Title of Invention	HIGH PERFORMANCE FLOCCULATING AGENTS AND VISCOSIFIERS BASED ON HYDROLYSED GRAFTED AMYLOPECTIN AND POLYACRYLAMIDE GRAFTED CARBOXYMETHYL CELLULOSE
Abstract	The invention relates to a process for the preparation of hydrolysed graft copolymers comprising preparing a solution of polysaccharide selected from carboxy-methylcellulose and amylopectin and adding acrylamide monomer thereto with stirring, followed by addition of a catalyst solution thereto and allowing the reaction to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to alkaline hydrolysis to obtain the hydrolysed graft copolymer. This invention further relates to hydrolyzed grafted copolymers for use as flocculants, viscosifiers and drag reducers.

Title of Invention

HIGH PERFORMANCE FLOCCULATING AGENTS AND VISCOSIFIERS BASED ON HYDROLYSED GRAFTED AMYLOPECTIN AND POLYACRYLAMIDE GRAFTED CARBOXYMETHYL CELLULOSE

Abstract

The invention relates to a process for the preparation of hydrolysed graft copolymers comprising preparing a solution of polysaccharide selected from carboxy-methylcellulose and amylopectin and adding acrylamide monomer thereto with stirring, followed by addition of a catalyst solution thereto and allowing the reaction to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to alkaline hydrolysis to obtain the hydrolysed graft copolymer. This invention further relates to hydrolyzed grafted copolymers for use as flocculants, viscosifiers and drag reducers.

Full Text	FIELD OF THE INVENTION This invention relates to hydrolysed graft copolymers and a process for the preparation thereof this invention further relates to hydrolysed graft copolymers for use as flocculating, viscosifiers and drag reducing agents. BACKGROUND OF THE INVENTION There are various types of known biodegradable flocculants, most of them are natural ones. Starch, Guar gum, algenic acid, carboxymethyl cellulose, hydroxypropyl guar gum etc, are the natural flocculants. The synthetic flocculants are PAM, poly (ethylene oxide), poly (dially dimethyl ammonium chloride), poly (acrylic acid) etc. Synthetic polymers are much more effective than the natural polymers, which is attributed to the easy tailorabiliry of the man made polymers. But the biggest drawback is their shear degradability. However, thy great advantage of natural polymers over synthetic ones is their low cost, non-toxicity, biodegradabiiity and shear resistance characteristics. They were obtained from the crop products or from trees extruder. Some of them are also produced by microbial roots. Therefore, the quantities obtained are also limited by availability of the sources. These and other objections of the invention will be apparent from the ensuing description. DESCRIPTION OF THE INVENTION According to this invention is provided hydroiysed graft copolymers for use as flocculants, drag reducers and viscosifiers. According to this invention is further provided a process for the preparation of hydroiysed graft copolymers comprising preparing a solution of polysaccharide selected from carboxy-methylcellulose and amylopectin and adding acrylamide monomer thereto with stirring, followed by addition of a catalyst solution thereto and allowing the reaction to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to alkaline hydrolysis to obtain the hydroiysed graft copolymer. In accordance with this invention, the catalyst used may be compounds of inner-transition elements such as Cerium (IV) preferably cerric ammonium nitrate (CAN). The polysaccharide used may be amylopectin (AP) and carboxymethylcellulose, (CMC) and the acrylamide may be substituted or unsubstituted acrylamide compounds. The reaction is generally carried out at a temperature in the range of 25 to 35 oC, preferably 30 °C and is conducted over 20 to 30 hrs, at atmospheric pressure. 10 to 20 gms of acrylamide are used for every 2 to 2.5 gm of the polysaccharide. 0.8 to 0% 2 x 10 -3 moles of CAN is used for every 0.4 to 0.6 gms of AP-g-PAM and 0.1 to 0.3 x 10 -3 moles of CAN are used every 0.4 to 0.6 moles of CMC-g-PAM. Hydrolysis is carried out in the usual manner, using an alkali such as sodium hydroxide. The invention will now be explained in greater deatils with the help of the following non- limiting examples. EXAMPLES Synthesis of CMC-g-PAM graft copolymer The applicants have synthesized CMC-g-PAM graft copolymer by grafting PAM onto the CMC backbone by using CAN (cerie ammonium nitrate) as initiator. First 2 gm of purified CMC was dissolved in 150 cc of distilled water in a conical flask- It was stirred with a magnetic stirrer and heated to 60 °C wife simultaneous stirring. It was cooled down to room temperature. Then, 10 to 20 gm of acrytamide was dissolved to 125 cc of distilled water and mixed with CMC solution. The mixture solution was stirred with a magnetic stirrer. The solution was then flushed with nitrogen gas for 25 minutes. At this stage desired quantity of 25 cc of CAN solution was added to the reaction mixture followed by further purging with nitrogen gas for 10 minutes. The reaction mixture was maintained at 28+0.1°C by immersing the flask in constant temperature bath. The reaction was allowed to continue for 24 hours. At the end of the reaction., the resulting polymer was taken into a IL beaker, where it. was made into homogenous slurry with further addition of distilled water. The graft copolymer was extracted by formamide and acetic acid mixture (1:1 by volume) in order to remove the homopolymer. The graft copolymer was taken in a 500 ml beaker. Then 200 ml of the solvent was added to it and then it was kept at 40 °C for 12 hours. After that the mixture was filtered using Buchner funnel. The residue is washed with same solvent mixture for ten times and in every time the filtrate was checked with acetone whether there was a precipitation of polyacrylamide or not. After washing, the graft copolymer was again washed with methanol to remove the solvent. It was then kept into methanol for 24 hours. After that it was dried in a vacuum over at 70 °C. Alkaline hydrolysis of CM-g-PAM .5 gm of CMC-g-PAM was dissolved in 500 cc of distilled water. Then, 25 ml to 100 ml of 1 (IN) KOH solution was added to it. The mixture solution was then placed in a thermostated water bath at specified temperature. After 1 hour, the content of the flask was taken out and poured into IL of ethyl alcohol. The product was filtered and washed with ethanol-water (70:30) and finally with ethanol. It was then dried. Synthesis of AP-g-PAM graft copolymer First 2.5 gm of amylopectin was put into a conical flask with 100 cc of distilled water. It was stirred with a magnetic stirrer and heated to 80 °C with simultaneous