CN114736420B - Modified phenolic resin foam and preparation method thereof - Google Patents
Modified phenolic resin foam and preparation method thereof Download PDFInfo
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- CN114736420B CN114736420B CN202210670508.7A CN202210670508A CN114736420B CN 114736420 B CN114736420 B CN 114736420B CN 202210670508 A CN202210670508 A CN 202210670508A CN 114736420 B CN114736420 B CN 114736420B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
- C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
- C08J9/141—Hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
- C08G8/28—Chemically modified polycondensates
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2203/00—Foams characterized by the expanding agent
- C08J2203/14—Saturated hydrocarbons, e.g. butane; Unspecified hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2361/00—Characterised by the use of condensation polymers of aldehydes or ketones; Derivatives of such polymers
- C08J2361/04—Condensation polymers of aldehydes or ketones with phenols only
- C08J2361/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols
- C08J2361/14—Modified phenol-aldehyde condensates
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
A preparation method of modified phenolic resin foam comprises the steps of modifying 4-hydroxybenzylamine by polyacrylic acid, further reacting with formaldehyde to obtain modified phenolic resin, uniformly mixing with a surfactant, adding a foaming agent, uniformly stirring, adding a curing agent, stirring, pouring into a preheated mold, heating, curing, cooling and curing to obtain the modified phenolic resin foam. The modified phenolic resin foam prepared by the invention has good high temperature resistance and heat insulation performance, and provides a foam material which can be used under the high-temperature environment condition.
Description
Technical Field
The invention relates to the field of high polymer materials, in particular to modified phenolic resin foam and a preparation method thereof.
Background
The phenol resin is a resin obtained by polycondensation of a phenol compound and an aldehyde compound, and among them, a phenol-formaldehyde resin obtained by polycondensation of phenol and formaldehyde is most important. The phenolic resin is found by Bayer (A. Baeyer) of German chemists in 1872, commercialized in 1902, applied to the field of paint, and put into practical use in 1905 by Bakland (L.H. Baekaland), an American scientist, and the production and application of the phenolic resin are greatly promoted. The phenolic resin has the advantages of simple preparation process, excellent performance and low price, and can be widely applied to the fields of foam, coating, plastic, adhesive and the like.
The modified phenolic resin foam has good low smoke toxicity, low smoke density and flame retardant property, has no dripping and melting phenomena during combustion, has excellent heat insulation property, is widely used for building heat insulation, and further realizes industrial heat insulation, thereby saving a large amount of fuel oil and coal for heat insulation. Although the modified phenolic resin foam has excellent heat insulation performance, when the ambient temperature is higher than 150 ℃, the modified phenolic resin foam begins to crack and thermally decompose, and gradually loses the heat insulation effect.
Disclosure of Invention
The invention aims to provide a high-temperature-resistant and high-heat-preservation modified phenolic resin foam and a preparation method thereof.
The invention provides a modified phenolic resin foam which comprises modified phenolic resin, a foaming agent, a curing agent and a surfactant.
The technical scheme adopted by the invention is as follows:
the preparation method of the modified phenolic resin foam is characterized by comprising the following steps of:
(1) synthesizing modified phenolic resin:
4-hydroxybenzylamine is used as a reactant, DMF is used as a solvent, imidazole is used as a catalyst, tert-butyldimethylsilyl chloride is added, the reaction is carried out in a zero-degree ice-water bath, the solvent is removed, and column chromatography purification is carried out to obtain A1.
A1 and polyacrylic acid are used as reactants, THF is used as a solvent, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added, stirring reaction is carried out, and filtration and dissolution removal are carried out, thus obtaining A2.
A2 as reactant, THF as solvent, adding tetrabutylammonium fluoride, stirring, adding saturated NH 4 And (5) extracting, desolventizing and drying the Cl solution to obtain A3.
A3 and formaldehyde are used as reactants, water is used as a solvent, heating and temperature rising are carried out, NaOH aqueous solution is slowly dripped into the system under the condition of rapid stirring, temperature rising reaction is continuously carried out, cold water is used for rapid temperature reduction, acid solution is used for adjusting the pH value of the system to be neutral, and vacuum dehydration is carried out to obtain red viscous liquid, namely the modified phenolic resin.
