CN111732713B - Preparation method of standard substance with high anhydride group content for epoxy resin condensate - Google Patents
Preparation method of standard substance with high anhydride group content for epoxy resin condensate Download PDFInfo
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- CN111732713B CN111732713B CN202010672013.9A CN202010672013A CN111732713B CN 111732713 B CN111732713 B CN 111732713B CN 202010672013 A CN202010672013 A CN 202010672013A CN 111732713 B CN111732713 B CN 111732713B
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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
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
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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
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
- C08G59/686—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used containing nitrogen
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
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Abstract
The invention provides a preparation method of a standard substance with high anhydride group content for epoxy resin condensate and the standard substance prepared by the method, which comprises the following steps: 1) preparing materials: calculating the use amount of each material according to the epoxy value of the epoxy resin with low molecular weight and high epoxy value and the molecular weight of the acetic anhydride, calculating the use amount of the amine catalyst according to the use amounts of the epoxy resin and the acetic anhydride, mixing the epoxy resin, the acetic anhydride and the amine catalyst, adding the mixture into a reactor with a condenser, and uniformly stirring; 2) heating and reacting: heating the reactor, and then refluxing and heating the materials for reaction; 3) setting the value: the standard substance was subjected to value determination by gas chromatography to obtain the desired content of the standard substance. The preparation method of the epoxy resin cured substance high-acid anhydride group content standard substance is simple to operate, mild in conditions, stable in physical and chemical properties of the prepared standard substance, especially stable in acid anhydride group content in the epoxy resin, and suitable for being used as the standard substance under various conditions.
Description
Technical Field
The invention belongs to the technical field of stoichiometry, relates to a standard substance preparation technology, and particularly relates to a preparation method of a high-content epoxy resin cured substance anhydride group content standard substance.
Background
The epoxy resin is a polymer oligomer having a molecular structure containing two or more epoxy groups, having an organic compound such as an aliphatic, alicyclic or aromatic compound as a skeleton, and being capable of forming a useful thermosetting product by a crosslinking reaction of the epoxy groups with various curing agents. The method is widely applied to high-tech fields such as chemical industry, national defense, aerospace, nuclear industry and the like.
The epoxy resin belongs to thermoplastic linear resin, and the unique performance of the epoxy resin can be embodied only by generating a three-dimensional network structure after an epoxy curing agent is added. The epoxy curing agents for epoxy resins are mainly classified into acid anhydride curing agents and amine curing agents. Compared with amine curing agents, the anhydride curing agent has the characteristics of low toxicity, large mixing amount with epoxy resin, low shrinkage rate of cured products, excellent heat resistance, mechanical properties, electrical properties and the like.
Common anhydride curing agents are maleic anhydride, nadic methyl anhydride, methylhexahydrophthalic anhydride, and the like. Epoxy condensate prepared by methyl hexahydrophthalic anhydride in 'high heat-resistant transparent flame-retardant epoxy resin curing system research' (Chinese adhesive 2010) of chenfeng and the like has good heat resistance and flame retardance. Wang Yi et al in "flame-retardant DOPO-maleic anhydride modified epoxy resin research" ("insulating material" 2010) adopted the reaction of maleic anhydride, DOPO and epoxy resin, and the flame-retardant property of the prepared cured product was significantly improved.
In order to provide the curing system with suitable processing and use properties, the anhydride curing agent is often used in excess amounts during actual operation. Although a proper excess of the acid anhydride curing agent can improve the thermal properties of the cured product, more reactive groups are introduced at the same time, which affects the aging resistance and stability of the cured product. Therefore, the control of the content of residual anhydride groups in the epoxy resin is important.
A standard substance is a material or substance whose one or more characteristic values are sufficiently uniform and stable and can be accurately determined, which can be used to calibrate the system, evaluate measurement procedures or assign values to the material, etc., each determined characteristic value having an uncertainty of a given confidence level.
The research reported in the existing literature usually focuses on the synthesis process and performance of the cured epoxy resin, and the research on the content control of the residual anhydride group and the uniformity of the material is less, so that a standard substance capable of solving the traceability of the content value of the residual anhydride group in the epoxy resin needs to be developed, and the monitoring on the content of the residual anhydride group in the epoxy resin is effectively realized.
