CN102721765B - Method for determining content of acrylonitrile monomer in polyacrylonitrile polymer liquid - Google Patents
Method for determining content of acrylonitrile monomer in polyacrylonitrile polymer liquid Download PDFInfo
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- CN102721765B CN102721765B CN201210223104XA CN201210223104A CN102721765B CN 102721765 B CN102721765 B CN 102721765B CN 201210223104X A CN201210223104X A CN 201210223104XA CN 201210223104 A CN201210223104 A CN 201210223104A CN 102721765 B CN102721765 B CN 102721765B
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Abstract
The invention provides a method for determining the content of acrylonitrile monomer in a polyacrylonitrile polymer liquid. The method provided by the invention is simple and convenient to operate, low in limit of detection, free from miscellaneous peaks obtained in chromatogram, excellent in repeatability, environment-friendly, low in error and the like. The invention further provides a method for determining the content of water in the polyacrylonitrile polymer liquid by using polar organic solvents after the content of acrylonitrile monomer in the polyacrylonitrile polymer liquid is determined.
Description
Technical field
The present invention relates to detection field.Specifically, the present invention relates to measure the method for acrylonitrile monemer in polyacrylonitrile polymer fluid (AN) content.
Background technology
Carbon fiber is a kind of high strength, the high modulus material of succeeding in developing the sixties in 20th century, is widely used in Aero-Space, Leisure Sport articles for use and general industry field.The carbon fiber made by polyacrylonitrile (PAN) has the performance of a series of excellences, and its production technology is comparatively simple, and therefore the good mechanical properties of product has obtained developing rapidly, is widely used in each field.
Polyacrylonitrile (PAN) precursor is the basis for preparing high-performance carbon fibre, is the bottleneck of restriction China carbon fiber development.The final performance of carbon fiber depends on the quality of precursor to a great extent.And the precursor of high-quality should possess high-purity, high strength, high-orientation, thin dawn and without characteristics such as adhesions.
The preparation of precursor comprises polymerization and spinning two steps.Wherein, polymerization is the first step for preparing precursor, is also the committed step that improves former yarn quality.The performance of polymer fluid directly affects the precursor performance, because the polymerization single polymerization monomer existed in polymer fluid can cause following harmful effect: (1) reduces the viscosity of polymer fluid, thereby makes the viscosity of polymer fluid and actual viscosity measured there are differences; (2) overflow from solidify strand and form than macroscopic void; (3), because its boiling point is lower, at the higher process section of boiling water drawing-off equitemperature, overflow and become impurity.Therefore, the micro-polymerization single polymerization monomer how detected in good polymer fluid is most important for obtaining high-quality precursor.
Current detection method has chemical titration and enriched gas phase chromatography.Chemical titration utilizes vinyl cyanide residual in polymer fluid and sodium sulphite to play addition reaction in aqueous solution and generates a certain amount of NaOH, then utilizes the titration of standard dilution heat of sulfuric acid, with alizarin yellow element-thymol phthalein, as indicator, is detected.The Experimental Establishment of the method is simple, without expensive testing apparatus.But the method is had relatively high expectations to the operator, operator's subjectivity is larger on result impact, especially in the situation that the less error of residual acrylonitrile monomer content is larger.
Though the enriched gas phase chromatography has solved the larger shortcoming of operator's subjectivity impact by chromatography, but the method pre-treatment step is loaded down with trivial details, the dimethyl sulfoxide, dimethyl acetamide, the dimethyl formamide equal solvent that adopt are larger to the human injury, and recovery yield of monomer is lower.
In sum, the detection method of easy and simple to handle, sensitive, environmental friendliness, mensuration acrylonitrile monomer content in polyacrylonitrile polymer fluid that error is little is badly in need of in this area.
Summary of the invention
The object of the present invention is to provide a kind of method of measuring acrylonitrile monomer content in polyacrylonitrile polymer fluid.
