阅读说明：本技术 一种含dopo的阻燃硅烷改性聚醚密封胶及其制备方法 (Flame-retardant silane modified polyether sealant containing DOPO and preparation method thereof ) 是由 徐金昌 杨雄发 樊丽改 李晓晨 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种含DOPO的阻燃硅烷改性聚醚密封胶及其制备方法,具体是按照如下步骤制备：(1)将两端羟基的聚醚与异氰酸酯硅氧烷反应,获得MS胶基础聚合物；(2)用氨基封端聚硅氧烷与间羟基苯甲醛反应,然后将产物与DOPO反应,并将反应体系中溶剂减压除去后,与异氰酸酯硅氧烷反应,获得两端烷氧基封端、含DOPO基团的有机硅阻燃添加剂；(3)在氮气保护下,将MS胶基础聚合物、有机硅阻燃添加剂、填料和催化剂按照比例在星型搅拌机内抽真空混炼,灌装,获得一种阻燃性能优良的无卤MS密封胶。(The invention discloses a flame-retardant silane modified polyether sealant containing DOPO and a preparation method thereof, and the flame-retardant silane modified polyether sealant is prepared by the following steps: (1) reacting polyether with hydroxyl at two ends with isocyanate siloxane to obtain an MS gum base polymer; (2) the amino-terminated polysiloxane reacts with m-hydroxybenzaldehyde, then the product reacts with DOPO, and after the solvent in the reaction system is removed under reduced pressure, the product reacts with isocyanate siloxane to obtain the organosilicon flame retardant additive with two-end alkoxy-terminated and DOPO groups; (3) under the protection of nitrogen, the MS gum base polymer, the organic silicon flame retardant additive, the filler and the catalyst are pumped in a star stirrer according to the proportion, mixed and filled to obtain the halogen-free MS sealant with excellent flame retardant property.)

1. A flame-retardant silane modified polyether sealant containing DOPO is characterized in that: the raw materials are as follows by weight:

80-150 parts of MS (modified polystyrene) gum base polymer, 5-40 parts of organosilicon flame retardant additive, 30-150 parts of filler and 1-5 parts of catalyst.

2. The DOPO-containing flame-retardant silane-modified polyether sealant as claimed in claim 1, wherein: the organosilicon flame retardant additive is an organosilicon flame retardant additive with two end alkoxy groups for blocking, and containing DOPO groups, and when the organosilicon flame retardant additive with two end alkoxy groups for blocking and containing DOPO groups is prepared, the molecular weight of amino-blocked polysiloxane is 248.5-40000, and the amino-blocked polysiloxane is at least one of dimethylpolysiloxane with two end amino groups, copolymer of dimethylpolysiloxane and methylphenyl polysiloxane, copolymer of dimethylpolysiloxane and diphenyl polysiloxane, copolymer of dimethylpolysiloxane and trifluoropropyl methyl polysiloxane, copolymer of dimethylpolysiloxane, methylphenyl polysiloxane and trifluoropropyl methyl polysiloxane, and copolymer of dimethylpolysiloxane, diphenyl polysiloxane and trifluoropropyl methyl polysiloxane.

3. The DOPO-containing flame-retardant silane-modified polyether sealant as claimed in claim 2, wherein: when preparing the organosilicon flame-retardant additive with two-end alkoxy end-capped and DOPO groups, m-hydroxybenzaldehyde and organosilicon with amino groups at two ends are catalytically reacted for 6-24h in a solvent by using acetic acid, the reaction temperature is 50-80 ℃, after the reaction is finished, the product is reacted with DOPO in the solvent for 6-24h, after the solvent is removed by decompression, the obtained product is reacted with isocyanate siloxane, and the organosilicon flame-retardant additive with two-end alkoxy end-capped and DOPO groups is obtained.

4. The DOPO-containing flame-retardant silane-modified polyether sealant as claimed in claim 1, wherein: the solvent used in the reaction is one of methanol, ethanol and isopropanol, and the dosage of the solvent is 1-4 times of the total mass of m-hydroxybenzaldehyde and organosilicon with amino groups at two ends.

5. The DOPO-containing flame-retardant silane-modified polyether sealant as claimed in claim 1, wherein: the filler is one or a mixture of two of fumed silica and nano calcium carbonate, and the filler is selected from commercially available products.

6. The DOPO-containing flame-retardant silane-modified polyether sealant as claimed in claim 1, wherein: the catalyst is dibutyltin dilaurate or chelate of tetrabutyl titanate and acetylacetone.

7. A method for preparing the flame retardant silane modified polyether sealant containing DOPO according to any one of claims 1 to 6, which is characterized in that: the preparation method of the flame-retardant silane modified polyether sealant containing DOPO comprises the following specific steps:

(1) reacting polyether with hydroxyl at two ends with isocyanate siloxane to obtain an MS gum base polymer;

wherein, the polyether with two terminal hydroxyl groups adopts a copolymer of ethylene oxide and propylene oxide with the molecular weight of 1000-20000; the isocyanate siloxane is at least one of isocyanate propyl trimethoxy silane and isocyanate propyl triethoxy silane; the using amount of the polyether with hydroxyl groups at two ends and the isocyanate siloxane is 1:1 according to the molar ratio of the hydroxyl groups to the isocyanate groups, the reaction catalyst is diisobutyl tin dilaurate, the using amount of the reaction catalyst is 0.04-0.4 percent of the total mass of the polyether with hydroxyl groups at two ends and the isocyanate siloxane, the reaction temperature is 60-80 ℃, and the reaction time is 2-12 hours;

(2) the amino-terminated polysiloxane reacts with m-hydroxybenzaldehyde, then the product reacts with DOPO, and after the solvent in the reaction system is removed under reduced pressure, the product reacts with isocyanate siloxane to obtain the organosilicon flame retardant additive with two-end alkoxy-terminated and DOPO groups;

(3) under the protection of nitrogen, the MS glue base polymer, the organosilicon flame-retardant additive, the filler, the plasticizer, the waterproof agent and the catalyst are vacuumized, mixed and filled in a star stirrer according to the proportion to obtain the halogen-free MS sealant with excellent flame retardant property, wherein the flame retardant property of the obtained MS sealant can reach V1-V0 level, the tensile strength is 0.8-4.8MPa, and the elongation at break is 180-350%.

Technical Field

The invention relates to the technical field of high polymer sealant materials, in particular to a flame-retardant silane modified polyether sealant containing DOPO and a preparation method thereof.

Background

The traditional polyurethane sealant contains free isocyanate, has great toxicity and great harm to human body, and easily forms bubbles during curing of the traditional polyurethane sealant, so that the mechanical property of the sealant is reduced. These disadvantages have limited the use of conventional polyurethane sealants in many applications. On the other hand, the silicone sealant has low tear strength, poor finishing property and easy pollution to building materials, so that the further application of the silicone sealant is influenced. The silane modified polyether sealant (MS sealant for short) is a high-performance environment-friendly sealant which takes silyl-terminated polyether (polyether is taken as a main chain, and both ends of the silyl-terminated polyether are terminated by siloxane) as a basic polymer, has the advantages of polyurethane sealant and silicone sealant, and overcomes the defects of various performances. The elastomer sealant has excellent mechanical strength, coating property and stain resistance, and the product does not contain isocyanate and organic solvent, thereby being the main development direction of novel elastomer sealants at home and abroad.

At present, fire frequently occurs due to the inflammability of high polymer materials, and people sometimes suffer immeasurable loss of lives and properties. Therefore, as a very important application field of high polymer materials, the MS sealant with good flame retardance is one of the future important development directions of MS glue.

The commonly used flame retardants in the field of sealants include halogen flame retardants, phosphorus flame retardants and nitrogen flame retardants, and patents CN102391820A and CN103320079A all prepare flame-retardant sealants by adding flame retardants, but the common defects of the flame retardants are that the flame retardants continuously migrate outwards and run away along with the passage of time, so that the flame-retardant effect of the sealants is reduced. In addition, the addition of such flame retardants in too large an amount will reduce the adhesive properties of the sealant.

There are a large number of literature and patent reports of flame retardant polyethers, summarizing two types: one is the addition of flame retardant, as reported in patents CN103497322B, CN 104292449B. However, these flame-retardant polyethers are currently used mainly in the production of polyurethane foams, in particular in the field of rigid foams.

At present, the MS sealant has few reports on flame retardance, and Chinese patent application No. 202011326452.0 discloses that bromine flame retardant containing active double bonds is copolymerized with alkenyl-containing polyether to prepare MS sealant with the advantages of high polymerization degree, long polyether chain length, high elongation at break and the like, and the flame retardance can reach FV-0 level. However, the flame-retardant sealant contains halogen bromine, and generates toxic and corrosive gases when catching fire, thereby being easy to cause secondary damage to human bodies. Therefore, the halogen-free flame retardant MS sealant needs to be developed to meet the application requirement of the MS sealant.

9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is a novel flame retardant additive, but the molecular weight of the DOPO is low, the DOPO is easy to migrate out of a high polymer material system, and the comprehensive properties of the DOPO, such as mechanical properties, durability and the like, of the DOPO are influenced. Aiming at the defects of the MS glue, the invention (1) reacts polyether with hydroxyl at two ends with isocyanate siloxane to obtain a base polymer of the MS glue; (2) reacting amino-terminated polysiloxane with m-hydroxybenzaldehyde, then reacting the product with DOPO, removing the solvent in the reaction system under reduced pressure, reacting with isocyanate siloxane to obtain an organosilicon flame-retardant additive (3) with two end alkoxy-terminated and DOPO groups, and vacuumizing and mixing the organosilicon flame-retardant additive, MS gum base polymer, filler, plasticizer, waterproof agent and catalyst in a star stirrer according to the proportion under the protection of nitrogen, and filling to obtain the halogen-free MS sealant with excellent flame-retardant property.

Disclosure of Invention

In order to overcome the defects of halogen-containing flame retardants, small molecular flame retardants which are easy to migrate out of high molecular materials and affect the flame retardant effect and the mechanical properties of the materials and the like, the invention adds the organosilicon flame retardant additive which is terminated by alkoxy groups at two ends and contains DOPO groups into the MS sealant, the additive participates in the curing reaction of the MS sealant, the additive cannot be separated out from the MS sealant, the content of organosilicon chain segments in the MS sealant is increased, and the flame retardant effect of the MS sealant can be obviously improved. The flame retardance of the obtained MS sealant can reach V1-V0 level, the tensile strength is 0.8-4.8MPa, and the elongation at break is 180-350 percent.

The invention aims to provide 1. a flame-retardant silane modified polyether sealant containing DOPO and a preparation method thereof, wherein the flame-retardant silane modified polyether sealant comprises the following raw materials in parts by weight:

80-150 parts of MS (modified polystyrene) gum base polymer, 5-40 parts of organosilicon flame retardant additive, 30-150 parts of filler and 1-5 parts of catalyst.

Preferably, the silicone flame retardant additive is a both terminal alkoxy terminated, DOPO group-containing silicone flame retardant additive, and when the both terminal alkoxy terminated, DOPO group-containing silicone flame retardant additive is prepared, the amino terminated polysiloxane has a molecular weight of 248.5 to 40000, and is at least one of a dimethyl polysiloxane of both terminal amino groups, a copolymer of dimethyl polysiloxane and methylphenyl polysiloxane, a copolymer of dimethyl polysiloxane and diphenyl polysiloxane, a copolymer of dimethyl polysiloxane and trifluoropropyl methyl polysiloxane, a copolymer of dimethyl polysiloxane, methylphenyl polysiloxane and trifluoropropyl methyl polysiloxane, and a copolymer of dimethyl polysiloxane, diphenyl polysiloxane and trifluoropropyl methyl polysiloxane.

Preferably, when the organosilicon flame retardant additive with two-end alkoxy end capping and DOPO groups is prepared, m-hydroxybenzaldehyde and organosilicon with two-end amino groups are catalytically reacted for 6-24h in a solvent by using acetic acid, the reaction temperature is 50-80 ℃, after the reaction is finished, the product is reacted with DOPO in the solvent for 6-24h, after the solvent is removed under reduced pressure, the obtained product is reacted with isocyanate siloxane, and the organosilicon flame retardant additive with two-end alkoxy end capping and DOPO groups is obtained.

Preferably, the solvent used in the reaction is one of methanol, ethanol and isopropanol, and the amount of the solvent used in the reaction is 1-4 times of the total mass of the m-hydroxybenzaldehyde and the organosilicon with amino groups at two ends.

Preferably, the filler is one or a mixture of two of fumed silica and nano calcium carbonate, and the filler is selected from commercially available products.

Preferably, the catalyst is dibutyltin dilaurate or a chelate of n-butyl titanate with acetylacetone.

The invention also provides a preparation method of the flame-retardant silane modified polyether sealant containing DOPO, which comprises the following specific steps:

(1) reacting polyether with hydroxyl at two ends with isocyanate siloxane to obtain an MS gum base polymer;

wherein, the polyether with two terminal hydroxyl groups adopts a copolymer of ethylene oxide and propylene oxide with the molecular weight of 1000-20000; the isocyanate siloxane is at least one of isocyanate propyl trimethoxy silane and isocyanate propyl triethoxy silane; the using amount of the polyether with hydroxyl groups at two ends and the isocyanate siloxane is 1:1 according to the molar ratio of the hydroxyl groups to the isocyanate groups, the reaction catalyst is diisobutyl tin dilaurate, the using amount of the reaction catalyst is 0.04-0.4 percent of the total mass of the polyether with hydroxyl groups at two ends and the isocyanate siloxane, the reaction temperature is 60-80 ℃, and the reaction time is 2-12 hours;

(2) the amino-terminated polysiloxane reacts with m-hydroxybenzaldehyde, then the product reacts with DOPO, and after the solvent in the reaction system is removed under reduced pressure, the product reacts with isocyanate siloxane to obtain the organosilicon flame retardant additive with two-end alkoxy-terminated and DOPO groups;

(3) under the protection of nitrogen, the MS glue base polymer, the organosilicon flame-retardant additive, the filler, the plasticizer, the waterproof agent and the catalyst are vacuumized, mixed and filled in a star stirrer according to the proportion to obtain the halogen-free MS sealant with excellent flame retardant property, wherein the flame retardant property of the obtained MS sealant can reach V1-V0 level, the tensile strength is 0.8-4.8MPa, and the elongation at break is 180-350%.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the organosilicon flame-retardant additive with alkoxy end capping at two ends and DOPO groups is added into the MS sealant, the additive participates in the curing reaction of the MS sealant, cannot be separated out of the MS sealant, the content of organosilicon chain segments in the MS sealant is increased, and the flame-retardant effect of the MS sealant can be obviously improved.

Drawings

FIG. 1 is a schematic view showing a process for preparing a raw material containing DOPO groups with phenolic hydroxyl groups at both ends;

FIG. 2 is a chart of the infrared spectra of DOPO, silicone Schiff base and silicone containing DOPO;

FIG. 3 is of DOPO and silicone Schiff base¹H-NMR spectrum chart;

FIG. 4 is a DOPO silicone-containing¹H-NMR spectrum chart.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

(1) Reacting 100g of polyether with two hydroxyl groups at two ends and a molecular weight of 1000 with 41.56g of isocyanate propyl trimethoxy silane at 80 ℃ for 6h under the catalysis of 0.566g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) 248.51g of 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane and 244.24g of m-hydroxybenzaldehyde are used for reaction in 492.75g of methanol at 80 ℃ for 8h, then the product is reacted with 432g of DOPO at 80 ℃ for 8h, and after the solvent in the reaction system is removed under reduced pressure, the reaction system is reacted with 415.6g of isocyanate propyl trimethoxy silane under the catalysis of 0.370g of diisobutyl tin dilaurate at 100 ℃ for 4h to obtain the organosilicon flame retardant additive with two end alkoxy end caps and DOPO groups;

(3) under the protection of nitrogen, 80 parts of MS (polystyrene) gum base polymer, 20 parts of organosilicon flame retardant additive, 30 parts of fumed silica and 1 part of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and the mixture is filled to obtain the halogen-free MS sealant. The MS sealant can achieve V0-grade flame retardance in vertical combustion, the tensile strength is 1.6MPa, and the elongation at break is 220%.

