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Patented Dec..31,_1946
2,413,463
UNITED’ STATES PATENT OFFICE
METHOD FOR PREPARING SOLUBLE
ALLYL STABOH
.
Peter L. Nichols, Jr., Philadelphia, Philip E. Meiss,
Fort Washington,
_
and Elias Yanovsky, Phila
delphia, Pa., assignors to the United States of
America as represented by the Secretary of
Agriculture
No‘Dr-awing. Application April 20, 1944,
Serial No. 531,971
8 Claims. (Cl. 260—209)
(Granted under the m‘ of March 3, 1883, as
amended April 30, 1928; 370 0. G. 757)‘
2
This application is _made under the act of
.
I March 3, 1883, as amended by the act of April
30, 1928, and the invention herein described, it
Water _____________________________ __cc__ 67
Sodium hydroxide __________________ __g__ 100
patented, may be manufactured and used by or
for the Government of the United States vof
America for governmental purposes without the
payment to us of any royalty thereon.
This invention relates to the preparation of
Starch
g _
50
Allyl bromide ___________ _'_ __________ __g__ 300
This mixture was refluxed on hot water bath
for 8 hours. The resulting product had about 1.5
allyl groups per glucose unit.
soluble allyl starch, and has among its objects
-
_
Acetone ___________________________ __cc__ 250
the. provision of an improved method of prepar
ing soluble allyl starch.
Example I
.
,
Example II
We have found that organic solvent soluble
allyl starch can be readily obtained if rapid oxida
Water _____________________________ __cc__. 67
tion and/or polymerization of the allyl starch
Sodium hydroxide __________________ __g__ 100
formed during the allylation reaction is pre 15 Starch _____________________________ __g__ 50
vented, Organic solvent soluble allyl starch if
Methylethyl ketone ______________ __.___cc__ 250
left exposed to air will, after a period of time,
Allyl bromide ______________________ __g__ 300
become coated with an insoluble layer. On the
other hand, if the soluble allyl starch is dissolved
This mixture was re?uxed on hot water bath
in acetone, it will keep for a long time without 20 for 10 hours. The resulting product had about
2.2 allyl groups per glucose unit.
change in its properties. It can be precipitated
from the acetone solution by water and the origi
Example III
nal product is obtained. In the application for
patent of Robert M. Hamilton and Peter L.
Water _____________________________ __cc__ 26
Nichols, Jr., Serial No. 518,976, ?led January 20, 25
Sodium hydroxide __________________ __g__
40
1944, a new method of preparing allyl starch is
Potato dextrin ______________________ __g__ 20
described which yields a product soluble in a
Methylethyl ketone _'_ _______________ __cc__ 100
Allyl bromide ________________ _i _____ __g__ 120
great many organic solvents. The success in ob
taining organic solvent soluble allyl starch by
mixture was re?uxed on hot water bath
the method described in that application is due 30 forThis
5 hours. The resulting product had about 2.1
in part to the fact that the allyl starch formed
allyl groups per glucose unit.
is immediately dissolved in acetone present in
Example IV
the reaction mixture. The disadvantage of this
method is that it requires a two-step process;
Water
Pc__ 61
namely, preparation of the acetate of the carbo 35 Sodium hydroxide ___________________ __g__ 100
hydrate followed by hydrolysis and allylation of
Thin-boiling starch __________________ __g__
the acetate. We have found that starch can be
Methylethyl ketone ____________ _'_ ____ __cc__ 250
allylated directly, provided strong alkali is used
Allyl bromide
g
56
300
and an organic solvent for allyl starch is present 40
This mixture was re?uxed on hot water bath
in the reaction. This solvent can be acetone,
for 5 hours. The resulting product had about 1.5
ethyl methyl ketone, benzene or any other organic
allyl groups per glucose unit.
solvent for allyl ether of starch. The starch can
'
Emample V
be any native starch, such as corn starch,
potato starch, Wheat‘starch, and so forth, or a 45 Water
.
_
cc__
52
modi?ed starch, such as thin boiling starches,
Sodium hydroxide
g
80
dextrines, and oxidized starches.
Starch
"
_'__g__
40
The examples given below illustrate reaction
mixtures which can be used in the preparation
50
of allyl starch ether by this method.
I
Acetone
Pl‘
100
Allyl ch1oride_________-_.._____________cc__ 82
This mixture was heated in autoclave at 85° C. ,
2,418,483
4
' 3
1.5 allyl' groups per glucose unit.
.
2. The process or preparing organic solvent
soluble allyl starch which comprises allylating
for six hours. The resulting product had about.
.
starch with an allyl halide in the presence or
All of the products obtained above were soluble
concentrated alkaline solution and an organic‘
in acetone and various other organic solvents.
solvent
for the allyi starch.
in
With each of them, 30 to 50 percent solutions
3. The process of preparing organic solvent
could be readily prepared. Also, by varying the
soluble allyl starch which comprises allylating
time or temperature of the reaction, and the rela
starch with allyl bromide in the presence of con
.tive amounts of starch and allyl halide used,
centrated sodium hydroxide solution and an or
' products of various degree of solubility and of '
ganic solvent for the allyl starch.
various degress of viscosity could be obtained.
The various ingredients oi-t-h'e reaction mix
ture can be mixed in several ways.
.
times preferable to make alkali starch (a solu
tion of starch in alkali which is allowed to set to
'a solid) in a separate container, and then put it
in the reaction ?ask and add the other reagents.
The alkali starch can also be prepared in the
4. The process of preparing organic solvent
soluble allyi starch which comprises allylating
starch with allyl chloride in the presence or con
It is some
' centrated'sodium hydroxide solution and ‘an or
reaction ?ask, followed by addition of the other
reagents. A third alternative is to mix all of the
reagents simultaneously, in which case, however,‘
a stouter stirrer is required. After the reaction
is over, the mixture is poured into a large volume
of water and the separated allyl starch is washed
until free from alkali. Or, the mixture is poured ‘
ganic solvent for the allyl starch.
_ 5. The process of preparing allyl starch which
comprises allylating starch in the presence of
concentrated alkaline solution and a lower alkyl
ketone.
‘
6. The process otpreparing allyi starch which
comprises allylating starch with an allyl halide
in the presence of concentrated alkaline solution
and a lower alkyl ketone.
'7. The process of preparing allyl starch which
into water and steam distilled, the excess of ‘allyl 25 comprises ailylating starch with allyl bromide inv
the presence of concentrated sodium hydroxide
solution and a lower alkyl ketone.
8. The process of preparing allyi starch which
comprises
allylating starch with allyl chloride in
either as powder or a gummy mass.
Having thus described our invention, we claim: 30 the presence or concentrated sodium hydroxide
solution and a lower alkyl ketone.
1. The process of preparing organic solvent
-halide and the acetone is recovered, and the
separated allyl starch is then thoroughly washed
until free from alkali. Allyl starch is obtained
soluble allyl starch which comprises allylating‘
starch in the presence of concentrated alkaline
solution and an organic solvent for the allyl
.35
starch.
PETER L. NICHOLS, JR.
PHILIP E. MEISS.
ELIAS YANOVSKY.
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