The weight average molecular weight of the polyacrylic acid in the above step was 5000 g/mol.
The mass ratio of A3 to formaldehyde in the above step is 1: 3.
The acid solution of the adjusting system in the step is hydrochloric acid, phosphoric acid, glacial acetic acid or p-toluenesulfonic acid.
The viscosity of the red viscous liquid in the step is 4000-7000 mPa.s.
(2) Preparing modified phenolic resin foam:
and (2) rapidly and uniformly stirring the modified phenolic resin and the surfactant by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mold, heating in an oven, and then cooling and curing to obtain the modified phenolic resin foam.
In the steps, the addition amount of each substance is 100 parts of modified phenolic resin, 2-8 parts of surfactant, 6-18 parts of foaming agent and 3-15 parts of curing agent according to the mass ratio.
The surfactant in the above step is one of tween-20, tween-60 and tween-80.
The foaming agent in the above step is one of n-pentane, isopentane, petroleum ether and n-hexane.
The curing agent in the above step is a complex system of inorganic acid and organic acid, wherein, phosphoric acid: p-toluenesulfonic acid: the mass ratio of the water is 1: 2-4: 1-2.
Has the beneficial effects that:
1. the modified phenolic resin foam has good thermal insulation performance, and the polyacrylic acid is grafted with phenolic hydroxyl and then condensed with formaldehyde to form phenolic resin, so that the network structure of the modified phenolic resin foam is tighter, the wall of the foam hole is prevented from being torn, the closed pore rate is improved, the thermal conductivity coefficient is reduced, and the thermal insulation performance of the foam is improved.
2. The modified phenolic resin foam has good high-temperature resistance and can still keep good heat preservation performance at high temperature.
Drawings
FIG. 1 is an infrared spectrum of the modified phenolic resin of example 1.
Detailed Description
The following examples further illustrate the present invention but are not to be construed as limiting the invention. Modifications and substitutions to methods, steps or conditions of the present invention may be made without departing from the spirit and scope of the invention.
Example 1
10.9 g (0.089 mol) of 4-hydroxybenzylamine is taken as a reactant, 100 mL of DMF is taken as a solvent, 1.5 eq (molar weight) of imidazole is taken as a catalyst, 1.5 eq (molar weight) of tert-butyldimethylsilyl chloride is added, and a zero-temperature ice-water bath is used for reaction for 4 hours, so as to obtain A1 after desolventization and column chromatography purification.
10 g A1 and 7.5g polyacrylic acid solution (weight average molecular weight 5000g/mol, purchased from Michelin, solid content 40%) as reactants, 150 mL THF as solvent, 4 g 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 4 g N-hydroxysuccinimide, stirring for reaction for 4 h, filtering, and removing the solvent to obtain A2.
12 g A2 as a reaction product, 100 mL THF as a solvent, 4 g tetrabutylammonium fluoride, stirring for 4 h, adding saturated NH 4 And (5) extracting, desolventizing and drying the Cl solution to obtain A3.
Heating 3 g A3 and 9 g of formaldehyde as reactants and 100 mL of water as a solvent to 40 ℃, slowly dropwise adding 3 mL of 50% NaOH aqueous solution into the system under rapid stirring, continuously heating to 50 ℃, reacting for 2 hours, heating to 80 ℃, reacting for 3 hours, rapidly cooling to below 40 ℃ with cold water, adjusting the pH of the system to be neutral with an acid solution, and dehydrating in vacuum to obtain red viscous liquid with the viscosity of 4000-7000 mPa.s, namely the modified phenolic resin, wherein the infrared spectrogram of the modified phenolic resin is shown in figure 1.
Comparative example 1
Heating 3 g of phenol and 9 g of formaldehyde as reactants and 100 mL of water as a solvent to 40 ℃, slowly dropwise adding 3 mL of 50% NaOH aqueous solution into the system under rapid stirring, continuously heating to 50 ℃, reacting for 2 hours, heating to 80 ℃, reacting for 3 hours, rapidly cooling to below 40 ℃ by using cold water, adjusting the pH of the system to be neutral by using an acid solution, and dehydrating in vacuum to obtain viscous liquid with the viscosity of 4000-7000 mPa.s, namely the phenolic resin.