Example 2

(1) 2000g of polyether with two hydroxyl groups at two ends and molecular weight of 20000 and 49.40g of isocyanate propyl triethoxysilane react for 12h at 100 ℃ under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) 2000g of 20000 molecular weight, 1, 3-bis (3-aminopropyl) -1, 3-dimethyl siloxy terminated dimethyl silicone oil and 24.424g of m-hydroxybenzaldehyde are reacted in 4048g of isopropanol at 70 ℃ for 12h, then the product is reacted with 43.2g of DOPO at 70 ℃ for 8h, the solvent in the reaction system is decompressed and removed, and then the product is reacted with 49.40g of isocyanate propyl triethoxysilane at 70 ℃ for 8h under the catalysis of 2.0g of diisobutyl tin dilaurate to obtain the organic silicon flame retardant additive with two end alkoxy end terminations and DOPO groups;

(3) under the protection of nitrogen, 150 parts of MS (polystyrene) gum base polymer, 40 parts of organic silicon flame retardant additive, 150 parts of fumed silica and 5 parts of n-butyl titanate chelate are pumped in a star stirrer in proportion for mixing and filling to obtain the halogen-free MS sealant. The MS sealant can achieve V0-grade flame retardance in vertical combustion, the tensile strength is 4.2MPa, and the elongation at break is 280%.

Example 3

(1) Reacting 2000g of polyether with two hydroxyl groups at two ends and a molecular weight of 2000 with 49.40g of isocyanate propyl triethoxysilane at the temperature of 100 ℃ for 12h under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) reacting 2000g of copolymer of 1, 3-bis (3-aminopropyl) -1, 3-dimethyl siloxy terminated dimethyl polysiloxane and methyl phenyl polysiloxane with molecular weight of 8000, 61.06g of m-hydroxybenzaldehyde in 8244g of ethanol at 50 ℃ for 24h, then reacting the product with 108g of DOPO at 50 ℃ for 24h, removing the solvent in the reaction system under reduced pressure, and reacting with 123.5g of isocyanate propyl triethoxysilane at 50 ℃ for 12h under the catalysis of 1.83g of diisobutyl tin dilaurate to obtain the organosilicon flame retardant additive with alkoxy terminated ends and containing DOPO groups;

(3) under the protection of nitrogen, 150 parts of MS (polystyrene) gum base polymer, 40 parts of organic silicon flame retardant additive, 100 parts of fumed silica, 50 parts of nano calcium carbonate and 3 parts of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and then the mixture is filled to obtain the halogen-free MS sealant. The MS sealant can achieve V0-grade flame retardance in vertical combustion, the tensile strength is 4.6MPa, and the elongation at break is 330%.

Example 4

(1) Reacting 2000g of polyether with two hydroxyl groups at two ends and a molecular weight of 2000 with 49.40g of isocyanate propyl triethoxysilane at the temperature of 100 ℃ for 12h under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) reacting 2000g of copolymer of 1, 3-bis (3-aminopropyl) -1, 3-dimethyl siloxy terminated dimethyl polysiloxane and diphenyl polysiloxane with molecular weight of 8000, 61.06g of m-hydroxybenzaldehyde in 8244g of ethanol at 50 ℃ for 24h, then reacting the product with 108g of DOPO at 50 ℃ for 24h, removing the solvent in the reaction system under reduced pressure, and reacting with 123.5g of isocyanate propyl triethoxysilane at 50 ℃ for 12h under the catalysis of 1.83g of diisobutyl tin dilaurate to obtain the organosilicon flame retardant additive with alkoxy terminated ends and containing DOPO groups;

(3) under the protection of nitrogen, 150 parts of MS (polystyrene) gum base polymer, 40 parts of organic silicon flame retardant additive, 100 parts of fumed silica, 50 parts of nano calcium carbonate and 3 parts of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and then the mixture is filled to obtain the halogen-free MS sealant. The MS sealant can achieve V0-grade flame retardance in vertical combustion, the tensile strength is 4.4MPa, and the elongation at break is 300%.

