CN109709261B - Method and instrument for measuring degree of hydrolysis of sulfonate-containing polyacrylamide polymer - Google Patents
Method and instrument for measuring degree of hydrolysis of sulfonate-containing polyacrylamide polymer Download PDFInfo
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- 230000007062 hydrolysis Effects 0.000 title claims abstract description 90
- 238000006460 hydrolysis reaction Methods 0.000 title claims abstract description 90
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 title claims abstract description 46
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- 229920002401 polyacrylamide Polymers 0.000 title claims abstract description 24
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 131
- 238000004448 titration Methods 0.000 claims abstract description 57
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- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical group NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 6
- 125000000542 sulfonic acid group Chemical group 0.000 claims description 6
- 150000007942 carboxylates Chemical class 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 238000004611 spectroscopical analysis Methods 0.000 claims description 4
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 claims description 3
- 238000003556 assay Methods 0.000 claims description 3
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- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 description 13
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- 239000002253 acid Substances 0.000 description 9
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- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 5
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- 229910052717 sulfur Inorganic materials 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 description 4
- -1 polytetrafluoroethylene Polymers 0.000 description 3
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- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- DBMJMQXJHONAFJ-UHFFFAOYSA-M Sodium laurylsulphate Chemical compound [Na+].CCCCCCCCCCCCOS([O-])(=O)=O DBMJMQXJHONAFJ-UHFFFAOYSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
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- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
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Abstract
The invention provides a method and a device for measuring the hydrolysis degree of a sulfonate-containing polyacrylamide polymer. The method comprises the following steps: measuring the content of the sulfonate, and calculating the volume V1 of the hydrochloric acid standard solution which contains the sulfonate to be consumed theoretically; titrating a hydrolysis degree analysis system of the polyacrylamide polymer containing the sulfonate by using a hydrochloric acid standard solution; monitoring the change of a hydrolysis degree analysis system in real time by using a pH sensor in the titration process, wherein the pH value is 4.10, namely the titration end point, and recording the volume V2 of the hydrochloric acid standard solution which is actually consumed; calculating the volume V of the hydrochloric acid standard solution consumed by carboxylate radicals from V2 to V1; calculating the degree of hydrolysis: HD is cvv 71/(1000m · S-23 cvv) × 100%. The measuring method avoids the interference of the sulfonate on the measuring result, and uses the pH meter to indicate the titration end point, thereby improving the sensitivity and the accuracy of the test.
Description
Technical Field
The invention belongs to the field of analytical chemistry. More particularly, relates to a method and a device for measuring the hydrolysis degree of a sulfonate-containing polyacrylamide polymer.
Background
The partially hydrolyzed polyacrylamide is widely applied to the technology of improving the recovery ratio of oil fields in China, the degree of hydrolysis is a basic parameter of the structural representation of a polymer, and refers to the percentage of chain links of carboxyl in polymer chain links, wherein acyl of polyacrylamide is converted into sodium carboxyl under the action of alkali. The degree of hydrolysis is an important index for evaluating the quality of partially hydrolyzed polyacrylamide products, and the size of the degree of hydrolysis directly influences the use performance of the polymer as an oil displacement agent. The polymer with too small hydrolysis degree has poor water solubility, and the polymer with too large hydrolysis degree has strong sensitivity to mineralization degree, hardness and shearing, so the method can quickly and accurately measure the hydrolysis degree of the polymer, and has important significance for controlling the product quality, evaluating the solubility and oil displacement effect.
The method is characterized in that methyl orange-indigo disulfonate is used as an indicator, a certain amount of oil displacement polymer aqueous solution is titrated by using a hydrochloric acid standard solution, the titration end point is obtained when the color of the solution is changed from yellow green to light grey, and the hydrolysis degree is calculated by the consumed hydrochloric acid amount. However, this method has the following problems: 1. the color change of the solution is visually observed, which varies from person to person, and particularly, the judgment of the end point is 'changed into light gray', and the error is large; 2. for the copolymeric polymer, if there are acid ions in the comonomer, such as sulfonate, excess hydrochloric acid is consumed, making the result larger.
Therefore, an analysis method capable of accurately measuring the hydrolysis degree of the sulfonate-containing polymer for oil displacement is urgently needed at present.
Disclosure of Invention
Based on the background technology, the invention provides a method and a device for measuring the hydrolysis degree of a sulfonate-containing polyacrylamide polymer. The measuring method avoids the interference of the sulfonate on the measuring result, and uses the pH meter to indicate the titration end point, thereby improving the sensitivity and the accuracy of the test.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for measuring the hydrolysis degree of a sulfonate-containing polyacrylamide polymer, which comprises the following steps:
measuring the content of the sulfonate, and calculating the volume V1 of the hydrochloric acid standard solution which contains the sulfonate to be consumed theoretically;
titrating a hydrolysis degree analysis system of the polyacrylamide polymer containing the sulfonate by using a hydrochloric acid standard solution; monitoring the change of a hydrolysis degree analysis system in real time by using a pH sensor in the titration process, wherein the pH value is 4.10, namely the titration end point, and recording the volume V2 of the hydrochloric acid standard solution which is actually consumed;
calculating the volume V of the hydrochloric acid standard solution consumed by carboxylate radicals from V2 to V1;
calculating the degree of hydrolysis: HD-CVV 71/(1000 mS-23 CV). times.100%
In the formula: HD: degree of hydrolysis,%;
c: the concentration of the hydrochloric acid standard solution, mol/L;
v: milliliters, mL, of hydrochloric acid standard solution consumed by the carboxylate;
m: sample mass, g;
s: solid content;
23: difference between mass of sodium acrylate and mass of acrylamide chain;
71: the mass of acrylamide units corresponding to 1.00mL of a standard hydrochloric acid solution having a concentration of 1.00 mol/L.
When the polyacrylamide polymer is dissolved to form an aqueous solution, ionization can occur to generate carboxylate, sulfonate, sodium ions and the like, so that a hydrolysis degree analysis system is formed.
According to the method, the content of the sulfonic acid group is measured, the volume of the hydrochloric acid standard solution which is theoretically consumed by the sulfonic acid and then consumed by the sulfonic acid group is subtracted from the volume of the consumed total hydrochloric acid standard solution when the hydrolysis degree is measured, so that the problem of inaccurate hydrolysis degree measurement caused by the sulfonic acid group is solved. The invention simultaneously adopts the pH sensor to monitor the change of the hydrolysis degree analysis system in real time, takes the pH value of 4.10 as the criterion of the titration end point, and avoids the error of artificially observing the color change.
In a general titration process, the concentration of the hydrochloric acid standard solution is 0-1.0mol/L, excluding 0. In the specific determination process, a tester can adjust the concentration of the most appropriate hydrochloric acid standard solution according to the concentration of the specific solution to be determined in the multiple determination processes, so that the volume of the consumed hydrochloric acid standard solution is too large, and meanwhile, the titration end point can be effectively controlled. For example, if the concentration of the hydrochloric acid standard solution is too low, the volume of the consumed hydrochloric acid standard solution is too large, and the titration time is too long. If the concentration of the hydrochloric acid standard solution is too high, although the consumption volume of the hydrochloric acid standard solution can be reduced, the titration endpoint is difficult to control, and a large error is caused. In the embodiment of the invention, the concentration of the hydrochloric acid standard solution is preferably 0.102 mol/L.
In the present invention, the measuring method of the sulfonate content includes, but is not limited to, an elemental analysis method, a titration method, a conductometry method, and a spectroscopic method. Preferably, the conductivity titration method and the energy spectrometry method are described in detail in the examples section of the present invention.
Preferably, after the sulfonate content is obtained, the calculation method for calculating the volume V1 of the hydrochloric acid standard solution theoretically consumed by the sulfonate content comprises the following steps: and calculating the volume V1 of the hydrochloric acid standard solution which is theoretically consumed by the contained sulfonate according to the measured sulfonate content, the sample quality and the concentration of the hydrochloric acid standard solution.
For example, when 8% of sulfur is obtained and all of the sulfur in the polymer is provided by sulfonate groups, the sulfonate group content of the polymer is 20% (80 × 8/32, wherein 80 is the molar mass of the sulfonate groups and 32 is the atomic mass of the sulfur). Assuming that 1g of the polymer has 0.2g of sulfonate groups, 0.001mol of hydrochloric acid is consumed, and V1 can be obtained according to the concentration of the hydrochloric acid.
The invention also provides an automatic hydrolysis degree tester, which is used for realizing the testing method; this automatic degree of hydrolysis apparatus includes:
the input module is used for inputting working instructions and parameters; preferably, the input module adopts a touch screen input mode;
the liquid crystal display screen is used for displaying an input interface, a working state and a measuring result;
the control processing module is used for controlling the titration process according to the input working instruction and parameters and calculating the measurement result;
a beaker for holding a hydrolysis degree analysis system;
a vertical stirrer for stirring the hydrolysis degree analysis system;
an automatic titration system for accurately dropping a hydrochloric acid standard solution into the hydrolysis degree analysis system;
pH sensor for monitoring the pH of a hydrolysis degree analysis system and
and the power supply module supplies power to the automatic hydrolysis degree tester.
The power module provides electric energy for the whole device, can select the electricity storage module that can charge and discharge of allotting on the instrument for use, also can connect external power supply. In view of the fact that the automatic hydrolysis degree tester is arranged at the same position for programming test in the using process, the automatic hydrolysis degree tester is preferably connected with an external power supply, so that the volume and the weight of the tester are reduced on one hand, and the cost of the tester is reduced on the other hand.
Preferably, the parameters include sample mass, solid content, concentration of hydrochloric acid standard solution, stirring speed, end point pH value, pre-control point pH value, titration liquid inlet speed, pre-control point liquid inlet speed and equilibrium time. The judgment of the end point adopts program control, the pH sensor senses the end point, and the instrument automatically slows down the liquid inlet speed when approaching the end point, so that the full reaction and the uniform mixing are realized, and the accuracy of the volume of the hydrochloric acid dripped into the hydrochloric acid is ensured.
The even stirring of the vertical stirrer can ensure that the titration solution is dispersed evenly and reacts completely, and the measurement of the pH sensor is more accurate. Preferably, the vertical stirrer comprises a stirring paddle extending into the hydrolysis degree analysis system, and the stirring paddle can move up and down and be detached, so that the beaker can be conveniently put in and taken out.
The titration of the hydrochloric acid standard solution adopts an automatic liquid inlet mode, a 2.5mL solution exchanger is connected with a liquid storage tank, and the liquid inlet speed is adjustable. The solution exchanger of the automatic hydrolysis degree measuring instrument uses a high-precision syringe pump used in an analytical instrument. The syringe used was a 2.5mL airtight microinjection syringe. The three-way switching valve uses a Japanese high-sand diaphragm valve and has the characteristics of sensitive switching and small pipeline liquid oscillation. The pipeline uses a polytetrafluoroethylene tube with the inner diameter of 0.5mm, and the liquid outlet part pipeline uses a 316 model stainless steel tube with the inner diameter of 0.2mm, so that the accuracy of the liquid flowing out is ensured.
When the automatic hydrolysis degree tester is used, only a hydrochloric acid standard solution and a hydrolysis degree analysis system need to be prepared in the early stage, a liquid crystal display screen of the automatic hydrolysis degree tester is clicked when the test is carried out, working instructions and parameters such as sample quality, solid content, concentration of the hydrochloric acid standard solution, stirring speed, end point pH value, pre-control point pH value, titration liquid inlet speed, pre-control point liquid inlet speed, balance time and the like are input, and various functions of the tester are called. And after the measurement is finished, the control processing module can automatically calculate the hydrolysis degree according to the calculation formula of the invention and display the hydrolysis degree on a liquid crystal display screen. The automatic hydrolysis degree tester realizes rapid and accurate automatic hydrolysis degree measurement, greatly reduces errors in the measurement process and simplifies the operation process.
The method for measuring the hydrolysis degree of the polymer for oil displacement containing the sulfonate avoids the interference of the sulfonate on the measurement result, and uses the pH meter to indicate the titration end point, thereby improving the sensitivity and accuracy of the test.
Drawings
FIG. 1 is a schematic view showing the structure of an automatic hydrolysis degree measuring apparatus according to a preferred embodiment of the present invention.
FIG. 2 is a rear view of an automatic hydrolysis degree measuring instrument according to a preferred embodiment of the present invention.
FIG. 3 is a plot of κ (conductivity) -V (CTAB aqueous solution volume) relationship in example 1 of the present invention.
Detailed Description
In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.
In order to more clearly understand the concept of the technical scheme of the invention, firstly, the hydrolysis degree analysis principle of polyacrylamide and the hydrolysis degree analysis principle of the sulfonate-containing oil displacement copolymer are described.
(1) Analysis principle of degree of hydrolysis of polyacrylamide
The system for analyzing the hydrolysis degree of polyacrylamide is a weak acid strong base salt which reacts with acid to generate macromolecular weak acid, and the pH value of the system is changed from weak alkalinity to weak acidity. And directly titrating the carboxylate radicals in the analysis system by using a hydrochloric acid standard solution, and calculating the hydrolysis degree of the sample according to the standard volume of the consumed hydrochloric acid solution. The reaction principle is as follows:
(2) principle for analyzing degree of hydrolysis of copolymer for oil displacement containing sulfonate
The hydrolysis degree analysis system of the polyacrylamide containing the sulfonate is also a weak acid strong base salt, both the sulfonate and the carboxylate can react with acid to generate macromolecular weak acid, and the pH value of the system is changed from weak alkalinity to weak acidity. Analyzing to obtain the content of the sulfonic acid group, calculating the volume V1 of the hydrochloric acid standard solution which needs to be consumed theoretically, directly titrating acid radicals in an analysis system by using the hydrochloric acid standard solution to obtain the standard volume V2 of the consumed hydrochloric acid solution, and calculating the hydrolysis degree of the sample by using V-V2-V1. The reaction principle is as follows:
(3) sulfonate determination method
The following methods, elemental analysis, titration, conductometry, spectroscopy, and the like can be used, but are not limited thereto.
(4) Determination principle of automatic hydrolysis degree determinator
The indicator, methyl orange-indigo disulfonate, changes color from yellow-green to light gray at a pH of 4.10, so that a pH of 4.10 is the titration end point for the degree of hydrolysis of the partially hydrolyzed polyacrylamide. The pH value of the titration end point is set to be 4.10, and the preset titration speed and the end point titration speed are set, so that the automatic hydrolysis degree tester can more accurately sense the pH value of the solution, and the automatic hydrolysis degree tester can quickly titrate and accurately titrate. At the end of the titration, the amount of hydrochloric acid consumed by the titration was measured to calculate the degree of hydrolysis of the partially hydrolyzed polyacrylamide.
The calculation formula of the hydrolysis degree is as follows: HD-CVV 71/(1000 mS-23 CV). times.100%
In the formula: HD-degree of hydrolysis,%;
c, the concentration of the hydrochloric acid standard solution, mol/L;
V-mL of hydrochloric acid standard solution consumed by carboxylate radical, mL;
m-mass of sample, g;
s-solid content;
23-difference in mass of sodium acrylate and acrylamide linkages;
71-mass of acrylamide segment corresponding to 1.00mL of hydrochloric acid standard solution [ c (hcl) ═ 1.00mol/L ].
The embodiment of the invention partially provides a design of a preferably automatic hydrolysis degree tester, as shown in fig. 1, the automatic hydrolysis degree tester adopts an integrated design, has a compact structure and is convenient to move; comprises a liquid crystal display screen, a titration needle fixing frame, a pH sensor fixing frame, a stirring paddle, a high-precision injection pump, a titration needle fixing frame, a beaker, a power switch and the like. As shown in fig. 2, a 220V power socket is provided on the back side for connecting an external power source, and a pH sensor interface is also provided on the back side. When the method is used for measurement, only a hydrochloric acid standard solution and a hydrolysis degree analysis system need to be prepared in the early stage, a liquid crystal display screen of an automatic hydrolysis degree measuring instrument is clicked during measurement, working instructions and parameters such as sample quality, solid content, concentration of the hydrochloric acid standard solution, stirring speed, end point pH value, pre-control point pH value, titration liquid inlet speed, pre-control point liquid inlet speed, balance time and the like are input, and various functions of the instrument are called. And after the measurement is finished, the control processing module can automatically calculate the hydrolysis degree according to the calculation formula of the invention and display the hydrolysis degree on a liquid crystal display screen.
The titration solution adopts an automatic liquid inlet mode, a 2.5mL exchange unit is connected with a storage tank, liquid is automatically fed, and the liquid inlet speed and the stirring speed are adjustable.
The judgment of the end point is controlled by a program, a pH composite electrode probe senses the end point, and the liquid inlet speed of the instrument is automatically slowed down when the end point is approached, so that the full reaction and the uniform mixing are realized, and the accuracy of the liquid inlet volume of the hydrochloric acid is ensured.
The even stirring of the vertical stirrer can ensure that the titration solution is dispersed evenly and reacts completely, so that the electrode measurement is more accurate. The stirring paddle can move up and down and be detached, so that the beaker solution can be conveniently put in and taken out.
The solution exchanger of the instrument uses a high precision syringe pump used on analytical instruments. The syringe used was a 2.5mL airtight microinjection syringe. The three-way switching valve uses a Japanese high-sand diaphragm valve and has the characteristics of sensitive switching and small pipeline liquid oscillation. The pipeline uses a polytetrafluoroethylene tube with the inner diameter of 0.5mm, and the liquid outlet part pipeline uses a 316 model stainless steel tube with the inner diameter of 0.2mm, so that the accuracy of the liquid flowing out is ensured.
The following examples of 3 assay procedures are provided to illustrate the specific procedures of the assay method of the present invention.
Example 1
Sulfonate determination-conductivity titration method
Accurately weighing a certain amount of Cetyl Trimethyl Ammonium Bromide (CTAB), and preparing an aqueous solution with the concentration of about 0.01mol/L by using a volumetric flask to be used as a titration solution for later use; the concentration of CTAB titration solution is calibrated by a two-phase titration method by taking an acid mixed dye solution as an indicator and a sodium dodecyl sulfate solution as a standard solution, and the concentration is 0.011 mol/L.
Accurately weighing a copolymer sample, swelling the copolymer sample for 24 hours by using a small amount of distilled water, stirring to completely dissolve the copolymer sample, transferring the copolymer sample to a 1000mL volumetric flask, diluting to a scale, and standing for 24 hours for later use.
Transferring 20mL of the aqueous polymer solution into an iodometry bottle by using a pipette, adding about 15-20mL of distilled water for dilution, then immersing the conductive electrode into the aqueous copolymer solution, titrating with 0.011mol/L of CTAB aqueous solution, continuously stirring in the process of titration, and simultaneously recording volume and conductivity data of the CTAB titration solution consumed at different times. The κ (conductivity) -V (CTAB aqueous solution volume) relationship was plotted as shown in fig. 3. And calculating the content of the sulfonate in the copolymer according to the volume of CTAB titration liquid corresponding to the titration end point and the concentration of the CTAB titration liquid.
The break point on the kappa-V straight line is the equivalent point of the equimolar reaction of CTAB and the sulfonate ions on the macromolecular chain of the copolymer, and the point is taken as the titration end point.
Because CTAB reacts with sulfonate equimolar, the volume of CTAB titration liquid corresponding to the titration end point and its concentration can be used to calculate the sulfonate content in the copolymer. In this example CTAB was used in an amount of 18.97mL at a concentration of 0.011mol/L so that the amount of sulfonate species was 0.2087 mmol. Then, the volume of hydrochloric acid consumed by the theory of the sulfonic acid group is calculated, and the concentration of the hydrochloric acid is 0.102 mol/L. The test was performed four times in parallel, and the results are shown in table 1.
TABLE 1 amount of sulfonate species and volume of hydrochloric acid theoretically consumed
Example 2
Sulfonate radical determination-energy spectrum method
Taking several samples with known sulfonate content, carrying out surface gold spraying pretreatment, placing the samples in an energy spectrometer for detection, measuring the sulfur content, and converting the sulfur content into sulfonate content to obtain a correction coefficient. And carrying out the same pretreatment and test on the sample to be tested, and correcting to obtain the sulfonate content.
The results are shown in table 2 below:
TABLE 2 sulfonate content
The polymer with unknown sulfonate content had an energy spectrum measuring 26.9632% sulfonate content, which was corrected to give a polymer with a sulfonate content of 26.06%.
Example 3
Determination of degree of hydrolysis of sulfate-containing polyacrylamide polymer for oil displacement
Firstly, a polymer sample A containing sulfonate for oil displacement is measured to have 25.73 percent of sulfonate content and 88 percent of solid content by an element analysis method (refer to GB/T12005.2-1989, a polyacrylamide solid content measuring method), and m is weighed1＝0.0315g，m2＝0.0309g，m30.0316g of sample a (cf. GB/T12005.6-1989, method for determining degree of hydrolysis of partially hydrolyzed polyacrylamide);
preparing hydrochloric acid standard solution c (HCl) 0.102mol/L for standby.
And secondly, clicking a setting menu of the automatic hydrolysis degree measuring instrument, and respectively inputting parameters such as a titration end point (pH is 4.10), a pre-control point titration speed, a titration end point speed, a stirring speed, a titration end point balance time and the like.
Clicking an HD parameter menu of the automatic hydrolysis degree tester, and inputting values such as the concentration of the hydrochloric acid standard solution, the quality of the sample, the solid content value, the sulfonate content and the like.
Starting the automatic hydrolysis degree tester, automatically titrating the hydrochloric acid standard solution into the partially hydrolyzed polyacrylamide solution until the pH value of the solution system of the tested sample is stabilized at 4.10, and stopping feeding the liquid. At this time, the degree of hydrolysis of the three samples A was calculated by the program in the automatic degree of hydrolysis measuring apparatus to be 25.16%, 25.18%, and 24.93%, respectively.
It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.
Claims (8)
1. A method for measuring the degree of hydrolysis of a sulfonate-containing polyacrylamide polymer is characterized by comprising the following steps:
measuring the content of the sulfonate, and calculating the volume V1 of the hydrochloric acid standard solution which is theoretically consumed by the sulfonate according to the measured content of the sulfonate, the sample quality and the concentration of the hydrochloric acid standard solution; the method for measuring the content of the sulfonic acid group is an element analysis method, a titration method, a conductance titration method or an energy spectrum method;
titrating a hydrolysis degree analysis system of the polyacrylamide polymer containing the sulfonate by using a hydrochloric acid standard solution; monitoring the change of a hydrolysis degree analysis system in real time by using a pH sensor in the titration process, wherein the pH value is 4.10, namely the titration end point, and recording the volume V2 of the hydrochloric acid standard solution which is actually consumed;
calculating the volume V of the hydrochloric acid standard solution consumed by carboxylate radicals from V2 to V1;
calculating the degree of hydrolysis: HD-CVV 71/(1000 mS-23 CV). times.100%
In the formula: HD: degree of hydrolysis,%;
c: the concentration of the hydrochloric acid standard solution, mol/L;
v: milliliters, mL, of hydrochloric acid standard solution consumed by the carboxylate;
m: sample mass, g;
s: solid content;
23: difference between mass of sodium acrylate and mass of acrylamide chain;
71: the mass of acrylamide units corresponding to 1.00mL of a standard hydrochloric acid solution having a concentration of 1.00 mol/L.
2. The method according to claim 1, wherein the concentration of the hydrochloric acid standard solution is 0 to 0.5mol/L excluding 0.
3. The method according to claim 1, wherein the method for measuring the sulfonate content is a conductometry method or a spectroscopic method.
4. An automatic hydrolysis degree measuring instrument for carrying out the measuring method according to any one of claims 1 to 3; this automatic degree of hydrolysis apparatus includes:
the input module is used for inputting working instructions and parameters;
the liquid crystal display screen is used for displaying an input interface, a working state and a measuring result;
the control processing module is used for controlling the titration process according to the input working instruction and parameters and calculating the measurement result;
a beaker for holding a hydrolysis degree analysis system;
a vertical stirrer for stirring the hydrolysis degree analysis system;
an automatic titration system for accurately dropping a hydrochloric acid standard solution into the hydrolysis degree analysis system;
a pH sensor to monitor pH of the hydrolysis assay system; and
and the power supply module supplies power to the automatic hydrolysis degree tester.
5. The automatic hydrolysis degree measuring instrument according to claim 4, wherein the parameters include sample mass, solid content, concentration of hydrochloric acid standard solution, stirring speed, end point pH value, pre-control point pH value, titration feed speed, pre-control point feed speed, and equilibrium time.
6. The automatic hydrolysis degree measuring instrument according to claim 4, wherein the vertical stirrer comprises a stirring paddle extending into the hydrolysis degree analyzing system, and the stirring paddle can be moved up and down and detached.
7. The automated hydrolyzometer of claim 4 wherein the automatic titration system includes a syringe pump and a reservoir for supplying liquid to the syringe pump.
8. The automatic hydrolysis degree measuring instrument according to claim 4, wherein the input module adopts a touch screen input mode.
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| CN104730202A (en) * | 2015-04-13 | 2015-06-24 | 菏泽学院 | Automatic acid-base titration instrument |
| CN205665217U (en) * | 2016-06-12 | 2016-10-26 | 西华大学 | Full automatic titration analytical equipment |
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