KR20220084674A - Water-soluble polymer for pipe plugging - Google Patents

Abstract

The present invention is based on the weight of the total composition of the water-soluble polymer for water-soluble pipes, 40 to 98% by weight of an acrylic acid derivative, 0.1 to 40% by weight of an alginic acid-based polymer compound, 0.01 to 5% by weight of an accelerator, 0.01 to 5% by weight Provided is a water-soluble polymer for waterproofing pipes comprising a crosslinking agent and 0.01 to 10% by weight of an initiator.

Description

Water-soluble polymer for pipe plugging

The embodiment relates to a water-soluble polymer for water-soluble plumbing. More particularly, it relates to a water-soluble polymer for pipe blocking using a water-soluble polymer for blocking a pipe used to block the flow of a fluid during fluid transfer piping construction.

In general, water supply is inevitably operated for maintenance and new connection of water pipes buried underground, but this causes inconvenience to citizens and a lot of economic damage.

In view of the current process that consumes most of the time for draining water, which is a pre-preparation work, and for filling the pipe with water after work, rather than direct plumbing work, it is urgent to develop a device to shorten the work time. .

In order to replace the old water pipe and expand the pipe, it is possible to maintain the water pipe smoothly only when the water pipe is cut off and various works such as valve installation and piping are performed.

However, in most cases, the normal replacement or repair of the pipe is carried out after long-term use. In this case, there is a problem in that the valve installed for the shutoff of the pipe is aged and cannot perform its role, and water leakage occurs.

For this reason, it is difficult to weld during the individual construction of the pipe, so a method using an expensive device such as a hot-tapping method is applied.

As described above, a new method for waterproofing a pipe has been developed and used. However, in the case of the previously developed method, it is necessary to drill a hole on the outside of the pipe to work, and thereby there is a problem that a new damaged part is formed.

An object of the embodiment is to provide a water-soluble polymer for blocking the pipe for blocking the pipe without secondary external damage when the pipe is blocked.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the following description.

An embodiment of the present invention, based on the weight of the total composition of the water-soluble polymer for water-soluble pipe, 40 to 98% by weight of an acrylic acid derivative, 0.1 to 40% by weight of an alginic acid-based polymer compound, 0.01 to 5% by weight of an accelerator, 0.01 to 5% by weight of a crosslinking agent and 0.01 to 10% by weight of an initiator.

Preferably, the alginic acid-based polymer compound may include at least one of alginic acid, hyaluronic acid, chitosan, gelatin, and chitin.

Preferably, the acrylic acid derivative may be acrylamide-based or acrylic acid-based.

Preferably, the initiator may include ammonium persulfate.

Preferably, the accelerator may include tetramethylethylenediamine (N,N,N′,N′-tetramethylethylenediamine).

Preferably, the crosslinking agent may include N,N-methylenebisacrylamide (N,N'-methylene bisacrylamide).

Preferably, the crosslinking agent may be characterized in that N,N-methylene bisacrylamide (N,N'-methylene bisacrylamide) and ethylene glycol diacrylate (Ethylene glycol diacrylate) are mixed.

Preferably, the N,N-methylenebisacrylamide and the ethylene glycol diacrylate may be mixed in a ratio of 3:7 to 1:9.

According to the embodiment, in order to shut off the pipe, there is an effect that the pipe can be blocked without secondary external damage.

In addition, there is an effect that the process for removing the water blocking device can be omitted by using a water-soluble material to naturally dissolve and disappear after a certain period of time has elapsed.

Various and advantageous advantages and effects of the present invention are not limited to the above, and will be more easily understood in the course of describing specific embodiments of the present invention.

1 is a view showing the use state of the pipe shutoff part of the present invention,
2 is a view showing the structure of a pipe shutoff part manufacturing apparatus according to a first embodiment of the present invention,
Figure 3 is a view seen from the top of Figure 2,
4 is a view showing the shape of the third mold of FIG. 2;
5 is a view showing the structure of a pipe shutoff part manufacturing apparatus according to a second embodiment of the present invention,
6 is a view showing an embodiment of the third mold of FIG. 5;
7 is a flowchart of a water-soluble polymer pipe shutoff manufacturing method using a pipe shutoff manufacturing apparatus according to another embodiment of the present invention;
8 is a view for explaining the configuration of a water-soluble polymer for water-soluble pipe according to an embodiment of the present invention,
9 is a view showing the synthesis mechanism of acrylamide hydrogel,
10 and 11 are graphs of stress-strain according to the concentration of the crosslinking agent MBAA,
12 shows a stress-strain curve for each concentration of a polymer using DEGDA (dotted line) having the same crosslinking density as MBAA (solid line) as a crosslinking agent,
13 shows the stress-strain curves of a polymer having a mixing ratio of MBAA and DEGDA 2:8, 4:6 and a polymer without DEGDA,
14 is a stress-strain curve of a hydrogel synthesized by mixing MBAA and DEGDA, MBAA and EGDA by ratio (fixed total crosslinking density);
15 is a stress-strain curve of a hydrogel synthesized by mixing DEGDA and EGDA by ratio after fixing the MBAA concentration.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected between the embodiments. It can be used by combining or substituted with .

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention belongs, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art.

In addition, the terminology used in the embodiments of the present invention is for describing the embodiments and is not intended to limit the present invention.

In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as “at least one (or more than one) of A and (and) B, C”, it is combined with A, B, and C It may include one or more of all possible combinations.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

These terms are only for distinguishing the component from other components, and are not limited to the essence, order, or order of the component by the term.

And, when it is described that a component is 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also with the component It may also include a case of 'connected', 'coupled' or 'connected' due to another element between the other elements.

In addition, when it is described as being formed or disposed on “above (above) or under (below)” of each component, the top (above) or bottom (below) is one as well as when two components are in direct contact with each other. Also includes a case in which another component as described above is formed or disposed between two components. In addition, when expressed as “upper (upper) or lower (lower)”, the meaning of not only the upward direction but also the downward direction based on one component may be included.

Hereinafter, the embodiment will be described in detail with reference to the accompanying drawings, but the same or corresponding components are given the same reference numerals regardless of reference numerals, and overlapping descriptions thereof will be omitted.

1 to 7, in order to clearly understand the present invention conceptually, only the main characteristic parts are clearly shown, as a result, various modifications of the illustration are expected, and the scope of the present invention is limited by the specific shape shown in the drawings it doesn't have to be

1 to 15, in order to clearly understand the present invention conceptually, only the main characteristic parts are clearly shown, as a result, various modifications of the illustration are expected, and the scope of the present invention is limited by the specific shape shown in the drawings it doesn't have to be

The present invention relates to an apparatus and method for manufacturing a pipe shutoff unit 10 using a water-soluble polymer, and the pipe shutoff unit 10 may be formed of a water-soluble polymer material.

The most problematic thing in the conventional plumbing is that it is necessary to remove a separate shutoff member after the individual construction of the pipe. Such separate construction has a problem in that time and cost increase.

In the present invention, the pipe shutoff portion 10 made of a water-soluble material is made of a water-soluble polymer material and does not need to be removed separately after being installed in the pipe for water blocking, thereby saving time and money.

These water-soluble polymer materials take a certain amount of time during plumbing work, and as time elapses, they dissolve naturally. Through this, the time and cost of removing the pipe shutoff unit 10 can be reduced, and there is an advantage that a separate pipe breakage for installing the pipe shutoff unit 10 is not required.

1 is a view showing a state of use of the pipe shutoff unit 10 of the present invention.

Referring to FIG. 1 , the pipe shutoff unit 10 has an empty structure, and air is blown into the interior using the air supply unit 20 to expand the pipe to perform the order of the pipe.

First, after disposing the pipe shutoff unit 10 inside the pipe, the air supply unit 20 is connected and air is injected. Thereafter, the expanded pipe shutoff part 10 is sealed to the air injection area through the sealing part 30 to perform the pipe shutoff.

2 is a view showing the structure of an apparatus for manufacturing the pipe shutoff part 10 according to the first embodiment of the present invention, FIG. 3 is a view seen from the top of FIG. 2 , and FIG. 4 is the third mold 300 of FIG. ) is a diagram showing the shape of

2 to 4 , the apparatus for manufacturing the pipe shutoff part 10 according to the first embodiment of the present invention may include a first mold 100 , a second mold 200 , and a third mold 300 . can

The first mold 100, the second mold 200, and the third mold 300 provide a frame for providing a shape by injecting a water-soluble polymer through bonding, and may be connected to be removed after the water-soluble polymer is dried. have.

The first mold 100 may form a spherical inner space by combining the lower mold 110 and the upper mold 130 . The first mold 100 may form an internal space to form the spherical pipe shutoff portion 10 . In one embodiment, the lower mold 110 and the upper mold 130 are provided at the same height, so that the dismantling of the mold can be easily performed after the water-soluble polymer is injected and dried.

A connection hole is formed on the upper side of the upper mold 130 , and the second mold 200 may be connected to the connection hole.

The second mold 200 may be connected to an upper portion of the connection hole. In one embodiment, the inner diameter of the second mold 200 may be provided to be the same as the diameter of the connection hole. Also, the second mold 200 may have a tubular structure.

The third mold 300 may be inserted into an internal space formed by the combination of the first mold 100 and the second mold 200 . In this case, the third mold 300 may be connected to the second mold 200 to form a separation distance from the inner walls of the first mold 100 and the second mold 200 .

Here, the first mold 100 and the second mold 200 support the outer surface of the pipe shutoff part 10 made of a water-soluble polymer, and the third mold 300 forms the inner surface of the pipe shutoff part 10 . can support

The third mold 300 may be spaced apart from each other through the spacing maintaining part 210 disposed on the inner surface of the second mold 200 .

