CA1200943A - Process for producing water-exchanging, non-toxic polymer material based on acrylamide/n,n'-methylene- bisacrylamide - Google Patents
Process for producing water-exchanging, non-toxic polymer material based on acrylamide/n,n'-methylene- bisacrylamideInfo
- Publication number
- CA1200943A CA1200943A CA000369885A CA369885A CA1200943A CA 1200943 A CA1200943 A CA 1200943A CA 000369885 A CA000369885 A CA 000369885A CA 369885 A CA369885 A CA 369885A CA 1200943 A CA1200943 A CA 1200943A
- Authority
- CA
- Canada
- Prior art keywords
- water
- acrylamide
- weight
- soil
- methylene bisacrylamide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/52—Amides or imides
- C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
- C08F220/56—Acrylamide; Methacrylamide
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
Abstract The novel, water-exchanging and non-toxic polymer material based on acrylamide and N,N'-methylenebis-acrylamide is obtained by means of a specific process.
The physical properties of the polymer resulting from the novel process permit the use thereof in important agricultural applications.
The physical properties of the polymer resulting from the novel process permit the use thereof in important agricultural applications.
Description
Process for producin~ water-exchan~in~, non-toxic polymer material based on acr~lamide/N,N'~meth~lene-bisacrylamide The invention relates to a process for the controlled pol~merization of inter alia acrylamide and N,N'-methylenebisacrylamide to water-exchanging, r-insoluble~
, non toxic~polymer materials, the thus obtained polymer materials with specifically defined physical properties as a result of their production procedure and to the use of the novel polymer material in agriculture.
The use of acrylamides in copolyrnerization reactions is known. In this connection, reference is made to Kirk-Othmer, 2nd edition, Vol,l, pp.282-284.
This publication contains a detailed bibliography regarding acrylamides and its use in polymers and copolymers.
A further publication dealing with acrylamide and its use in polymers is C.E.Schildknecht: Vinyl and Related Polymers; John Wiley & Sons, Inc., New York.
There ls also a large amount of patent literature on acrylamide copolymers and reference is only made thereto in extract forrn.
Austrian Patent 349,759 (American Cyanamid Co) describes a process for producing water-soluble co~
polymers containing acrylamide, styrene, alkylesters of acrylic and/or methacrylic acids. The product is water-soluble and all its uses are based on this property.
U.S.Patent 2,953,546 (American Cyanamid Co) relates to a polymerization process for the copolymeriza-tion of acrylamide, methanol acrylamide, methacrylamide, ',,~
, non toxic~polymer materials, the thus obtained polymer materials with specifically defined physical properties as a result of their production procedure and to the use of the novel polymer material in agriculture.
The use of acrylamides in copolyrnerization reactions is known. In this connection, reference is made to Kirk-Othmer, 2nd edition, Vol,l, pp.282-284.
This publication contains a detailed bibliography regarding acrylamides and its use in polymers and copolymers.
A further publication dealing with acrylamide and its use in polymers is C.E.Schildknecht: Vinyl and Related Polymers; John Wiley & Sons, Inc., New York.
There ls also a large amount of patent literature on acrylamide copolymers and reference is only made thereto in extract forrn.
Austrian Patent 349,759 (American Cyanamid Co) describes a process for producing water-soluble co~
polymers containing acrylamide, styrene, alkylesters of acrylic and/or methacrylic acids. The product is water-soluble and all its uses are based on this property.
U.S.Patent 2,953,546 (American Cyanamid Co) relates to a polymerization process for the copolymeriza-tion of acrylamide, methanol acrylamide, methacrylamide, ',,~
-2--N,N'-methylenebisacrylamide, vinylcarbazole, etc in liquid, non-aqueous medium in which neither the monomer nor the copolymer are soluble. Due to the omission of the solvent-~lute mixing phase, the invention provides a more economic copolymer production.
The products are always water-sdLIble (column 2J line l)o U.SOPatents 4,098,987 and 4,171,418 (both American Cyanamid Co) in each case describe a water-soluble copolymer of 40 to 70% by weight acrylamide and at least 30% of other, partly acrylic acid-based monomers. The water-soluble polyelectrolytes obtained according to the invention are used as cationic or nonionic surEactants.
Thus, most of the prior art relates to the ]5 copolymerization of acrylamide to water-soluble products.
The most important use of acrylamide in probably difficult~ soluble to even water~insoluble copolymers i ~ he commercial product AM-9 ~ of American Cyanamid Co. The material is a so-called chemical mortar which is injected as aqueous solutions of mainly acrylamide and a little N,N'-methylenebisacrylamide for sealing and strengthening of floors. The gelling time is mainly controlled by the catalyst quantity.
None of the above publications teaches or makes obvious a process for the controlled copolymeri-zation oE acrylamide, N,N'-methylenebisacrylamide and optionally further acrylic acid derivative monomers to give a solid, water-insoluble, non-decaying, water-exchanging and non-toxic polymer material which, in ~3
The products are always water-sdLIble (column 2J line l)o U.SOPatents 4,098,987 and 4,171,418 (both American Cyanamid Co) in each case describe a water-soluble copolymer of 40 to 70% by weight acrylamide and at least 30% of other, partly acrylic acid-based monomers. The water-soluble polyelectrolytes obtained according to the invention are used as cationic or nonionic surEactants.
Thus, most of the prior art relates to the ]5 copolymerization of acrylamide to water-soluble products.
The most important use of acrylamide in probably difficult~ soluble to even water~insoluble copolymers i ~ he commercial product AM-9 ~ of American Cyanamid Co. The material is a so-called chemical mortar which is injected as aqueous solutions of mainly acrylamide and a little N,N'-methylenebisacrylamide for sealing and strengthening of floors. The gelling time is mainly controlled by the catalyst quantity.
None of the above publications teaches or makes obvious a process for the controlled copolymeri-zation oE acrylamide, N,N'-methylenebisacrylamide and optionally further acrylic acid derivative monomers to give a solid, water-insoluble, non-decaying, water-exchanging and non-toxic polymer material which, in ~3
-3~
addition has very specific physical propert:i.es and such is obtained by the novel. process. As a result, it is suitable for extremely important agricultural uses.
The aforementioned aims are achieved by the presently described invention.
The process of the invention is defined in claim l, the product in claim 8 and the use in claim 9.
The inventors/Applicants have optimized the specific process of the invention in a long series of tests. For the purpose of controlling the most important physical characteristics of the product, novel and simple testing methods have been developed.
Thus, the novel, water-exchanging, non-toxic,water-lnsol-~ uble polymer material is obtained in that - acrylamide and N,N'-methylenebisacrylamide are dissolved together in water in a monomer to water weight ratio of max~ 2:8, - optionally further N-substituted acrylarnide monomers are added, whilst not exceeding the above monomer to water wei.ght ratio, - at least one finely divided, suspended and/or dissolved polymerization initiator i.s added, accompanied by stirring to the solution, ~5 - copolymerization is performed at temperature above soo C ~
- the gel is granulated and is then washed to a maximum acrylamide monomer content of ~ 0.1% by weight, based on the end product, and, - the gel granulate is dried at temperatures below 100C
addition has very specific physical propert:i.es and such is obtained by the novel. process. As a result, it is suitable for extremely important agricultural uses.
The aforementioned aims are achieved by the presently described invention.
The process of the invention is defined in claim l, the product in claim 8 and the use in claim 9.
The inventors/Applicants have optimized the specific process of the invention in a long series of tests. For the purpose of controlling the most important physical characteristics of the product, novel and simple testing methods have been developed.
Thus, the novel, water-exchanging, non-toxic,water-lnsol-~ uble polymer material is obtained in that - acrylamide and N,N'-methylenebisacrylamide are dissolved together in water in a monomer to water weight ratio of max~ 2:8, - optionally further N-substituted acrylarnide monomers are added, whilst not exceeding the above monomer to water wei.ght ratio, - at least one finely divided, suspended and/or dissolved polymerization initiator i.s added, accompanied by stirring to the solution, ~5 - copolymerization is performed at temperature above soo C ~
- the gel is granulated and is then washed to a maximum acrylamide monomer content of ~ 0.1% by weight, based on the end product, and, - the gel granulate is dried at temperatures below 100C
4 ~
to a maximum water content of 12% by weight, based ~_~hereL)y on the end product and~ Ietely copolymerized an~ cured.
The two main monomers, i.e. the acrylamide and the N,N'-methylenebisacrylamide can be used in the process in weight ratio s between 9:1 and 99:1 The weights of the monomers added to the solvent water can be in the ratio l:9.
The polymerization initiators can be tertiary amines, specifically triethanolamine or 3-dimethylamino-propionitrile. In addition to these organic initiatorsit is also possible to use inorganic peroxy compoundsO
The total weight of the monomers used can be in a ratio of 9:1 to 99:1 to the total weight of the polymerization initiators usedO
Advantageously, polymerization is performed at temperatures of 70 - 5C.
With reasonable expenditure and effort, the gelled granulate can be washed to a residual acrylamide monomer content of 0.05% by weight, based on the end product~
The gel granulate is best dried in hot air at approxi~ately 95 - 5 C. This leads to an end product containing max. 3% by weight of water, based on the end product. The inventors/Applicants are reasonably sure that the crosslinking of the product is completed during this drying stage. Thus~ gels dried at much lower temperatures or only mechanically squeezed off, lead to granulates with much lower dimensional stab~ity values during temperature cycle tests.
The dry granu~ te can then be ground and screened out to the desired ~article size. In particular, three such particle sizes were used for tests:
G 01 H 0 - lmm; G 12 H 1 - 2mm and G 30 G 2 - 3mm.
The following example illustrates the process of the invention.
Exarnple 9.5kg of acrylamide and 0.5kg of methylene-bisacrylamide were dissolved in 90kg of water. Following complete monomer dissolving, 0.4kg of 3-dimethyleneamino-propionitrile was added. The solution was then slowly heated and during heating mixed with 0.5kg of ammonium peroxysulphate. Polymerization starts at 70C and this temperature is maintained throughout the polymerization process.
The set gel was fed into a screw extruder whose outlet was provided wlth a 4mm circular perforated disk. A granulate with a diameter of 4mm was obtained.
It was washed in flowing water in order to remove monomer constituents. The washing water was also used for the following gelling process.
After washing out the granulate was dried in a hot air conduit at an air temperature of 90 to 100 C.
The residual moisture content of the granulate was bctween 2 and 3~/~ by weight. Analysis of the free monomer content revealed a value of 0.05% by weight.
The polymer material produced according to the invention has the following lmportant physical charac-teristics:
- a density of 1.0 - 0.2g.cm 3, -3~3 - a water absorption in the cylinder test of at least 200 volume %, - a free acrylamide monomer content of max. 0. l~/o by weight, and - a max. 10% water absorptivity reduction, based on the initial absorptivity, after four cycles in the absorption drying test.
The cylinder test used for measuring the water absorption of the polymer material according to the invention is performed in the following manner.
In each case, lOcm of polymer material with particle size limits of up to lmm (G 01 H) 9 1-2mm (G 12 H) and 2-3mm (G 30 H) were added to a graduated glass cylinder with a capacity of 500 cm . Distilled water was used to top up to 500cm . After 60 minutes, the gel volume was determined, in the same way as it had previously been determined at various intermediate times. The test temperature was 1 C and the water absorption in volume % was calculated as:
Water absorption (%) =
gel,after 60min(cm ) Vdry polymer material(Cm )] 100 Vdry polymer material( ~ he results of the tests with samples having the aforementioned particle sizes are given in the attached drawing.
The reduction of the water absorption of the polymer material according to the invention after a given number of water`exchanges is apparent from the following test:
In each case equal weights of quartz sand of particle size 0.1 to 0O3mm and particle size 0,8 to 1.2mm were mixed together to form a standard mixture.
In each case, 6g of polymer material of the above particle sizes was admixed to 400g of standard sand, Cycle l: Water absorption in 115ml high, 90ml diarneter and 600cm3 capacity (50cm3 graduations) beakers -symmetrically arranged holes with a diameker of 1.2mmwere drilled on the outer edge of the concave base 6.
Six of these beakers were filled for each mixture, The first rnixture consisted only of 400g of standard sand, In addition to the sand, the test samples in each case contained 6g of the polymer material under investigation, All the beakers were placed in a flat plastic tank. The tank and the beakers were illed to the 600cm mark with water at 22 to 24C. All the samples were left for 60 minutes in the water to ensure complete absorption. After 60 minutes, the samples were rernoved from the water tank and placed on a grating to enable superfluous, i.e, non-absorbed water to drip off. At the end of a dripping time of 60 minutes, these samples were weighed.
The absorbed water quantity was determined by the following calculation procedure, Cycle 2: Drying, The samples were dried for 16 hours in air at 100 C
~ , . .. . . .. .. .. ... . .... . . .. .
and then weighed5 The followlng values were obtained.
G0111 G12H G30~1 1st cycle 242.4 265~6 287.1 2nd Gycle 24703 253.5 269.1 3rd cycle 245.2 246.4 258.4 4th cycle 236.6 243.7 258.5 The novel polymer material can be used in agriculture to permit the cultivation of uncultivatable soils such as desert or prairie soils, as well as for the stabilization of intensely cultivated soils.
to a maximum water content of 12% by weight, based ~_~hereL)y on the end product and~ Ietely copolymerized an~ cured.
The two main monomers, i.e. the acrylamide and the N,N'-methylenebisacrylamide can be used in the process in weight ratio s between 9:1 and 99:1 The weights of the monomers added to the solvent water can be in the ratio l:9.
The polymerization initiators can be tertiary amines, specifically triethanolamine or 3-dimethylamino-propionitrile. In addition to these organic initiatorsit is also possible to use inorganic peroxy compoundsO
The total weight of the monomers used can be in a ratio of 9:1 to 99:1 to the total weight of the polymerization initiators usedO
Advantageously, polymerization is performed at temperatures of 70 - 5C.
With reasonable expenditure and effort, the gelled granulate can be washed to a residual acrylamide monomer content of 0.05% by weight, based on the end product~
The gel granulate is best dried in hot air at approxi~ately 95 - 5 C. This leads to an end product containing max. 3% by weight of water, based on the end product. The inventors/Applicants are reasonably sure that the crosslinking of the product is completed during this drying stage. Thus~ gels dried at much lower temperatures or only mechanically squeezed off, lead to granulates with much lower dimensional stab~ity values during temperature cycle tests.
The dry granu~ te can then be ground and screened out to the desired ~article size. In particular, three such particle sizes were used for tests:
G 01 H 0 - lmm; G 12 H 1 - 2mm and G 30 G 2 - 3mm.
The following example illustrates the process of the invention.
Exarnple 9.5kg of acrylamide and 0.5kg of methylene-bisacrylamide were dissolved in 90kg of water. Following complete monomer dissolving, 0.4kg of 3-dimethyleneamino-propionitrile was added. The solution was then slowly heated and during heating mixed with 0.5kg of ammonium peroxysulphate. Polymerization starts at 70C and this temperature is maintained throughout the polymerization process.
The set gel was fed into a screw extruder whose outlet was provided wlth a 4mm circular perforated disk. A granulate with a diameter of 4mm was obtained.
It was washed in flowing water in order to remove monomer constituents. The washing water was also used for the following gelling process.
After washing out the granulate was dried in a hot air conduit at an air temperature of 90 to 100 C.
The residual moisture content of the granulate was bctween 2 and 3~/~ by weight. Analysis of the free monomer content revealed a value of 0.05% by weight.
The polymer material produced according to the invention has the following lmportant physical charac-teristics:
- a density of 1.0 - 0.2g.cm 3, -3~3 - a water absorption in the cylinder test of at least 200 volume %, - a free acrylamide monomer content of max. 0. l~/o by weight, and - a max. 10% water absorptivity reduction, based on the initial absorptivity, after four cycles in the absorption drying test.
The cylinder test used for measuring the water absorption of the polymer material according to the invention is performed in the following manner.
In each case, lOcm of polymer material with particle size limits of up to lmm (G 01 H) 9 1-2mm (G 12 H) and 2-3mm (G 30 H) were added to a graduated glass cylinder with a capacity of 500 cm . Distilled water was used to top up to 500cm . After 60 minutes, the gel volume was determined, in the same way as it had previously been determined at various intermediate times. The test temperature was 1 C and the water absorption in volume % was calculated as:
Water absorption (%) =
gel,after 60min(cm ) Vdry polymer material(Cm )] 100 Vdry polymer material( ~ he results of the tests with samples having the aforementioned particle sizes are given in the attached drawing.
The reduction of the water absorption of the polymer material according to the invention after a given number of water`exchanges is apparent from the following test:
In each case equal weights of quartz sand of particle size 0.1 to 0O3mm and particle size 0,8 to 1.2mm were mixed together to form a standard mixture.
In each case, 6g of polymer material of the above particle sizes was admixed to 400g of standard sand, Cycle l: Water absorption in 115ml high, 90ml diarneter and 600cm3 capacity (50cm3 graduations) beakers -symmetrically arranged holes with a diameker of 1.2mmwere drilled on the outer edge of the concave base 6.
Six of these beakers were filled for each mixture, The first rnixture consisted only of 400g of standard sand, In addition to the sand, the test samples in each case contained 6g of the polymer material under investigation, All the beakers were placed in a flat plastic tank. The tank and the beakers were illed to the 600cm mark with water at 22 to 24C. All the samples were left for 60 minutes in the water to ensure complete absorption. After 60 minutes, the samples were rernoved from the water tank and placed on a grating to enable superfluous, i.e, non-absorbed water to drip off. At the end of a dripping time of 60 minutes, these samples were weighed.
The absorbed water quantity was determined by the following calculation procedure, Cycle 2: Drying, The samples were dried for 16 hours in air at 100 C
~ , . .. . . .. .. .. ... . .... . . .. .
and then weighed5 The followlng values were obtained.
G0111 G12H G30~1 1st cycle 242.4 265~6 287.1 2nd Gycle 24703 253.5 269.1 3rd cycle 245.2 246.4 258.4 4th cycle 236.6 243.7 258.5 The novel polymer material can be used in agriculture to permit the cultivation of uncultivatable soils such as desert or prairie soils, as well as for the stabilization of intensely cultivated soils.
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the controlled copolymerization of acrylamide and N,N'-methylene bisacrylamide to form a water-exchanging, non-toxic water-insoluble polymer material, wherein - acrylamide and N,N'-methylene bisacrylamide are dissolved together in water in a monomer to water weight ratio of max. 2:8, - at least one finely divided, suspended or dissolved polymerization initiator is added, accompanied by stirring the solution, - copolymerization is performed at temperatures above 50°C, - the gel is granulated and is then washed to a maximum acrylamide monomer content of ? 0.1% by weight, based on the end product, and, - the gel granulate is dried at temperatures below 100°C to a maximum water content of 12% by weight, based on the end product and thereby completely copolymerized and cured.
2. A process according to claim 1, wherein acrylamide and N,N'-methylene bisacrylamide are used in a weight ratio of 9:1 to 99:1 and the monomers and water in a weight ratio of 1:9.
