CA1328031C - Preparation of copolymers of polyvinyl alcohols - Google Patents
Preparation of copolymers of polyvinyl alcoholsInfo
- Publication number
- CA1328031C CA1328031C CA000553633A CA553633A CA1328031C CA 1328031 C CA1328031 C CA 1328031C CA 000553633 A CA000553633 A CA 000553633A CA 553633 A CA553633 A CA 553633A CA 1328031 C CA1328031 C CA 1328031C
- Authority
- CA
- Canada
- Prior art keywords
- modifying agent
- pva
- temperature
- molecular weight
- polyvinyl alcohol
- 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 - Fee Related
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
- C08F8/00—Chemical modification by after-treatment
- C08F8/30—Introducing nitrogen atoms or nitrogen-containing groups
Landscapes
- Chemical & Material Sciences (AREA)
- General 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 OF THE DISCLOSURE
A one-step process for the preparation of high viscosity modified polyvinyl alcohols comprises forming at room temperature a water slurry of a polyvinyl alcohol having a degree of hydrolysis varying from about 90% to about 95% or more, an alpha, beta-unsaturated carbonyl compound modifying agent such as acrylamide wherein said polyvinyl alcohol and said modifying agent are present in a molar ratio of from about 1:10, and a base, and heating the mixture to a temperature of less than 100°C for a time sufficient to obtain the resultant modified high viscosity high molecular weight product. Such products have higher viscosity than those prepared via a two-step high temperature modification reaction.
A one-step process for the preparation of high viscosity modified polyvinyl alcohols comprises forming at room temperature a water slurry of a polyvinyl alcohol having a degree of hydrolysis varying from about 90% to about 95% or more, an alpha, beta-unsaturated carbonyl compound modifying agent such as acrylamide wherein said polyvinyl alcohol and said modifying agent are present in a molar ratio of from about 1:10, and a base, and heating the mixture to a temperature of less than 100°C for a time sufficient to obtain the resultant modified high viscosity high molecular weight product. Such products have higher viscosity than those prepared via a two-step high temperature modification reaction.
Description
-"`` 1328~31 .
PREPARATION OF COPOLYMERS OF POLYVINYL ALCOHOLS
This invention is directed to a simplified method of preparing improved copolymers of polyvinyl alcohols (PVA). More specifically, it is directed to the modification of PVA with various alpha, beta-unsaturated carbonyl compounds.
It is known that PVA may be modified, e.g., by chemical means such as grafting and hydrolysis. Modification of PVA with ¦ acrylamide was first reported by H. Ito, et al. Lindemann filed a i patent on "~ater Soluble Modified PVA Films" (U.S. Patent ~,505,303). In these reports, PVA is first dispersed in water at low temperature followed by high temperature dissolution to obtain a PVA solution after which the modifying agent is added to start the reaction. The above process is useful for PVA which are soluble in water below 100C tmolecular weight less than 1 X 105 and degrees of hydrolysis less than 90%.) As PVA molecular weight and degree of hydrolysis increase, its dissolution temperature requirement becomes much greater than 100C. For example, PVA having a MW of 3.5x105 at 90% hydrolysis requires greater than 120C for its dissolution. At the same molecular weight and at 99% hydrolysis its dissolution temperature is greater than 160C. For both cases, a pressurized reactor is required. Precautions must be taken to prevent oxidative degradation of PVA at these temperatures. We now find that high molecular wei~ht PVA having a high degree of hydrolysis (99%) can be modified with acrylamide in a simple one-step, low-temperature reaction tless than 100C) to produce acrylamide modified PVA
(AMPVA) which has a much higher viscosity than a sample prepared via a two-step, high-temperature dissolution-modification reaction process.
The concept of the present invention involves modifying PVA
with acrylamide and other alpha, beta-unsaturated carbonyl compounds by low temperature (less than 100C) reaction, producing high molecular weight modified PVA with minimal thermal degradation, and eliminating the need to dissolve PVA at high temperatures prior to : , ~ -; ;:
'. ,' ~' ' . ', F-4114 -~- 13 2 8 ~ 31 - .-~
its reaction with modifying compounds, thereby reducing production costs.
Accordingly, the present invention provides a one-step process for the preparatio~ of high viscosity modified polyYinyl alcohols comprising forming at room temperature a water slurry of a polyvinyl alcohol having a degree of hydrolysis varying from about 90% to about 95% or more, an alpha, beta-u~saturated carbonyl compound modifying agent wherein said polyvinyl alcohol and said modifying agent are present in a molar ratio of from about 10:1 to about 1:10, and a base, and heating said mixture to a temperature of less than 100C for a time sufficient to obtain the resultant modified high viscosity high molecular weight .
product.
Modifying PVA with alpha, beta-unsaturated carbonyl compounds as modifying agent produces a class of very useful materials.
, .
~ ;''~'.
OH OH .
(Eq. 1) ' . ' O OH O
~ ' .
R X
2û wherein n=a+b;
x = -N~2 , -NHR , H, ~H
-NH-C-CH2SO3 Na (AMPS);
. CH3 ! 25 - ;
-S~ where R and R2 in~ependently are selected from H, alkyl, aryl or A alkylaryl with from about 12 oarbons or less, preferably about 8 to _ _.. _. _ . . . . _ ... , . _ F-4114 -3- 1328~3~
abcut 12 carbon atoms. A~rylonitr;le or substituted acrylonitrile m~y also be advantageously used.
Modified products are cold water soluble contrary to the high molecular weight parent PVA which has very low solubility in ' 5 cold water, especially when the degree of hydrolysis is high (more than 90%). They are also more tolerant to brine (including NaCl, KCl solutions) than the unmodified PVA. Furthermore, these materials are thermally and hydrolytically stable in concentrated brines, which makes them potentially useful as oilfield chemicals, adhesives, etc. In addition, the added functional groups can be used as synthetic handles for further reactions. Other modifying agents also can be used to modify the high molecular weight, highly hydrolyzed PVA; e.g., methacrylamide, ` -2-acrylamido-2-methyl-propane-3-(sulfonate) (AMPS), acrylonitrile and others described in Equation 1. It also should be noted that PVA having lower molecular weight and lower degree of hydrolysis can also be modified by thls method. Py high molecular weight PVA's is meant a molecular weight at least of 1 x 105.
The general reaction conditions for these highly hydrolyzed PVA's (99%+) include temperatures up to but not including 100C
dependlng on the particular PVA. Preferred is a temperature of from about 80-95C with pressures varying from amblent. Higher pressures may be used if desired but usually the pressure is autogeneous;
reaction times vary from about 2 hours to 24 hours or more. The molar ratio of PVA to modifying agent varies from about 10:1 to about 1:10 and preferably from about 2:1 to about 1:3 depending upon the desired degree of modification. Higher reaction parameters, i.e., higher temperatures, longer reaction tlmes, higher molar ratios, etc., will provide higher degrees of modificatlon.
Any suit~ble basic substance which will not interfere with `
the modification reaction may be used. Preferred are such bases as NaOH.
The following examples are illustrative of the invention embodied herein.
~A :-~2~Q~
- F-4114 ~4~
A 59 sample of 3.5x105 molecular weight PVA, 99~
hydrolyzed was dissolved in 959 of deaired distilled water in an autoclave under argon atmosphere at 160C for two hours. The resulting PVA solution was reacted with 2ûg of acrylamide and 19 of NaOH for 10 hours at about 85C. The product was isolated by precipitating from i-propanol. Crude product was purified by redissolving in cold water and reprecipitating in i-propanol three times. Nitrogen analysis showed 2.99~ N which is equivalent to 10.7% acrylamide incorporation. A 5% water solution of the copolymer had a viscosity of 70 cp.
59 of 3.5x105 molecular weight PVA, 99% hydrolyzed, 209 acrylamide and 19 NaOH formed a slurry in 959 of water at room temperature. This mixture was heated to 85C for ten hours. During the process of heating, PVA solid particles gradually disappeared.
The product was collected and purified as in Example 1. Analysis showed 3.2%N or 11.5% acrylamide. A 5% solution has a viscosity of 294cp.
The method of Example 2 produces a more viscous product than does the method of Example 1. It is obvious that the lower temperature process of Example 2 which is in accordance with the invention is, among other advantages, significantly more cost efficient.
AMPVA and AMPS PVA in particular are therefore viewed as important profile control gel precursors. The ability to modify these highly hydrolyzed, high molecular weight PVAs conveniently and economically enhances the attractiveness of these copolymers compared with other candidate systems, such as the AMPS-vinyl pyrrolidone- acrylamide copolymers.
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.
, '
PREPARATION OF COPOLYMERS OF POLYVINYL ALCOHOLS
This invention is directed to a simplified method of preparing improved copolymers of polyvinyl alcohols (PVA). More specifically, it is directed to the modification of PVA with various alpha, beta-unsaturated carbonyl compounds.