In one embodiment, the gap maintaining part 210 may include a circular guide part 201 and a plurality of support parts 203 connected to a side surface of the guide part 201 .

The plurality of support parts 203 may support the guide part 201 by connecting the inner wall of the second mold 200 and the guide part 201 .

In an embodiment, the support part 203 may be connected to the upper end of the second mold 200 without affecting the water-soluble polymer injected therein.

A height adjustment unit 311 for controlling the insertion height of the third mold 300 may be disposed in one region of the outer wall of the third mold 300 . The height adjustment part 311 is provided to protrude from the outside of the third mold 300 and is inserted into the inner space where the third mold 300 is formed by the combination of the first mold 100 and the second mold 200 . In this case, the height adjustment unit 311 is caught on the guide unit 201 on the interval maintaining unit 210 so that the height can be controlled.

In one embodiment, the height adjustment unit 311 is provided with an O-ring of an elastic material, the height can be adjusted as needed.

Also, the third mold 300 may include an insertion part 310 and a connection part 330 .

The insertion part 310 may be provided in a cylindrical shape, and when inserted into the first mold 100 and the second mold 200 , it is disposed to have a predetermined interval with the inner wall of the second mold 200 , so that the water-soluble polymer is constant. to be formed in thickness.

The connection part 330 may be provided as a structure having a cross section of a sphere or an ellipse. The connection part 330 may be deformed according to the shape of the first mold 100 , and it is preferable to have a shape so as to have a predetermined distance from the inner wall of the first mold 100 . As an embodiment, when the first mold 100 is a sphere having a diameter of 50, the connection part 330 may have a diameter of 30 cm to have a width of 10 cm.

In addition, the connection part 330 may be provided with an elastic material and have a structure that expands inside the first mold 100 by injection of air.

When the connection part 330 is provided with an elastic material, the thickness of the pipe blocking part 10 can be variously deformed as needed, thereby reducing the cost of additionally manufacturing the mold.

FIG. 5 is a view showing the structure of an apparatus for manufacturing a pipe shutoff part 10 according to a second embodiment of the present invention, and FIG. 6 is a view showing an embodiment of the third mold 300 of FIG. 5 .

5 and 6 , the second embodiment of the present invention is an apparatus for manufacturing the pipe shutoff unit 10 for manufacturing the cylindrical pipe shutoff part 10 .

In the case of the spherical pipe shutoff part 10 according to the first embodiment of the present invention, the actual amount of water-soluble polymer material can be reduced to reduce manufacturing costs, but when gas is injected, the area in contact with the pipe is limited. . Therefore, when half of the gas is injected, the contact area of the pipe increases, but there is a problem in that the thickness of the pipe shutoff part 10 becomes thin. In addition, when a small amount of gas is injected, the thickness of the pipe shutoff part 10 increases, but the area in contact with the pipe is small, so there is a problem in that the possibility of being pushed out by the water pressure in the pipe increases.

Accordingly, the second embodiment of the present invention aims to increase the contact area with the pipe.

The apparatus for manufacturing the pipe shutoff part 10 according to the second embodiment of the present invention includes a first cylindrical mold 100 having a connection hole on the upper side, a second mold 200 having a tubular structure connected to the upper portion of the connection hole, and and a third mold 300 having a cylindrical structure inserted into an inner space formed by the combination of the first mold 100 and the second mold 200, and the first mold 100 and the second mold 200 are It is formed in a cylindrical structure having the same diameter, and the third mold 300 may be connected to the second mold 200 to form a separation distance from the inner walls of the first mold 100 and the second mold 200 . .

The third mold 300 may be connected through the gap maintaining part 210 so as to have a constant distance from the inner walls of the first mold 100 and the second mold 200 . Through this, the sidewalls of the pipe blocking part 10 manufactured through the first to third molds 300 may have the same thickness.

The gap maintaining part 210 may include a circular guide part 201 and a plurality of support parts 203 connected to the side surfaces of the guide part 201, as in the first embodiment, and the outer wall of the third mold 300 . The insertion height of the third mold 300 may be adjusted through the height adjusting unit 311 formed in one region.

In one embodiment, the separation distance between the bottom surface of the third mold 300 and the bottom surface of the first mold 100 and the separation distance between the side wall of the first mold 100 and the outer wall of the third mold 300 are arranged to be the same can be

This is to prevent a problem in that, when air is blown into the pipe shutoff part 10 , the expansion region is biased to one side when the thickness is different.

However, when more than a certain amount of air is injected, there is a problem in that damage occurs in the area of the bottom surface of the third mold 300 .

In the second embodiment of the present invention, in order to prevent this problem, the separation distance between the bottom surface of the third mold 300 and the bottom surface of the first mold 100 is the sidewall of the first mold 100 and the outer wall of the third mold 300 . It may be formed longer than the separation distance of

In addition, in order to solve the problem of damage occurring at the end of the third mold 300 provided in a cylindrical shape, the end of the third mold 300 may be provided with a curved surface to complement the installation.

