Polyurethane composition for the preparation of composites

Abstract

The present application relates to a polyurethane composition for preparing a composite material, a polyurethane composite material prepared by the polyurethane composition and a method for preparing the polyurethane composite material. The polyurethane composition comprises: a) an isocyanate component; b) an isocyanate-reactive component; c) a free radical reaction initiator and d) an organic metal catalyst; the hydroxyl value of the isocyanate-reactive component of the component b) is 200 mgKOH / g-700 mgKOH / g, and the molar ratio of isocyanate groups to hydroxyl groups of the composition is 0.6-1.5. The polyurethane composition of the present application has the advantages of long workable time and simple construction process, and the polyurethane composite material comprising the polyurethane resin matrix prepared by the polyurethane composition of the present application has excellent weather resistance and mechanical strength.

Description

Technical Field

[0001] This invention relates to a polyurethane composition for preparing composite materials, the polyurethane composite materials obtained therefrom, and a method for preparing polyurethane composite materials. Background Technology

[0002] Composite materials composed of polymer matrices and fibrous fillers are primarily used as lightweight structural materials in motor vehicle construction, shipbuilding, aircraft manufacturing, sports, construction, petroleum, and power and energy sectors. The polymer matrix of the composite material can immobilize the fibrous filler, ensuring load transfer and protecting it from environmental influences, while the fibrous filler guides the load. Through appropriate combinations of polymer matrices and fibrous fillers, composite materials with excellent mechanical strength and physical properties can be obtained.

[0003] Common polymer matrices used in composite materials include epoxy resin, polyester, polyurethane, and polyvinyl ester.

[0004] Polyurethanes based on aromatic polyisocyanates, when used as the polymer matrix in composite materials, exhibit excellent physical properties for indoor applications. However, when applied outdoors, they suffer from poor weather resistance, are prone to discoloration and loss of luster, and are susceptible to degradation. Therefore, a protective coating is necessary for outdoor use. Furthermore, industrially produced aromatic polyisocyanates are often pre-colored brown, making light coloring or specific hues impossible or dependent on specific raw material batches for systems using polyurethanes as the polymer matrix. In addition, common aromatic polyisocyanates such as TDI, MDI, and PMDI are highly reactive, reacting rapidly during polyurethane preparation and exhibiting extreme sensitivity to moisture, leading to rapid gelation and curing, loss of fluidity, and difficulty in subsequent composite material preparation. This results in short work-life times and stringent application requirements for polyurethane-based composite materials, prompting industry efforts to develop polyurethane matrices with extended work-life times.

[0005] Patents CN10290614, CN10321001, and CN103298862 disclose prepregs of storage-stable reactive or highly reactive polyurethane compositions. The polyurethane in the prepreg is prepared using an aliphatic polyisocyanate with internal end-capping (e.g., in the form of diurea) and / or end-capping by an external end-capping agent. The disadvantages of these prepregs are high curing temperatures and long curing times, making them difficult to apply to processes requiring rapid curing.

[0006] Patent CN1221587 discloses an LPA hybrid comprising: a first component having at least one olefinic unsaturated bond and an isocyanate-reactive group; a second component being an olefinic unsaturated monomer capable of free radical polymerization with the first component; a third component being a polyisocyanate having an average functionality of at least 1.75 capable of reacting with the first component via polyurethane; a fourth component being a free radical catalyst; and a thermoplastic polymer comprising 3-20% of the hybrid with a molecular weight of at least 10,000 Daltons. This method requires the addition of multiple components and is complex to operate.

[0007] Patent CN103974986 discloses a free radical polymerizable resin composition comprising two polyurethanes (I) and (II) containing (meth)acryloyl groups with different structures and free radical polymerizable unsaturated monomers. Structure (I) is generated by reacting a polyol containing an aliphatic cyclic structure with an isocyanate containing an aliphatic cyclic structure, and structure (II) is generated by reacting a polyether polyol with an isocyanate. This method requires the prior synthesis of these two special polyurethane structures.

[0008] CN11023368 describes a polymerizable composition containing components that can be crosslinked via both isocyanurate bonds and free radical reaction mechanisms. The polymerizable composition comprises at least one component containing olefinic double bonds and / or isocyanate reactive groups, an isocyanate, a trimerizing catalyst, and a free radical initiator, wherein the molar ratio of isocyanate groups to isocyanate reactive groups is at least 2:1. When the reactive components used to prepare this polymerizable composition are heated, the trimerization of the isocyanate itself, the addition reaction between the isocyanate and the isocyanate reactive groups, and the free radical-initiated polymerization of the olefinic double bonds occur simultaneously.

[0009] CN110372823 discloses a one-component thermosetting polyurethane composition, comprising: a modified polyurethane oligomer, an active compound, a polymerization inhibitor, and a free radical initiator; the modified polyurethane oligomer is prepared by reactive polymerization of polycaprolactone, including diisocyanate and single / double bond-terminated polycaprolactone. This method requires the prior synthesis of the modified polyurethane oligomer.

[0010] CN104045803 discloses a pultrusion composite material based on an aliphatic polyurethane system, comprising a transparent aliphatic polyisocyanate with a viscosity of no more than 1000 centipoise at 25°C and an amine-starting polyol with a molecular weight of 150-400 and an OH functionality greater than or equal to 3. The aliphatic polyisocyanate and polyol raw materials are costly.

[0011] CN105985505 and CN105778005 both describe a free-radical polymerizable composition consisting of a polyurethane containing double bonds and a reactive diluent based on various methacrylates. The former's isocyanate component is a toluene diisocyanate residue, while the latter is a diphenylmethane diisocyanate or a diphenylmethane diisocyanate prepolymer. This composition involves a two-stage reaction mechanism and is complex to operate.

[0012] CN104974502 and WO2019 / 053061 both describe a composite material obtainable from a reinforcing material and a polyurethane composition. This polyurethane composition comprises at least one aromatic polyisocyanate, an isocyanate reactive component, and a free radical initiator. The isocyanate reactive component consists of at least one polyol and at least one methacrylate having hydroxyl groups. The addition reaction between the isocyanate groups and hydroxyl groups occurs simultaneously with the free radical-initiated chain polymerization of the methacrylate. This polyurethane composition, without a polyurethane reaction catalyst, increases the gel time compared to conventional polyurethane systems, but still lags significantly behind commonly used epoxy and unsaturated resin systems in industry. Furthermore, the system without a polyurethane reaction catalyst, due to its reduced reaction rate, is difficult to apply to processes requiring rapid, open-loop operation, such as pultrusion and filament winding.

[0013] Therefore, the purpose of this invention is to provide a polyurethane composite material that combines excellent weather resistance and mechanical strength. The polyurethane composition used to form the polyurethane matrix of the polyurethane composite material has the advantages of long working time and simple construction process. Summary of the Invention

[0014] This invention relates to a polyurethane composition for preparing composite materials, the polyurethane composite materials obtained therefrom and their uses, as well as a method for preparing polyurethane composite materials.

[0015] A polyurethane composition for preparing composite materials according to the present invention comprises:

[0016] a) An isocyanate component comprising not less than 97.5% by weight of an aliphatic isocyanate and optionally an aromatic isocyanate;

[0017] b) Isocyanate reactive components, including:

[0018] b1) at least one organic polyol, said organic polyol being in an amount of 20% to 80% by weight, based on an amount of 100% by weight of the isocyanate reactive component; and

[0019] b2) At least one compound that conforms to the structure of formula I:

[0020]

[0021] Wherein, R1 is selected from hydrogen, methyl or ethyl; R2 is selected from alkylene groups having 2-6 carbon atoms, 2,2-bis(4-phenylene)propane, 1,4-bis(methylene)benzene, 1,3-bis(methylene)benzene or 1,2-bis(methylene)benzene; n is an integer from 1 to 6;

[0022] c) Free radical reaction initiators; and

[0023] d) Organometallic catalysts;

[0024] The hydroxyl value of component b) isocyanate reactive component is 200 mg KOH / g-700 mg KOH / g.

[0025] The molar ratio of isocyanate groups to hydroxyl groups in the composition is 0.6-1.5.

[0026] According to one aspect of the present invention, a polyurethane composite material is provided, comprising a polyurethane resin matrix and a reinforcing material, said polyurethane resin matrix being prepared by means of a polyurethane composition provided according to the present invention.

[0027] According to another aspect of the present invention, a method for preparing a polyurethane composite material comprising a polyurethane resin matrix and a reinforcing material is provided, the method comprising the step of preparing the polyurethane resin matrix under reaction conditions in which a polyurethane composition provided according to the present invention is simultaneously subjected to a free radical polymerization reaction and an addition polymerization reaction of isocyanate groups and hydroxyl groups.

[0028] According to another aspect of the invention, the use of the polyurethane composite material provided according to the invention in the preparation of articles is provided.

[0029] The polyurethane composition of the present invention has the advantages of long working time and simple construction process, and the polyurethane composite material with polyurethane resin matrix prepared by the polyurethane composition of the present invention has both excellent weather resistance and mechanical strength. Detailed Implementation

[0030] This invention provides a polyurethane composition for preparing composite materials, comprising:

[0031] a) An isocyanate component comprising not less than 97.5% by weight of an aliphatic isocyanate and optionally an aromatic isocyanate;

[0032] b) Isocyanate reactive components, including:

[0033] b1) at least one organic polyol, said organic polyol being in an amount of 20% to 80% by weight, based on an amount of 100% by weight of the isocyanate reactive component; and

[0034] b2) At least one compound that conforms to the structure of formula I:

[0035]

[0036] Wherein, R1 is selected from hydrogen, methyl or ethyl; R2 is selected from alkylene groups having 2-6 carbon atoms, 2,2-bis(4-phenylene)propane, 1,4-bis(methylene)benzene, 1,3-bis(methylene)benzene or 1,2-bis(methylene)benzene; n is an integer from 1 to 6;

[0037] c) Free radical reaction initiators; and

[0038] d) Organometallic catalysts;

[0039] The hydroxyl value of component b) isocyanate reactive component is 200 mg KOH / g-700 mg KOH / g.

[0040] The molar ratio of isocyanate groups to hydroxyl groups in the composition is 0.6-1.5. This invention also provides polyurethane composite materials prepared from polyurethane compositions, their uses, and methods for preparing polyurethane composite materials.

[0041] As used herein, the term "gel time" refers to the time from when the polyurethane composition is mixed until it begins to exhibit a gel state. In this invention, the gel time is measured using a gelation apparatus.

[0042] As used herein, the term "polyurethane polymer" refers to polyurethane urea polymers and / or polyurethane polyurea polymers and / or polyurea polymers and / or polythiourethane polymers.

[0043] As used herein, the term "isocyanate reactive group" refers to a group containing the zeravitinov- active hydrogen. The definition of zeravitinov- active hydrogen is found in Rompp's Chemical Dictionary (Rommp Chemie Lexikon), 10th ed., Georg Thieme Verlag Stuttgart, 1996. Generally, groups containing the zeravitinov- active hydrogen are understood in this art to refer to hydroxyl (OH), amino (NH4) groups, etc. x ) and thiol group (SH).

[0044] Polyurethane composition

[0045] The molar ratio of isocyanate groups to hydroxyl groups in the composition is preferably 0.9-1.1.

[0046] Component a) Isocyanate component

[0047] The isocyanate component comprises not less than 97.5% by weight of aliphatic isocyanate, more preferably not less than 98% by weight of aliphatic isocyanate, and most preferably 100% by weight of aliphatic isocyanate, relative to the total weight of the isocyanate component.

[0048] The isocyanate group content of component a) is preferably 10%-61% by weight, more preferably 15%-50% by weight, and most preferably 18%-40% by weight, relative to the total weight of component a) isocyanate.

[0049] The aliphatic isocyanate is preferably one or more of the following: unblocked aliphatic diisocyanate, unblocked aliphatic polyisocyanate, unblocked alicyclic diisocyanate, unblocked alicyclic polyisocyanate, and their polymers and prepolymers. The polymer may be an isocyanate dimer, trimer, tetramer, pentamer, or a combination thereof.

[0050] The aliphatic isocyanate is further preferably one or more of the following: oligomers of aliphatic diisocyanates and oligomers of aliphatic triisocyanates, and most preferably one or more of the following: hexane diisocyanate (hexamethylene-1,6-diisocyanate, HDI), pentane-1,5-diisocyanate, butane-1,4-diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 3,5,5-trimethyl-1-isocyanate-3-isocyanate-methylcyclohexane (isoflurone diisocyanate, IPDI), 4-isocyanate-methyl-1,8-octane diisocyanate, 1,3-bis(isocyanate-methyl)benzene (XDI), hydrogenated phenylenediethylene diisocyanate, and hydrogenated toluene diisocyanate.

[0051] The average functionality of component a) the isocyanate component is preferably 2.0-3.5, and most preferably 2.1-3.0.

[0052] The viscosity of component a) isocyanate is preferably 5 mPa·s-700 mPa·s, most preferably 10 mPa·s-300 mPa·s, and is determined at 25°C according to DIN 53019-1-3.

[0053] The aromatic isocyanate is preferably one or more of the following: 1,2-diisocyanate-based benzene, 1,3-diisocyanate-based benzene, 1,4-diisocyanate-based benzene, 2,4-diisocyanate-based toluene, ethylbenzene diisocyanate, isopropylbenzene diisocyanate, toluene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, biphenyl diisocyanate, toluidine diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 4,4'-methylenebis(2-methylphenyl isocyanate), bibenzyl-4,4'-diisocyanate, bis(phenyl isocyanate-based)ethylene, bis(methyl isocyanate-based)benzene, bis(ethyl isocyanate-based)benzene. Benzene, bis(propyl isocyanate)benzene, α,α,α',α'-tetramethylphenyl dimethylene diisocyanate, bis(butyl isocyanate)benzene, bis(methyl isocyanate)naphthalene, bis(methyl isocyanate phenyl) ether, bis(ethyl isocyanate)phthalate, 2,6-di(methyl isocyanate)furan, 2-phenyl isocyanate-4-phenyl isocyanate sulfide, bis(4-phenyl isocyanate) sulfide, bis(4-methyl isocyanate phenyl) sulfide, bis(4-phenyl isocyanate) disulfide, bis(2-methyl-5-phenyl isocyanate) disulfide, bis(3-methyl-5-phenyl isocyanate) disulfide, bis(3-methyl-6-phenyl isocyanate) disulfide, bis(4-methyl -5-phenyl isocyanate disulfide, bis(4-methoxy-3-phenyl isocyanate) disulfide, 1,2-diisothiocyanate-benzene, 1,3-diisothiocyanate-benzene, 1,4-diisothiocyanate-benzene, 2,4-diisothiocyanate-toluene, 2,5-diisothiocyanate-m-xylene, 4,4'-methylenebis(phenyl isothiocyanate), 4,4'-methylenebis(2-methylphenyl isothiocyanate), 4,4'-methylenebis(3-methylphenyl isothiocyanate), 4,4'-diisothiocyanate-benzophenone, 4,4'-diisothiocyanate-3,3'-dimethylbenzophenone, bis(4-phenyl isothiocyanate) ether, 1-isothiocyanate- 4-[(2-isothiocyanate)sulfonyl]benzene, thiobis(4-isothiocyanate benzene), sulfonyl(4-isothiocyanate benzene), hydrogenated toluene diisocyanate (H6TDI), diphenylmethane diisocyanate and dithiobis(4-isothiocyanate benzene), most preferably one or more of the following: 1,2-diisocyanate benzene, 1,3-diisocyanate benzene, 1,4-diisocyanate benzene, diphenylmethane diisocyanate, 2,4-diisocyanate toluene, and their derivatives having iminooxadiazine dione, isocyanurate, urea dione, carbamate, urethane carbamate, biuret, urea, oxadiazine trione, oxazolidinone, acylurea and / or carbodiimide groups.

[0054] The amount of the aromatic isocyanate is preferably 0-2.5% by weight, more preferably 0-2% by weight, and most preferably does not contain aromatic isocyanate, relative to the total weight of the isocyanate component.

[0055] Component b) Isocyanate reactive component

[0056] The hydroxyl functionality of the organic polyol in component b1) is preferably 1.7-6, more preferably 1.7-4, and most preferably 1.7-3.3.

[0057] The hydroxyl value of component b1) organic polyol is preferably 20 mg KOH / g to 2000 mg KOH / g, and most preferably 20 mg KOH / g to 1200 mg KOH / g. The hydroxyl value is measured by a method well known to those skilled in the art, for example, as disclosed in Houben Weyl, Methoden der Organischen Chemie, vol. XIV / 2 Makromolekulare Stoffe, p. 17, Georg Thieme Verlag; Stuttgart 1963. The entire contents of that document are incorporated herein by reference.

[0058] The amount of component b1) organic polyol is preferably 20%-80% by weight, most preferably 50%-60% by weight, relative to the total weight of component b) isocyanate reactive component.

[0059] The component b1) organic polyol can be an organic polyol commonly used in the art to prepare polyurethane, including but not limited to: polyether polyol, polyether carbonate polyol, polyester polyol, polycarbonate diol, polymer polyol, bio-based polyol, vegetable oil-based polyol or a combination thereof.

[0060] The polyether polyol can be prepared by known processes, for example, by reacting an olefin oxide with an initiator in the presence of a catalyst. The catalyst for preparing the polyether polyol is preferably one or more of the following: basic hydroxides, basic alkoxides, antimony pentachloride, and boron fluoride diethyl ether. The olefin oxide for preparing the polyether polyol is preferably one or more of the following: tetrahydrofuran, ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide, most preferably one or more of the following: ethylene oxide and propylene oxide. The initiator for preparing the polyether polyol is preferably one or more of the following: a polyhydroxy compound and a polyamine compound. The polyhydroxy compound is preferably one or more of the following: water, ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene glycol, trimethylolpropane, glycerol, bisphenol A, and bisphenol S. The polyamine compound is preferably one or more of the following: ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, and toluenediamine.

[0061] The polyether polyol is preferably one or more of the following: a polyether polyol based on propylene oxide with glycerol as the initiator and a polyether polyol based on propylene oxide and ethylene oxide with glycerol as the initiator.

[0062] The polyether carbonate polyol can be prepared by adding carbon dioxide and epoxide alkylate to a starting material containing active hydrogen via a bimetallic cyanide catalyst.

[0063] The polyester polyol can be prepared by reacting a dicarboxylic acid or a dicarboxylic acid anhydride with a polyol. The dicarboxylic acid is preferably an aliphatic carboxylic acid containing 2-12 carbon atoms, and most preferably one or more of the following: succinic acid, malonic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, dodecyl carboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid. The dicarboxylic acid anhydride is preferably one or more of the following: phthalic anhydride, tetrachlorophthalic anhydride, and maleic anhydride. The polyol reacting with the dicarboxylic acid or dicarboxylic acid anhydride is preferably one or more of the following: ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 1,3-methylpropanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, 1,10-decanediol, glycerol, and trimethylolpropane.

[0064] The polyester polyol also includes polyester polyols prepared from lactones, preferably ε-caprolactone.

[0065] The molecular weight of the polyester polyol is preferably 200 g / mol to 3000 g / mol.

[0066] The functionality of the polyester polyol is preferably 1.7-6, further preferably 1.7-4, and most preferably 1.7-3.3.

[0067] The polycarbonate diol can be prepared by reacting a diol with a dialkyl carbonate, a diaryl carbonate, or phosgene. The diol is preferably one or more of the following: 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and trioxymethylenediol. The dialkyl carbonate or diaryl carbonate is preferably diphenyl carbonate.

[0068] The polymeric polyol is preferably a polymer-modified polyether polyol and a bio-based polyol, and most preferably one or more of the following: grafted polyether polyol and polyether polyol dispersion.

[0069] The grafted polyether polyol is preferably one or more of the following: styrene-based grafted polyether polyol and acrylonitrile-based grafted polyether polyol, wherein the styrene and / or acrylonitrile is preferably polymerized in situ from styrene, acrylonitrile, or a mixture of styrene and acrylonitrile. In the mixture of styrene and acrylonitrile, the ratio of styrene to acrylonitrile is preferably 90:10-10:90, and most preferably 70:30-30:70.

[0070] The dispersed phase of the polyether polyol dispersion is preferably one or more of the following: a base-free filler, polyurea, polyhydrazide, or polyurethane containing bonded tertiary amino groups and melamine. The amount of the dispersed phase (i.e., the solid component) of the polyether polyol dispersion is preferably 1%-50% by weight, more preferably 1%-45% by weight, and most preferably 20%-45% by weight, relative to the total weight of the polyether polyol dispersion. The hydroxyl value of the polyether polyol dispersion is preferably 20 mg KOH / g-50 mg KOH / g.

[0071] The bio-based polyol is preferably one or more of the following: castor oil and wood tar.

[0072] The plant oil-based polyol is preferably one or more of the following: plant oil, plant oil polyols and their modified products.

[0073] The vegetable oil is preferably one or more of the following: compounds prepared from unsaturated fatty acids and glycerol, oils extracted from the fruits, seeds, and germs of plants, and most preferably one or more of the following: peanut oil, soybean oil, flaxseed oil, castor oil, rapeseed oil, and palm oil.

[0074] The plant oil polyol is preferably a polyol starting from one or more plant oils. The starting agents for synthesizing plant oil polyols are preferably one or more of the following: soybean oil, palm oil, peanut oil, low-erucic acid rapeseed oil, and castor oil. The starting agents for plant oil polyols can be used to introduce hydroxyl groups through processes such as pyrolysis, oxidation, or transesterification, and then the corresponding plant oil polyols can be prepared using processes well known to those skilled in the art.

[0075] The most preferred organic polyol component b1) is one or more of the following: polyether polyol and bio-based polyol.

[0076] When the polyurethane composition contains two or more organic polyols, unless otherwise specified, the hydroxyl functionality and hydroxyl value of the organic polyols refer to the average functionality and average hydroxyl value.

[0077] When the polyurethane composition contains two or more organic polyols, it is most preferably that the hydroxyl functionality and hydroxyl value of each organic polyol meet the requirements of the present invention.

[0078] Component b2) of the compound conforming to Formula I has an alkylene group having 2-6 carbon atoms in R2, preferably selected from: ethylene, propylene, butylene, pentanylene, 1-methyl-1,2-ethylene, 2-methyl-1,2-ethylene, 1-ethyl-1,2-ethylene, 2-ethyl-1,2-ethylene, 1-methyl-1,3-propylene, 2-methyl-1,3-propylene, 3-methyl-1,3-propylene, etc. Propylene, 1-ethyl-1,3-propylidene, 2-ethyl-1,3-propylidene, 3-ethyl-1,3-propylidene, 1-methyl-1,4-butylidene, 2-methyl-1,4-butylidene, 3-methyl-1,4-butylidene, 4-methyl-1,4-butylidene, 2,2-di(4-phenylene)propane, 1,4-dimethylbenzene, 1,3-dimethylbenzene or 1,2-dimethylbenzene.

[0079] The compound of formula I (component b2) is further preferably one or more of the following: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxypentyl methacrylate, hydroxyhexyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate, with hydroxypropyl methacrylate being the most preferred.

[0080] The amount of the compound conforming to Formula I in component b2) is preferably 20%-80% by weight, most preferably 40%-50% by weight, relative to the total weight of the isocyanate reactive component in component b).

[0081] The compound conforming to Formula I (component b2) can be prepared using methods commonly used in the art, for example, by reacting (meth)acrylic anhydride or (meth)acrylic acid, (meth)acryloyl halide compounds with HO-(R2O). n -H is prepared by esterification reaction, a method well known to those skilled in the art, for example, as described in Chapter 3 of "Handbook of Polyurethane Raw Materials and Additives" (Liu Yijun, published April 1, 2005) and Chapter 2 of "Polyurethane Elastomers" (Liu Houjun, published August 2012). The entire contents of these documents are incorporated herein by reference.

[0082] Component c) Free radical reaction initiator

[0083] The amount of component c) free radical reaction initiator is preferably 0.1%-8% by weight, most preferably 1%-3% by weight, relative to the total weight of component b) isocyanate reactive component.

[0084] The free radical reaction initiator may be added to component a) isocyanate component or component b) isocyanate reactive component, or to both of the above components.

[0085] The free radical reaction initiator is preferably one or more of the following: peroxides, persulfides, peroxycarbonates, peroxyboronic acid, azo compounds, and other suitable free radical initiators capable of initiating the curing of compounds containing double bonds, and most preferably one or more of the following: tert-butyl isopropyl carbonate, tert-butyl peroxide-3,5,5-trimethylhexanoate, methyl ethyl ketone peroxide, cumene hydroperoxide, and benzoyl peroxide.

[0086] Component d) Organometallic catalyst

[0087] The amount of component d) the organometallic catalyst is preferably 0.001%-10% by weight, most preferably 0.1%-1% by weight, relative to the total weight of component b) the isocyanate reactive component.

[0088] The organometallic catalyst is used to catalyze the reaction between isocyanate groups (NCO) and hydroxyl groups (OH) in the composition.

[0089] The organometallic catalyst is preferably one or more of the following: organotin, organobismuth, organozinc, and zinc-bismuth composites, and most preferably one or more of the following: tin(II) acetate, tin(II) octoate, tin ethylhexanoate, tin laurate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin maleate, dioctyltin diacetate, bismuth octoate, bismuth 2-ethylhexanoate, bismuth decanoate, bismuth oleate, bismuth stearate, zinc octoate, zinc 2-ethylhexanoate, zinc decanoate, zinc isobutyrate, and composite catalysts in which organozinc and organobismuth are mixed in a weight ratio of 1:1 to 1:8.

[0090] Component e) Reaction accelerator

[0091] The polyurethane composition preferably further comprises a component e) a reaction accelerator.

[0092] The reaction accelerator is preferably one or more of the following: cobalt compounds and amine compounds.

[0093] Component f) Additives

[0094] The polyurethane polymer preferably further comprises a component f) additive.

[0095] The additives are preferably one or more of the following: fillers, internal release agents, flame retardants, smoke inhibitors, dyes, pigments, antistatic agents, antioxidants, UV stabilizers, diluents, defoamers, coupling agents, surface wetting agents, leveling agents, dehydrating agents, catalysts, molecular sieves, thixotropic agents, plasticizers, foaming agents, foam stabilizers, foam leveling agents, chelating agents, and free radical reaction inhibitors.

[0096] The additive may optionally be included in isocyanate component a) and / or isocyanate reactive component b). The additive may also be stored independently and, when used to prepare the polyurethane resin matrix for polyurethane composites, be mixed with isocyanate component a) and / or isocyanate reactive component b) before preparation.

[0097] The filler is preferably one or more of the following: aluminum hydroxide, bentonite, fly ash, wollastonite, perlite powder, cenospheres, calcium carbonate, talc powder, mica powder, kaolin, fumed silica, expandable microspheres, diatomaceous earth, volcanic ash, barium sulfate, calcium sulfate, glass microspheres, stone powder, wood powder, sawdust, bamboo powder, bamboo shavings, rice grains, straw fragments, sorghum stalk fragments, graphite powder, metal powder, recycled thermosetting composite material powder, plastic granules, and plastic powder. The glass microspheres can be solid or hollow.

[0098] The internal release agent can be any conventional release agent used in the production of polyurethane, preferably one or more of the following: long-chain carboxylic acids, amines of long-chain carboxylic acids, metal salts of long-chain carboxylic acids, and polysiloxanes. The long-chain carboxylic acid is preferably a fatty acid, most preferably stearic acid. The amine of the long-chain carboxylic acid is preferably one or more of the following: stearamides and fatty acid esters. The metal salt of the long-chain carboxylic acid is preferably zinc stearate.

[0099] The flame retardant is preferably one or more of the following: triaryl phosphate, trialkyl phosphate, halogenated triaryl phosphate, halogenated trialkyl phosphate, melamine, melamine resin, halogenated paraffin, and red phosphorus.

[0100] The dehydrating agent is preferably a molecular sieve.

[0101] The defoamer is preferably polydimethylsiloxane.

[0102] The coupling agent is used to improve the adhesion between the polyurethane resin matrix and the reinforcing material, and preferably one or more of the following: monoethylene oxide and organic amine-functionalized trialkoxysilane.

[0103] The thixotropic agent is preferably a fine-particle filler, and most preferably one or more of the following: clay and fumed silica.

[0104] The preferred chelating agent is one or more of the following: acetylacetone, benzoylacetone, trichloroacetylacetone, and ethyl acetoacetate.

[0105] The free radical reaction inhibitor is preferably one or more of the following: polymerization inhibitors and polymerization retarders, more preferably one or more of the following: phenolic compounds, quinone compounds and hindered amine compounds, and most preferably one or more of the following: methylhydroquinone, p-methoxyphenol, benzoquinone, polymethylguanidine derivatives and low-valent copper ions.

[0106] The amount of the additive is not limited, as long as it does not affect the performance of the polyurethane composition of the present invention.

[0107] Polyurethane composite materials

[0108] Preferably, the polyurethane resin matrix is ​​prepared under reaction conditions in which the polyurethane composition is simultaneously subjected to free radical polymerization and addition polymerization of isocyanate groups and hydroxyl groups.

[0109] The addition polymerization reaction of the isocyanate group and the hydroxyl group, wherein the isocyanate group can be an isocyanate group contained in isocyanate component a), or an isocyanate group contained in the intermediate product of the reaction between isocyanate component a) and isocyanate reactive component b); wherein the hydroxyl group can be a hydroxyl group contained in isocyanate reactive component b), or a hydroxyl group contained in the intermediate product of the reaction between isocyanate component a) and isocyanate reactive component b).

[0110] The free radical polymerization reaction is an addition polymerization reaction of olefin bonds, wherein the olefin bonds can be olefin bonds contained in component b2), or olefin bonds contained in the intermediate product of the reaction between component b2) and isocyanate component a).

[0111] The addition polymerization reaction (i.e., the addition polymerization reaction between isocyanate groups and hydroxyl groups) and the free radical polymerization reaction occur simultaneously.

[0112] As is known to those skilled in the art, suitable reaction conditions can be selected so that addition polymerization and free radical polymerization occur sequentially. However, the polyurethane resin matrix obtained in this way has a different structure than the polyurethane resin matrix prepared by simultaneous addition polymerization and free radical polymerization, which results in different mechanical strength and processability of the prepared polyurethane composite material.

[0113] The polyurethane composite material is preferably prepared by one or more of the following processes: pultrusion molding, filament winding molding, hand lay-up molding, spray molding, injection molding, and resin transfer molding, with vacuum injection molding being the most preferred method.

[0114] The reinforcing material is preferably a fibrous material, and most preferably one or more of the following: glass fiber, carbon fiber, carbon nanotube, polyester fiber, natural fiber, basalt fiber, aromatic polyamide fiber, nylon fiber, boron fiber, silicon carbide fiber, asbestos fiber, whiskers, hard particles and metal fiber.

[0115] Methods for preparing polyurethane composite materials

[0116] As is known to those skilled in the art, tin-based or amine-based catalysts can promote the addition polymerization reaction of isocyanate groups with hydroxyl groups, while heating or accelerators such as aniline compounds can accelerate the free radical polymerization reaction. Accelerators such as cobalt salts can simultaneously promote addition polymerization and free radical polymerization. Therefore, those skilled in the art can select appropriate conditions so that the polyurethane composition simultaneously exhibits free radical polymerization and addition polymerization of isocyanate groups with hydroxyl groups.

[0117] The method preferably includes one or more of the following: pultrusion molding, filament winding, hand lay-up molding, spray molding, injection molding, and resin transfer molding, with vacuum injection being the most preferred.

[0118] The content of the reinforcing material is preferably 1%-90% by weight, more preferably 30%-85% by weight, and most preferably 50%-80% by weight, relative to the total weight of the polyurethane composite material.

[0119] The reinforcing material is preferably a fibrous material, and most preferably one or more of the following: glass fiber, carbon fiber, carbon nanotube, polyester fiber, natural fiber, basalt fiber, aromatic polyamide fiber, nylon fiber, boron fiber, silicon carbide fiber, asbestos fiber, whiskers, hard particles and metal fiber.

[0120] Those skilled in the art are familiar with the operation methods of polyurethane vacuum infusion process, such as the content described in patent CN1954995A, the entire contents of which are incorporated herein by reference.

[0121] In the vacuum infusion process, one or more core materials are placed in a mold, optionally wholly or partially covered by reinforcing material. A negative pressure is then created within the mold, causing the polyurethane composition to be infused into it. Before curing, the polyurethane composition completely impregnates the reinforcing material, and the core material is also wholly or partially impregnated with the polyurethane composition. Then, under suitable conditions, the polyurethane composition undergoes both addition polymerization and free radical polymerization simultaneously, thereby curing the polyurethane composition to form a polyurethane resin matrix. In the above vacuum infusion process, the mold can be a commonly used mold in the art, and those skilled in the art can select a suitable mold based on the required performance and size of the final product. When using the vacuum infusion process to prepare large objects, to ensure sufficient working time, the polyurethane composition needs to maintain a sufficiently low viscosity during the infusion process to maintain good flowability. If the viscosity is higher than 600 mPa·s, the polyurethane composition is considered to have excessively high viscosity, resulting in poor flowability and making it unsuitable for the vacuum infusion process.

[0122] The use of the core material in conjunction with the polyurethane resin matrix and reinforcing materials facilitates the molding of the polyurethane composite and reduces its weight. The polyurethane composite of this invention can use core materials commonly used in the art, including but not limited to polystyrene foams such as COMP. Foam; polyester PET foam; polyimide PMI foam; polyvinyl chloride foam; metal foam, such as metal foam available from Mitsubishi; balsa wood, etc.

[0123] When the hydroxyl functionality of the organic polyol component (b1) in the polyurethane composition is preferably 1.7-6, more preferably 1.9-4.5, even more preferably 2.6-4.0, and most preferably 2.8-3.3, and the hydroxyl value is 150 mgKOH / g-550 mgKOH / g, more preferably 250 mgKOH / g-400 mgKOH / g, and most preferably 300 mgKOH / g-370 mgKOH / g, the polyurethane composition is suitable for preparing polyurethane composites using a polyurethane vacuum infusion process. This process provides a longer workability time, and the polyurethane composites prepared by the polyurethane vacuum infusion process exhibit good mechanical strength, particularly a high heat distortion temperature. This solves the problem in the prior art that the workability time of the polyurethane composition and the heat distortion temperature of the prepared polyurethane composites cannot be improved simultaneously. These polyurethane composites can be used to prepare wind turbine blades, wind turbine nacelle covers, ship blades, ship hulls, vehicle interior and exterior trim and housings, radomes, structural materials for mechanical equipment, decorative and structural components for buildings and bridges, or copper-clad laminates for electronic and electrical equipment.

[0124] The polyurethane composite material of the present invention can also be prepared by pultrusion molding, filament winding molding, hand lay-up molding, spray molding, or combinations thereof. For detailed descriptions of these processes, please refer to Chapters 2 and 6-9 of "Composite Material Processes and Equipment" (Liu Xiong-ya et al., 1994, Wuhan University of Technology Press). The entire contents of the foregoing disclosure are incorporated herein by reference.

[0125] When the polyurethane composition comprises a polyether polyol having a functionality of 1.7-6, preferably 1.7-5.8, most preferably 1.7-4.5, and a hydroxyl value of 150 mgKOH / g-1100 mgKOH / g, preferably 250 mgKOH / g-550 mgKOH / g, most preferably 300 mgKOH / g-450 mgKOH / g, the polyurethane composition is suitable for preparing polyurethane composite materials, such as fiber-reinforced bars or anchor bolts, as substitutes for steel bars, by pultrusion molding. Specific preparation processes are described in CN1562618A, CN1587576A, CN103225369A, US5650109A, US5851468A, US2002031664A, WO2008128314A1, and US5047104A. The entire contents of the foregoing disclosures are incorporated herein by reference.

[0126] use

[0127] The product is selected from structural components or lightweight structural components such as profiles, carriers, reinforcing supports.

[0128] The components comprising the article may be selected from: pipe covers, luggage compartments, engine hoods, crash barriers, bumpers, partitions, baffles, pipes, utility poles, pressure vessels, storage tanks, wind turbine blades, wind turbine nacelle covers, ship blades, ship hulls, vehicle interior and exterior trim and housings, radomes, mechanical equipment, decorative and structural components of buildings and bridges, or copper-clad laminates for electronic and electrical equipment.

[0129] Example

[0130] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any discrepancy between the definitions of terms in this specification and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0131] Unless otherwise stated, all numerical values ​​for the amounts of expressed components, reaction conditions, etc., used in the specification and claims are to be understood as being modified by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth herein are approximate values ​​that can be varied to obtain the desired performance.

[0132] Unless otherwise stated, the terms “a,” “an,” “an,” and “the” as used in this specification are intended to include “at least one” or “one or more.” For example, “a component” refers to one or more components, and therefore more than one component may be considered and may be employed or used in the implementation of the described embodiments.

[0133] The word “and / or” as used in this article refers to one or all of the elements mentioned.

[0134] The terms "include" and "contain" as used in this article cover both cases where only the mentioned elements exist and cases where other unmentioned elements exist in addition to the mentioned elements.

[0135] All percentages in this invention are weight percentages, unless otherwise stated.

[0136] All analytical measurements of this invention are performed at 23±2℃ and 50+5% humidity, unless otherwise stated.

[0137] The isocyanate group (NCO) content was determined according to DIN-EN ISO 11909:2007-05, and the data included the content of free and potentially free NCO.

[0138] Gel Time: At 23°C, the gel time of the fresh polyurethane composition mixed with Speedmixer was measured using a Paul N. Gardner GTS-THP gel apparatus. Timing began immediately after mixing; when gelation occurred and the torque became excessive, the motor automatically stopped, and the gel time was automatically calculated and displayed. A gel time of 60 minutes or more is considered acceptable for the polyurethane composition. A longer gel time results in a longer workable time for the polyurethane composition, meaning fewer restrictions on application processes and easier suitability for industrial applications.

[0139] Curing Time: First, preheat the heating platform to 180°C. At 23°C, weigh 10g of the freshly mixed polyurethane composition using Speedmixer and place it in a metal pan. Then, place the pan on the 180°C heating platform and record the time required for the composition to fully cure from the start of curing. The longer the curing time, the lower the hardness of the polyurethane composition. A shorter curing time is more beneficial for actual process operation. The desired curing time in this invention is less than 2 minutes.

[0140] Viscosity: At 23 °C, the viscosity of the freshly prepared polyurethane composition mixed with a Speedmixer was measured using a Brookfield DV-II+Pro viscometer in accordance with DIN EN ISO 3219. The polyurethane composition is considered qualified if its viscosity is less than 1000 mPas. High viscosity is not conducive to the wetting of the reinforcing material by the polyurethane composition during the preparation of the polyurethane composite and is not conducive to the construction of the composition.

[0141] Shore hardness: At room temperature, the Shore hardness of the cured polyurethane resin matrix was measured in accordance with DIN EN ISO 868. The polyurethane composition is considered qualified if its Shore hardness is greater than or equal to 70. The higher the hardness, the better the mechanical strength of the polyurethane resin matrix.

[0142] Barcol hardness: At room temperature, the Barcol hardness of the cured polyurethane resin matrix was measured in accordance with GB / T 3854-2017.

[0143] Yellowing grade test: The cured polyurethane resin matrix was placed in a Q-Lab QUV / se ultraviolet accelerated aging test machine and aged for 500 hours in accordance with DIN EN ISO 11507 UVB. The color before and after aging was compared with a standard gray scale card, and the result was expressed as a grade from 1 to 5. Grade 5 indicates no distinguishable color change by the naked eye, indicating that the material is not prone to yellowing, and grade 1 indicates a significant darkening of the color, indicating that the material is prone to yellowing. The polyurethane resin matrix is considered qualified if its weather resistance yellowing grade is greater than or equal to 4. The higher the yellowing grade, the better the weather resistance of the polyurethane resin matrix.

[0144] Raw materials and reagents

[0145] Desmocomp AP200: An aliphatic isocyanate with an isocyanate group content of 23 wt% and an average isocyanate functionality of 3, purchased from Covestro;

[0146] Desmodur 1511L: An aromatic isocyanate with an isocyanate group content of 31.4 wt% and an average isocyanate functionality of 2.7, purchased from Covestro;

[0147] Castor oil: A polyol derived from natural oil, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0148] Polyether polyol 1: A polyether polyol based on propylene oxide with glycerol as the initiator, having a hydroxyl functionality of 3 and a hydroxyl value of 470 mg KOH / g;

[0149] Polyether polyol 2: A polyether polyol based on propylene oxide with glycerol as the initiator, having a hydroxyl functionality of 3 and a hydroxyl value of 245 mg KOH / g;

[0150] Polyether polyol 3: A polyether polyol based on propylene oxide and ethylene oxide, using glycerol as an initiator, with a hydroxyl functionality of 3 and a hydroxyl value of 35 mgKOH / g;

[0151] Polyether polyol 4: A polyether polyol based on propylene oxide and ethylene oxide, using glycerol as an initiator, with a hydroxyl functionality of 3 and a hydroxyl value of 1120 mgKOH / g;

[0152] Hydroxypropyl methacrylate (HPMA): Purchased from Heshibi Company, purity 98% by weight;

[0153] Benzoyl peroxide (BPO): 98% purity, purchased from Sinopharm Reagent.

[0154] UL 29: Organotin catalyst, purchased from Momentive, trade name Formrez UL-29;

[0155] INT 1940 RTM: Mold release agent, purchased from Axel Plastics Research Laboratories, INC.

[0156] BYK 066N: Defoamer, purchased from BYK Company;

[0157] 3A molecular sieve: purchased from Shanghai Hengye Molecular Sieve Co., Ltd.;

[0158] Glass fiber: purchased from Owens Corning, brand name ADVANTEX 366, with 4800 tex.

[0159] Preparation methods of polyurethane resin matrices in the examples and comparative examples

[0160] At 23°C, the components were prepared according to the proportions listed in Table 1 to obtain the composition. The composition was then placed in a Hauschild Speedmixer DAC 150.1FVZ and mixed at 2750 rpm for 1 minute. Subsequently, the composition was poured into a suitable mold and cured in an oven at 160°C for 10 minutes to obtain the polyurethane resin matrix of the examples and comparative examples.

[0161] Table 1. Components and performance test results of the polyurethane composition

[0162]

[0163] The polyurethane compositions of Examples 1-6 have suitable viscosity, long gel time, short curing time, high hardness and good weather resistance.

[0164] In Comparative Example 1, the polyurethane composition contains component b) isocyanate reactive component (component b2), resulting in high viscosity of the polyurethane composition, which is not conducive to the wetting of the reinforcing material by the polyurethane composition during the preparation of polyurethane composite materials; the polyurethane resin matrix prepared from the polyurethane composition has low hardness and poor mechanical strength.

[0165] Comparing Example 6 and Comparative Example 2, the content of aromatic isocyanate in component a) of the polyurethane composition of Comparative Example 2 exceeds 2.5% by weight. The gel time of the polyurethane composition of Comparative Example 2 is significantly reduced, making it difficult to achieve the operating time required for actual process operation. In order to use this composition, a dispensing machine is required, which increases equipment costs.

[0166] In Comparative Example 3, the hydroxyl value of component b) of the isocyanate reactive component in the polyurethane composition is 177 mg KOH / g. The polyurethane resin matrix prepared from the polyurethane composition has low hardness, a soft feel, and poor mechanical properties.

[0167] In Comparative Example 4, the hydroxyl value of component b) of the isocyanate reactive component in the polyurethane composition is 755 mg KOH / g. The high viscosity of the polyurethane composition is not conducive to the wetting of the reinforcing material by the polyurethane composition during the preparation of polyurethane composite materials, and is not conducive to the construction of the composition.

[0168] Comparing Example 3 and Comparative Example 5, the polyurethane composition of Comparative Example 5 contains only aromatic isocyanates in component a) isocyanate and no aliphatic isocyanates. The polyurethane composition of Comparative Example 5 has a very short gel time, which makes it difficult to achieve the operating time required for actual process operation. In addition, the polyurethane resin matrix prepared by the polyurethane composition has very poor weather resistance.

[0169] Comparing Example 3 and Comparative Example 6, the polyurethane composition of Comparative Example 6 does not contain an organometallic catalyst, resulting in reduced catalytic activity, longer curing time, and decreased hardness of the polyurethane resin matrix prepared from the composition.

[0170] Example 7: Preparation of polyurethane composite materials by pultrusion process

[0171] The polyurethane composition was obtained by mixing according to the proportions in Table 1, Example 3, and then 1% by weight of INT 1940 RTM (relative to the total weight of the polyurethane composition of Example 3) was added. The mixture was mixed evenly, the viscosity was 200 mPa·s, and the gel time was greater than 10 hours.

[0172] On a commercially available pultrusion molding machine, glass fiber bundles (126 rovings) are oriented and guided through an impregnation tank, into which a polyurethane composition is poured. The glass fibers, fully impregnated with the polyurethane composition, are then directly drawn into a preheated mold with a cross-section of 110mm x 4.0mm using a traction device. The mold is subsequently heated in three sections at temperatures of H1 = 150℃, H2 = 190℃, and H3 = 210℃. The drawing speed is 0.5m / min, and the traction force is approximately 0.3t. The resulting polyurethane composite material exhibits good wetting, stable traction force with fluctuations less than 10%, and a uniform surface. The glass fiber content is 80% by weight, and the surface hardness is >50.

[0173] Example 8: Preparation of polyurethane composite materials using a winding process

[0174] The polyurethane composition was obtained by mixing according to the proportions of Example 1 in Table 1, and then 1% by weight of BYK 066N and 2% by weight of 3A molecular sieve (relative to the total weight of the polyurethane composition of Example 1) were added. The mixture was mixed evenly, the viscosity was 300 mPa·s, and the gel time was greater than 10 hours.

[0175] In a commercially available winding machine, a polyurethane composition is poured into an open impregnation tank. Glass fibers impregnated with the polyurethane composition are reciprocated between the two ends of a rotating mandrel according to the set winding process parameters. After the process is completed, the mandrel with the polyurethane composite material wound on its surface is hoisted onto a rotating support in a curing oven. The curing oven is started, and the rotating support drives the mandrel to rotate. At the same time, hot air enters the curing oven to cure the composite material. The curing time is 2 hours, and the curing temperature is 120℃-155℃. The resulting polyurethane composite material has good wetting, a uniform surface, a glass fiber content of 65% by weight, and a surface Barcol hardness >50.

[0176] The polyurethane compositions of Examples 7 and 8 were processed in an open impregnation tank, eliminating the need for a closed impregnation equipment, thus simplifying the process. Furthermore, the resulting composite materials exhibited excellent properties: uniform surface, good glass fiber wetting, and high surface hardness, meeting mechanical requirements.

[0177] It will be readily apparent to those skilled in the art that this invention is not limited to the specific details described above, and that it may be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments described should be considered illustrative rather than restrictive in any way, and the scope of the invention is determined by the claims rather than the foregoing description; and thus any modifications that fall within the meaning and scope of the equivalents of the claims should be considered part of this invention.

Claims

1. A polyurethane composition for preparing composite materials, comprising: a) An isocyanate component comprising not less than 97.5% by weight of an aliphatic isocyanate and optionally an aromatic isocyanate; b) Isocyanate reactive components, including: b1) At least one organic polyol, said organic polyol being in an amount of 20% to 80% by weight, relative to the total weight of the isocyanate reactive component; and b2) At least one compound that conforms to the structure of formula I: in, R1 is selected from hydrogen, methyl, or ethyl; R2 is selected from alkylene, 2,2-bis(4-phenylene)propane, 1,4-bis(methylene)benzene, 1,3-bis(methylene)benzene, or 1,2-bis(methylene)benzene, having 2-6 carbon atoms; n is an integer from 1 to 6, and the amount of component b2) of the compound conforming to the structure of formula I is 20%-80% by weight, relative to the total weight of the isocyanate reactive component of component b). c) A free radical reaction initiator selected from peroxides, persulfides and azo compounds, wherein the amount of component c) the free radical reaction initiator is 0.1% to 8% by weight relative to the total weight of component b) the isocyanate reactive component; and d) An organometallic catalyst selected from organotin catalysts, wherein the amount of component d) organometallic catalyst is 0.001 wt% to 10 wt% relative to the total weight of component b) isocyanate reactive component; The hydroxyl value of component b) isocyanate reactive component is 200 mg KOH / g-700 mg KOH / g, and the molar ratio of isocyanate groups to hydroxyl groups in the composition is 0.9-1.

1. The aliphatic isocyanate contained in component a) is an unblocked aliphatic polyisocyanate polymer or prepolymer. The polyurethane composition undergoes both free radical polymerization and addition polymerization of isocyanate groups and hydroxyl groups.

2. The polyurethane composition according to claim 1, characterized in that, The free radical reaction initiator of component c) is selected from peroxycarbonate and peroxyboric acid.

3. The polyurethane composition according to claim 1, characterized in that, The aliphatic isocyanate contained in component a) is an unblocked aliphatic diisocyanate polymer or prepolymer.

4. The polyurethane composition according to claim 1, characterized in that, The aliphatic isocyanate contained in component a) is a polymer or prepolymer of an unclosed alicyclic diisocyanate.

5. The polyurethane composition according to claim 1, characterized in that, The aliphatic isocyanate contained in component a) is a polymer or prepolymer of an unclosed alicyclic polyisocyanate.

6. The polyurethane composition according to claim 1, characterized in that, The isocyanate group content of component a) is 10%-61% by weight, relative to the total weight of component a) isocyanate.

7. The polyurethane composition according to claim 1, characterized in that, The isocyanate group content of component a) is 18%-40% by weight, relative to the total weight of component a) isocyanate.

8. The polyurethane composition according to claim 1, characterized in that, The hydroxyl functionality of component b1) organic polyol is 1.7-6.

9. The polyurethane composition according to claim 1, characterized in that, The hydroxyl value of component b1) organic polyol is 20 mgKOH / g-2000 mgKOH / g.

10. The polyurethane composition according to claim 1, characterized in that, The compound that conforms to the structure of Formula I (component b2) is one or more of the following: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxypentyl methacrylate, hydroxyhexyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

11. The polyurethane composition according to claim 1, characterized in that, The polyurethane composition further comprises a component e) a reaction accelerator, said reaction accelerator being one or more of the following: cobalt compounds and amine compounds.

12. A polyurethane composite material comprising a polyurethane resin matrix and a reinforcing material, wherein the polyurethane resin matrix is ​​prepared by a polyurethane composition according to any one of claims 1-11.

13. The polyurethane composite material according to claim 12, characterized in that, The polyurethane composite material is prepared by one or more of the following methods: pultrusion, filament winding, hand lay-up, spray molding, injection molding, and resin transfer molding.

14. The polyurethane composite material according to claim 12, characterized in that, The reinforcing material is fibrous.

15. The polyurethane composite material according to claim 12, characterized in that, The reinforcing material is selected from one or more of the following: glass fiber, carbon fiber, carbon nanotube, polyester fiber, natural fiber, basalt fiber, aromatic polyamide fiber, nylon fiber, boron fiber, silicon carbide fiber, asbestos fiber, whiskers, hard particles, and metal fiber.

16. A method for preparing a polyurethane composite material, the polyurethane composite material comprising a polyurethane resin matrix and a reinforcing material, the method comprising the step of preparing the polyurethane resin matrix under reaction conditions in which the polyurethane composition according to any one of claims 1-11 simultaneously undergoes a free radical polymerization reaction and an addition polymerization reaction of isocyanate groups and hydroxyl groups.

17. The method according to claim 16, characterized in that, The method is one or more of the following: pultrusion, filament winding, hand lay-up, spray molding, injection molding, and resin transfer molding.

18. The method according to claim 16, characterized in that, The reinforcing material is fibrous.

19. The method according to claim 16, characterized in that, The reinforcing material is selected from one or more of the following: glass fiber, carbon fiber, carbon nanotube, polyester fiber, natural fiber, basalt fiber, aromatic polyamide fiber, nylon fiber, boron fiber, silicon carbide fiber, asbestos fiber, whiskers, hard particles, and metal fiber.

20. Use of the polyurethane composite material according to any one of claims 12-15 in the preparation of articles.

21. The use as described in claim 20, characterized in that, The product is selected from structural components or lightweight structural components such as profiles, carriers, reinforcing supports.

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