stirring. It was cooled down to room temperature. The 15 gm of acrylamide was dissolved in 75 cc of distilled water and was mixed with the amylopectin solution. Then the conical flask was fitted with the nitrogen inlet and outlet tubes and oxygen free nitrogen was purged through the solution for 20 minutes. At this stage, 25 cc of catalyst solution (0.22 g of CAN in 100 cc of distilled water) was added in the reaction mixture, followed by further purging with nitrogen for 10 minutes. Then the nitrogen inlet tube was taken out and the flask was sealed. The reaction was allowed to continue for 24 hours. At the end of the reaction, the resulting polymer was taken into a IL beaker, where it. was made into homogeneous slurry with further addition of distilled water. The reaction was terminated by adding sutured solution of hydroquiuone. The viscous polymer slurry was then precipitated by adding excess of acetone and then dried in a vacuum oven at. 60 °C. Finally it was pulverized and sieved. The unreacted homopolymer was removed by using formamide and acetic acid mixture (1:1 by volume) as above. Alkaline hydrolysis of AP-g-PAM In a similar way, we synthesized hydrolysed AP-g-PAM. It was also hydrolysed in similar way, by adding 1 (N) NaOH solution. At first 5 gm of AP-g-PAM was dissolved in 500 cc of distilled water. To this mixture 50 ml to 100 ml of 1 (N) NaOH solution was added. After 2 hours the content of the glask was poured into IL of ethyl alcohol. Finally it was precipitated with alcohol as above and dried. It has been observed that, this alkaline hydrolysed graft copolymer perform better fioceulation characteristics man the other biodegradable floceulants known earlier. It has been observed very recently that the shear viscosity of optimally hydrolysed polyacrylamide grafted amylopectin and carboxymethyl cellulose in several hundered times then the polyacrylamide grafted amylopectin and carboxymethyl cellulose. As amylopectin and carboxyamethyl cellulose are abundantly available from renewable resources, amylopectin and carboxymethyl cellulose based fiocculants, drag reducers and viscosifiers would go a long way in their applications for treatment of industrial effluents and various other technical applications at natural and international levels. WE CLAIM: 1. A process for the preparation of hydrolysed graft copolymers comprising preparing a solution of polysaccharide selected from carboxy-raethylcellulose and amylopectin mid adding aerylamide monomer thereto with stirring, followed by addition of a catalyst solution thereto and allowing the reaction to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to alkaline hydrolysis to obtain the hydrolysed graft copolymer. 2. The process as claimed in claim 1, wherein said polysaccharide is for eg. amylopectin and carboxymethylcetlulose. 3. The process as claimed in claim 1, wherein the acrylamide is a substituted or unsubstituted acrylamide. 4. The process as claimed in claim 2, wherein (he catalyst is a cerium (IV) compound such as cerric ammonium nitrate. 5. The process as claimed in claim 1, wherein the reaction is conducted at a temperature in the range of 25-35 °C, preferably at 30°C. 6. The process as claimed in claim 1, wherein the reaction is carried out over a period of 20-30 hrs., preferably 24 hrs. 7. The process as claimed in claim 1, wherein the reaction is conducted at atmospheric pressure. 8. The process as claimed in claim 1, wherein the reaction mixture is purged with a gas such as nitrogen before and after addition of the catalyst. 9. The process as claimed in claim 1, wherein the reaction mixture is purged with a gas such as nitrogen for 10-30 mitts., preferably 20 mins., before and after the addition of the catalyst. 10. The process as claimed in claim 1, wherein said acrylamide is used in a proportion of 10 to 20 gms per 2 to 2.5 gms of the polysaccharide. 11. The process as claimed in claim 1, wherein 0.8 to 0.12 x 10-3 moles of catalyst is used per 0.4 to 0.6 gms of AP-g-PAM and 0.1 to 0.3 x 10-3 moles of catalyst is used per 0.4 to 0.6 gms of CMC-g-PAM. 12. The process for the preparation of a graft copolymer for use as a flocculating agent substantially as herein described and illustrated. 13. The process as claimed in claim 1, wherein for the step of hydrolysis, an alkali solution is used. 14. Hydrolysed grafted copolymers for use as flocculants, viscosifiers and drag reducers. ') 15. Hydrolysed grafted copolymers as claimed in claim 14, wherein said graft copolymers are polyacryiamide grafted polysacchamide such as polyacrylamide grafted amylopectm and polyacryiamide grafted carboxymethylcellulose. The invention relates to a process for the preparation of hydrolysed graft copolymers comprising preparing a solution of polysaccharide selected from carboxy-methylcellulose and amylopectin and adding acrylamide monomer thereto with stirring, followed by addition of a catalyst solution thereto and allowing the reaction to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to alkaline hydrolysis to obtain the hydrolysed graft copolymer. This invention further relates to hydrolyzed grafted copolymers for use as flocculants, viscosifiers and drag reducers.

