阅读说明：本技术 一种二氧化硅复合气凝胶、pet聚酯纤维、聚酯织物 (silicon dioxide composite aerogel, PET polyester fiber and polyester fabric ) 是由 杨金兰 于 2019-11-29 设计创作，主要内容包括：本发明涉及聚酯纤维技术领域,具体是一种二氧化硅复合气凝胶、PET聚酯纤维、聚酯织物。二氧化硅复合气凝胶,由以下方法制备,混合硅源、第一有机溶剂和水混合,经过酸性水解和碱性缩合得到湿凝胶,再经过老化、第一次无水乙醇置换、表面改性剂改性、加热、第二次无水乙醇置换、干燥制得,所述混合硅源为正硅酸乙酯、4-三乙氧基硅基乙烯基苯并环丁烯和乙炔基三乙氧基硅烷的混合物；PET聚酯纤维,按重量份数计,由100份纤维级PET聚酯和0.5-5份上述二氧化硅复合气凝胶采用熔融纺丝的工艺制备。本发明的PET聚酯纤维具有密度低、导热性能差的特点,由其纺织而成的织物具有轻盈、保温隔热性能好的特点。(The invention relates to the technical field of polyester fibers, in particular to silicon dioxide composite aerogel, PET polyester fiber and polyester fabric, wherein the silicon dioxide composite aerogel is prepared by the following method of mixing a silicon source, a organic solvent and water, carrying out acidic hydrolysis and alkaline condensation to obtain wet gel, carrying out aging, times of absolute ethyl alcohol replacement, surface modifier modification, heating, carrying out second time of absolute ethyl alcohol replacement and drying, the mixed silicon source is a mixture of ethyl orthosilicate, 4-triethoxysilylbenzocyclobutene and ethynyltriethoxysilane, and the PET polyester fiber is prepared by using 100 parts by weight of fiber-grade PET polyester and 0.5-5 parts by weight of the silicon dioxide composite aerogel through a melt spinning process.)

The silicon dioxide composite aerogel is characterized by being prepared by the following method, mixing a silicon source, an organic solvent and water, carrying out acidic hydrolysis and alkaline condensation to obtain wet gel, carrying out aging, times of absolute ethyl alcohol displacement, surface modifier modification, heating, secondary absolute ethyl alcohol displacement and drying to obtain the silicon dioxide composite aerogel, wherein the mixed silicon source is a mixture of ethyl orthosilicate, 4-triethoxysilylbenzocyclobutene and ethynyltriethoxysilane.

2. The silica composite aerogel according to claim 1, characterized in that: the molar ratio of the ethyl orthosilicate, the 4-triethoxysilylbenzocyclobutene and the ethynyltriethoxysilane is 1:0.5-1.5: 0-0.3.

3. The silica composite aerogel according to claim 2, wherein: the molar ratio of the ethyl orthosilicate, the 4-triethoxysilylbenzocyclobutene and the ethynyltriethoxysilane is 1:0.7-1.2: 0.1-0.25.

4. The silica composite aerogel according to claim 1, characterized in that: the molar ratio of the mixed silicon source to the organic solvent to the water is 1:5-15: 4-9.

5. The silica composite aerogel according to claim 1, characterized in that: the surface modifier is a solution of trimethylchlorosilane or hexamethyldisilazane, the concentration is 30-200g/L, and the modification time is 1-4 hours; the solvent used in the solution is a polar solvent, and the boiling point of the polar solvent at normal atmospheric pressure is not lower than 120 ℃.

6. The silica composite aerogel according to claim 1, characterized in that: the heating is carried out at the temperature of not less than 120 ℃ under normal pressure for 10 minutes to 5 hours, and then the temperature is cooled to the room temperature.

7. The silica composite aerogel according to claim 1, characterized in that: and replacing the anhydrous ethanol for the second time by soaking the heated wet gel in the anhydrous ethanol for 1-5 hours, and filtering to remove the solvent.

8, PET polyester fibers, characterized in that, by weight, 100 parts of fiber grade PET polyester and 0.5-5 parts of the silica composite aerogel described in any of claims 1-7 and are prepared by melt spinning.

9. The PET polyester fiber according to claim 8, which is prepared from 100 parts by weight of fiber-grade PET polyester and 1.5-4 parts by weight of the silica composite aerogel according to any of claims 1-7 by melt spinning.

A polyester fabric of , which is woven from the PET polyester fiber of claim 8 or 9.

Technical Field

The invention relates to the technical field of aerogel, in particular to silicon dioxide composite aerogel, PET polyester fiber and polyester fiber.

Background

The silica aerogel is applied to the field of heat-insulating fabrics due to low density and low heat conductivity, has the heat-insulating effect, and can lighten the weight of the fabrics due to the low density, so that the silica aerogel is lighter and more comfortable to wear.

Journal preparation and performance research of SiO2 aerogel thermal insulation coating fabric (surface technology, 2014,43(3), 95-100) reports that a coating agent is prepared from SiO2 aerogel and then coated on the surface of cotton cloth, so that the cotton cloth has an obvious thermal insulation effect. However, the fabric surface layer SiO2 aerogel thermal insulation coating obtained by the method is easy to fall off gradually along with wearing and cleaning, so that the practicability is poor.

Silica aerogel is prepared in a master thesis of silica aerogel preparation and application (Beijing chemical university, 2015), and is directly filled between double-layer ultrathin sun-proof breathable cloth to prepare a heat-insulating material with a sandwich structure, so that the heat-insulating effect is obvious, but powder easily overflows along cloth fibers and a needle seam gap; after being treated by NaOH alcoholic solution, polyester cotton flocculus is respectively loaded with silica sol and silica aerogel, so that the thermal insulation effect is achieved, but a large amount of powder falls off after the flocculus is slightly bent or shaken, and the applicability is poor; the silica aerogel is used as functional particles, the silicon modified polyacrylate emulsion, the waterborne polyurethane emulsion, the polytetrafluoroethylene emulsion and the DMF solution of PVDF-HFP are respectively used as binders, other auxiliary agents are added to prepare four different kinds of heat-insulating coating agents, and the heat-insulating coating agents are coated on primary color cotton cloth to form a heat-insulating coating, wherein the heat-insulating effect of the PTFE base coating and the PVDF-HFP base coating is the best. However, the coating applied to the surface of the cotton cloth is easily peeled off during application and cleaning processes, resulting in failure.

The invention patent of application publication No. CN103397516A discloses silica aerogel composite fabrics, which are prepared by immersing high-strength synthetic fibers in silica sol, aging, and then performing supercritical drying.

The invention patent of application publication No. CN110257946A discloses a preparation method of aerogel fibers, which comprises the steps of mixing silicon dioxide aerogel powder with purified terephthalic acid, then carrying out polymerization reaction with a reaction solvent to obtain an aerogel mixed polyester melt, spinning and post-treating to obtain the aerogel fibers.

The following requirements are imposed on the silica aerogel modified fibrous material: 1. is stable and is not easy to fall off in application; 2. the production is more convenient and flexible; 3. the heat insulation performance is better.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides PET fibers which have the characteristics of low density and low heat conductivity coefficient.

Another aims at providing silicon dioxide composite aerogels, which can be dried under normal pressure in the preparation process and have the characteristic of higher mechanical strength.

objects of the invention are to provide polyester fabrics which are light and have good heat retention property.

The invention adopts the following technical scheme:

silicon dioxide composite aerogel is prepared by mixing a mixed silicon source, an organic solvent and water, performing acidic hydrolysis and alkaline condensation to obtain wet gel, aging, performing times of absolute ethyl alcohol displacement, modifying a surface modifier, heating, performing second time of absolute ethyl alcohol displacement, and drying, wherein the mixed silicon source is a mixture of tetraethoxysilane, 4-triethoxysilylbvinylbenzocyclobutene and ethynyltriethoxysilane.

Preferably, the molar ratio of the ethyl orthosilicate, the 4-triethoxysilylbenzocyclobutene and the ethynyltriethoxysilane is 1:0.5-1.5: 0-0.3.

More preferably, the molar ratio of the ethyl orthosilicate, the 4-triethoxysilylbenzocyclobutene and the ethynyltriethoxysilane is 1:0.7-1.2: 0.1-0.25.

Preferably, the molar ratio of the mixed silicon source to the organic solvent to the water is 1:5-15: 4-9. the organic solvent may be or more selected from anhydrous ethanol, methanol, acetone, tetrahydrofuran and isopropanol.

The acidic hydrolysis is carried out by adding acidic substance and adjusting pH of reaction system to 2-4, wherein the acidic substance can be at least selected from sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, formic acid and acetic acid, the alkaline condensation is carried out by adding alkaline substance and adjusting pH of reaction system to 8-12, and the alkaline substance can be at least selected from ammonia water, sodium hydroxide, potassium hydroxide, tetramethyl ammonium hydroxide, sodium carbonate and potassium carbonate.

The aging is to maintain the wet gel in a water bath at 30-80 ℃ for 1-3 hours.

Preferably, the surface modifier is a solution of trimethylchlorosilane or hexamethyldisilazane, the concentration is 30-200g/L, the modification time is 1-4 hours, the solvent used in the solution is a polar solvent, the boiling point of the solvent at the standard atmospheric pressure is not lower than 120 ℃, in a more preferred scheme, the boiling point of the solvent at the standard atmospheric pressure is not higher than 250 ℃, and the solvent can be or more selected from butyl acetate, N-Dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethylene glycol phenyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1, 2-propylene glycol monoethyl ether, dipropylene glycol methyl ether, dimethyl succinate, dimethyl malonate, dimethyl oxalate, ethylene glycol diethyl ether, dibutyl ether, N-dimethylacetamide, ethyl benzoate and formamide.

Preferably, the heating is carried out at a temperature of not less than 120 ℃ under normal pressure for 10 minutes to 5 hours, and then the temperature is cooled to room temperature. In a more preferred embodiment, the heating is carried out at a temperature of not higher than 205 ℃ under normal pressure. If the solvent in the wet gel is more strongly volatilized when heated, a condensing device can be added to avoid or reduce the volatilization of the solvent.

Preferably, the second anhydrous ethanol is replaced by soaking the heated wet gel in anhydrous ethanol for 1-5 hours, and then taking out. The purpose of the second anhydrous ethanol replacement is to replace the high boiling point polar solvent in the wet gel, which is beneficial to the subsequent drying step.

The drying may be carried out by heating under normal pressure to remove the organic solvent, or by heating under normal pressure to remove the solvent and then heating under negative pressure to remove the remaining organic solvent.

PET polyester fibers are prepared from 100 parts of fiber-grade PET polyester and 0.5-5 parts of the silica composite aerogel described in any embodiment by a melt spinning process.

Preferably, the silica composite aerogel prepared by the method comprises 100 parts of fiber-grade PET polyester and 1.5-4 parts of any embodiment of the silica composite aerogel by using a melt spinning process.

polyester fabrics woven from the PET polyester fibers of any of the embodiments described above.

The invention has the beneficial effects that:

(1) the density of the obtained PET polyester fiber can be as low as 0.862g/cm³The density is 62.3 percent of the density of the conventional PET polyester fiber, the heat conductivity coefficient can be as low as 0.021W/(m.k), the heat conductivity coefficient is 24.7 percent of the heat conductivity coefficient of the conventional PET polyester fiber,

(2) according to the invention, tetraethoxysilane, 4-triethoxy silicon-based vinylbenzocyclobutene and ethynyltriethoxysilane are mixed to be used as a silicon source, vinylbenzocyclobutene and ethynyl are carried on the surface of a silicon dioxide particle after hydrolytic condensation, the vinylbenzocyclobutene can realize a ring-opening reaction under heating to form a polymer, and also can generate a Diels-Alder reaction with the ethynyl to form the polymer, so that the strength of a three-dimensional network structure of the silicon dioxide particle is improved, and the drying of the silicon dioxide composite aerogel can be carried out under normal pressure.

(3) The silicon dioxide composite aerogel is dispersed in the PET polyester fiber, is not easy to fall off in the application and cleaning processes, and has better performance durability.

Detailed Description

The technical solution of the present invention is illustrated and described in step by the following detailed description.

Unless otherwise specified, the parts described in the embodiments in the following embodiments are all parts by weight.

Preparation of silica composite aerogel

Mixing tetraethoxysilane, 4-triethoxysilylbvinylbenzocyclobutene and ethynyltriethoxysilane according to a molar ratio of 1:0.55:0.2 to form a mixed silicon source, mixing the mixed silicon source, acetone and water according to a molar ratio of 1:8:3.9, uniformly stirring, adding oxalic acid to adjust the pH value to 3.0 for hydrolysis, adding ammonia water to adjust the pH value to 10.0 for condensation to obtain wet gel, aging the wet gel in a water bath at 30 ℃ for 3 hours, taking out the wet gel, soaking the wet gel in absolute ethyl alcohol for solvent replacement for 2 times, taking out the wet gel, soaking the wet gel in a surface modifier (dipropylene glycol methyl ether solution of trimethylchlorosilane, the concentration of which is 120g/L) for 2 hours, and performingModifying, heating to 170 ℃, reacting for 2 hours at constant temperature, cooling to room temperature, soaking in absolute ethyl alcohol again for replacement for 3 times, drying wet gel in a 50 ℃ forced air drying oven for 3 hours, drying in a 90 ℃ forced air drying oven for 2 hours, and drying in a 120 ℃ forced air drying oven for 2 hours in sequence to obtain the silicon dioxide composite aerogel 1. The silica composite aerogel 1 had a thermal conductivity of 0.0143W/(m.k) and a density of 0.113g/cm³。

Mixing tetraethoxysilane and 4-triethoxysilylbvinylbenzocyclobutene according to a molar ratio of 1:0.9 to form a mixed silicon source, mixing the silicon source, absolute ethyl alcohol and water according to a molar ratio of 1:8:4, uniformly stirring, adding oxalic acid to adjust the pH value to 3.0 for hydrolysis, adding ammonia water to adjust the pH value to 10.5 for condensation to obtain wet gel, aging the wet gel in a water bath at 50 ℃ for 2 hours, taking out the wet gel, soaking the wet gel in absolute ethyl alcohol for solvent replacement for 2 times, taking out the wet gel, soaking the wet gel in a surface modifier (a DMSO solution of trimethylchlorosilane with the concentration of 120g/L) for 2 hours for modification, heating to 200 ℃ for constant-temperature reaction for 3 hours, cooling to room temperature, soaking the wet gel in absolute ethyl alcohol again for replacement for 3 times, drying the wet gel in a drying oven at 50 ℃ for 3 hours, and drying the wet gel in a blowing drying oven at 90 ℃ for 2 hours, And drying in a 120 ℃ air blast drying oven for 2 hours to obtain the silicon dioxide composite aerogel 2. The silica composite aerogel 2 has a thermal conductivity of 0.0147W/(m.k) and a density of 0.115g/cm³。

Mixing tetraethoxysilane, 4-triethoxysilylbvinylbenzocyclobutene and ethynyltriethoxysilane according to a molar ratio of 1:1.2:0.25 to form a mixed silicon source, mixing the mixed silicon source, absolute ethyl alcohol and water according to a molar ratio of 1:9:3.7, uniformly stirring, adding oxalic acid to adjust the pH value to 3.0 for hydrolysis, adding ammonia water to adjust the pH value to 10.5 for condensation to obtain wet gel, aging the wet gel in a water bath at 30 ℃ for 3 hours, taking out the wet gel, soaking the wet gel in absolute ethyl alcohol for solvent replacement for 2 times, taking out the wet gel, soaking the wet gel in a surface modifier (DMF solution of hexamethyldisilazane, the concentration of which is 120g/L) for 3 hours for modification, heating to 180 ℃ for constant-temperature reaction for 2 hours, cooling to room temperature, soaking the wet gel in absolute ethyl alcohol again for replacement for 3 times, and replacing the wet gel for 3 timesAnd drying the glue in a 50 ℃ forced air drying oven for 3 hours, a 90 ℃ forced air drying oven for 3 hours and a 120 ℃ forced air drying oven for 3 hours in sequence to obtain the silicon dioxide composite aerogel 3. The silica composite aerogel 1 has a thermal conductivity of 0.0141W/(m.k) and a density of 0.112g/cm³。

And drying the wet gel subjected to the second absolute ethyl alcohol replacement in the preparation of the silicon dioxide composite aerogel 3 by adopting a supercritical silicon dioxide drying process to obtain the silicon dioxide composite aerogel 4. The thermal conductivity coefficient of the silicon dioxide composite aerogel 1 is 0.0139W/(m.k), and the density is 0.110g/cm³。