Example 5

(1) Reacting 2000g of polyether with two hydroxyl groups at two ends and a molecular weight of 2000 with 49.40g of isocyanate propyl triethoxysilane at the temperature of 100 ℃ for 12h under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) reacting 2000g of 8000 molecular weight 1, 3-bis (3-aminopropyl) -1, 3-dimethyl siloxy terminated dimethyl polysiloxane, diphenyl polysiloxane and methyl trifluoropropyl polysiloxane copolymer, 61.06g of m-hydroxy benzaldehyde in 8244g of ethanol at 50 ℃ for 24h, then reacting the product with 108g of DOPO at 50 ℃ for 24h, removing the solvent in the reaction system under reduced pressure, and reacting with 123.5g of isocyanate propyl triethoxysilane at 50 ℃ for 12h under the catalysis of 1.83g of diisobutyl tin dilaurate to obtain the organosilicon flame retardant additive with alkoxy end capping at two ends and containing DOPO groups;

(3) under the protection of nitrogen, 150 parts of MS (polystyrene) gum base polymer, 40 parts of organic silicon flame retardant additive, 100 parts of fumed silica, 50 parts of nano calcium carbonate and 3 parts of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and then the mixture is filled to obtain the halogen-free MS sealant. The MS sealant can achieve V0-grade flame retardance in vertical combustion, the tensile strength is 4.8MPa, and the elongation at break is 350%.

Example 6

(1) Reacting 2000g of polyether with two hydroxyl groups at two ends and a molecular weight of 2000 with 49.40g of isocyanate propyl triethoxysilane at the temperature of 100 ℃ for 12h under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) reacting 2000g of 8000 molecular weight 1, 3-bis (3-aminopropyl) -1, 3-dimethyl siloxy terminated dimethyl polysiloxane, diphenyl polysiloxane and methyl trifluoropropyl polysiloxane copolymer, 61.06g of m-hydroxy benzaldehyde in 8244g of ethanol at 50 ℃ for 24h, then reacting the product with 108g of DOPO at 50 ℃ for 24h, removing the solvent in the reaction system under reduced pressure, and reacting with 123.5g of isocyanate propyl triethoxysilane at 50 ℃ for 12h under the catalysis of 1.83g of diisobutyl tin dilaurate to obtain the organosilicon flame retardant additive with alkoxy end capping at two ends and containing DOPO groups;

(3) under the protection of nitrogen, 150 parts of MS (polystyrene) gum base polymer, 5 parts of organic silicon flame retardant additive, 100 parts of fumed silica, 50 parts of nano calcium carbonate and 3 parts of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and then the mixture is filled to obtain the halogen-free MS sealant. The MS sealant can achieve V1-grade flame retardance in vertical combustion, the tensile strength is 3.6MPa, and the elongation at break is 300%.

Comparative examples

(1) Reacting 2000g of polyether with two hydroxyl groups at two ends and a molecular weight of 2000 with 49.40g of isocyanate propyl triethoxysilane at the temperature of 100 ℃ for 12h under the catalysis of 1.640g of diisobutyl tin dilaurate to obtain an MS gum base polymer;

(2) under the protection of nitrogen, 150 parts of MS gum base polymer, 100 parts of fumed silica, 50 parts of nano calcium carbonate and 3 parts of diisobutyl tin dilaurate are mixed in a star stirrer in proportion by vacuum pumping, and the mixture is filled to obtain the MS sealant. The MS sealant has the advantages of V2-grade vertical combustion flame retardance, 3.8MPa tensile strength and 330% elongation at break.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.