Full Text

FIELD OF THE INVENTION
This invention relates to hydrolysed graft copolymers and a process for the preparation
thereof this invention further relates to hydrolysed graft copolymers for use as
flocculating, viscosifiers and drag reducing agents.
BACKGROUND OF THE INVENTION
There are various types of known biodegradable flocculants, most of them are natural
ones. Starch, Guar gum, algenic acid, carboxymethyl cellulose, hydroxypropyl guar gum
etc, are the natural flocculants. The synthetic flocculants are PAM, poly (ethylene oxide),
poly (dially dimethyl ammonium chloride), poly (acrylic acid) etc. Synthetic polymers
are much more effective than the natural polymers, which is attributed to the easy
tailorabiliry of the man made polymers. But the biggest drawback is their shear
degradability. However, thy great advantage of natural polymers over synthetic ones is
their low cost, non-toxicity, biodegradabiiity and shear resistance characteristics.
They were obtained from the crop products or from trees extruder. Some of them are also
produced by microbial roots. Therefore, the quantities obtained are also limited by
availability of the sources.
These and other objections of the invention will be apparent from the ensuing description.
DESCRIPTION OF THE INVENTION
According to this invention is provided hydroiysed graft copolymers for use as
flocculants, drag reducers and viscosifiers.
According to this invention is further provided a process for the preparation of
hydroiysed graft copolymers comprising preparing a solution of polysaccharide selected
from carboxy-methylcellulose and amylopectin and adding acrylamide monomer thereto
with stirring, followed by addition of a catalyst solution thereto and allowing the reaction
to continue, to obtain the graft copolymers, followed by subjecting the graft copolymer to
alkaline hydrolysis to obtain the hydroiysed graft copolymer.
In accordance with this invention, the catalyst used may be compounds of inner-transition
elements such as Cerium (IV) preferably cerric ammonium nitrate (CAN).
The polysaccharide used may be amylopectin (AP) and carboxymethylcellulose, (CMC)
and the acrylamide may be substituted or unsubstituted acrylamide compounds. The
reaction is generally carried out at a temperature in the range of 25 to 35 oC, preferably
30 °C and is conducted over 20 to 30 hrs, at atmospheric pressure.
10 to 20 gms of acrylamide are used for every 2 to 2.5 gm of the polysaccharide. 0.8 to
0% 2 x 10 -3 moles of CAN is used for every 0.4 to 0.6 gms of AP-g-PAM and 0.1 to 0.3
x 10 -3 moles of CAN are used every 0.4 to 0.6 moles of CMC-g-PAM.
Hydrolysis is carried out in the usual manner, using an alkali such as sodium hydroxide.
The invention will now be explained in greater deatils with the help of the following non-
limiting examples.
EXAMPLES
Synthesis of CMC-g-PAM graft copolymer
The applicants have synthesized CMC-g-PAM graft copolymer by grafting PAM onto the
CMC backbone by using CAN (cerie ammonium nitrate) as initiator. First 2 gm of
purified CMC was dissolved in 150 cc of distilled water in a conical flask- It was stirred
with a magnetic stirrer and heated to 60 °C wife simultaneous stirring. It was cooled
down to room temperature. Then, 10 to 20 gm of acrytamide was dissolved to 125 cc of
distilled water and mixed with CMC solution. The mixture solution was stirred with a
magnetic stirrer. The solution was then flushed with nitrogen gas for 25 minutes. At this
stage desired quantity of 25 cc of CAN solution was added to the reaction mixture
followed by further purging with nitrogen gas for 10 minutes. The reaction mixture was
maintained at 28+0.1°C by immersing the flask in constant temperature bath. The
reaction was allowed to continue for 24 hours. At the end of the reaction., the resulting
polymer was taken into a IL beaker, where it. was made into homogenous slurry with
further addition of distilled water. The graft copolymer was extracted by formamide and
acetic acid mixture (1:1 by volume) in order to remove the homopolymer. The graft
copolymer was taken in a 500 ml beaker. Then 200 ml of the solvent was added to it and
then it was kept at 40 °C for 12 hours. After that the mixture was filtered using Buchner
funnel. The residue is washed with same solvent mixture for ten times and in every time
the filtrate was checked with acetone whether there was a precipitation of polyacrylamide
or not. After washing, the graft copolymer was again washed with methanol to remove
the solvent. It was then kept into methanol for 24 hours. After that it was dried in a
vacuum over at 70 °C.
Alkaline hydrolysis of CM-g-PAM
.5 gm of CMC-g-PAM was dissolved in 500 cc of distilled water. Then, 25 ml to 100 ml
of 1 (IN) KOH solution was added to it. The mixture solution was then placed in a
thermostated water bath at specified temperature. After 1 hour, the content of the flask
was taken out and poured into IL of ethyl alcohol. The product was filtered and washed
with ethanol-water (70:30) and finally with ethanol. It was then dried.
Synthesis of AP-g-PAM graft copolymer
First 2.5 gm of amylopectin was put into a conical flask with 100 cc of distilled water. It
was stirred with a magnetic stirrer and heated to 80 °C with simultaneous stirring. It was
cooled down to room temperature. The 15 gm of acrylamide was dissolved in 75 cc of
distilled water and was mixed with the amylopectin solution. Then the conical flask was
fitted with the nitrogen inlet and outlet tubes and oxygen free nitrogen was purged
through the solution for 20 minutes. At this stage, 25 cc of catalyst solution (0.22 g of
CAN in 100 cc of distilled water) was added in the reaction mixture, followed by further
purging with nitrogen for 10 minutes. Then the nitrogen inlet tube was taken out and the
flask was sealed. The reaction was allowed to continue for 24 hours. At the end of the
reaction, the resulting polymer was taken into a IL beaker, where it. was made into
homogeneous slurry with further addition of distilled water. The reaction was terminated
by adding sutured solution of hydroquiuone. The viscous polymer slurry was then
precipitated by adding excess of acetone and then dried in a vacuum oven at. 60 °C.
Finally it was pulverized and sieved.
The unreacted homopolymer was removed by using formamide and acetic acid mixture
(1:1 by volume) as above.
Alkaline hydrolysis of AP-g-PAM
In a similar way, we synthesized hydrolysed AP-g-PAM. It was also hydrolysed in
similar way, by adding 1 (N) NaOH solution. At first 5 gm of AP-g-PAM was dissolved
in 500 cc of distilled water. To this mixture 50 ml to 100 ml of 1 (N) NaOH solution was
added. After 2 hours the content of the glask was poured into IL of ethyl alcohol. Finally
it was precipitated with alcohol as above and dried.
It has been observed that, this alkaline hydrolysed graft copolymer perform better
fioceulation characteristics man the other biodegradable floceulants known earlier. It has
been observed very recently that the shear viscosity of optimally hydrolysed
polyacrylamide grafted amylopectin and carboxymethyl cellulose in several hundered
times then the polyacrylamide grafted amylopectin and carboxymethyl cellulose.
As amylopectin and carboxyamethyl cellulose are abundantly available from renewable
resources, amylopectin and carboxymethyl cellulose based fiocculants, drag reducers and
viscosifiers would go a long way in their applications for treatment of industrial effluents
and various other technical applications at natural and international levels.
WE CLAIM:
1. A process for the preparation of hydrolysed graft copolymers comprising
preparing a solution of polysaccharide selected from carboxy-raethylcellulose and
amylopectin mid adding aerylamide monomer thereto with stirring, followed by
addition of a catalyst solution thereto and allowing the reaction to continue, to
obtain the graft copolymers, followed by subjecting the graft copolymer to
alkaline hydrolysis to obtain the hydrolysed graft copolymer.
2. The process as claimed in claim 1, wherein said polysaccharide is for eg.
amylopectin and carboxymethylcetlulose.
3. The process as claimed in claim 1, wherein the acrylamide is a substituted or
unsubstituted acrylamide.
4. The process as claimed in claim 2, wherein (he catalyst is a cerium (IV)
compound such as cerric ammonium nitrate.
5. The process as claimed in claim 1, wherein the reaction is conducted at a
temperature in the range of 25-35 °C, preferably at 30°C.
6. The process as claimed in claim 1, wherein the reaction is carried out over a
period of 20-30 hrs., preferably 24 hrs.
7. The process as claimed in claim 1, wherein the reaction is conducted at
atmospheric pressure.
8. The process as claimed in claim 1, wherein the reaction mixture is purged with a
gas such as nitrogen before and after addition of the catalyst.
9. The process as claimed in claim 1, wherein the reaction mixture is purged with a
gas such as nitrogen for 10-30 mitts., preferably 20 mins., before and after the
addition of the catalyst.
10. The process as claimed in claim 1, wherein said acrylamide is used in a
proportion of 10 to 20 gms per 2 to 2.5 gms of the polysaccharide.
11. The process as claimed in claim 1, wherein 0.8 to 0.12 x 10-3 moles of catalyst is
used per 0.4 to 0.6 gms of AP-g-PAM and 0.1 to 0.3 x 10-3 moles of catalyst is
used per 0.4 to 0.6 gms of CMC-g-PAM.
12. The process for the preparation of a graft copolymer for use as a flocculating
agent substantially as herein described and illustrated.
13. The process as claimed in claim 1, wherein for the step of hydrolysis, an alkali
solution is used.
14. Hydrolysed grafted copolymers for use as flocculants, viscosifiers and drag
reducers. ')
15. Hydrolysed grafted copolymers as claimed in claim 14, wherein said graft
copolymers are polyacryiamide grafted polysacchamide such as polyacrylamide
grafted amylopectm and polyacryiamide grafted carboxymethylcellulose.

The invention relates to a process for the preparation of hydrolysed graft
copolymers comprising preparing a solution of polysaccharide selected
from carboxy-methylcellulose and amylopectin and adding acrylamide
monomer thereto with stirring, followed by addition of a catalyst solution
thereto and allowing the reaction to continue, to obtain the graft
copolymers, followed by subjecting the graft copolymer to alkaline
hydrolysis to obtain the hydrolysed graft copolymer.
This invention further relates to hydrolyzed grafted copolymers for use as
flocculants, viscosifiers and drag reducers.

Documents:

196-kol-2003-granted-abstract.pdf

196-kol-2003-granted-claims.pdf

196-kol-2003-granted-correspondence.pdf

196-kol-2003-granted-description (complete).pdf

196-kol-2003-granted-examination report.pdf

196-kol-2003-granted-form 1.pdf

196-kol-2003-granted-form 18.pdf

196-kol-2003-granted-form 2.pdf

196-kol-2003-granted-form 3.pdf

196-kol-2003-granted-form 5.pdf

196-kol-2003-granted-gpa.pdf

196-kol-2003-granted-reply to examination report.pdf

196-kol-2003-granted-specification.pdf

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Patent Number

233669

Indian Patent Application Number

196/KOL/2003

PG Journal Number

14/2009

Publication Date

03-Apr-2009

Grant Date

01-Apr-2009

Date of Filing

01-Apr-2003

Name of Patentee

INDIAN INSTITUTE OF TECHNOLOGY

Applicant Address

AN INDIANINSTITUTE OF KHARAGPUR 721 302,

Inventors:

#	Inventor's Name	Inventor's Address
1	SINGH R. P.	MATERIAL, SCIENCE CENTRE TECHNOLOGY, KHARAGPUR 721 302
2	BISWAL DIPTIRANI	MATERIAL, SCIENCE CENTRE TECHNOLOGY, KHARAGPUR 721 302

PCT International Classification Number

C08F 32C

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA