SiCN(O) fiber and method for producing the same

Abstract

The application belongs to the technical field of high-performance fiber preparation and relates to SiCN(O) fiber and a preparation method thereof.The SiCN(O) fiber is prepared from a precursor including (poly)silazane containing C=C and / or isocyanurate-containing polycarbosilane through steps including spinning, ultraviolet radiation crosslinking and high-temperature sintering.The (poly)silazane containing C=C and / or isocyanurate-containing polycarbosilane raw material of the application is used in combination with the ultraviolet radiation crosslinking process, and the preparation of SiCN(O) fiber with smooth and dense surface is successfully realized, and the ultraviolet radiation crosslinking is used for infusibilization instead of air infusibilization, so that the infusibilization time is greatly shortened, and the comprehensive preparation cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-performance fiber preparation and relates to a SiCN(O) fiber and a preparation method thereof. BACKGROUND

[0002] The SiCN(O) fiber has excellent properties such as high strength, high modulus, low density, oxidation resistance, corrosion resistance, wave absorption and the like, is an ideal reinforcing body of high-performance ceramic matrix composite materials, and has a wide application prospect in the fields of aerospace and military weapons.

[0003] The precursor transformation method is one of main methods for preparing silicon nitride ceramic fibers, mainly including four steps of precursor synthesis, spinning, infusibilization treatment and high-temperature sintering. The infusibilization treatment is a key step for preparing the SiCN(O) fiber. After the primary fiber is formed, if the high-temperature sintering is directly performed, the fiber will be melted to lose the fiber shape under the high-temperature condition; and through the infusibilization treatment, the primary fiber is crosslinked, and in the high-temperature sintering process, the fiber will not be dissolved or melted, and the fiber shape can be maintained in the inorganic process.

[0004] At present, there are many kinds of infusibilization treatment methods, including thermal oxidation crosslinking, chemical vapor crosslinking, electron beam irradiation crosslinking and the like. Gary E. Legrow et al. (J. Chim. Phys., 1986, 83: 869-873) synthesized perhydro-polysilazane (PHPS) by using hexamethyldisilazane and trichlorosilane in the 1980s, melt-spun the PHPS under the protection of inert gas, then performed chemical vapor crosslinking infusibilization treatment in the HSiCl3 atmosphere, and finally obtained the Si3N4 fiber through high-temperature pyrolysis. However, because the structure of the precursor is unstable, a large number of pores appear in the fiber after high-temperature pyrolysis, and the fiber performance is poor.

[0005] Domaine et al. (J. Mater. Sci., 1993, 28: 3059-3068) mainly prepared silazane by using Me2SiCl2 and ClMeHSi-NH-SiHMeCl as raw materials through Wurtz reaction, then obtained the precursor polycarbosilazane (PCSZ) through high-temperature rearrangement, prepared the primary fiber through melt spinning, then performed γ-ray or air infusibilization treatment and high-temperature pyrolysis to finally obtain the SiCN ceramic fiber. Lanlin (Functional Materials, 2013: 2981-2984) performed nitrogenization pyrolysis and decarburization ammonia on the electron beam radiation cured polycarbosilane (PCS) fiber in the ammonia atmosphere, then performed high-temperature thermal initiation condensation / amino group transfer reaction in the nitrogen atmosphere to generate silazane, and finally formed the Si3N4 fiber.

[0006] However, the above non-melting process is complicated, time-consuming, and requires harsh equipment and high preparation cost, and even causes environmental pollution, which limits the development and application of SiCN fiber to some extent. SUMMARY

[0007] The present application aims at solving the problems in the prior art, and provides a SiCN(O) fiber and a preparation method thereof, which reduces the crosslinking time and improves the curing efficiency through ultraviolet light irradiation crosslinking.

[0008] One object of the present application is achieved by the following technical solutions:

[0009] A SiCN(O) fiber is prepared by using a precursor including (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate, and through steps including spinning, ultraviolet light irradiation crosslinking, and high-temperature sintering.

[0010] In the above SiCN(O) fiber, the polycarbosilane including (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate refers to polycarbosilane including (poly)silazane containing C=C, polycarbosilane including C=C isocyanurate, or polycarbosilane including (poly)silazane containing C=C and C=C isocyanurate.