In first aspect, the invention provides a kind of method of measuring acrylonitrile monomer content in polyacrylonitrile polymer fluid, said method comprising the steps of:
A. utilize the acrylonitrile monemer in water extraction polyacrylonitrile polymer fluid in airtight container;
B. adopt vapor-phase chromatography to detect acrylonitrile monomer content;
C. obtain the acrylonitrile monomer content in described polyacrylonitrile polymer fluid by conversion.
In concrete embodiment, the weight ratio of water and described polyacrylonitrile polymer fluid is 10:1 – 400:1, preferably 20:1 – 200:1, more preferably 30:1 – 100:1.
In concrete embodiment, adopt internal standard method to carry out described vapor-phase chromatography.
In concrete embodiment, the internal standard compound of described internal standard method utilization is C
1-6Lower alcohol, particular methanol, ethanol or propyl alcohol, more preferably ethanol.
In concrete embodiment, described water comprises deionized water, distilled water, reverse osmosis water or ultrapure water.
In concrete embodiment, the temperature of described extraction is 20-70 ℃, preferably 50-60 ℃.
In concrete embodiment, the time of described extraction is 20-120min, preferably 20-90min, more preferably 30-60min.
In concrete embodiment, described extraction comprises oscillation extraction or ultrasonic extraction.
In concrete embodiment, described method is further comprising the steps of after detecting acrylonitrile monomer content in polyacrylonitrile polymer fluid:
A '. separately get polyacrylonitrile polymer fluid, in airtight container, utilize the polar organic solvent dissolved each other with water to extract the water in described polyacrylonitrile polymer fluid;
B '. the moisture that test extracts;
C '. utilize described polar organic solvent to carry out the solvent blank test; With
D '. utilize following formula to calculate moisture;
H
2O（%）=[(C
1-C
0)*m
0]/m
1*100%
Wherein, m
0: the organic solvent weight added;
M
1: the polymer fluid weight added;
C
0: organic solvent blank solution water percentage;
C
1: organic solvent extraction liquid water percentage.
In further embodiment, described polar organic solvent comprises methyl alcohol, ethanol or acetone.
In a preferred embodiment, utilize the karl Fischer moisture teller to carry out described step b.
In should be understood that within the scope of the present invention, above-mentioned each technical characterictic of the present invention and can combining mutually between specifically described each technical characterictic in below (eg embodiment), thus form new or preferred technical scheme.As space is limited, tire out and state no longer one by one at this.
The accompanying drawing explanation
Fig. 1 has shown the chromatogram of embodiment 1 gained.
Fig. 2 has shown the chromatogram of reference examples gained.
Embodiment
The inventor, through research, utilizes polyacrylonitrile polymer fluid to mix and cause polyacrylonitrile and acrylonitrile monemer to be separated with the water of specified quantitative, and acrylonitrile monemer spreads in water, thereby can adopt vapor-phase chromatography easy and detect delicately the content of acrylonitrile monemer.Completed on this basis the present invention.
Method of the present invention
Produce and be separated when method of the present invention utilizes polyacrylonitrile polymer fluid to mix with the water of specified quantitative, thereby cause the polyacrylonitrile precipitation to be solidified, and acrylonitrile monemer spreads in water, and then utilize vapor-phase chromatography to detect the content of acrylonitrile monemer.
In concrete embodiment, detection method of the present invention can comprise the following steps:
A. utilize the acrylonitrile monemer in water extraction polyacrylonitrile polymer fluid in airtight container;
B. adopt vapor-phase chromatography to detect acrylonitrile monomer content;
C. obtain the acrylonitrile monomer content in described polyacrylonitrile polymer fluid by conversion.
In concrete embodiment, described water comprises deionized water, distilled water, reverse osmosis water or ultrapure water.
In concrete embodiment, the weight ratio of water and described polyacrylonitrile polymer fluid is 10:1-400:1, preferably 20:1-200:1, more preferably 30:1-100:1.
