Heat-resistant phenolic aerogel and preparation method thereof

An airgel and phenolic technology, applied in the field of heat-resistant phenolic airgel and its preparation, can solve the problems of high raw material prices, inconvenient application and promotion, and complicated preparation process, and achieve high network skeleton strength, low price, and easy operation Environmentally friendly effect

Active Publication Date: 2020-06-05
SUZHOU TUNABLE MATERIALS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the preparation of phenolic aerogels has been reported in many literatures and patents, there are still some problems: (1) high cost, complicated preparation process, and environmental pollution: in the traditional preparation process of phenolic aerogels, many The preparation process of supercritical drying is adopted, but the drying process has the disadvantages of high cost, complicated operation, and low safety factor; in addition, the use of resorcinol raw materials has high raw material prices, which brings inconvenience to application and promotion; When novolac is used as the raw material, since novolac itself cannot be cross-linked and cured, it is necessary to add a curing agent hexamethylenetetramine, and hexamethylenetetramine will release ammonia gas during the curing process, which will bring pollution to the airgel preparation environment. Pollution
(2) Due to the characteristics of the molecular structure of phenolic resin, such as methylene is easy to break, phenolic hydroxyl is easy to oxidize, etc., through organic-inorganic hybrid technology, silicon, boron, zirconium and other elements are introduced into the phenolic resin, which can effectively improve the phenolic resin. The heat resistance of the resin, but how to prepare the organic-inorganic hybrid phenolic resin into an aerogel still needs a technological breakthrough

Method used

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  • Heat-resistant phenolic aerogel and preparation method thereof
  • Heat-resistant phenolic aerogel and preparation method thereof
  • Heat-resistant phenolic aerogel and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Step 1, the synthesis of boron phenolic resin: phenol, formaldehyde, boric acid are added in the reactor in the ratio of 1:1.5:0.3 by molar ratio, then add catalyst zinc oxide, wherein the amount of zinc oxide is 1% of phenol weight, Raise the temperature to 90°C, react for 6 hours, and then distill and dehydrate under reduced pressure to obtain a boron-modified phenolic resin.

[0039] Step 2: fully mix the boron-modified phenolic resin, sulfuric acid, and ethanol in a ratio of 100:10:75 by weight to obtain a boron-modified phenolic resin ethanol solution.

[0040] Step 3: Treat the boron-modified phenolic resin ethanol solution at 60° C. for 24 hours under airtight conditions to obtain a phenolic wet gel.

[0041] Step 4, drying the phenolic wet gel at 50° C. under normal pressure for 24 hours, and then drying at 80° C. under normal pressure for 36 hours to obtain the final heat-resistant phenolic aerogel.

[0042] The heat-resistant phenolic airgel has a density of ...

Embodiment 2

[0044]This example is basically the same as Example 1, except that the boron-modified phenolic resin, sulfuric acid, and ethanol are fully mixed in a weight ratio of 100:5:100.

[0045] The density of the heat-resistant phenolic aerogel obtained is 0.41g / cm , and the aperture is 500nm-1 μm (see figure 2 ), the residual weight rate is 56.5%.

Embodiment 3

[0047] This embodiment is basically the same as Embodiment 1, the differences are: the molar ratio of phenol, formaldehyde, and boric acid is 1:1.8:0.2; the amount of zinc oxide is 1.5% of the phenol weight; boron modified phenolic resin, sulfuric acid, ethanol The weight ratio is 100:10:200 and mixed well; the boron-modified phenolic resin ethanol solution is treated under airtight conditions at 60°C for 48 hours; the phenolic wet gel is dried at 50°C under normal pressure for 48 hours, and then 80°C Press dry for 36 hours to obtain the final heat-resistant phenolic airgel.

[0048] The density of this phenolic airgel is 0.28g / cm3, and aperture is 1-2 μm (referring to image 3 ), the residual weight is 54.5%.

[0049] In summary, the present invention adopts sol-gel-normal pressure drying process to prepare heat-resistant phenolic airgel, and through boron modification, the obtained phenolic airgel has the advantages of high heat resistance, high network skeleton strength, e...

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Abstract

The invention relates to a preparation method of heat-resistant phenolic aerogel. The preparation method comprises the following steps: S1, synthesizing boron-modified phenolic resin; S2, mixing the boron-modified phenolic resin with a curing accelerator and a solvent to obtain a phenolic resin solution; S3, gelatinizing the phenolic resin solution under a closed condition to obtain phenolic aldehyde wet gel; and S4, drying the phenolic aldehyde wet gel at normal pressure to obtain the heat-resistant phenolic aldehyde aerogel. The heat-resistant phenolic aerogel is prepared by adopting a sol-gel-normal-pressure drying process, so that the prepared phenolic aerogel has the advantages of high heat resistance, high network skeleton strength and the like through boron modification; the raw materials in the preparation method are all general chemical raw materials and are low in price; a curing agent hexamethylenetetramine does not need to be added in the preparation process, so that no ammonia gas is released in the curing process, and the operation environment is friendly.

Description

technical field [0001] The invention relates to a heat-resistant phenolic airgel and a preparation method thereof. Background technique [0002] Airgel is a porous three-dimensional network structure constructed by the interconnection of gel particles. Due to its low density, high porosity, large specific surface area and low thermal conductivity, it is widely used in adsorption, separation, catalysis, energy conversion and storage and other fields. Phenolic airgel is a porous, organic material composed of phenolic polymer molecular chains to form a gel network. Phenolic resin has the characteristics of heat resistance, high carbon residue, and flame retardancy. Phenolic aerogel is injected into the boundary layer during the ablation process to produce thermal blocking effect, and the pyrolytic carbon layer dissipates heat through the reverse radiation effect. Furthermore, due to the low thermal conductivity of phenolic airgel and carbon airgel obtained by pyrolysis, it ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J9/28C08L61/14C08G8/28
CPCC08J9/28C08G8/28C08J2361/14C08J2201/05C08J2205/026Y02P20/54
Inventor 闫哲张兔子
Owner SUZHOU TUNABLE MATERIALS TECH CO LTD
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