Disclosure of Invention
In view of the above problems in the prior art, an object of the present invention is to provide a standard substance with high anhydride group content for epoxy resin cured material, which solves the problem that the existing standard substance is lack, and the quality control for the test of the anhydride group content for epoxy resin cured material cannot be performed, and realizes accurate measurement of the index, and also provides a preparation method of the standard substance with high anhydride group content for epoxy resin cured material.
According to the preparation method of the epoxy resin cured substance high-anhydride-group-content standard substance, the epoxy resin with low molecular weight and the acid anhydride with low molecular weight are used as raw materials, the reaction is promoted by the amine catalyst, the reaction of the epoxy resin and the acid anhydride is realized in the heating process, and the epoxy resin cured substance high-anhydride-group-content standard substance with the expected anhydride group content is prepared.
Specifically, the preparation method of the standard substance comprises the following steps:
1) preparing materials: calculating the use amount of each material according to the epoxy value of the epoxy resin with low molecular weight and high epoxy value and the molecular weight of acetic anhydride, calculating the use amount of an amine catalyst according to the use amounts of the epoxy resin and the acetic anhydride, mixing the epoxy resin, the acetic anhydride and the amine catalyst, adding the mixture into a reactor with a condenser, and uniformly stirring;
2) heating and reacting: heating the temperature of the reactor to 80-100 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 4 hours, then heating the temperature to 120-140 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 4 hours, finally heating the temperature to 160-180 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 2 hours, and cooling the reactants to room temperature after the reaction is finished;
3) setting the value: the standard substance candidates were subjected to the quantification by gas chromatography to obtain the expected content of the standard substance.
Preferably, in the method for preparing a standard substance according to the present invention, the low molecular weight high epoxy resin has an epoxy value of 0.8 to 1.5mol/100g and a weight average molecular weight of 200 to 500.
Preferably, the amine catalyst is selected from aniline or benzylamine and the like, more preferably benzylamine.
Preferably, the amine-based catalyst is added in an amount of 0.5 to 1.5 parts by weight, based on 100 parts by weight of the total weight of the low molecular weight high epoxy value epoxy resin and acetic anhydride.
Preferably, in step 3) of the method for preparing a standard substance according to the present invention, the gas chromatography is performed as follows:
the instrument comprises the following steps: agilent 7890A gas chromatograph (Agilent), detector: a FID detector; a chromatographic column: HP-1(30m × 0.53mm × 2.65 μm), injection port temperature 150 deg.C; the temperature of the detector is 250 ℃; the column temperature is that after the initial temperature is 80 ℃ and kept for 5min, the temperature is increased to 120 ℃ at the speed of 10 ℃/min and kept for 5 min. The split ratio is as follows: 20: 1; the sample injection mode is direct sample injection, and the sample injection amount is 1 mu L.
The invention also aims to provide the standard substance with high content of the anhydride group for the cured epoxy resin, and the standard substance is prepared by the preparation method of the standard substance.
Preferably, the content of the acid anhydride group in the high acid anhydride group content standard substance for the epoxy resin cured product according to the present invention is 0.8mol/100g to 0.9mol/100 g.
Advantageous effects
The preparation method of the epoxy resin cured substance high-acid anhydride group content standard substance is simple to operate, mild in conditions, stable in physical and chemical properties of the prepared standard substance, especially stable in acid anhydride group content in the epoxy resin, and suitable for being used as the standard substance under various conditions.
Detailed Description
Hereinafter, the present invention will be described in detail. Before the description is made, it should be understood that the terms used in the present specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Accordingly, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the invention, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the invention.
The following examples are given by way of illustration of embodiments of the invention and are not to be construed as limiting the invention, and it will be understood by those skilled in the art that modifications may be made without departing from the spirit and scope of the invention. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products.
Example 1
(1) 170g of epoxy resin (epoxy value of 0.90mol/100g, weight average molecular weight of 298, etc.), 2850g of acetic anhydride and 30g of benzylamine are weighed, added with magnetons and stirred uniformly on a magnetic stirrer.
(2) Connecting a condensing reflux device, and heating under continuous stirring. The heating time is 80 ℃ and 4 hours; 4h at 130 ℃; 2h at 160 ℃; and cooling to room temperature.
(3) Subpackaging the prepared standard substance into glass bottles according to the minimum packaging unit (50g), covering with inner lids, sealing and storing. And weighing a standard substance sample at a fixed value, dissolving the standard substance sample in acetone, measuring by adopting a gas chromatography, simultaneously measuring an acetic anhydride reagent, and determining the value according to the proportional relation between the acetic anhydride peak area and the acetic anhydride reagent peak area in the standard substance sample. The content of acid anhydride groups was found to be 0.85mol/100 g.
Example 2
(1) 189g of epoxy resin (the epoxy value is 1.35mol/100g, the weight-average molecular weight is 422), 2811g of acetic anhydride and 30g of benzylamine are weighed, and after magnetons are added, the mixture is stirred uniformly on a magnetic stirrer.
(2) Connecting a condensing reflux device, and heating under continuous stirring. The heating time is 80 ℃ and 4 hours; 4h at 130 ℃; 2h at 160 ℃; and cooling to room temperature.
(3) Subpackaging the prepared standard substance into glass bottles according to the minimum packaging unit (50g), covering an inner cover, and sealing for storage. And (3) weighing a standard substance sample at a fixed value, dissolving the standard substance sample in acetone, measuring by adopting a gas chromatography, simultaneously measuring an acetic anhydride reagent, and fixing the value according to the proportional relation of the acetic anhydride peak area in the standard substance sample and the acetic anhydride reagent peak area. The content of acid anhydride groups was found to be 0.86mol/100 g.
Example 3
(1) 160g of epoxy resin (the epoxy value is 0.90mol/100g, the weight-average molecular weight is 298)160g, 2840g of acetic anhydride and 20g of benzylamine are weighed, and added with magnetons and then stirred evenly on a magnetic stirrer.
(2) Connecting a condensing reflux device, and heating under continuous stirring. The heating time is 100 ℃ and 4 hours; 4h at 120 ℃; at 180 ℃ for 2 h; and cooling to room temperature.
(3) Subpackaging the prepared standard substance into glass bottles according to the minimum packaging unit (50g), covering with inner lids, sealing and storing. And weighing a standard substance sample at a fixed value, dissolving the standard substance sample in acetone, measuring by adopting a gas chromatography, simultaneously measuring an acetic anhydride reagent, and determining the value according to the proportional relation between the acetic anhydride peak area and the acetic anhydride reagent peak area in the standard substance sample. The content of acid anhydride groups was found to be 0.90mol/100 g.
Example 4
(1) 220g of epoxy resin (epoxy value is 1.35mol/100g, weight average molecular weight is 422), 2780g of acetic anhydride and 20g of benzylamine are weighed, and magnetons are added to the epoxy resin and stirred uniformly on a magnetic stirrer.
(2) Connecting a condensing reflux device, and heating under continuous stirring. The heating time is 100 ℃ and 4 hours; 4h at 120 ℃; 2h at 180 ℃; and cooling to room temperature.
(3) Subpackaging the prepared standard substance into glass bottles according to the minimum packaging unit (50g), covering with inner lids, sealing and storing. And weighing a standard substance sample at a fixed value, dissolving the standard substance sample in acetone, measuring by adopting a gas chromatography, simultaneously measuring an acetic anhydride reagent, and determining the value according to the proportional relation between the acetic anhydride peak area and the acetic anhydride reagent peak area in the standard substance sample. The content of acid anhydride groups was found to be 0.83mol/100 g.
Detection example 1: uniformity detection
The standard substance was prepared in three times according to the method of example 1, and each prepared standard substance was dispensed into 50 glass bottles, a total of 150 bottles were sampled, 10 bottles were randomly drawn therefrom, and the content of acid anhydride groups was measured by gas chromatography in example 1 as shown in table 1 below.
TABLE 1
| Sample numbering | Acid anhydride group content (mol/100g) | Sample numbering | Acid anhydride group content (mol/100g) |
| 1 | 0.853 | 9 | 0.849 |
| 2 | 0.851 | 10 | 0.853 |
| 3 | 0.851 | 11 | 0.850 |
| 4 | 0.849 | 12 | 0.850 |
| 5 | 0.851 | 13 | 0.851 |
| 6 | 0.852 | 14 | 0.851 |
| 7 | 0.850 | 15 | 0.849 |
| 8 | 0.850 |
From the data in table 1, it can be seen that the acid anhydride group contents of the standard substances obtained by the preparation method of the present invention have no significant difference, and thus the acid anhydride group content characteristics of the standard substances are uniform.
Detection example 2: stability detection
The standard substance was prepared in three times according to the method of example 1, and each prepared standard substance was dispensed into 50 glass bottles, 150 bottles in total were sampled, 40 bottles of samples were randomly taken from them, 10 samples were stored at different temperatures of-20 ℃, 0 ℃, 20 ℃ and 60 ℃, and sampled and tested at time points of 0 day (initial storage of the samples), 3 days, 7 days, 15 days and 30 days, respectively, and the stability of the standard substance was evaluated by detecting the change in the content of the acid anhydride group in the standard substance.
Similarly, the measurement was carried out by gas chromatography in example 1, and the measurement results of 10 samples stored at the same temperature were averaged to obtain the acid anhydride group content shown in Table 2 below.
TABLE 2
As can be seen from the data in Table 2, after the samples are stored for 30 days under the temperature conditions of-20 ℃, 0 ℃, 20 ℃ and 60 ℃, the characteristic values of the anhydride group contents of the samples are not obviously changed, and the difference of the changes of the samples does not reach a significant level. This indicates that the acid anhydride group content characteristics of the standard substance are very stable even when stored for a long period of time (30 days) at both low temperatures (-20 ℃) and high temperatures (60 ℃).
Claims (6)
1. A preparation method of a standard substance with high anhydride group content for epoxy resin condensate comprises the following steps:
1) preparing materials: calculating the use amount of each material according to the epoxy value of the epoxy resin with low molecular weight and high epoxy value and the molecular weight of acetic anhydride, calculating the use amount of an amine catalyst according to the use amounts of the epoxy resin and the acetic anhydride, mixing the epoxy resin, the acetic anhydride and the amine catalyst, adding the mixture into a reactor with a condenser, and uniformly stirring;
2) heating and reacting: heating the temperature of the reactor to 80-100 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 4 hours, then heating the temperature to 120-140 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 4 hours, finally heating the temperature to 160-180 ℃, heating the uniformly mixed materials at the temperature for reflux reaction for 2 hours, and cooling the reactants to room temperature after the reaction is finished;
3) setting the value: performing gas chromatography to obtain standard substance candidate with desired content;
in the preparation method, the epoxy value of the low-molecular-weight high-epoxy-value epoxy resin is 0.8-1.5 mol/100g, and the weight-average molecular weight is 200-500;
the content of the acid anhydride group in the high acid anhydride group content standard substance of the epoxy resin condensate is 0.8mol/100g to 0.9mol/100 g.
2. The process according to claim 1, wherein the amine catalyst is aniline or benzylamine.
3. The production method according to claim 1, wherein the amine catalyst is benzylamine.
4. The preparation method according to claim 1, characterized in that the amine catalyst is added in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of the total weight of the low molecular weight high epoxy value epoxy resin and acetic anhydride.
5. The production method according to claim 1, characterized in that, in step 3) of the production method, the gas chromatography is performed as follows:
the instrument comprises: agilent 7890A gas chromatograph, detector: a FID detector; a chromatographic column: HP-1(30m × 0.53mm × 2.65 μm), injection port temperature of 150 deg.C, detector temperature of 250 deg.C; column temperature, initial temperature 80 ℃ is kept for 5min, then the temperature is raised to 120 ℃ at the speed of 10 ℃/min, the temperature is kept for 5min, and the split ratio: 20: 1; the sample injection mode is direct sample injection, and the sample injection amount is 1 mu L.
6. A high-acid-anhydride-group-content standard substance for an epoxy resin cured product, which is produced by the production method for the standard substance according to any one of claims 1 to 5.
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| US5576216A (en) * | 1992-07-14 | 1996-11-19 | Zipora Patchornik | Universal standard reagents, method of preparing same and use thereof |
| CN108314777A (en) * | 2018-03-26 | 2018-07-24 | 华北电力大学（保定） | A kind of epoxy/acid acid anhydride solidfied material corsslinking molecular model construction and its glass transition temperature extracting method |
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| US20050112635A1 (en) * | 2003-09-22 | 2005-05-26 | Becton, Dickinson And Company | Quantification of analytes using internal standards |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US5576216A (en) * | 1992-07-14 | 1996-11-19 | Zipora Patchornik | Universal standard reagents, method of preparing same and use thereof |
| CN108314777A (en) * | 2018-03-26 | 2018-07-24 | 华北电力大学（保定） | A kind of epoxy/acid acid anhydride solidfied material corsslinking molecular model construction and its glass transition temperature extracting method |
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