Synthesis and surface active properties of novel carbohydrate-based cationic surfactants

Article abstract of DOI:10.1007/s11743-010-1225-4

The synthesis of new cationic carbohydrate surfactants is presented in this paper. The obtained surfactants have structures that are typical for saponins, which contain fatty amide hydrophobic chains and hydrophilic heads with cationic carbohydrate units. Their surface active properties and biodegradability have been studied. For two types, the biodegradability was above 85% and comparable to standard carbohydrate surfactants. AOCS 2010.

Full text of DOI:10.1007/s11743-010-1225-4

J Surfact Deterg (2011) 14:179–184
DOI 10.1007/s11743-010-1225-4
ORIGINAL ARTICLE
Synthesis and Surface Active Properties of Novel
Carbohydrate-based Cationic Surfactants
•
Janusz Nowicki Adam Sokołowski
•
Dagmara Reksa
Received: 23 December 2009 / Accepted: 20 July 2010 / Published online: 21 August 2010
ꢀ AOCS 2010
Abstract The synthesis of new cationic carbohydrate
surfactants is presented in this paper. The obtained sur-
factants have structures that are typical for saponins, which
contain fatty amide hydrophobic chains and hydrophilic
heads with cationic carbohydrate units. Their surface active
properties and biodegradability have been studied. For two
types, the biodegradability was above 85% and comparable
to standard carbohydrate surfactants.
They are very similar to each other in regards to their
properties.
Research on carbohydrate surfactants have been inten-
sively promoted, and studies are oriented not only on
nonionic surfactants but on ionic surfactants as well,
because of their advantageous environmental performance.
Many reports have been published in recent years on the
synthesis of numerous interesting cationic surface active
compounds which contained carbohydrate segments in
their structures. Those compounds offer specific properties
and fields of applications; their main outlets are: compo-
nents of personal care products, flocculating and dispersing
agents. Carbohydrate ethers with reactive alkylhalide
groups make intermediates in the production of many of
them.
Keywords Cationic surfactants ꢀ Surface activity ꢀ
Synthesis
Introduction
Carbohydrate surfactants make up a very important group
of surface active compounds. Their principal advantage
results from the fact that they are based on natural and
renewable resources. Attention was paid fairly long ago to
the possibility of using carbohydrate segments to substitute
the hydrophilic section, which contained polyoxyethylene
chains in traditional surface active compounds. Extensive
research in that area was conducted as early as over
40 years ago [1]. Processes were then developed for the
synthesis of basic groups of carbohydrate surfactants.
Apart from alkylpolyglucosides, alkylglucamides may be
classified as the most popular carbohydrate surfactants [2].
A key stage in their synthesis is the etherification of
glucose or other carbohydrates with aliphatic chlorohydr-
oxyl compounds, such as: diethylene chlorohydrin, glycerol
chlorohydrin, 2-chloroethanol or 3-chloro-1,2-propanediol
[3–5]. The etherification of glucose with diethylene chlo-
rohydrin gives a corresponding ether. This is then subjected
to amination with dodecyl and to quaternisation with methyl
chloride to yield the product 1, which may be used in pre-
paring hair and body care formulations.
OH
H
O
HO
HO
CH3
OH
Cl
R
OCH2CH2OCH2CH2N
CH3
J. Nowicki (&)
Institute of Heavy Organic Synthesis ‘‘Blachownia’’,
1
´
ul. Energetykow 9, 47-225 Ke˛dzierzyn Kozle, Poland
e-mail: nowicki.j@icso.com.pl
´
The same ether, in the reaction with 3-(N,N-dimethyl-
amino)-propylamide of methacrylic acid, will yield a cat-
ionic monomer. Its polymerisation will produce a polymer
with very good hair and body care properties [3].
A. Sokołowski ꢀ D. Reksa
Faculty of Chemistry, Wrocław University of Technology,
Wrocław, Poland
123