In concrete embodiment, described vapor-phase chromatography can adopt internal standard method or external standard method, preferably internal standard method.In a preferred embodiment, described interior mark is C
1-6Lower alcohols, particular methanol, ethanol or propyl alcohol, more preferably ethanol.
In concrete embodiment, the temperature of described extraction is 20-70 ℃, preferably 50-60 ℃.
In concrete embodiment, the time of described extraction is 20-120min, preferably 20-90min, more preferably 30-60min.Another preferred embodiment in, described extraction comprises oscillation extraction or ultrasonic extraction.
In concrete embodiment, described method also is included in and detects the step that acrylonitrile monomer content in polyacrylonitrile polymer fluid detects liquid water content in acrylonitrile polymerization liquid afterwards, and described step comprises:
A '. separately get polyacrylonitrile polymer fluid, in airtight container, utilize the polar organic solvent dissolved each other with water to extract the water in described polyacrylonitrile polymer fluid;
B '. the moisture that test extracts;
C '. utilize described polar organic solvent to carry out the solvent blank test; With
D '. utilize following formula to calculate moisture;
H
2O（%）=[(C
1-C
0)*m
0]/m
1*100%
Wherein, m
0: the organic solvent weight added;
M
1: the polymer fluid weight added;
C
0: organic solvent blank solution water percentage;
C
1: organic solvent extraction liquid water percentage.
In concrete embodiment, described polar organic solvent comprises methyl alcohol, ethanol or acetone.
In a preferred embodiment, utilize the karl Fischer moisture teller to carry out described step b.
Deionized water
Term used herein " deionized water " has with those of ordinary skills are conventional understands identical implication, and it has referred to remove the pure water be after ionic species impurity.
Distilled water
Term used herein " distilled water " has the implication identical with the conventional understanding of those of ordinary skills, and it refers to the pure water prepared with distillating method.
Reverse osmosis water
Term used herein " reverse osmosis water " has with those of ordinary skills are conventional understands identical implication, and it refers to adopt principle of reverse osmosis to remove and desalt and impurity and the water that obtains.
Ultrapure water
Term used herein " ultrapure water " has the implication identical with the conventional understanding of those of ordinary skills, it refers to the conducting medium in water is almost completely removed, and will in water, from colloidal material, gas and the organism separated, all not be removed to the very water of low degree again.Described ultrapure resistivity of water is greater than 18M Ω * cm, or approaches 18.3M Ω * cm ultimate value.
Conversion method of the present invention
Take acrylonitrile concentration as horizontal ordinate, and it is ordinate that standard solution sample peak area is internally marked peak area ratio, drawing standard acrylonitrile content working curve.
Obtain sample and internal standard compound peak area ratio in the testing sample chromatogram, by working curve, obtain acrylonitrile monemer concentration, extension rate while finally processing per sample, calculate the actual content of acrylonitrile monemer.
The advantage of the inventive method
1. the sample preparation of detection method of the present invention is simple, does not need sample is carried out to the secondary processing processing;
2. the detectability of detection method of the present invention is low, the minimum 0.1mg/kg that reaches;
3. the assorted peak of the clean and non interference of the chromatogram of detection method gained of the present invention;
4. the repeatability of detection method of the present invention is good;
Detection method of the present invention solvent used to human body without injury, pre-treatment step is easy, recovery yield of monomer is high;
6. detection method of the present invention is simple to operate, is subject to subjective random impact little, and error is low.
Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiment only are not used in and limit the scope of the invention for the present invention is described.The experimental technique of unreceipted actual conditions in the following example, usually according to normal condition, or the condition of advising according to manufacturer.Unless otherwise indicated, otherwise number percent and umber are percentage by weight and parts by weight.
