KR20210045293A - Method and system for analysis of additives in water-based polymer sample - Google Patents

Abstract

The present invention provides a method for analyzing additives in a water-based polymer sample. According to the present invention, the method comprises the following steps: (S1) putting a water-based polymer sample including a polymer, an additive, and water as a solvent into a vial; (S2) putting a porous pouch containing a super absorbent polymer (SAP) in the vial to absorb the water into the SAP; (S3) removing the porous pouch from the vial and collecting the concentrated polymer sample remaining in the vial; and (S4) introducing the concentrated polymer sample to a pyrolysis gas chromatography (Py-GC)-mass spectrometry (MS) to perform a Py-GC/MS analysis. Accordingly, after the concentrated polymer sample is acquired through a simple pre-treatment process of removing the water from the aqueous polymer sample including the additives by the SAP contained in the porous pouch, the Py-GC/MS analysis is performed, thereby quickly and accurately analyzing components of small molecular weight additives included in the polymer without loss.

Description

Method and system for analysis of additives in aqueous polymer samples {METHOD AND SYSTEM FOR ANALYSIS OF ADDITIVES IN WATER-BASED POLYMER SAMPLE}

This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0128141 filed on October 16, 2019, and all contents disclosed in the patent document are included as part of this specification.

The present invention relates to a method and system for analyzing an additive in an aqueous polymer sample, more specifically, to an analysis method including a pretreatment process for an aqueous polymer sample using a super absorbent polymer, and a system therefor.

The polymer may be prepared from a polymer composition containing one or more monomers and additives, and as the additive, a polymerization initiator, a coupling agent, a crosslinking agent, and the like may be used. These additives function to improve the stability or physical properties of the polymer in a small amount, and the additives can have a decisive effect on the final performance of the polymer, so qualitative and quantitative analysis of the additive is required.

In the component analysis of the polymer, a method of extracting and concentrating a component contained in the polymer by an appropriate extraction method, and then analyzing it with an analysis device is used. Examples of the extraction method include liquid-liquid extraction, liquid-solid extraction, solvent extraction, and reprecipitation extraction.

Since these extraction methods use a solvent, the concentration of the sample may change during the extraction process, or loss and contamination of the sample may occur during the drying process for concentration. For example, in the case of a water-based polymer sample, _{a method of drying the sample by nitrogen purging (N 2} purging) after raising the temperature to remove water from the sample is used, but volatile low molecular weight additives may be lost during this process. There is a disadvantage in that it takes several hours to perform the analysis, which lengthens the analysis time.

Accordingly, the present invention is to solve the drawbacks of the prior art, by efficiently removing water in a water-based polymer sample in a short time, thereby providing a method and system capable of quickly and accurately analyzing the volatile low-molecular additive contained in the sample without loss. To provide.

According to an aspect of the present invention,

(S1) putting an aqueous polymer sample containing water as a polymer, an additive, and a solvent into a vial;

(S2) putting a porous pouch containing a super absorbent polymer (SAP) in the vial to absorb water into the super absorbent polymer;

(S3) removing the porous pouch from the vial and collecting the concentrated polymer sample remaining in the vial; And

(S4) Introducing the concentrated polymer sample into a pyrolysis gas chromatography (Py-GC)-mass spectrometer (MS) to perform Py-GC/MS analysis. Is provided.

In addition, the present invention is a system for applying the analysis method,

A vial containing a sample solution containing water as a polymer, an additive, and a solvent;

A porous pouch that can be accommodated in the vial and contains a super absorbent polymer; And

An analysis system including pyrolysis gas chromatography (Py-GC)-mass spectrometry (MS) is provided.

Additionally, the present invention provides a computer-readable recording medium in which a program for executing the analysis method is recorded.

According to the present invention, Py-GC/MS analysis is performed after obtaining a concentrated polymer sample through a simple pretreatment process in which water is removed from an aqueous polymer sample containing an additive using a super absorbent polymer (SAP) contained in a porous pouch. By doing so, it is possible to quickly and accurately analyze the volatile low-molecular additive component in the polymer sample without loss.