[0011] In the above SiCN(O) fiber, the polycarbosilane including (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate is prepared by mixing (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate with polycarbosilane. The mixing method of (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate with polycarbosilane is not limited, and any step capable of mixing (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate with polycarbosilane is within the protection scope of the present application. As an example, the mixing method of (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate with polycarbosilane includes the following steps: dissolving polycarbosilane with (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate in an organic solvent, and then removing the organic solvent by distillation to obtain polycarbosilane including (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate. The organic solvent refers to any organic solvent capable of dissolving polycarbosilane, (poly)silazane containing C=C, and / or polycarbosilane containing C=C isocyanurate, such as tetrahydrofuran and the like.

[0012] Preferably, in the precursor, the mass ratio of (poly)silazane containing C=C and / or polycarbosilane containing C=C isocyanurate to polycarbosilane is 1:100-100:100.

[0013] In the SiCN(O) fiber, the (poly)silazane containing C=C is a silazane or polysilazane containing C=C and Si-N in the molecular structure; preferably, the (poly)silazane containing C=C includes but is not limited to one or more of tetramethyltetraethenylcyclotetrasilazane, 2,4,6-trivinyl-2,4,6-trimethylcyclotrisilazane, tetramethyldivinyldisilazane, and vinyl polysilazane.

[0014] In the SiCN(O) fiber, the isocyanurate containing C=C is an isocyanate compound containing C=C and N-C=O in the molecular structure; preferably, the isocyanurate containing C=C includes but is not limited to one or more of triallyl isocyanurate, tris(2-acryloyloxyethyl) isocyanurate, and diallyl isocyanurate.

[0015] In the SiCN(O) fiber, the polycarbosilane is an organosilicon polymer with Si-C bond as the main chain, and has a CH3SiHCH2 structural unit in the molecular main chain and is in a solid state at room temperature; preferably, the polycarbosilane has a softening point greater than 100°C and a number average molecular weight of 100-5000.

[0016] Preferably, the polycarbosilane contains a hetero element; further preferably, the hetero element includes one or more of aluminum, yttrium, nickel, hafnium, lithium, iron, cobalt, lanthanum, zirconium, titanium, beryllium, magnesium, calcium, vanadium, and boron. When the polycarbosilane contains a hetero element, the SiCN(O) fiber prepared therefrom can more effectively reduce the oxygen content of the SiCN(O) fiber and impart certain functional properties to the SiCN(O) fiber, such as wave absorption, electromagnetic shielding, etc. The content of the hetero element in the polycarbosilane is not limited.

[0017] Preferably, the spinning is melt spinning, dry spinning, or electrospinning. The precursor of the present application can be spun by any one of melt spinning, dry spinning, or electrospinning to obtain the original fiber.

[0018] When the spinning is melt spinning, as an example, the process conditions of the melt spinning include: grinding the polycarbosilane containing (poly)silazane containing C=C and / or isocyanurate containing C=C into powder, placing the powder in a spinning barrel, heating to 100-250°C under an inert atmosphere, spinning through a spinneret under the action of pressure (as an example, 0.01-2 MPa), and collecting by a spinning drum to obtain an original fiber with a diameter of 5-20 μm;

[0019] When the spinning is electrospinning, as an example, the process conditions of the electrospinning include: a spinneret inner diameter of 0.5-3 mm, a spinning voltage of 10-20 kV, a distance between the spinneret and the fiber collector of 5-40 cm, and a spinning speed of 10-50 μL / min;

[0020] When the spinning is dry spinning, as an example, the process conditions of the dry spinning include: under the protection of inert atmosphere, the spinning solution is raised to 50-150℃ in the spinning device, kept for 0.5-5h, and then discharged through the spinneret under the action of pressure to form the proto-fiber.

[0021] In electrospinning and dry spinning, the polycarbosilane including the (poly)silazane containing C=C and / or the isocyanurate containing C=C is dissolved in an organic solvent to form a spinning solution, and then the spinning solution is placed in a spinning device to perform spinning. The above-mentioned organic solvent is any solvent capable of dissolving the polycarbosilane including the (poly)silazane containing C=C and / or the isocyanurate containing C=C, including one or more of toluene, xylene, tetrahydrofuran, acetone, n-hexane, chloroform.