Embodiment
Embodiment 1
Draw a certain amount of polymer fluid with the syringe with scale, 1～2g sample is injected to the air-tight bottle that contains 100mL distilled water, tighten bottle cap, accurate weighing injects air-tight bottle polymer fluid sample quality.6 samples of same operation nominal amount, quality is respectively: 1.6748g, 2.1779g, 1.2578g, 1.7040g, 1.5255g, 1.6221g, sample is placed in 50 ℃ of water bath with thermostatic control oscillators and shakes 30min.After cooling, add respectively mark in 10 μ L ethanol, shake up.Suck 1 μ L sample with micro syringe, inject gas chromatograph is tested successively, in selected chromatographic column condition, (chromatogram is selected condition: chromatographic column 30m * 0.32mm, 0.5 the capillary column of μ m, 50～70 ℃ of post case initial temperatures, 10～20 ℃/min of heating rate, final temperature is 160～200 ℃, split ratio 30:1, injector temperature is 160～180 ℃, hydrogen flowing quantity 30mL/min, air mass flow 300mL/min, nitrogen flow 30mL/min, detecting device adopts flame ionization ditector (FID), detector temperature is 200～300 ℃) under measured the peak area of acrylonitrile monemer, calculate acrylonitrile concentration in polymer fluid (referring to accompanying drawing 1) by internal standard method.Acrylonitrile content is respectively 2.61%, 2.56%, 2.55%, 2.61%, 2.59%, 2.60%, and the mean value value is 2.59%, and result standard deviation (SD) is 0.026.
According to the operation steps of embodiment 1, adopt same sample, weighing 1.6221g, 1.6444g sample, be placed in 60 ℃ of water bath with thermostatic control oscillators respectively, concussion 30min.After cooling, add mark in 10 μ L ethanol, shake up.According to chromatographic condition in embodiment 1, measure the peak area of acrylonitrile monemer, calculate acrylonitrile concentration in polymer fluid by internal standard method and be respectively 2.61%, 2.60%.
Embodiment 3
According to the operation steps of embodiment 1, adopt same sample, weighing 1.44495g, 1.7060g sample, be placed in 60 ℃ of water bath with thermostatic control oscillators respectively, concussion 60min.After cooling, add mark in 10 μ L ethanol, shake up.According to chromatographic condition in embodiment 1, measure the peak area of acrylonitrile monemer, calculate acrylonitrile concentration in polymer fluid by internal standard method and be respectively 2.59%, 2.60%.
Embodiment 4
Add methanol solution in sealing the fine specimen bottle, taking its weight is that 27.6318g(is accurate to 0.0001g), inject original polyacrylonitrile polymer fluid 2.0949g(and be accurate to 0.0001g in above-mentioned sample bottle), then be placed in exsiccator and extract 30min.Carry out equally methanol solvate space management (do not add polyacrylonitrile polymer fluid in sample bottle, other steps are processed equally) by above-mentioned steps.Finally, use the karl Fischer moisture teller to complete rapidly test.Calculate as follows content:
H
2O（%）=[(C
1-C
0)*m
0]/m
1*100%
M
0: the methyl alcohol weight added
M
1: the polymer fluid weight that adds the people
C
0: methyl alcohol blank solution water percentage
C
1: methanol extraction liquid water percentage
Test value C
0=0.026%, C
1=0.047%, calculating the polymer fluid water percentage is 0.28%.
Reference examples
According to patent of invention, " CN201010211096.8, " assay method of acrylonitrile monemer in polyacrylonitrile polymer fluid " is described, adopts same sample, distinguishes weighing 1.1002g, 1.2365g sample, uses the 100ml dimethyl sulfoxide (DMSO) as solvent, fully dissolution sample.Adopt the same chromatographic separation condition of embodiment 1 (to detect the content of acrylonitrile monemer, fully whether checking AN monomer extraction), measure the peak area of acrylonitrile monemer, calculate acrylonitrile concentration in polymer fluid by internal standard method and be respectively 2.61%, 2.62% (referring to accompanying drawing 2).
From reference examples, in the polyacrylonitrile polymer fluid of the inventive method gained, the acrylonitrile monemer measurement result accurately and reliably.And comparative drawings figs 1 and 2 can also obviously be found, with prior art, utilizes the chromatogram of organic solvent gained to compare, the clean and assorted peak of non interference of the chromatogram of the inventive method gained.And utilize organic solvent not only to increase cost, also can cause serious problem of environmental pollution.In addition, a lot of assorted peaks appear in the chromatogram that utilizes organic solvent to obtain, thus can Interference Detection.
All documents of mentioning in the present invention are all quoted as a reference in this application, just as each piece of document quoted separately as a reference.Should be understood that in addition those skilled in the art can make various changes or modifications the present invention after having read above-mentioned instruction content of the present invention, these equivalent form of values fall within the application's appended claims limited range equally.
Claims (16)
1. a method of measuring acrylonitrile monomer content in polyacrylonitrile polymer fluid, is characterized in that, said method comprising the steps of:
A. utilize the acrylonitrile monemer in water extraction polyacrylonitrile polymer fluid in airtight container;
B. adopt vapor-phase chromatography to detect acrylonitrile monomer content;
C. obtain the acrylonitrile monomer content in described polyacrylonitrile polymer fluid by conversion;
Wherein, the weight ratio of water and described polyacrylonitrile polymer fluid is 10:1 – 400:1.
2. the method for claim 1, is characterized in that, the weight ratio of water and described polyacrylonitrile polymer fluid is 20:1 – 200:1.
3. method as claimed in claim 2, is characterized in that, the weight ratio of water and described polyacrylonitrile polymer fluid is 30:1 – 100:1.
4. the method for claim 1, is characterized in that, adopts internal standard method to carry out described vapor-phase chromatography.
5. method as claimed in claim 4, is characterized in that, the internal standard compound of described internal standard method utilization is C
1-6Lower alcohol.
6. method as claimed in claim 5, is characterized in that, the internal standard compound of described internal standard method utilization is methyl alcohol, ethanol or propyl alcohol.
7. method as claimed in claim 6, is characterized in that, the internal standard compound of described internal standard method utilization is ethanol.
8. the method for claim 1, is characterized in that, described water comprises deionized water, distilled water, reverse osmosis water or ultrapure water.
9. the method for claim 1, is characterized in that, the temperature of described extraction is 20-70 ℃.
10. method as claimed in claim 9, is characterized in that, the temperature of described extraction is 50-60 ℃.
11. the method for claim 1, is characterized in that, the time of described extraction is 20-120min.
12. the method for claim 1, is characterized in that, the time of described extraction is 20-90min.
13. method as claimed in claim 12, is characterized in that, the time of described extraction is 30-60min.
14. the method for claim 1, is characterized in that, described extraction comprises oscillation extraction or ultrasonic extraction.
15. the method for claim 1, is characterized in that, described method is further comprising the steps of after detecting acrylonitrile monomer content in polyacrylonitrile polymer fluid:
A '. separately get polyacrylonitrile polymer fluid, in airtight container, utilize the polar organic solvent dissolved each other with water to extract the water in described polyacrylonitrile polymer fluid;
B '. the moisture that test extracts;
C '. utilize described polar organic solvent to carry out the solvent blank test; With
D '. utilize following formula to calculate moisture;
H
2O（%）=[(C
1-C
0)*m
0]/m
1*100%
Wherein, m
0: the organic solvent weight added;
M
1: the polymer fluid weight added;
C
0: organic solvent blank solution water percentage;
C
1: organic solvent extraction liquid water percentage.
16. method as claimed in claim 15, is characterized in that, described polar organic solvent comprises methyl alcohol, ethanol or acetone.
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| CN104181156B (en) * | 2014-09-10 | 2016-08-17 | 江苏恒神股份有限公司 | The method of testing of ammonia content in polyacrylonitrile polymer stock solution |
| CN111323495B (en) * | 2018-12-14 | 2023-03-14 | 乐凯华光印刷科技有限公司 | Method for measuring residual amounts of acrylonitrile and styrene in thermoplastic nano-micron particle emulsion |
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