It is known that PVA may be modified, e.g., by chemical means such as grafting and hydrolysis. Modification of PVA with ¦ acrylamide was first reported by H. Ito, et al. Lindemann filed a i patent on "~ater Soluble Modified PVA Films" (U.S. Patent ~,505,303). In these reports, PVA is first dispersed in water at low temperature followed by high temperature dissolution to obtain a PVA solution after which the modifying agent is added to start the reaction. The above process is useful for PVA which are soluble in water below 100C tmolecular weight less than 1 X 105 and degrees of hydrolysis less than 90%.) As PVA molecular weight and degree of hydrolysis increase, its dissolution temperature requirement becomes much greater than 100C. For example, PVA having a MW of 3.5x105 at 90% hydrolysis requires greater than 120C for its dissolution. At the same molecular weight and at 99% hydrolysis its dissolution temperature is greater than 160C. For both cases, a pressurized reactor is required. Precautions must be taken to prevent oxidative degradation of PVA at these temperatures. We now find that high molecular wei~ht PVA having a high degree of hydrolysis (99%) can be modified with acrylamide in a simple one-step, low-temperature reaction tless than 100C) to produce acrylamide modified PVA
(AMPVA) which has a much higher viscosity than a sample prepared via a two-step, high-temperature dissolution-modification reaction process.
The concept of the present invention involves modifying PVA
with acrylamide and other alpha, beta-unsaturated carbonyl compounds by low temperature (less than 100C) reaction, producing high molecular weight modified PVA with minimal thermal degradation, and eliminating the need to dissolve PVA at high temperatures prior to : , ~ -; ;:
'. ,' ~' ' . ', F-4114 -~- 13 2 8 ~ 31 - .-~
its reaction with modifying compounds, thereby reducing production costs.
Accordingly, the present invention provides a one-step process for the preparatio~ of high viscosity modified polyYinyl alcohols comprising forming at room temperature a water slurry of a polyvinyl alcohol having a degree of hydrolysis varying from about 90% to about 95% or more, an alpha, beta-u~saturated carbonyl compound modifying agent wherein said polyvinyl alcohol and said modifying agent are present in a molar ratio of from about 10:1 to about 1:10, and a base, and heating said mixture to a temperature of less than 100C for a time sufficient to obtain the resultant modified high viscosity high molecular weight .
product.
Modifying PVA with alpha, beta-unsaturated carbonyl compounds as modifying agent produces a class of very useful materials.
, .
~ ;''~'.
OH OH .
(Eq. 1) ' . ' O OH O
~ ' .
R X
2û wherein n=a+b;
x = -N~2 , -NHR , H, ~H
-NH-C-CH2SO3 Na (AMPS);
. CH3 ! 25 - ;
-S~ where R and R2 in~ependently are selected from H, alkyl, aryl or A alkylaryl with from about 12 oarbons or less, preferably about 8 to _ _.. _. _ . . . . _ ... , . _ F-4114 -3- 1328~3~
abcut 12 carbon atoms. A~rylonitr;le or substituted acrylonitrile m~y also be advantageously used.
Modified products are cold water soluble contrary to the high molecular weight parent PVA which has very low solubility in ' 5 cold water, especially when the degree of hydrolysis is high (more than 90%). They are also more tolerant to brine (including NaCl, KCl solutions) than the unmodified PVA. Furthermore, these materials are thermally and hydrolytically stable in concentrated brines, which makes them potentially useful as oilfield chemicals, adhesives, etc. In addition, the added functional groups can be used as synthetic handles for further reactions. Other modifying agents also can be used to modify the high molecular weight, highly hydrolyzed PVA; e.g., methacrylamide, ` -2-acrylamido-2-methyl-propane-3-(sulfonate) (AMPS), acrylonitrile and others described in Equation 1. It also should be noted that PVA having lower molecular weight and lower degree of hydrolysis can also be modified by thls method. Py high molecular weight PVA's is meant a molecular weight at least of 1 x 105.
The general reaction conditions for these highly hydrolyzed PVA's (99%+) include temperatures up to but not including 100C
dependlng on the particular PVA. Preferred is a temperature of from about 80-95C with pressures varying from amblent. Higher pressures may be used if desired but usually the pressure is autogeneous;
reaction times vary from about 2 hours to 24 hours or more. The molar ratio of PVA to modifying agent varies from about 10:1 to about 1:10 and preferably from about 2:1 to about 1:3 depending upon the desired degree of modification. Higher reaction parameters, i.e., higher temperatures, longer reaction tlmes, higher molar ratios, etc., will provide higher degrees of modificatlon.
Any suit~ble basic substance which will not interfere with `
the modification reaction may be used. Preferred are such bases as NaOH.
The following examples are illustrative of the invention embodied herein.
~A :-~2~Q~
- F-4114 ~4~
A 59 sample of 3.5x105 molecular weight PVA, 99~
hydrolyzed was dissolved in 959 of deaired distilled water in an autoclave under argon atmosphere at 160C for two hours. The resulting PVA solution was reacted with 2ûg of acrylamide and 19 of NaOH for 10 hours at about 85C. The product was isolated by precipitating from i-propanol. Crude product was purified by redissolving in cold water and reprecipitating in i-propanol three times. Nitrogen analysis showed 2.99~ N which is equivalent to 10.7% acrylamide incorporation. A 5% water solution of the copolymer had a viscosity of 70 cp.
59 of 3.5x105 molecular weight PVA, 99% hydrolyzed, 209 acrylamide and 19 NaOH formed a slurry in 959 of water at room temperature. This mixture was heated to 85C for ten hours. During the process of heating, PVA solid particles gradually disappeared.
The product was collected and purified as in Example 1. Analysis showed 3.2%N or 11.5% acrylamide. A 5% solution has a viscosity of 294cp.
The method of Example 2 produces a more viscous product than does the method of Example 1. It is obvious that the lower temperature process of Example 2 which is in accordance with the invention is, among other advantages, significantly more cost efficient.
AMPVA and AMPS PVA in particular are therefore viewed as important profile control gel precursors. The ability to modify these highly hydrolyzed, high molecular weight PVAs conveniently and economically enhances the attractiveness of these copolymers compared with other candidate systems, such as the AMPS-vinyl pyrrolidone- acrylamide copolymers.
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.
, '
Claims (5)
1. A one-step process for the preparation of high viscosity modified polyvinyl alcohols comprising forming at room temperature a water slurry of a polyvinyl alcohol having a degree of hydrolysis varying from about 90% to about 95% or more, an alpha, beta-unsaturated carbonyl compound modifying agent wherein said polyvinyl alcohol and said modifying agent are present in a molar ratio of from about 10:1 to about 1:10,and a base, and heating said mixture to a temperature of less than 100°C for a time sufficient to obtain the resultant modified high viscosity high molecular weight product.
2. The process of claim 1 wherein the base is sodium hydroxide.
3. The process of claim 1 or 2 wherein the modifying agent is selected from acrylamide, methacrylamide, acrylonitrile and sodium 2 - acrylamido - 2 methyl-propane - 3-(sulfonate).
4. The process of claim 1 wherein the polyvinyl achohol molecular weight ranges from 1 to 5.0 x 10?.
5. The process of claim 1 wherein the temperature ranges from ambient to about 90°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94473686A | 1986-12-22 | 1986-12-22 | |
| US944,736 | 1986-12-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1328031C true CA1328031C (en) | 1994-03-22 |
Family
ID=25481975
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553633A Expired - Fee Related CA1328031C (en) | 1986-12-22 | 1987-12-07 | Preparation of copolymers of polyvinyl alcohols |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1328031C (en) |
| GB (1) | GB2199834B (en) |
| NO (1) | NO172647C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2125452A1 (en) * | 1993-07-01 | 1995-01-02 | Rhone-Poulenc Specialty Chemicals Co. | Anionic sulfonated thickening composition |
| US5350801A (en) * | 1993-07-07 | 1994-09-27 | Air Products And Chemicals, Inc. | Solid state process for modification of polyvinyl alcohol using Michael-type addition |
| US5783628A (en) * | 1996-03-07 | 1998-07-21 | Dai-Ichi Kogyo Seiyaku Co., Ltd. | Modified polyvinyl alcohol |
| KR102447937B1 (en) * | 2018-07-23 | 2022-09-27 | 주식회사 엘지화학 | Preparation method for 2-cyanoethyl group-containing polymer |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE563086A (en) * | 1956-12-11 |
-
1987
- 1987-12-07 CA CA000553633A patent/CA1328031C/en not_active Expired - Fee Related
- 1987-12-15 NO NO875231A patent/NO172647C/en unknown
- 1987-12-15 GB GB8729181A patent/GB2199834B/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| NO172647B (en) | 1993-05-10 |
| NO875231D0 (en) | 1987-12-15 |
| NO172647C (en) | 1993-08-18 |
| GB2199834B (en) | 1991-05-22 |
| GB8729181D0 (en) | 1988-01-27 |
| GB2199834A (en) | 1988-07-20 |
| NO875231L (en) | 1988-06-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |