are observed. Above the 200 W threshold, excessive cavitation leads to heterogeneous bubble collapse, embedding the bubbles in the polymer matrix and degrading the mechanical properties. This weakening may be due to mechanisms such as micropore formation or polymer degradation, which are typical at high cavitation intensities.

[0169] Initiation time is directly related to energy consumption. Energy consumption and manufacturing efficiency are key requirements for FP curing strategies, especially in the context of green manufacturing initiatives aimed at reducing CO2 emissions. Since thermal-FROMP has been shown to be an energy-efficient curing strategy, we here discuss the energy consumption of U-FROMP, a new FROMP method that demonstrates energy savings compared to conventional oven curing. Figure 15 a). Compared to the oven curing strategy using the recommended curing cycle (0.5-40L resin (this is the maximum capacity of our curing oven) the energy consumption is approximately 5×10 5 J.cm -3 ), the implementation of U-FROMP significantly reduces energy consumption by several orders of magnitude ( Figure 15 a). According to information provided by the Hong Kong Electric Company, the CO2 emissions from electricity consumption in 2021 were 0.71 kg CO2 per kilowatt-hour. Therefore, for a conventional oven curing strategy, approximately 13 tons of CO2 are generated, while for our U-FROMP, this value can be significantly reduced to 1-5×10 -5 Furthermore, unlike thermal-FROMP, where increasing the amount of resin results in a linear decrease in energy consumption per cubic centimeter, U-FROMP exhibits an increase in energy consumption as the amount of resin increases. Thus, in U-FROMP, the energy consumption per unit volume remains roughly constant when the resin amount increases from 10 mL to 200 mL. This behavior is attributed to the volume dependence of U-FROMP, whereas thermal-FROMP is primarily affected by the initiation point, not the resin amount.

[0170] After optimizing the acoustic power, we focused on the front characteristics and structural changes during U-FROMP. In the optimized U-FROMP, the average front velocity was very close to that of thermal-FROMP. However, the front temperature was much lower in U-FROMP than in thermal-FROMP. Furthermore, the reaction exotherm was reduced. The significant differences in reaction exotherm and front temperature highlight the distinct changes in thermal behavior during the U-FROMP curing process.

[0171] To confirm the observed front-end polymerization initiated by ROMP without other polymerization or dimerization, pure DCPD was sonicated under the same conditions and showed no significant changes under our sonication conditions ( Figure 15 b), and short-term ultrasonic treatment without heating does not change the monomer composition. In addition, a series of nuclear magnetic resonance (NMR) tests were performed, indicating that our FROMP can be initiated by necessary ultrasonic treatment without obvious thermal behavior. Figure 15 In b, after the mixture of Grubbs catalyst and phosphite inhibitor was sonicated for different times, free PCy3 species (10 ppm) and new ruthenium phosphite species (130 ppm) were observed in 31P NMR, indicating that ligand exchange occurred during this sonication process, while the temperature change was negligible. During this exchange process, the dissociation of the phosphine ligand can lead to 14e - The formation of ruthenium species is followed by the recombination of ruthenium phosphite species. In this process, 14e - The ruthenium intermediate is the active center in normal ROMP, and this observed ligand exchange further explains how sonication can initiate FROMP. The lower front temperature observed while maintaining similar front speeds suggests that, as observed in 31P NMR measurements, the catalytic efficiency is enhanced by the accelerated initiation of the G2 catalyst, which allows for lower reaction temperatures and improved efficiency ( Figure 15 b). These substances increase the activity of the catalyst, allowing the polymerization reaction to proceed efficiently at reduced temperatures. In addition, the reaction kinetics are likely to be optimized, thereby minimizing the exotherm, as observed in dynamic DSC ( Figure 15 ), while still enabling rapid dissemination.

[0172] The U-FROMP samples exhibited an average tensile strength of 50-80 MPa and a ductility of 10-15%. The yield strength and ductility were improved compared to hot-FROMP. The simultaneous increase in tensile strength and ductility resulted in a 100-350% increase in the toughness of the polymer. The toughness of the polymer obtained by U-FROMP was also approximately 255% higher than that of pure epoxy resin (2.7 MPa). Based on the tensile and compressive properties, it appears that the plastic deformation behavior and fracture resistance of p-DCPD are altered by the applied ultrasonic field. The reduced front temperature achieved by the U-FROMP process suggests that this approach has great promise in using a multi-point ignition strategy, which will help achieve efficient manufacturing with greater scalability, such as Figure 4c. The main disadvantage of the multi-point ignition strategy is the sudden temperature spike that occurs when the two high-temperature fronts meet, followed by polymer degradation, causing the joint to become a weak point during use. In terms of the mechanical properties of the resulting samples, a significant improvement in the elongation at break was observed for the U-FROMP sample, implying that the two fused fronts with lower front temperatures resulted in a more uniform boundary and reduced polymer degradation caused by the temperature spike.

[0173] FROMP of COD is initiated using ultrasonic treatment or heat, with the reaction solution combining a G2 catalyst and a TBP inhibitor. The reaction mixture, contained in a vial, is initiated with an ultrasonic probe and a soldering iron. After FROMP solidification, the samples are subjected to various characterizations, including NMR, GPC, and DSC. For H NMR testing, samples are collected at a sufficient distance from the initiation point to ensure stable front propagation and at a sufficient distance from the initiation point to qualitatively analyze the trans content in the range of 5.3-5.5 ppm ( Figure 16 a). Interestingly, it was found that sonication increased the trans content, and longer sonication times resulted in trans-enriched p-COD that was firmer than the heat-induced p-COD ( Figure 16 a), and exhibits endothermic behavior, as observed in the DSC curve ( Figure 16 b). This structural change and increase in polymer crystallinity can be attributed to the difference between thermal initiation and ultrasonication initiation. The mechanical waves during ultrasonication affect the entire mixture more effectively than heating alone, promoting a more ordered structure during the FROMP process. In addition to affecting the trans / cis ratio, ultrasonication initiation also leads to higher molecular weight ( Figure 16 c) As observed in the cured microstructures of other materials, the lower heat generated in U-FROMP and cavitation-induced polymerization can reduce chain transfer behavior during polymerization, leading to longer polymer chains.

[0174] Polyolefins developed via remote U-FROMP (water or air)

[0175] The use of water as a medium in the RW U-FROMP method enhances the thermal management of the reaction, provides a more consistent temperature distribution and accelerates the curing process. Similarly, the RAU-FROMP method, although slightly less efficient than RW U-FROMP, still offers significant time savings, making both methods attractive for industrial applications where time efficiency is critical. Remote U-FROMP methods, using water or air as a medium (results such as Figure 17The results (shown in Figure 2) show a significant reduction in cure time compared to conventional oven curing. The data demonstrates a dramatic improvement in production efficiency. This significant reduction in cure time is attributed to the rapid propagation of the polymerization front facilitated by ultrasonic energy, which effectively initiates and sustains the reaction with minimal energy input.

[0176] Despite the significant reduction in cure time, the mechanical properties of p-DCPD polyolefins cured via remote U-FROMP remained comparable to those of oven-cured samples. Tensile properties, including tensile strength and elongation at break, are crucial for assessing a material's ability to withstand forces and deformation. The comparable tensile properties achieved via remote U-FROMP indicate that the rapid cure process does not compromise the integrity or strength of the polyolefin. This is likely due to the ultrasonic energy promoting efficient polymerization and cross-linking, which ensures a consistent and strong polymer network.

[0177] CFRP developed through U-FROMP

[0178] The development and optimization of composite materials is crucial to advancing technologies that require high-performance materials and reduced environmental impact. Figure 18 Significant advances in energy efficiency and mechanical properties of carbon fiber reinforced polymer (CFRP) manufactured using the U-FROMP method are shown. Figure 18 a shows an infrared (IR) camera image captured during the propagation of the reaction wave, highlighting the heat distribution associated with the U-FROMP process. The image demonstrates the localized heating effect, a particular advantage of this method, allowing for targeted energy application and minimizing unnecessary heat dissipation. Figure 18 In b, a real-time photograph captures the propagation of the polymerization front. This visual evidence highlights the efficiency of the U-FROMP method in terms of time and energy utilization, as the reaction proceeds rapidly and uniformly throughout the material. Figure 18 The comparative analysis in Figure c quantifies the energy consumption and curing time of CFRP produced via direct U-FROMP versus CFRP produced via conventional curing methods. The data demonstrates significant reductions in energy consumption and production time, highlighting the potential of this method for sustainable manufacturing. Conventional oven curing is energy-intensive, while the direct U-FROMP process saves time by avoiding lengthy oven curing. Figure 21 The degree of cure (%) of CFRP containing 12 layers of carbon fiber prepared using U-FROMP, remote U-FROMP, and oven curing is shown. The U-FROMP CFRP exhibited a degree of cure of 0.986-0.992, which is a very high degree of cure.

[0179] Figure 18Figures 18d and 18e provide a comparison of the mechanical properties of CFRP produced using the U-FROMP method with those of CFRP cured in a conventional oven. Tensile and flexural properties are important indicators of material performance, especially in applications requiring high strength and durability. The tensile strength of the U-FROMP samples ranged from 430 to 500 MPa, with a tensile modulus of 42 to 70 GPa. Figure 18 d shows an improvement in tensile properties compared to conventional oven-cured CFRP. This improvement is attributed to the homogeneous polymer matrix and optimal fiber-matrix bonding achieved through the U-FROMP process, which contributes to excellent load transfer and mechanical stability. Similarly, Figure 18 Figure e shows the flexural properties of CFRP, further demonstrating the mechanical advantages of the U-FROMP approach. The U-FROMP composites exhibit flexural strengths in the range of 250-300 MPa and flexural moduli in the range of 30-40 GPa. The increased flexural strength and modulus indicate the material's enhanced resistance to bending forces, making it suitable for structural applications where stiffness and elasticity are crucial.

[0180] Copolymers developed via remote U-FROMP

[0181] Developing copolymers with tailored properties is crucial for advancing materials science, especially in applications requiring specific mechanical and thermal properties. Remote U-FROMP offers a new approach to manufacturing copolymers that offers significant advantages over conventional thermal methods. Photographic evidence shows that copolymers with varying methacrylate content manufactured via remote U-FROMP exhibit fairly consistent structures ( Figure 19 a). In contrast, the copolymers developed by thermal FROMP exhibited a pronounced finger-like structure ( Figure 19 b), i.e., the formation of different phases due to heterogeneous polymerization kinetics. This difference becomes particularly evident when adding more than 40-60% methyl methacrylate (MMA), where the hot FROMP sample shows obvious phase separation due to the boiling of methacrylate and the failure of successful front propagation ( Figure 19 b). Scanning electron microscopy (SEM) micrographs further illustrate these structural differences, indicating that the copolymers synthesized by U-FROMP ( Figure 19 c) has a more uniform microstructure, which indicates that the thermal FROMP product ( Figure 19 d) The polymer network is well integrated. This consistency is likely the result of a rapid and localized polymerization front promoted by ultrasonic energy, which promotes consistent crosslinking and minimizes phase separation. In contrast, the hot FROMP sample exhibits significant structural irregularities with visible phase boundaries and less cohesive polymer domains, which is because the low boiling temperature of MMA induces boiling rather than front polymerization during heating ( Figure 19 d) These findings highlight the advantages of remote U-FROMP for producing copolymers with excellent structural consistency, especially when incorporating large amounts of methacrylates that cannot be produced by thermal FROMP. Achieving a homogeneous copolymer structure without phase separation is crucial to ensuring consistent material properties and performance.

[0182] Polyolefins developed through low-temperature-FROMP

[0183] The development of polyolefins through low-temperature front-end ring-opening metathesis polymerization (low-temperature-FROMP) represents a significant advancement in polymer synthesis, particularly in terms of improving material properties and scalability. This process uses ultrasonic energy to initiate polymerization at low temperatures (-20 to -15°C), as shown by infrared images of the front propagation. Figure 20 These infrared images shown in a highlight the controllable and efficient polymerization front at low temperatures, which is crucial for maintaining the integrity and consistency of the resulting polymer structure. Figure 20 b shows the innovative approach of two-site initiation in low-temperature-FROMP, where polymerization is initiated simultaneously at two different locations, promoting more consistent front propagation and improving the overall process efficiency. Figure 20 The infrared camera image in c provides further evidence of the reaction kinetics, showing that the polymerization fronts are able to converge without causing harmful temperature spikes. This convergence is particularly beneficial because it prevents the formation of weak points or defects at the joint where the fronts meet, which is a common problem in conventional front polymerization techniques. Figure 20 As shown in Figure d, this approach significantly improves the ductility of polyolefins, a key mechanical property that represents the ability of a material to deform under stress without breaking. The improved ductility achieved through two-point initiation in low-temperature-FROMP paves the way for better scalability of the process, making it more suitable for industrial applications. This is because the absence of inferior parts caused by temperature spikes ensures that the material maintains consistent quality and performance over a wide range. In summary, low-temperature-FROMP (especially using a two-point initiation strategy) provides a promising route for producing high-quality polyolefins with excellent mechanical properties and scalability, addressing key challenges in polymer manufacturing and expanding the potential applications of these versatile materials.

Claims

1. A method for performing a metathesis reaction, comprising: providing a reaction solution comprising at least one olefin substrate and a metathesis catalyst; and Ultrasonic waves are used to induce the reaction solution to undergo a metathesis reaction, provided that the metathesis catalyst is not an oxyhalide, halide, oxide or organic ammonium salt of tungsten, molybdenum, tantalum, ruthenium or rhenium, a vinylidene, propadienylene or higher cumene complex containing ruthenium or osmium, (p-methylisopropylphenyl)RuCl(PCy3)(=C=C=CPh2) + , WCl6 / Me4Sn or where R 1 It is methoxypoly(butylene oxide)butyl.

2. The method according to claim 1, characterized in that The metathesis catalyst is a ruthenium metathesis catalyst, a molybdenum metathesis catalyst, an osmium metathesis catalyst or a tungsten metathesis catalyst.

3. The method according to claim 1, characterized in that The metathesis catalyst has Formula 1: where L is PR 3 3; X 1 is independently in each case an anionic ligand; Ar is optionally substituted phenyl; R 2 is independently at each occurrence alkyl, cycloalkyl, or aryl; and R 3 Each occurrence is independently alkyl, cycloalkyl or aryl.

4. The method according to claim 1, wherein The CAS number of the metathesis catalyst is selected from the group consisting of the following CAS numbers: CAS number 250220-36-1, CAS number 172222-30-9, CAS number 340810-50-6, CAS number 1307233-23-3, CAS number 536724-67-1, CAS number 254972-49-1, CAS number 246047-72-3, CAS number 927429-60-5, CAS number 373640-75-6, CAS number 253688-91-4, CAS number 1190427-50-9, CAS number 1190427-49-6. CAS No. 255536-61-8, CAS No. 1031262-76-6, CAS No. 934538-12-2, CAS No. 203714-71-0, CAS No. 1025728-56-6, CAS No. 1212008-99-5, CAS No. 301224-40-8, CAS No. 927429-61-6, CAS No. 635679-24-2, CAS No. 1025728-57-7, CAS No. 1212009-05-6, CAS No. 1383684-54-5, CAS No. 1632041-02-1 and CAS No. 1352916-84-7.

5. The method according to claim 1, characterized in that The CAS number of the metathesis catalyst is 246047-72-3.

6. The method according to claim 1, characterized in that The at least one olefinic substrate comprises a cyclic olefin.

7. The method according to claim 1, characterized in that The at least one olefin substrate comprises a cyclic olefin selected from the group consisting of norbornene, dicyclopentadiene, tricyclopentadiene, cyclooctene, cyclooctadiene, cyclobutene, cyclopropene, and oxanorbornene.

8. The method according to claim 1, characterized in that The metathesis reaction is carried out at -20°C to -10°C.

9. The method according to claim 1, characterized in that The frequency of the ultrasonic wave is 20-100 kHz.

10. The method according to claim 1, characterized in that The reaction solution also contains P(OR 5 )3, where R 5 In each case, independently C1-C 12 alkyl.

11. The method according to claim 1, wherein The reaction solution further comprises nanoparticles selected from the group consisting of metal oxide nanoparticles and carbon-based nanoparticles.

12. A method for performing a ring-opening metathesis polymerization reaction, the method comprising: providing a reaction solution comprising at least one olefin substrate, tributyl phosphite, and a metathesis catalyst; and exposing the reaction solution to ultrasonic waves to initiate the ring-opening metathesis polymerization reaction; The CAS number of the metathesis catalyst is 246047-72-3, the at least one olefin substrate includes a cycloolefin selected from the group consisting of norbornene, dicyclopentadiene, tricyclopentadiene, cyclooctene, cyclooctadiene, cyclobutene, cyclopropene and oxa-norbornene, and optionally methyl methacrylate, N-hydroxymethyl acrylamide or methacrylate, and the frequency of the ultrasonic wave is 20-100 kHz.

13. The method according to claim 12, characterized in that The at least one olefinic substrate comprises dicyclopentadiene.

14. A polymer prepared according to the method of claim 12.

15. The polymer according to claim 14, characterized in that The polymer further comprises metal oxide nanoparticles or carbon-based nanoparticles.

16. The polymer according to claim 14, characterized in that The polymer comprises polydicyclopentadiene, dicyclopentadiene-methacrylate copolymer or dicyclopentadiene-methyl methacrylate copolymer.

17. The polymer of claim 16, further comprising carbon nanotubes.

18. An apparatus for performing the metathesis reaction of claim 1, comprising: The mold body is used to receive the reaction solution; a first ultrasonic probe; and A cover plate is arranged on the mold body to form a reaction surface for the reaction solution to undergo a metathesis reaction, wherein the mold body is provided with a first opening for receiving the first ultrasonic probe.

19. The device according to claim 18, characterized in that A second ultrasonic probe is further included, and the mold body is provided with a second opening for receiving the second ultrasonic probe, wherein the first ultrasonic probe and the second ultrasonic probe are arranged at opposite ends of the mold body.

20. The device according to claim 18, characterized in that The mold body comprises polytetrafluoroethylene.

21. The device according to claim 18, characterized in that One or more thermocouples for measuring the temperature of the reaction solution are also included.

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