Example 2
And (2) rapidly and uniformly stirring the modified phenolic resin and the surfactant by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mold, heating in a 75 ℃ oven for 10-15 min, and continuously curing at 50 ℃ for 30 min to obtain the modified phenolic resin foam.
In the steps, the addition amount of each substance is 100 parts of modified phenolic resin, 2 parts of surfactant, 6 parts of foaming agent and 3 parts of curing agent according to the mass ratio.
The surfactant Tween-80 in the above steps.
The foaming agent in the above step is petroleum ether.
The curing agent in the above step is a complex system of inorganic acid and organic acid, wherein, phosphoric acid: p-toluenesulfonic acid: the mass ratio of water is 1:2: 1.
Example 3
And (2) rapidly and uniformly stirring the modified phenolic resin and the surfactant by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mold, heating in a 75 ℃ oven for 10-15 min, and continuously curing at 50 ℃ for 30 min to obtain the modified phenolic resin foam.
In the steps, the addition amount of each substance is 100 parts of modified phenolic resin, 5 parts of surfactant, 15 parts of foaming agent and 9 parts of curing agent according to the mass ratio.
The surfactant in the above step is tween-80.
The foaming agent in the above step is petroleum ether.
The curing agent in the above step is a complex system of inorganic acid and organic acid, wherein, phosphoric acid: p-toluenesulfonic acid: the mass ratio of water is 1:3: 1.5.
Example 4
And (2) rapidly and uniformly stirring the modified phenolic resin and the surfactant by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mold, heating in a 75 ℃ oven for 10-15 min, and continuously curing at 50 ℃ for 30 min to obtain the modified phenolic resin foam.
In the steps, the addition amount of each substance is 100 parts of modified phenolic resin, 8 parts of surfactant, 18 parts of foaming agent and 15 parts of curing agent according to the mass ratio.
The surfactant in the above step is tween-80.
The foaming agent in the above step is petroleum ether.
The curing agent in the above step is a complex system of inorganic acid and organic acid, wherein, phosphoric acid: p-toluenesulfonic acid: the mass ratio of water is 1: 4: 2.
Comparative example 2
And (2) rapidly and uniformly stirring the phenolic resin and the surfactant prepared in the comparative example 1 by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mould, heating in a 75 ℃ oven for 10-15 min, and continuously curing at 50 ℃ for 30 min to obtain the phenolic resin foam.
In the steps, the addition amount of each substance is 100 parts of phenolic resin, 2 parts of surfactant, 6 parts of foaming agent and 3 parts of curing agent according to the mass ratio.
The surfactant in the above step is tween-80.
The foaming agent in the above step is petroleum ether.
The curing agent in the above step is a complex system of inorganic acid and organic acid, wherein, phosphoric acid: p-toluenesulfonic acid: the mass ratio of water is 1:2: 1.
Example 5
The foams prepared in comparative example 2 of examples 2, 3 and 4 were tested for water absorption: weighing 100 × 100 × 50 mm foam with mass of m1 and volume of V1, soaking in distilled water for 24 h, sucking off surface water, weighing again with mass of m2 to obtain a volume of absorbed water V = (m 2-m 1)/ρ (Water) And foam water absorption (%) = V/V1 × 100%.
The foams prepared in comparative example 2 of examples 2, 3 and 4 were tested for closed cell content using a closed cell content analyzer.
The insulation properties of the foams prepared in comparative example 2 of examples 2, 3 and 4 were tested using a thermal conductivity tester with reference to GB/T10294.
The maximum service temperature of the foams prepared in comparative example 2 of examples 2, 3 and 4 was determined with reference to GB/T17430.
Table 1 results of performance testing
| Performance of | Comparative example 2 | Example 2 | Example 3 | Example 4 |
| Water absorption (%) | 2.9 | 1.8 | 1.6 | 1.5 |
| Closed cell content (%) | 94.1 | 98.5 | 98.6 | 98.7 |
| Coefficient of thermal conductivity (W/m.k) | 0.035 | 0.010 | 0.010 | 0.009 |
| Maximum service temperature (. degree. C.) | 200 | 280 | 281 | 283 |
As can be seen from Table 1:
(1) the modified phenolic resin foam has good high-temperature resistance.
(2) The modified phenolic resin foam has good thermal insulation performance, and the connection of the polyacrylic acid and phenolic resin molecules enables the network structure of the modified phenolic resin foam to be tighter, prevents the pore walls of the foam from being torn, improves the closed pore rate, reduces the thermal conductivity coefficient, and is further beneficial to improving the thermal insulation performance of the foam.
In conclusion, the modified phenolic resin foam can keep good heat preservation performance at high temperature.
Claims (9)
1. The preparation method of the modified phenolic resin foam is characterized by comprising the following steps of:
(1) synthesizing modified phenolic resin:
4-hydroxybenzylamine is used as a reactant, DMF is used as a solvent, imidazole is used as a catalyst, tert-butyldimethylsilyl chloride is added, the reaction is carried out in a zero-degree ice-water bath, the solvent is removed, and column chromatography purification is carried out to obtain A1;
a1 and polyacrylic acid are used as reactants, THF is used as a solvent, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added, stirring reaction is carried out, and filtration and dissolution removal are carried out, thus obtaining A2;
a2 as reactant, THF as solvent, adding tetrabutylammonium fluoride, stirring, adding saturated NH 4 Extracting, desolventizing and drying the Cl solution to obtain A3;
a3 and formaldehyde are used as reactants, water is used as a solvent, heating and temperature rising are carried out, NaOH aqueous solution is slowly dripped into the system under the condition of rapid stirring, temperature rising reaction is continued, cold water is used for rapid temperature reduction, acid solution is used for adjusting the pH value of the system to be neutral, vacuum dehydration is carried out, and red viscous liquid, namely modified phenolic resin, is obtained;
(2) preparing modified phenolic resin foam:
and (3) rapidly and uniformly stirring the modified phenolic resin and the surfactant by using a high-speed dispersion machine, adding the foaming agent, uniformly stirring again, adding the curing agent, stirring, rapidly pouring into a preheated mold, heating in an oven, and cooling and curing to obtain the modified phenolic resin foam.
2. The method of claim 1, wherein the polyacrylic acid of step (1) has a weight average molecular weight of 5000 g/mol.
3. The method for preparing a modified phenolic resin foam as claimed in claim 1, wherein the mass ratio of A3 to formaldehyde in step (1) is 1: 3.
4. The method for preparing modified phenolic resin foam as claimed in claim 1, wherein the acid solution of the adjusting system in step (1) is hydrochloric acid, phosphoric acid, glacial acetic acid or p-toluenesulfonic acid.
5. The method for preparing a modified phenolic resin foam as claimed in claim 1, wherein the viscosity of the red viscous liquid in the step (1) is 4000 to 7000 mPa.s.
6. The method for preparing the modified phenolic resin foam as claimed in claim 1, wherein the addition amount of each substance in the step (2) comprises 100 parts of modified phenolic resin, 2-8 parts of surfactant, 6-18 parts of foaming agent and 3-15 parts of curing agent by mass ratio.
7. The method for preparing the modified phenolic resin foam as claimed in claim 1, wherein the surfactant in step (2) is one of tween-20, tween-60 and tween-80.
8. The method for preparing the modified phenolic resin foam as claimed in claim 1, wherein the foaming agent in step (2) is one of n-pentane, isopentane, petroleum ether and n-hexane.
9. The method for preparing modified phenolic resin foam according to claim 1, wherein the curing agent in the step (2) is a compound system of inorganic acid and organic acid, wherein the ratio of phosphoric acid: p-toluenesulfonic acid: the mass ratio of the water is 1: 2-4: 1-2.
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| CN101440170B (en) * | 2008-12-17 | 2012-02-22 | 中国林业科学研究院林产化学工业研究所 | Preparation of biomass modified phenolic foam plastic |
| CN101880365A (en) * | 2010-07-30 | 2010-11-10 | 山东圣泉化工股份有限公司 | Foaming phenolic resin preparation method and phenolic resin foam |
| CN102659992B (en) * | 2012-05-11 | 2014-06-25 | 黄山学院 | Phenolic lignin-based modified foaming phenolic resin, foamed plastic and preparation method of phenolic lignin-based modified foaming phenolic resin |
| CN105524404A (en) * | 2015-11-11 | 2016-04-27 | 陕西聚洁瀚化工有限公司 | Preparation method for liquefied bamboo-based phenolic foamed plastic |
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