[0022] Preferably, the step of ultraviolet light radiation crosslinking includes: ultraviolet light radiation crosslinking the proto-fiber obtained by spinning, the light intensity of the ultraviolet lamp is 10-1000 mW / cm 2 , the wavelength of the ultraviolet light is 185-400 nm, and the radiation time is 1-180 min.

[0023] Preferably, the step of high-temperature sintering includes: raising the temperature of the fiber after ultraviolet light radiation crosslinking to 1000-1400℃ at a rate of 1-20℃ / min under an inert atmosphere, and keeping for 0.5-5h.

[0024] The inert atmosphere herein includes but is not limited to one of an argon atmosphere and a nitrogen atmosphere.

[0025] Another object of the present application is achieved by the following technical solutions:

[0026] A preparation method of SiCN(O) fiber, comprising the following steps:

[0027] spinning a precursor including polycarbosilane containing (poly)silazane containing C=C and / or isocyanurate containing C=C to obtain a proto-fiber,

[0028] ultraviolet light radiation crosslinking the proto-fiber;

[0029] high-temperature sintering of the fiber after ultraviolet light radiation crosslinking.

[0030] Preferably, the conditions of ultraviolet light radiation crosslinking include: the light intensity of the ultraviolet lamp is 10-1000 mW / cm 2 , the wavelength of the ultraviolet light is 185-400 nm, and the radiation time is 1-180 min.

[0031] Preferably, the conditions of high-temperature sintering include: raising the temperature to 1000-1400℃ at a rate of 1-20℃ / min under an inert atmosphere, and keeping for 0.5-5h.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] (1) The present application provides a new SiCN(O) fiber preparation method: using polycarbosilane including (poly)silazane containing C=C and / or isocyanurate containing C=C as a precursor, precursor fibers are prepared by spinning, then the precursor fibers are not fused by UV radiation crosslinking at room temperature, and then the non-fused fibers are subjected to high-temperature heat treatment in an inert atmosphere to obtain SiCN(O) fibers.

[0034] (2) The present application successfully realizes the preparation of SiCN(O) fibers with smooth and dense surface and cross section by combining the use of polycarbosilane including (poly)silazane containing C=C and / or isocyanurate containing C=C and the UV radiation crosslinking process.

[0035] (3) The present application uses polycarbosilane including (poly)silazane containing C=C and / or isocyanurate containing C=C as a precursor, and performs non-fusion treatment under UV radiation crosslinking instead of air non-fusion, greatly shortening the non-fusion time and reducing the overall preparation cost.

[0036] (4) When polycarbosilane including (poly)silazane containing C=C and / or isocyanurate containing C=C contains a heterogeneous element, using it as a raw material to prepare SiCN(O) fibers can more effectively reduce the oxygen content in SiCN(O) fibers, and endow SiCN(O) fibers with certain functional properties, such as wave absorption, electromagnetic shielding, etc. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is the FT-IR spectrum of PVNACS1 precursor fiber in Example 1 of the present application, and PVNACS1 non-fused fiber after UV radiation crosslinking of PVNACS1;

[0038] Figure 2 is the scanning electron microscope image of SiCN(O) fiber prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further described and explained by specific examples and drawings. It should be understood that the specific examples described herein are only used to help understand the present application and are not used to limit the specific application. The drawings used herein are only used to better illustrate the disclosed content and do not limit the scope of protection. If not otherwise specified, the raw materials used in the examples of the present application are commonly used raw materials in the art, and the methods used in the examples are conventional methods in the art.

[0040] Example 1

[0041] The preparation method of the SiCN(O) fiber of the embodiment comprises the following steps:

[0042] (1) 21 g of polyaluminocarbosilane (PACS) and 9 g of tetramethyltetra-vinylcyclotetrasilazane were mixed and dissolved in tetrahydrofuran solvent, and after being fully dissolved and dispersed, the solvent was removed by reduced pressure distillation, and finally a milky white brittle resin containing vinylsilazane polyaluminocarbosilane (PVNACS1) was obtained. The softening point of the polyaluminocarbosilane is 205.5°C, the number average molecular weight is 883, the weight average molecular weight is 3191, and the aluminum content is 0.5 wt%.

[0043] (2) Melt spinning: 20 g of the PVNACS1 precursor was placed in a spinning cylinder of a melt spinning device, heated to 170°C under N2 protection for 2 h, and then the precursor was extruded from the spinneret under a pressure of 0.15 MPa, and a PVNACS1 fiber with a diameter of 12-16 μm was collected by a roller.

[0044] (3) UV radiation crosslinking: the spun PVNACS1 fiber was placed in a UV light box and irradiated for 30 min, wherein the irradiation wavelength was 365 nm, the light intensity was 300 mW / cm 2 , the distance from the light source was 15 cm, and a PVNACS1 non-melting fiber was obtained.

[0045] (4) High temperature sintering: the obtained PVNACS1 non-melting fiber was placed in a high temperature furnace, and heated to 1200°C at a rate of 3°C / min under nitrogen gas protection, and kept for 1 h, and then cooled to obtain a SiCN(O) fiber.

[0046] After testing, the oxygen content of the obtained SiCN(O) fiber was 9 wt%, the nitrogen content was 2 wt%, the C / Si ratio was 1.3, the fiber diameter was 11-13 μm, the tensile strength was 1.8 GPa, and the tensile modulus reached 190 GPa.

[0047] Figure 1 is the FT-IR spectrum of the PVNACS1 fiber and the PVNACS1 non-melting fiber after UV radiation crosslinking of the PVNACS1 fiber in Example 1 of the present application. In the figure, the characteristic absorption peaks at 2100 cm -1 belonging to Si-H and 1600 cm -1 belonging to CH2=CH2 all have a significant downward trend. According to the Lambert-Beer law, the peak intensity ratio of 2100 cm -1 (Si-H) to 1250 cm -1 (Si-CH3), 1600 cm -1 (CH2=CH2) to 1250 cm -1The peak intensity ratio of Si-H and CH2=CH2 groups is calculated as the reaction degree P of Si-H and CH2=CH2 groups respectively Si-H , P CH2＝CH2 are 20.5%, 41.7% respectively. It is proved that the self-polymerization of carbon-carbon double bond and the hydrosilation reaction between Si-H and Si-CH3 occur in the fiber under the UV irradiation, which makes the fiber crosslink and solidify.

[0048] Figure 2 is the scanning electron microscope image of the SiCN(O) fiber prepared in Example 1. After sintering at 1200℃, the surface and cross section of the SiCN(O) fiber are smooth and dense, and no obvious defects are found.

[0049] Example 2

[0050] The preparation method of the SiCN(O) fiber in this example comprises the following steps:

[0051] (1) 21g of polycarbosilane (PCS) and 9g of triallyl isocyanurate (TAIC) are mixed and dissolved in tetrahydrofuran solvent, and after being fully dissolved and dispersed, the solvent is removed by reduced pressure distillation, and finally a milky white brittle resin, vinyl isocyanurate-containing polycarbosilane PVNCS1, is obtained. The softening point of the polycarbosilane is 200.1℃, the number average molecular weight is 936, and the weight average molecular weight is 3160.

[0052] (2) Melt spinning: 20g of the PVNCS1 precursor is placed in the spinning cylinder of a melt spinning device, heated to 150℃ under N2 protection for 2h, and then the precursor is extruded from the spinneret under a pressure of 0.25MPa, and the PVNCS1 precursor fiber with a diameter of 15-19μm is collected by a roller.

[0053] (3) UV irradiation crosslinking: the spun PVNCS1 precursor fiber is placed in a UV lamp box for irradiation for 15min, the irradiation wavelength is 365nm, the light intensity is 400mW / cm 2 , the distance from the light source is 15cm, and the PVNCS1 non-melting fiber is obtained.

[0054] (4) High temperature sintering: the obtained PVNCS1 non-melting fiber is placed in a high temperature furnace, heated to 1200℃ at a rate of 5℃ / min under nitrogen gas protection, and kept for 1h, and then the SiCN(O) fiber is obtained after cooling.

[0055] The obtained SiCN(O) fiber is tested, and the oxygen content is 10wt%, the nitrogen content is 3.5wt%, the C / Si ratio is 1.24, the fiber diameter is 11-14μm, the tensile strength is 2.0GPa, and the tensile modulus is 185GPa.

[0056] Example 3

[0057] The preparation method of the SiCN(O) fiber of the present embodiment comprises the following steps:

[0058] (1) 2 g of polyaluminum carbosilane (PACS) and 1.6 g of tetramethyltetravinylcyclotetrasilazane were mixed and dissolved in tetrahydrofuran solvent, and after being fully dissolved and dispersed, the solvent was removed by reduced pressure distillation, and finally a milky white brittle resin containing vinylsilazane polyaluminum carbosilane (PVNACS2) was obtained. The softening point of the polyaluminum carbosilane is 205.5°C, the number average molecular weight is 883, the weight average molecular weight is 3191, and the Al content is 0.5wt%.

[0059] (2) Electrospinning: 2.5 g of PVNACS2 precursor, 0.5 g of acetone and 1.5 g of dimethylbenzene were uniformly mixed to prepare a spinning solution, and then the prepared spinning solution was loaded into a needle cylinder to remove bubbles, and electrospinning was carried out to obtain PVNACS2 fibrils; wherein the spinning conditions are: spinning voltage 8KV, spinning speed 22μL / min, spinning distance 10cm, drum rotating speed 200r / min, and spinning hole inner diameter 2.0mm;

[0060] (3) UV light irradiation crosslinking: the spun PVNACS2 fibrils were placed in a UV light box for irradiation for 20 min, wherein the irradiation wavelength is 365nm, the light intensity is 600mW / cm 2 , the distance from the light source is 15cm, and PVNACS2 non-melting fiber is obtained.

[0061] (4) High temperature sintering: the obtained PVNACS2 non-melting fiber was placed in a high temperature furnace, and under the protection of nitrogen gas, the temperature was raised to 1300°C at a rate of 2.5°C / min, and after 1h of heat preservation, SiCN(O) fiber was obtained after cooling.

[0062] After testing, the oxygen content of the obtained SiCN(O) fiber is 11wt%, the nitrogen content is 4wt%, and the fiber diameter is 2μm.

[0063] Example 4

[0064] The preparation method of the SiCN(O) fiber of the present embodiment comprises the following steps:

[0065] (1) 2.1 g of polycarbosilane (PACS) and 0.9 g of tetramethyldivinyl disilazane were mixed and dissolved in tetrahydrofuran solvent, and after being fully dissolved and dispersed, the solvent was removed by reduced pressure distillation, and finally a milky white brittle resin containing vinylsilazane polycarbosilane (PVNCS2) was obtained. The softening point of the polycarbosilane is 220.7°C, the number average molecular weight is 1020, and the weight average molecular weight is 3250.

[0066] (2) Electrospinning: 2.5 g of PVNCS2 precursor, 0.5 g of tetrahydrofuran and 2.5 g of dimethylbenzene were uniformly mixed to prepare a spinning solution, and then the prepared spinning solution was loaded into a needle cylinder to remove bubbles, and electrospinning was performed to obtain PVNCS2 fibrils; wherein the spinning conditions were: spinning voltage 13 KV, spinning speed 35 μL / min, spinning distance 15 cm, cylinder rotation speed 220 r / min, and spinning hole inner diameter 3.0 mm;

[0067] (3) UV radiation crosslinking: the spun PVNCS2 fibrils were placed in a UV light box for irradiation for 20 min, wherein the irradiation wavelength was 254 nm, the light intensity was 500 mW / cm 2 , the distance from the light source was 15 cm, and PVNCS2 non-melting fibers were obtained.

[0068] (4) High-temperature sintering: the obtained PVNCS2 non-melting fibers were placed in a high-temperature furnace, and were heated to 1200℃ at a rate of 5℃ / min under nitrogen gas protection, and were kept for 1 h, and after cooling, SiCN(O) fibers were obtained.

[0069] The obtained SiCN(O) fibers were tested, and the oxygen content was 8.9 wt%, the nitrogen content was 2.5 wt%, and the fiber diameter was 1.7 μm.