Meanwhile, in the following, a method for manufacturing the water-soluble polymer pipe shutoff unit 10 using the pipe shutoff part 10 manufacturing apparatus according to another embodiment of the present invention will be described with reference to the accompanying drawings. However, descriptions of the same things as those described in the apparatus for manufacturing the pipe shutoff unit 10 according to an embodiment of the present invention will be omitted.

7 is a flowchart of a method for manufacturing a water-soluble polymer pipe shutoff 10 using a pipe shutoff part 10 manufacturing apparatus according to another embodiment of the present invention. In the description of FIG. 4 , the same reference numerals as those of FIGS. 1 to 6 denote the same members, and detailed descriptions thereof will be omitted.

Referring to Figure 7, the water-soluble polymer pipe shutoff part 10 manufacturing method according to another embodiment of the present invention uses the pipe shutoff part 10 manufacturing apparatus according to the embodiment of the present invention, a mold assembly step (S100), It may include an injection step (S200), a drying step (S300), a mold removal step (S400), and a film formation step (S500).

In the mold assembly step S100 , the first mold 100 , the second mold 200 , and the third mold 300 may be assembled to assemble a mold for injecting the water-soluble polymer.

After the first mold 100 and the second mold 200 are combined, the third mold 300 is inserted into the gap maintaining part 210 disposed on the second mold 200 . In this case, the position may be fixed in the inner space formed by the combination of the first mold 100 and the second mold 200 through the height adjustment part 311 of the third mold 300 .

In the injection step (S200), a water-soluble polymer may be injected into the assembled mold.

In the injection step ( S200 ), the water-soluble polymer may be injected through a space formed by the arrangement of the second mold 200 and the third mold 300 . The injected water-soluble polymer may be filled from the bottom surface of the first mold 100 to form the pipe blocking portion 10 .

The drying step (S300) is a step of drying the injected water-soluble polymer. In the drying step, the drying time may be modified according to the type and material of the water-soluble polymer.

The mold removing step (S400) is a step of removing the dried mold after the water-soluble polymer is dried. In this case, the mold may sequentially remove the first mold 100 and the second mold 200 , and release the third mold 300 inserted into the water-soluble polymer.

The film forming step (S500) is a step of coating a film on the dried water-soluble polymer outer surface.

The pipe shutoff part 10 dried through the water-soluble polymer is provided with frictional force due to viscosity. When the pipe shutoff part 10 formed of such a water-soluble polymer is injected into the pipe, it is injected in a horizontal direction, and sag occurs in the direction of gravity.

When air is injected in this state, friction occurs between the inner wall of the pipe and the outer wall of the pipe shutoff unit 10 made of a water-soluble polymer, and the injected air expands upward. In this case, unequal expansion may occur, which may cause a problem in which the pipe shutoff part 10 is damaged.

Accordingly, in the film forming step ( S500 ), a film made of a material having a smaller frictional force than that of the water-soluble polymer may be formed on the outer surface of the dried water-soluble polymer.

In one embodiment, the film may be formed by impregnating or covering the cover, and may be performed by various known methods.

By forming such a film, it is possible to reduce the friction force received by the water-soluble polymer when air is injected, thereby preventing unequal expansion.

In addition, the film may be made of a water-soluble material, and may be melted before the water-soluble polymer.

The film can be made to expand evenly by blowing air into the pipe shutoff part 10 to reduce friction during expansion, and then melt before the pipe shutoff part 10 made of a water-soluble material when in contact with water, so that the pipe shutoff part (10) comes into contact with the pipe to be able to shut off the pipe.

8 is a view for explaining the configuration of a water-soluble polymer for water-blocking pipes according to an embodiment of the present invention.

Referring to FIG. 8 , the water-soluble polymer for shutting off a pipe according to an embodiment of the present invention aims to shut off a pipe, and when installed in a pipe, it shuts off the pipe through expansion at a certain temperature of water temperature, and at a predetermined temperature or more, naturally The purpose is to omit the process for removing the water blocking device by making it melt away.

In general, a water-soluble polymer refers to a polymer that dissolves in water, and there are various types of natural and synthetic water-soluble polymers. Representative water-soluble polymers are polyvinyl alcohol [poly(vinyl alcohol), PVA], polyvinylpyrrolidone [poly(vinyl pyrrolidone), PVP], polyacrylic acid [poly(acrylic acid), PAA], polyacrylamide [(poly (acrylamide), PAM] and the like.

The hydrogel is composed of a hydrophilic polymer having a three-dimensional network structure, and the hydrogel can hold a large amount of water and swell due to the hydrophilic group attached to the polymer chain. However, due to the network structure of a cross-linked polymer made by a simple reaction of one or more monomers, it exhibits insoluble properties in water.

Natural hydrogels are gradually being replaced by synthetic hydrogels in the direction of increasing durability, water absorption, and strength of hydrogels. can

In the present invention, the applicability of the water-repellent polymer to two types of PVA-based hydrogels and acrylamide-based hydrogels was confirmed.

As a result, the PVA-based hydrogel independently showed an unstable form in hot water at 90 ^o C, but when synthesized by mixing PVP and a crosslinking agent, it exhibits a stable form in hot water. However, in the case of PVA/PVP series polymers, their elasticity is very low, so there is a disadvantage that a large amount of polymers must be used to be applied to the actual waterproofing method.

In the present invention, based on these studies, a water-soluble polymer for waterproofing pipes will be described based on an acrylamide-based hydrogel that can have elasticity.

The water-soluble polymer for waterproofing pipes according to an embodiment of the present invention contains 40 to 98% by weight of an acrylic acid derivative, 0.1 to 40% of an alginic acid-based polymer compound, 0.01 to 5% of an accelerator, 0.01 to 5% by weight based on the total weight of the composition. % by weight of a crosslinking agent and 0.01 to 10% of an initiator.

In the case of an acrylic acid derivative, when the weight% is less than 40% by weight, the formation of a hydrogel is impossible, and when it is more than 98% by weight, there is a problem in that a hydrogel with poor elasticity is formed.

In the case of an alginic acid-based polymer compound, when it is contained in an amount less than 0.1% by weight, elasticity cannot be imparted and a brittle hydrogel is formed. there is

In the case of an accelerator, when it contains less than 0.01% by weight, the curing progress rate is very slow or does not proceed, so it is difficult to form a hydrogel. There is a problem that molding becomes impossible.

In the case of a crosslinking agent, when it contains less than 0.01% by weight, curing does not proceed completely due to insufficient crosslinking point, and when it contains more than 5% by weight, a hard hydrogel is formed and elasticity is insufficient. In the invention, it becomes impossible to achieve the purpose of proceeding with water flow through expansion inside the sewage pipe.

In the case of the initiator, if it is contained in an amount less than 0.01% by weight, it is impossible to harden and hydrogel formation is impossible.

The acrylic acid derivative is for forming a hydrogel matrix, and an acrylamide-based or acrylic acid-based material may be used.

The acrylamide series may be any one or two or more selected from the following formula (1).

[Formula 1]

(In Formula 1,

R ₁ is -H or -CH _3,

R ₂ and R ₃ may be selected from -H, -CH _3, CH ₂ CH ₃ , -CH ₂ CH ₂ CH _3, -CH(CH ₃ ))

The acrylic acid series may be any one or two or more selected from the following formula (2).

[Formula 2]

(In Formula 2,

R ₁ is -H or CH ₃ ,

R ₂ may be selected from -H, -CH ₂ CH ₂ OH, -(CH ₂ CH2O) _n -H, -(CH ₂ CH2O) _n -CH ₃ )

The alginic acid-based polymer compound is for imparting elasticity, and may include at least one of alginic acid, hyaluronic acid, chitosan, gelatin, and chitin.

The initiator initiates a reaction in which acrylamide forms a polymer, and may include ammonium persulfate.

The accelerator may include tetramethylethylenediamine (N,N,N',N'-tetramethylethylenediamine) to promote the initiation reaction of gel formation.

The crosslinking agent forms a crosslinking of acrylamide polymers, and may include N,N-methylene bisacrylamide (N,N'-methylene bisacrylamide).

When a hydrogel, which is one of the types of water-soluble polymers, is crosslinked, a three-dimensional network structure is formed between polymer chains, and in this case, it can be provided with elasticity that returns to its original state even when the chains are stretched.

At this time, depending on which compound is selected as a crosslinking agent, physical properties such as length elongation or elastic modulus of the crosslinked polymer or chemical properties such as stability to hot water may vary.

The difference between the amide bond and the ester bond lies in stability, and it is generally known that the amide bond has a slower hydrolysis rate than the ester bond.

If the crosslinking agent crosslinks between chains by means of amide or ester bonds, the hydrolysis rate by hydrothermal water will be different. Therefore, the required hydrothermal decomposition properties can be achieved by appropriately controlling the amount and ratio of amide bonds and ester bonds.

In addition, since the chemical and physical properties of the cross-linking structure may vary depending on the type and amount of the cross-linking agent, it is necessary to synthesize a hydrogel having physical/mechanical properties applicable to the water-ordering method while having the necessary hydrothermal decomposition properties.

The acryl acrylamide hydrogel used in an embodiment of the present invention is obtained by irreversibly polymerizing a mixture of an acrylamide monomer and a crosslinkable monomer having two alkene functional groups, such as N,N'-methylene bisacrylamide (hereinafter referred to as MBAA). It is a hydrophilic polymer hydrogel having a three-dimensional cross-linked network structure formed.

Since acrylamide is soluble in water, it is initiated using an initiator Ammonium persulfate (hereinafter referred to as APS) that can form radicals in water.

When using APS, use N,N,N',N'-tetramethylethylenediamine (hereinafter referred to as TEMED) to speed up the reaction. TEMED can act as a reaction accelerator to promote free radical generation from persulfate.

9 is a view showing the synthesis mechanism of acrylamide hydrogel.

Referring to FIG. 9 , each chain is linked through an amide bond of MBAA to form a three-dimensional structure. Since the amide bond is known to have a higher binding energy than other chemical functional groups such as esters and acetals, stability to hot water can be increased.

First, a hydrogel standard was prepared according to the content of the crosslinking agent MBAA.

Polymer synthesis was performed to confirm the physical properties of alginate-acrylamide hydrogel according to crosslinking density by controlling the content of MBAA, a crosslinking agent, and the size of 5 cm × 4 cm × 0.5 cm produced for mechanical properties and hydrothermal stability tests of plate-shaped polymer was manufactured, and the manufacturing method is as follows.

(a) A mold was made by laying polyethylene vinyl on a mold of 5 cm × 4 cm × 0.5 cm.

(b) each polymer aqueous solution was prepared separately

b-1) Dissolve 30 g of acrylamide in 30 g of distilled water to prepare a 50 wt.% aqueous solution, followed by stirring for 24 hours. (#One)

b-2) 1.14 g of sodium alginate was added to 53.76 g of distilled water and dissolved to make a 2 wt.% aqueous solution, and then 4.5 g of NaHCO3 was added and stirred for 48 hours. (#2)

b-3) 1 g of TEMED was mixed with 9 g of distilled water to prepare a 10 wt.% aqueous solution, followed by stirring for 24 hours. (#3)

b-4) 0.18 g of MBAA was dissolved in 17.82 g of distilled water, and a 1 wt.% solution was prepared and stirred for 24 hours. (#4-1)

b-5) Dissolving 1 g of APS in 9 g of distilled water to prepare a 10 wt.% aqueous solution. (#5)

(c) Measure and mix the solution prepared in the flask as follows, and put it in the flask.

#1 aqueous solution 3.11 g, #2 aqueous solution 9.9 g, #3 aqueous solution 0.1 g

(d) Add #4-1 aqueous solution with the following parameters, mix and dissolve cleanly.

- 0.1 g (existing amount of MBAA)

- 0.11 g (110% compared to the previous one)

- 0.13 g (130% compared to the previous one)

- 0.14 g (140% compared to the previous one)

- 0.15 g (150% compared to before)

- 0.20 g (200% compared to before)

- 0.30 g (300% compared to before)

- 0.50 g (500% compared to before)

(e) Add 0.155 g of #5 aqueous solution to the flask and mix immediately.

(f) Stirring using a glass rod and stop stirring when gelation progresses. If the agitation is continued, the shape of the agglomerated state is changed, and a shape of the hydrogel that does not fit into the mold is obtained.

(g) heated in an oven at 40 oC for 20 hours.

(h) Stored in an airtight container that prevents moisture from escaping.

NaHCO3 added in the hydrogel manufacturing process is added in excess to compensate for the lowered solubility due to the COOH function remaining in the alginic acid polymer, and the remaining molecules are dissolved in water without significantly affecting the physical properties of the hydrogel. When it comes into contact with it, it is released by osmotic pressure.

A water-soluble polymer tensile test was performed according to the content of the crosslinking agent MBAA of the alginate-acrylamide hydrogel prepared in this way, and FIGS. 10 and 11 show the results.

In the case of noise that is minutely generated in the test results of FIGS. 10 and 11, it may occur due to the slippery nature of the hydrogel, but it is confirmed that it does not affect the tendency of the stress-strain curve and the reliability of the measurement value of the break point. became

10 and 11, it can be seen from the experimental results that as the concentration of MBAA increases, the elongation at the break point is lowered. can check that

Table 1 below shows the change in breaking strength and elongation at the breaking point according to the MBAA content.

MBAA content* (g) Breaking strength (MPa) Elongation (%) 0.10 0.0891 2,337 0.11 0.0730 2,228 0.13 0.0856 2,218 0.15 0.0317 942 0.20 0.0248 887 0.30 0.0368 508 0.50 0.0296 301

The MBAA content shown in Table 1 means the addition amount of 1 wt.% MBAA aqueous solution input based on the 5 cm × 4 cm × 0.5 cm plate-shaped polymer manufacturing standard.

Therefore, when more than 0.15 g of MBAA is used as a crosslinking agent, the elongation of the spherical polymer is lowered, and thus the breakage can proceed quickly.

Even when only MBAA is used, significant results are obtained in a certain range of content, but in order to solve the problem of a decrease in elongation in the case of more than a specific content, a new crosslinking agent was introduced to solve this problem.

In the case of the new crosslinking agent, ethylene glycol diacrylate (EGDA) and diethylene glycol diacrylate (DEGDA), which are hydrolyzable, have an ester bond with a relatively smaller binding energy than an amide bond, and have a relatively longer molecular length, unlike MBAA, were selected.

In the case of DEGDA, since the molecular length is longer than that of MBAA, when the hydrogel is stretched, the force applied to the cross-linking agent is relatively small, so it was expected that the length elongation rate would be less affected even if the cross-linking density was increased. EGDA and DEGDA have the same functional group, but EGDA Since the ethylene glycol unit is repeated once and DEGDA is repeated twice, the length of DEGDA is longer, so EGDA with shorter molecular length is expected to have a larger elastic modulus than DEGDA.

To test this prediction, an acrylamide-based hydrogel in which MBAA and DEGDA were mixed as a crosslinking agent was prepared as follows.

In the case of a hydrogel synthesized using only the cross-linking agent DEGDA, it was confirmed that the mechanical properties according to the cross-linking agent concentration, that is, the cross-linking density, were maintained without much change. It was not clearly maintained in shape.

In addition, because the surface of the synthesized hydrogel is not smooth and sticky, it is judged that it is difficult to manufacture and handle a water-repellent polymer, so the hydrogel synthesis using only DEGDA was excluded from the experiment. It was decided to synthesize an amide-based hydrogel.

The first experiment was conducted by making the sum of moles of MBAA and DEGDA of all samples the same, fixing the crosslinking density, and varying the ratio of MBAA and DEGDA. After fixation, only the concentration of DEGDA was adjusted to synthesize a hydrogel.

First, to find out what changes in the physical properties of the hydrogel when changing the mixing ratio of MBAA and DEGDA while maintaining the crosslinking density, the amount of crosslinking agent was adjusted to 1 wt% MBAA 0.5 g to keep the overall crosslinking density constant. fixed.

For this, a sample was prepared by varying the mixing ratio of the crosslinking agent MBAA and DEGDA as shown in [Table 2].

MBAA:DEGDA (mol) 1 wt% MBAA (g) 1 wt% DEGDA (g) 10:0 0.500 0.000 8:2 0.400 0.139 6:4 0.300 0.278 4:6 0.200 0.417 3:7 0.150 0.486 2:8 0.100 0.556 1:9 0.050 0.625 0:10 0.000 0.695

Table 2 shows the mass (g) (the same crosslinking density) according to the molar ratio of MBAA and DEGDA.

In the case of a hydrogel synthesized by adding a crosslinking agent in the ratio of MBAA and DEGDA while fixing the crosslinking density according to the ratio written in Table 2, if a very small amount of MBAA is added (eg, MBAA:DEGDA(mol)=1:9 sample) ) It was confirmed that the form of the gel was not disturbed and the form was maintained in the same manner as the hydrogel synthesized by adding only MBAA.

Therefore, in order to produce a spherical polymer that can maintain its shape, the addition of MBAA is essential, and the change in the physical properties of the hydrogel according to the amount of DEGDA by varying the concentration ratio of DEGDA as shown in Table 3 in the state of adding a small amount of MBAA I found out

MBAA:DEGDA (mol) 1 wt% MBAA (g) 1 wt% DEGDA (g) 1:0.5 0.100 0.069 1:1 0.100 0.139 1:2 0.100 0.278 1:5 0.100 0.695 1:6 0.100 0.834 1:7 0.100 0.973 1:8 0.100 1.112 1:9 0.100 1.250

In addition, a standard of acrylamide-based hydrogel in which MBAA and EGDA were mixed as a crosslinking agent was prepared.

Synthesis was carried out using EGDA instead of DEGDA in the same way, and the amount of EGDA added when the crosslinking density was the same can be confirmed in Table 4 below.

MBAA:EGDA (mol) 1 wt% MBAA (g) 1 wt% EGDA (g) 8:2 0.400 0.129 6:4 0.300 0.257 4:6 0.200 0.386 3:7 0.150 0.450 2:8 0.100 0.514 1:9 0.050 0.579 0:10 0.000 0.643

Table 4 shows the mass (g) (the same crosslinking density) according to the molar ratio of MBAA and EGDA.

Similarly to DEGDA, in the case of a hydrogel synthesized using only EGDA, it was confirmed that it was difficult to handle due to the stickiness of the surface, unlike a hydrogel synthesized using MBAA. was decided to synthesize.

MBAA:EGDA (mol) 1 wt% MBAA (g) 1 wt% EGDA (g) 1:0.5 0.100 0.064 1:1 0.100 0.129 1:2 0.100 0.257 1:5 0.100 0.643 1:6 0.100 0.771 1:7 0.100 0.900 1:8 0.100 1.029 1:9 0.100 1.157

Hereinafter, check the results of the water-soluble polymer tensile test according to the mixing ratio of MBAA, DEGDA, and EGDA.

First, check the tensile test results of the polymer synthesized using only DEGDA with the same crosslinking density as MBAA that is not mixed with MBAA.

12 shows a stress-strain curve for each concentration of polymer using DEGDA (dotted line) having the same crosslinking density as MBAA (solid line) as a crosslinking agent, and Table 6 below shows the tensile test results for each content of MBAA and DEGDA.

MBAA content (g) Breaking strength (MPa) Elongation (%) note 0.10 0.0891 2,337 0.20 0.0248 887 0.50 0.0296 301 DEGDA content (g) Breaking strength (MPa) Elongation (%) note 0.14 0.0078 2,500 Density equal to 0.1 g of MBAA 0.28 0.0207 2,601 Density equal to 0.2 g of MBAA 0.70 0.0144 2,271 Density equal to 0.5 g of MBAA

12 and Table 8, as shown in the elongation rate by content of MBAA, in the case of MBAA, when 0.15 g or more was included, the elongation rate decreased sharply, but in the case of DEGDA, there was no significant difference as the content increased, and all 2,000 % or more can be confirmed.

However, when DEGDA is used independently, it is difficult to maintain the shape and it is difficult to manufacture a spherical polymer.

13 shows the stress-strain curves of a polymer having a mixing ratio of MBAA and DEGDA of 2:8 and 4:6 and a polymer without DEGDA.

Referring to FIG. 13, when the mixing ratio of MBAA and DEGDA is 2:8, the MBAA content is 0.1 g, and when MBAA alone is added, a high elongation of 2,300% or more is shown as shown in the result (solid gray line in FIG. 13) , showed similar elongation even when DEGDA was added.

When the mixing ratio of MBAA and DEGDA was 4:6, the MBAA content was 0.2 g, which was 887% as the result when MBAA alone was added.

Therefore, the crosslinking agent that affects elongation is MBAA, and it is judged that even if DEGDA is mixed with a certain MBAA, elongation and strength are not significantly affected.

14 is a stress-strain curve of a hydrogel synthesized by mixing MBAA and DEGDA, MBAA and EGDA by ratio (fixed overall crosslinking density), and FIG. 15 is a combination of DEGDA and EGDA after fixing the MBAA concentration. The stress-strain curve of the hydrogel.

14 and 15 , it can be seen that the length elongation rate decreases while the MBAA concentration increases in all of the samples synthesized with MBAA and DEGDA, and MBAA and EGDA.

However, unlike the DEGDA sample, in which the tensile strength increases gradually as the length elongation increases during tension, the EGDA sample remains similar to DEGDA, and the tensile strength increases rapidly from about 1,000% or more.

In the case of DEGDA, since the length of the cross-linking agent is relatively longer than that of MBAA, most of the force is applied to MBAA when the sample is tensioned. From an elongation rate of about 1,000% or more, it is judged that this is the result of the distribution of power to EGDA and MBAA.

As described above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains may make various modifications, changes and substitutions within the scope without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are for explaining, not limiting, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

10: pipe blocking part
20: air supply
30: sealing part
100: first mold
110: lower mold
130 ; upper mold
200: second mold
201: guide part
203: support
210: gap maintaining unit
300 ; 3rd mold
310: insertion part
311: height adjustment unit
330: connection part

Claims (8)

Based on the weight of the total composition of the water-soluble polymer for waterproofing pipes, 40 to 98% by weight of an acrylic acid derivative, 0.1 to 40% by weight of an alginic acid-based polymer compound, 0.01 to 5% by weight of an accelerator, 0.01 to 5% by weight of a crosslinking agent, and A water-soluble polymer for waterproofing pipes comprising 0.01 to 10% by weight of an initiator. According to claim 1,
The alginic acid-based polymer compound is a water-soluble polymer for water-soluble pipes comprising at least one of alginic acid, hyaluronic acid, chitosan, gelatin, and chitin. According to claim 1,
The acrylic acid derivative is an acrylamide-based or acrylic acid-based water-soluble polymer for waterproofing pipes. According to claim 1,
The initiator is a water-soluble polymer for plumbing containing ammonium persulfate (Ammonium persulfate). According to claim 1,
The accelerator is tetramethylethylenediamine
(N,N,N',N'-tetramethylethylenediamine) A water-soluble polymer for sealing pipes. According to claim 1,
The crosslinking agent is a water-soluble polymer for water-soluble pipe containing N,N-methylenebisacrylamide (N,N'-methylene bisacrylamide). According to claim 1,
The crosslinking agent is a water-soluble polymer for pipe blocking, characterized in that N,N-methylene bisacrylamide (N,N'-methylene bisacrylamide) and ethylene glycol diacrylate are mixed. 8. The method of claim 7,
The N,N-methylenebisacrylamide and the ethylene glycol diacrylate are mixed in a ratio of 3:7 to 1:9, a water-soluble polymer for pipe blocking.

Images