3. A process according to claim 1, wherein the polymerization initiators used are tertiary amines or inorganic peroxy compounds in a monomer to polymerization initiator weight ratio of 9:1 to 99:1.
4. A process according to claim 1, wherein polymerization is performed at 70 + 5°C.
5. A process according to claim 1, wherein the gel granulate is washed out to a 0.05% by weight acrylamide monomer content.
6. A process according to claim 1, wherein the gel granulate is dried to a residual water content of 3% by weight, based on the end product, by bringing into contact with air at 95 + 5°C and in this way is completely polymerized.
7. A process according to claim 1, wherein the dried gel granulate is further ground to the desired particle size and screened off.
8. A water-exchanging, non-toxic water-insoluble, polymer material based on acrylamide and N,N'-methylene bisacrylamide, produced according to the process of claim 1, having - a density of 1.0 + 0.2g.cm-3, - a water absorption in the cylinder test of at least 200 volume %, - a free acrylamide monomer content of max. 0.1% by weight, and - a max. 10% water absorptivity reduction, based on the initial absorptivity, after four cycles in the absorption drying text.
9. A method for rendering uncultivable soils cultivatable, which comprises mixing the soil with a 1% to 20%
proportion by weight of a water exchanging, non-toxic water-insoluble polymer material according to claim 8.
proportion by weight of a water exchanging, non-toxic water-insoluble polymer material according to claim 8.
10. A method for increasing the water absorptivity and water retention capacity of soil for growing plants, said method comprising the steps of:
mixing the soil with a 1 to 20% proportion of cross-linked, dry, solid, granular acrylamide polymer by weight, said acrylamide polymer being the product of cross-linking acrylamide with N,N'-methylene bisacrylamide in the absence of an inert filler, said dry, acrylamide polymer being the form of granular particles having an average size in the range of 0.5 to 5.0 mm:
introducing this soil mixture to the main root areas of the plants; and watering said soil mixture such that said acrylamide polymer absorbs water and swells to at least 200% of its original volume.
mixing the soil with a 1 to 20% proportion of cross-linked, dry, solid, granular acrylamide polymer by weight, said acrylamide polymer being the product of cross-linking acrylamide with N,N'-methylene bisacrylamide in the absence of an inert filler, said dry, acrylamide polymer being the form of granular particles having an average size in the range of 0.5 to 5.0 mm:
introducing this soil mixture to the main root areas of the plants; and watering said soil mixture such that said acrylamide polymer absorbs water and swells to at least 200% of its original volume.
11. The method as recited in claim 10, wherein said mixing step includes adding at least one agent selected from the group consisting of conditioning agents, fertilizers, and pesticides, to said soil and said cross-linked, dry, granular acrylamide polymer.
12. A soil conditioning agent able to absorb water and subsequently release it again in repeated cycles over an indefinite period of time, said agent consisting essentially of a dry, solid, granular acrylamide polymer formed by cross-linking 95% acrylamide with 5% N,N'-methylene bisacrylamide by weight, said cross-linked acrylamide polymer granules being gellable, water-insoluble, difficult to rot and having an average particle size in the range of 0.5 to 5.0 mm.
13. A method for increasing the water absorptivity and water retention capacity of soils in desert climates for growing plants without rendering the soil impermeable, said method comprising the step of mixing the existing soil with a 1 to 20% proportion by weight of a cross-linked anionic or nonionic acrylamide polymer obtained by the copolymerization of acrylamide and N,N'-methylene bisacrylamide, said acrylamide polymer being formed as a dry, solid, granular material having an average particle size in the range of 0.5 to 5.0 mm, being able to absorb water and become a gel and being difficult to rot.
14. The method as recited in claim 10, wherein said granular acrylamide polymer is formed by cross-linking 95%
acrylamide with 5% N,N'-methylene bisacrylamide by weight.
acrylamide with 5% N,N'-methylene bisacrylamide by weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH2250/80-5 | 1980-03-21 | ||
| CH225080A CH643569A5 (en) | 1980-03-21 | 1980-03-21 | METHOD FOR PRODUCING WASSERAUSTAUSCHENDEM, non-toxic POLYMER MATERIAL BASED ON ACRYLAMIDE / N, N'-methylenebisacrylamide. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1200943A true CA1200943A (en) | 1986-02-18 |
Family
ID=4229376
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000369885A Expired CA1200943A (en) | 1980-03-21 | 1981-02-02 | Process for producing water-exchanging, non-toxic polymer material based on acrylamide/n,n'-methylene- bisacrylamide |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0037138A3 (en) |
| JP (1) | JPS56145908A (en) |
| AU (1) | AU537812B2 (en) |
| CA (1) | CA1200943A (en) |
| CH (1) | CH643569A5 (en) |
| ES (1) | ES8201606A1 (en) |
| IL (1) | IL61973A (en) |
| IN (1) | IN153454B (en) |
| ZA (1) | ZA81521B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6063209A (en) * | 1983-09-16 | 1985-04-11 | Mitsui Petrochem Ind Ltd | Manufacture of water-swellable crosslinked polymer |
| DE3464761D1 (en) | 1983-04-14 | 1987-08-20 | Mitsui Petrochemical Ind | Process for producing granular, water-swellable crosslinked acrylic copolymer, and its use |
| US4579578A (en) * | 1983-06-04 | 1986-04-01 | Chemical Discoveries S.A. | Plant growing media |
| EP0365011B1 (en) * | 1988-10-21 | 1994-03-16 | Canon Kabushiki Kaisha | A polymer gel manufacturing method, a polymer gel and an actuator employing the same |
| JP2697782B2 (en) * | 1995-03-10 | 1998-01-14 | 工業技術院長 | Displacement velocity or strain velocity measurement method and apparatus used for the method |
| UA67354U (en) * | 2011-11-24 | 2012-02-10 | Людмила Дмитрівна Желдак | Water-soluble linear hetero-chain dipolymer |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2801984A (en) * | 1955-08-15 | 1957-08-06 | American Cyanamid Co | Resin-forming composition for stabilization of soil and process of using same |
| US3212577A (en) * | 1959-07-09 | 1965-10-19 | Sinclair Research Inc | Method for decreasing the permeability of a permeable well area |
| SE306073B (en) * | 1962-04-18 | 1968-11-18 | Pharmacia Ab | |
| US3545130A (en) * | 1967-07-21 | 1970-12-08 | Dow Chemical Co | Soil conditioning and erosion control |
-
1980
- 1980-03-21 CH CH225080A patent/CH643569A5/en not_active IP Right Cessation
-
1981
- 1981-01-23 IL IL61973A patent/IL61973A/en unknown
- 1981-01-26 ZA ZA00810521A patent/ZA81521B/en unknown
- 1981-01-27 IN IN85/CAL/81A patent/IN153454B/en unknown
- 1981-01-29 AU AU66695/81A patent/AU537812B2/en not_active Ceased
- 1981-02-02 CA CA000369885A patent/CA1200943A/en not_active Expired
- 1981-02-06 ES ES499191A patent/ES8201606A1/en not_active Expired
- 1981-02-27 JP JP2709781A patent/JPS56145908A/en active Pending
- 1981-03-11 EP EP81200276A patent/EP0037138A3/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| AU537812B2 (en) | 1984-07-12 |
| JPS56145908A (en) | 1981-11-13 |
| EP0037138A2 (en) | 1981-10-07 |
| ES499191A0 (en) | 1982-01-01 |
| AU6669581A (en) | 1981-09-24 |
| CH643569A5 (en) | 1984-06-15 |
| EP0037138A3 (en) | 1982-04-21 |
| ES8201606A1 (en) | 1982-01-01 |
| IN153454B (en) | 1984-07-14 |
| ZA81521B (en) | 1982-02-24 |
| IL61973A0 (en) | 1981-02-27 |
| IL61973A (en) | 1984-04-30 |
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