1 to 5 show Py-GC/MS analysis results for components in aqueous polymer samples according to Examples and Comparative Examples of the present invention, respectively.

Hereinafter, terms or words used in the present specification and claims should not be construed as being limited to a conventional or dictionary meaning, and the inventor appropriately defines the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

An embodiment of the present invention relates to a method for analyzing an additive in an aqueous polymer sample, including a pretreatment of the aqueous polymer sample using a super absorbent polymer (SAP). Hereinafter, the method will be described step by step.

In the present invention, a water-based polymer sample is an analysis target, and specifically, a water-based polymer sample containing water as a polymer, an additive, and a solvent is prepared and put into a vial (S1).

As long as the vial can accommodate a liquid sample, its shape and material may be used without particular limitation.

The polymer included in the sample is a compound obtained by polymerization of one or more monomers, and examples of the monomer may include butyl acrylate, styrene, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like. In addition, the polymer may have a molecular weight of 5,000 to 5,000,000 g/mol.

The additive is used in a small amount during polymerization of the polymer to improve stability or physical properties of the polymer, and may be a volatile low molecular weight compound having a molecular weight of 50 to 700 g/mol. Examples of such additives include butylated hydroxytoluene (BHT), Tinuvin P, or a mixture thereof.

In addition, the sample may include an inorganic material that acts as a filler or an insulating material as necessary, and for example, an inorganic oxide such as alumina or titania, or an inorganic hydroxide may be used.

In order to remove the water contained in the sample, a porous pouch containing a super absorbent polymer (SAP) is placed in a vial containing the sample, and water is absorbed by the super absorbent polymer (S2).

The super absorbent polymer (SAP) is a material made by partially crosslinking a water-soluble polymer, and is a polymer having a three-dimensional network structure and a large amount of hydrophilic groups. For example, it can be obtained by polymerizing an acrylic acid monomer, a neutralizing agent, a blowing agent, a polymerization initiator, and a crosslinking agent.

These SAPs exhibit water insolubility and hydrophilicity at the same time, so they can absorb a large amount of water without being soluble in water. In addition, the super absorbent polymer may be in the form of a powder, beads, fiber, or the like, and after absorbing water, the superabsorbent resin becomes a gel form while swelling out of the initial form and swelling.

In the case of performing pretreatment in which water contained in an aqueous polymer sample is absorbed and removed by using such a super absorbent polymer, the temperature is raised to remove water from the sample when analyzing the existing aqueous polymer sample, followed by nitrogen purging (N ₂ purging). Compared to the pretreatment method of drying the sample by the method, it is possible to shorten the analysis time and minimize the loss of components included in the sample by simply concentrating the polymer sample and applying it to analysis.

For example, if a pouch containing a super absorbent polymer is placed in a vial and shaken for about 5 seconds to 2 minutes, water in the sample is sufficiently absorbed in the super absorbent polymer, and this process can be performed at room temperature and requires drying under nitrogen. Therefore, the loss of components such as volatile low molecular weight additives is minimized.

The porous pouch has a pore structure such that the super absorbent polymer does not escape, and the pore size is sufficient to have a small size of 1/2 or less than the average particle diameter of the super absorbent polymer. For example, the average particle diameter of the super absorbent polymer may be 100 to 3,0000 µm, specifically 300 to 2,000 µm, more specifically 500 to 1,500 µm, and the pore size of the porous pouch is 250 µm or less, in detail May be 150 μm or less, more specifically 50 μm or less.

After water is absorbed by the super absorbent polymer, the porous pouch is removed from the vial, and the concentrated polymer sample remaining in the vial is collected (S3).

If a super absorbent polymer is added without using a porous pouch in the vial, the separation of the super absorbent polymer containing the acrylic monomer component may not be properly separated and may remain in the vial together with the polymer sample. It can be difficult to obtain accurate results in the process.

Subsequently, the concentrated polymer sample is introduced into a pyrolysis gas chromatography (Py-GC)-mass spectrometer (MS) to perform Py-GC/MS analysis (S4).

In this step, the thermal decomposition of the concentrated polymer sample may be performed at a constant temperature without raising the temperature in the range of 400 to 800°C, for example 500 to 600°C. In addition, the temperature of the injection part of the Py-GC/MS analyzer may be adjusted to a constant temperature in the range of 250 to 350°C, for example, 300 to 320°C.

In GC analysis, any column used as a stationary phase may be used as long as it is used for GC/MS analysis without any particular limitation. For example, the length (L) of the column may be in the range of 10 to 100 m, the inner diameter (ID) may be in the range of 0.18 to 0.53 mm, and the material to be coated may be applied in various ways from siloxane to PEG. I can.

In addition, during the GC analysis, while the sample passes through the column, the temperature in the column can be controlled at a starting temperature of 50 to 100 °C and a heating rate of 10 to 50 °C/min using an oven capable of temperature control. have. When the temperature in the column is lower than the above range, the analysis time may be lengthened, and when the temperature in the column exceeds the above range, the sample may be deformed due to excessive application of temperature, and the function of the column may be impaired.

During GC analysis, the flow rate of the moving gas used for the movement of the sample in the column can be adjusted in the range of 1 to 5 ml/min, for example, 1 to 2 ml/min, and the moving gas may be helium (He). have.

In the same process as described above, Py-GC/MS analysis of a concentrated polymer sample obtained by absorbing and removing water from an aqueous polymer sample containing an additive using a super absorbent polymer (SAP) contained in a porous pouch is analyzed. Due to its low molecular weight, volatile low molecular weight additive components can be analyzed quickly and accurately without loss. For example, according to the present invention, the additive in the polymer sample can be detected as much as 2.3 to 2.5 times as compared to the conventional method using heating and nitrogen drying.

In addition, the present invention provides an analysis system for applying the analysis method as described above, the system comprising: a vial containing a sample containing water as a polymer, an additive, and a solvent; A porous pouch that can be accommodated in the vial and contains a super absorbent polymer; And pyrolysis gas chromatography (Py-GC)-mass spectrometry (MS).

In the analysis system, the description of the configuration overlapping with the analysis method is the same.

Additionally, the present invention provides a computer-readable recording medium in which a program for executing the analysis method is recorded.

Hereinafter, examples will be described in detail to aid understanding of the present invention. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the following examples. The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art.

Example 1:

A polymer containing butyl acrylate (BA), styrene, 2-ethylhexyl acrylate (2-EHA) and 2-ethylhexyl methacrylate (2-EHMA) as a monomer, alumina as an inorganic substance, and water as a solvent. An aqueous polymer composition was prepared. Here, a sample solution was obtained by mixing BHT (butylated hydroxytoluene) having a molecular weight of 220.36 g/mol as an additive, and then placed in a glass vial.

Into the vial, a porous pouch (pore size: 100 μm) containing a super absorbent polymer (SAP) in the form of a powder having a particle diameter of about 150 μm was placed and shaken for about 5 seconds to sufficiently absorb water in the super absorbent polymer. . The water-absorbed super absorbent polymer pouch was removed from the vial, and a concentrated polymer sample attached to the vial wall was collected.

For Py-GC/MS analysis of the collected samples, 5020AS (CDS) and GCMS-QP2010 ultra (Shimadzu) were used. Pyrolysis was performed by applying heat at 600° C. for 10 seconds under inert conditions, and a fragment was obtained therefrom. GC/MS was performed by using Ultra Alloy +-5 (30m L × 0.25mm I.D, 0.25㎛ d.f., capillary) as a column, and flowing helium (He) as a moving gas at a rate of 1ml/min. The temperature of the injection part was 300° C., and the column temperature was maintained at 50° C. for 5 minutes, and then the temperature was raised at a rate of 10° C./min, and the temperature was maintained at 300° C. for 10 minutes.

<Structure of BHT>

Comparative Example 1: N instead of using SAP ₂ Using purging with gas

The aqueous polymer sample solution used in Example 1 was placed in a glass vial, heated to 60° C., _{and purged with N 2} gas to remove water (it took about 3 hours). After removing the water, the sample attached to the bottom of the vial was collected, and Py-GC/MS analysis was performed under the same conditions as in Example 1.

Example 2:

An aqueous polymer composition (CR-366, BASF) containing styrene, n-butyl acrylate, α-methylstyrene and 2-ethylhexyl acrylate as a monomer was prepared, and Tinuvin P having a molecular weight of 225.25 g/mol was prepared therein. The same procedure as in Example 1 was carried out, except that the mixture was mixed to obtain a sample solution.

<Structure of Tinuvin P>

Comparative Example 2: N instead of using SAP ₂ Using purging with gas

The same procedure as in Comparative Example 1 was performed using the aqueous polymer sample used in Example 2.

Example 3:

A sample solution was prepared by preparing an aqueous polymer composition containing methyl methacrylate (MMA) and 2-ethylhexyl acrylate (2-EHA) as monomers, and mixing BHT (butylated hydroxytoluene) having a molecular weight of 220.36 g/mol thereto. The same procedure as in Example 1 was carried out, except to obtain.

For Py-GC/MS analysis of the collected samples, 3030D (Frontierlab) and GCMS-7890B/5977A (Agilent) were used. Pyrolysis was carried out by heating at 600° C. under inert conditions, and a fragment was obtained therefrom. GC/MS was performed by using Ultra Alloy +-5 (30m L × 0.25mm I.D, 0.25㎛ d.f., capillary) as a column, and flowing helium (He) as a moving gas at a rate of 1ml/min. The temperature of the injection part was 300° C., and the column temperature was maintained at 50° C. for 5 minutes, then the temperature was raised at a rate of 10° C./min, and the temperature was maintained at 300° C. for 13 minutes.

Comparative Example 3: Non-use of porous pouch

A sample solution was prepared by preparing an aqueous polymer composition containing methyl methacrylate (MMA) and 2-ethylhexyl acrylate (2-EHA) as monomers, and mixing BHT (butylated hydroxytoluene) having a molecular weight of 220.36 g/mol thereto. After obtaining, it was put into a glass vial.

A powdery super absorbent polymer (SAP) having a particle diameter of about 150 μm was put into the vial as it is without a porous pouch, and then water was sufficiently absorbed into the super absorbent polymer for about 5 seconds. The water-absorbed superabsorbent resin was removed from the vial, and a concentrated polymer sample attached to the wall of the vial was collected.

For Py-GC/MS analysis of the collected samples, 3030D (Frontierlab) and GCMS-7890B/5977A (Agilent) were used. Pyrolysis was carried out by heating at 600° C. under inert conditions, and a fragment was obtained therefrom. GC/MS was performed by using Ultra Alloy +-5 (30m L × 0.25mm I.D, 0.25㎛ d.f., capillary) as a column, and flowing helium (He) as a moving gas at a rate of 1ml/min. The temperature of the injection part was 300° C., and the column temperature was maintained at 50° C. for 5 minutes, then the temperature was raised at a rate of 10° C./min, and the temperature was maintained at 300° C. for 13 minutes.

When comparing Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2 having the same analysis object, in Examples 1 and 2, the pretreatment process of removing water using a super absorbent polymer was only about 5 seconds, whereas the comparison The pretreatment of removing water by heating and purging with nitrogen in Examples 1 and 2 took about 3 hours.

On the other hand, FIG. 1 shows the results of Py-GC/MS analysis on the components in the aqueous polymer samples according to Example 1 and Comparative Example 1, and FIG. 2 is an additive based on 2-EHA among the components identified in FIG. It shows the analysis result of BHT. Table 1 below shows the results of FIG. 2 with specific values.

ingredient Retention time (R.T, min) GC/MS EIC area Area ratio (%) Example 1 2-EHA (m/z 112) 13.496 58020 93.87 BHT (m/z 205) 17.455 3786 6.13 BHT/2-EHA 0.065 Comparative Example 1 2-EHA (m/z 112) 13.499 140796 97.25 BHT (m/z 205) 17.453 3974 2.75 BHT/2-EHA 0.028

As can be seen from Fig. 2 and Table 1, the case of performing the pretreatment of removing water using a super absorbent polymer according to Example 1 compared to the nitrogen purging according to Comparative Example 1 is the GC/ The MS EIC area value was detected as high as 2.3 times, indicating that the loss of BHT was minimized during pretreatment with a super absorbent polymer.

Similarly, FIG. 3 shows the results of Py-GC/MS analysis of the components in the aqueous polymer samples according to Example 2 and Comparative Example 2, and FIG. 4 is an additive Tinuvin based on BA among the components identified in FIG. 3. It shows the analysis result of P. Table 2 below shows the results of FIG. 4 with specific values.

ingredient Retention time (R.T, min) GC/MS EIC area Area ratio (%) Example 2 BA (m/z 73) 6.8 378807 99.05 Tinubin P(m/z 225) 23.7 3645 0.95 Tinubin P/BA 0.0096 Comparative Example 2 BA (m/z 73) 6.8 345465 99.62 Tinubin P(m/z 225) 23.7 1308 0.38 Tinubin P/BA 0.0038

As can be seen from Fig. 4 and Table 2, the case of performing the pretreatment of removing water using a super absorbent polymer according to Example 2 compared to the nitrogen purging according to Comparative Example 2 was GC/MS of Tinuvin P compared to BA The EIC area value was detected more than 2.5 times higher, indicating that the loss of Tinuvin P was minimized during pretreatment using a super absorbent polymer.

On the other hand, Figure 5 is for comparing Example 3 and Comparative Example 3 for the use / non-use of a porous pouch while the analysis target is the same, specifically Figure 5 (a) is an Example in which water was removed by putting SAP into a porous pouch The thermal decomposition result of the sample according to 3, FIG. 5(b) shows the thermal decomposition result of the sample according to Comparative Example 3 without using a porous pouch, and FIG. 5(c) shows the thermal decomposition result of SAP itself.

In Fig. 5(a) showing the result of Example 3, the peaks of each monomer were clearly separated and analyzed, whereas in Fig. 5(b) showing the result of Comparative Example 3 without using a porous pouch, the peaks were clearly separated. This is the result of sampled with SAP as it was put into the vial without using a porous pouch.

Claims (11)

(S1) putting an aqueous polymer sample containing water as a polymer, an additive, and a solvent into a vial;
(S2) putting a porous pouch containing a super absorbent polymer (SAP) in the vial to absorb water into the super absorbent polymer;
(S3) removing the porous pouch from the vial and collecting the concentrated polymer sample remaining in the vial; And
(S4) Introducing the concentrated polymer sample into a pyrolysis gas chromatography (Py-GC)-mass spectrometer (MS) to perform Py-GC/MS analysis. The method of claim 1, wherein the polymer is obtained by polymerization of at least one monomer selected from butyl acrylate, styrene, 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate. The method of claim 1, wherein the additive is a compound having a molecular weight of 50 to 700 g/mol. The method of claim 2, wherein the additive comprises butylated hydroxytoluene (BHT), Tinuvin P, or a mixture thereof. The method of claim 1, wherein the superabsorbent polymer has an average particle diameter of 100 to 3,0000 µm. The method of claim 1, wherein the pore size of the porous pouch is 250 μm or less. The method of claim 1, wherein the step (S2) is performed at room temperature for 5 seconds to 2 minutes. The method of claim 1, wherein the thermal decomposition in step (S4) is performed at 400 to 800°C. The method of claim 1, wherein the GC analysis in the step (S4) is performed by adjusting the temperature in the column at a starting temperature of 50 to 100°C and a heating rate of 10 to 50°C/min. A vial containing a sample solution containing water as a polymer, an additive, and a solvent;
A porous pouch that can be accommodated in the vial and contains a super absorbent polymer; And
An analytical system for applying the analytical method according to claim 1, comprising a pyrolysis gas chromatography (Py-GC)-mass spectrometer (MS). A computer-readable recording medium on which a program for executing the analysis method according to claim 1 is recorded.

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