[0070] Example 5

[0071] The preparation method of the SiCN(O) fibers of the present example comprises the following steps:

[0072] (1) 1.95 g of boron-containing polycarbosilane (PBCS) and 1.05 g of tris(2-acryloyloxyethyl) isocyanurate were mixed and dissolved in tetrahydrofuran solvent, and after sufficient dissolution and dispersion, the solvent was removed by reduced pressure distillation, and finally a milky white brittle resin of polyborocarbosilane containing vinyl isocyanurate (PVBNCS) was obtained; wherein the softening point of the polyborocarbosilane was 260.5℃, the number average molecular weight was 1130, the weight average molecular weight was 3600, and the boron content was 0.3 wt%.

[0073] (2) Electrospinning: 2.5 g of PVBNCS precursor, 0.5 g of acetone and 2.5 g of dimethylbenzene were uniformly mixed to prepare a spinning solution, and then the prepared spinning solution was loaded into a needle cylinder to remove bubbles, and electrospinning was performed to obtain PVBNCS fibrils; wherein the spinning conditions were: spinning voltage 14 KV, spinning speed 40 μL / min, spinning distance 15 cm, cylinder rotation speed 250 r / min, and spinning hole inner diameter 1.0 mm;

[0074] (3) UV radiation crosslinking: the spun PVBNCS fibrils were placed in a UV light box for irradiation for 15 min, wherein the irradiation wavelength was 245 nm, the light intensity was 500 mW / cm2 , the distance from the light source is 15 cm, and the PVBNCS non-fusible fiber is obtained.

[0075] (4) High-temperature sintering: the obtained PVBNCS non-fusible fiber is placed in a high-temperature furnace, and heated to 1400°C at a rate of 5°C / min under the protection of nitrogen gas, and kept for 1 h. After cooling, the SiCN(O) fiber is obtained.

[0076] The obtained SiCN(O) fiber is tested, and the oxygen content is 9.2 wt%, the nitrogen content is 2.8 wt%, and the fiber diameter is 1.5 μm.

[0077] Example 6

[0078] The preparation method of the SiCN(O) fiber in the example comprises the following steps:

[0079] (1) 20 g of polyferrocenesilane (PFeCS) and 10 g of vinyl polysilazane are mixed and dissolved in tetrahydrofuran solvent. After being fully dissolved and dispersed, the solvent is removed by reduced pressure distillation, and finally a brittle resin containing vinyl polysilazane poly carbosilane PVNFeCS is obtained. The softening point of the PFeCS is 205°C, the number average molecular weight is 1030, the weight average molecular weight is 3250, and the Fe content is 1.1 wt%.

[0080] (2) Dry spinning: 20 g of the PVNFeCS precursor and 15 g of dimethylbenzene are uniformly mixed to prepare a spinning solution. The spinning solution is placed in a spinning cylinder, heated to 120°C under the protection of N2, and kept for 2 h. Then, the precursor is extruded from the spinneret under a pressure of 0.25 MPa, and collected by a roller to obtain PVNFeCS primary fibers with a diameter of 10-15 μm.

[0081] (3) Ultraviolet light irradiation crosslinking: the spun PVNFeCS primary fiber is placed in an ultraviolet lamp box and irradiated for 15 min. The irradiation wavelength is 254 nm, and the light intensity is 500 mW / cm 2 , the distance from the light source is 15 cm, and the PVNFeCS non-fusible fiber is obtained.

[0082] (4) High-temperature sintering: the obtained PVNFeCS non-fusible fiber is placed in a high-temperature furnace, and heated to 1200°C at a rate of 5°C / min under the protection of nitrogen gas, and kept for 1 h. After cooling, the SiCN(O) fiber is obtained.

[0083] The obtained SiCN(O) fiber is tested, and the oxygen content is 10 wt%, the nitrogen content is 3.8 wt%, the C / Si ratio is 1.24, the fiber diameter is 11-14 μm, the tensile strength is 1.6 GPa, and the tensile modulus is 180 GPa.

[0084] Aspects, embodiments, features of the present invention are to be considered illustrative only and not restrictive in all respects. The scope of the present invention is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art, and the embodiments are not to be considered limited to the specific embodiments set forth herein, but rather are to be given the full scope of the claims.

[0085] In the preparation method of the present invention, the order of the steps is not limited to the listed order, and for those skilled in the art, the order of the steps can be changed without creative effort, and such changes are within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0086] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the scope of the embodiments of the present invention. Those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, and it is not necessary or possible to fully describe all embodiments here. Any obvious changes or variations derived from the spirit of the present invention are still within the protection scope of the present invention, and any additional limitations are contrary to the spirit of the present invention.

Claims

1. A SiCN(O) fiber, characterized by, The SiCN(O) fiber is prepared by using the polycarbosilane containing C=C containing (poly) silazane and / or C=C containing isocyanurate as a precursor, and through the steps of spinning, ultraviolet radiation crosslinking and high temperature sintering. The polycarbosilane containing C=C containing (poly) silazane and / or C=C containing isocyanurate is prepared by mixing C=C containing (poly) silazane and / or C=C containing isocyanurate with polycarbosilane. The C=C containing (poly) silazane includes one or more of tetramethyltetra-vinylcyclotetrasilazane, 2,4,6-trivinyl-2,4,6-trimethylcyclotrisilazane, tetramethyldivinyl disilazane, and vinyl polysilazane. The C=C containing isocyanurate includes one or more of triallyl isocyanurate, tris(2-acryloyloxyethyl) isocyanurate, and diallyl isocyanurate.

2. The SiCN(O) fiber according to claim 1, wherein In the precursor, the mass ratio of C=C containing (poly) silazane and / or C=C containing isocyanurate to polycarbosilane is 1:100-100:

100.

3. The SiCN(O) fiber of claim 1, wherein, In the precursor, the softening point of the polycarbosilane is greater than 100 ℃, and the number average molecular weight is 100-5000.

4. The SiCN(O) fiber of claim 1, wherein, The polycarbosilane contains a heterogeneous element. The heterogeneous element includes one or more of aluminum, yttrium, nickel, hafnium, lithium, iron, cobalt, lanthanum, zirconium, titanium, beryllium, magnesium, calcium, vanadium, and boron.

5. The SiCN(O) fiber of claim 1, wherein, The spinning is melt spinning, dry spinning or electrospinning.

6. The SiCN(O) fiber of claim 1, wherein The step of cross-linking by ultraviolet radiation includes: cross-linking the original fiber obtained by spinning by ultraviolet radiation, the light intensity of the ultraviolet lamp is 10-1000 mW / cm 2 , the wavelength of the ultraviolet light is 185-400 nm, and the radiation time is 1-180 min.

7. The SiCN(O) fiber of claim 1, wherein The step of high temperature sintering includes: heating the fiber after ultraviolet radiation crosslinking to 1000-1400 ℃ at 1-20 ℃ / min under an inert atmosphere, and holding for 0.5-5 h.

8. A method for producing SiCN(O) fiber, characterized by, It includes the following steps: C=C containing (poly) silazane and / or C=C containing isocyanurate is mixed with polycarbosilane to prepare polycarbosilane containing C=C containing (poly) silazane and / or C=C containing isocyanurate; Spinning is performed using polycarbosilane containing C=C containing (poly) silazane and / or C=C containing isocyanurate as a precursor to obtain a primary fiber, The primary fiber is subjected to ultraviolet radiation crosslinking; The fiber after ultraviolet radiation crosslinking is subjected to high temperature sintering; The C=C containing (poly) silazane includes one or more of tetramethyltetra-vinylcyclotetrasilazane, 2,4,6-trivinyl-2,4,6-trimethylcyclotrisilazane, tetramethyldivinyl disilazane, and vinyl polysilazane. The C=C containing isocyanurate includes one or more of triallyl isocyanurate, tris(2-acryloyloxyethyl) isocyanurate, and diallyl isocyanurate.

9. The production method according to claim 8, characterized by, The ultraviolet radiation crosslinking includes: light intensity of ultraviolet lamp is 10-1000 mW / cm 2 , wavelength of ultraviolet light is 185-400 nm, and radiation time is 1-180 min.

10. The method of claim 8, wherein, The high temperature sintering includes: heating to 1000-1400 ℃ at 1-20 ℃ / min under an inert atmosphere, and holding for 0.5-5 h.

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