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J Surfact Deterg (2011) 14:179–184
Analogical monomers were also obtained when ether was
used which had been produced from carbohydrates and
3-chloro-1,2-propanediol
The post-reaction mixture was analysed by the liquid
chromatography method (HPLC), with the use of the GPC
technique, for which the HP 1050 chromatograph with the
RI4 detector (Varian) was employed. A chromatographic
column Asahipak GF-310HQ 7.6 9 300 mm (Showa
Denko, Japan) and DMF (with the admixture of 0.8% m/v
of lithium chloride) as the eluent were used to separate the
components. The eluent flow rate was adjusted to 0.5 ml/
min and the column temperature was 40 ꢁC. The samples
of raw materials and products were dissolved in the eluent
at the concentrations of 1% m/v (products) and 0.5% m/v
(raw materials). The Cl- content was determined by the
potentiometric method, with the use of AgNO3 solution.
[4].
Another type of surface active compounds were derived
from the etherification product of glucose with 3-chloro-1-
propanol. That ether, when esterified with lauric acid and
then quaternised with trimethylamine in the presence of
NaJ, yields the product 2, which additionally offers the
softening properties [5].
Surface Tension Measurements
The surface active compounds as described above
comprise three specific structural fragments: carbohydrate
segment, cationic centre and hydrophobic fatty chain.
This paper describes the synthesis of novel carbohydrate
surfactants in which the etherification of a carbohydrate
compound with aliphatic chloroalcohols is also a key step.
The structures of novel surfactants are analogical to the
surface active agents which have been discussed earlier.
They were obtained according to the scheme shown in
Fig. 1.
The surface tension of novel surfactants was measured by
means of a Kru¨ss K100 tensiometer using the dynamic
Wilhelmy plate technique (DWPT), for various surfactant
concentrations, at 20 ꢁC. Demineralised water (conductiv-
ity \ 0.055 lS; surface tension = 72.8 mN/m) was used to
prepare the solutions; the water was purified in a deioni-
sation kit.
Biodegradability
The biodegradability of aqueous solutions of new surfac-
tants was verified according to the procedure ISO 9888:
1991 (static test, Zahn–Wallens method) and according to
the method which was provided in OECD Guidelines for
the Testing of Chemicals—OECD 302 B.
Experimental
Glucose was supplied by POCh. 3-(N,N-dimethylamino)-
1-propylamine, 2-chloroethanol, 3-chloro-1,2-propanediol
and palmitoyl chloride were supplied by Aldrich. All of these
chemicals were of reagent grade. Stearoyl chloride (99.5%)
was supplied by Chemical Factory ‘‘Zachem’’–Bydgoszcz.
Syntheses were conducted in thermostatted glass reactors
The biodegradability of new surfactants was studied for
1 wt % aqueous solutions, with the use of activated sludge
from a sewage treatment plant as the inoculum. Solutions
of compounds 5a and 5b were investigated. Their biode-
gradability was evaluated by measuring the changes in
COD over 28 days.
¨
delivered by Normschliff Geratebau (Germany).
Synthesis of Quaternary Surface Active Compounds
OH
OH
H
H
O
O
HO-X-CH2Cl
kat.
HO
HO
HO
HO
Synthesis of 3-(N,N-Dimethylamino)-1-Propylamides (3)
OH
OH
4a,b
O-X-CH2Cl
OH
25.5 g of dimethylpropylamine were dissolved in toluene
(450 ml) and that solution was charged to the reactor. The
nitrogen blow-in was then activated and acid chloride was
added dropwise. The temperature was maintained at 30 ꢁC.
When the addition of acid chloride had completed (after
about 1.5 h), the mixture was agitated for another 30 min
and it was left to stand until the next day. The obtained
suspension was transferred to the solution of 20 g NaOH in
500 ml of water. After a short agitation, the precipitate
which separated from the solution was filtered and dried.
The final product had the form of a white powder.
RCOCl + H2NCH2CH2CH2N(CH3)2
RCONCH2CH2CH2N(CH3)2
-HCl
3
5a, 5b X = CH2
6a, 6b X = CH2CHOH
R = C15, C17
OH
H
O
HO
HO
CH3
OH
O-X-CH2NCH2CH2CH2NCOR
CH3
Cl
5a,b
6a,b
Fig. 1 Scheme for the synthesis of novel surfactants
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J Surfact Deterg (2011) 14:179–184
181
Synthesis of Chloroalkyl Ethers of Glucose (4a, b)
0.36 mol of glucose (65 g), 1.8 mol of chloroalcohol and a
catalyst (Amberlyst 15, 9.3 g) were placed in the reactor.
The temperature was adjusted to 70 ꢁC (thermostat) and
agitation was started. After the glucose was dissolved
completely, the agitation action was continued for 1 h.
Complete conversion was also confirmed by no glucose
being present in the TLC chromatogram. The catalyst was
separated and the solution was concentrated at a tempera-
ture \90 ꢁC (2 mmHg) to obtain thick syrup. After cooling
the syrup down, it was washed with acetone (3 9 30 mL)
and the product was held at elevated temperature, under
nitrogen atmosphere, to remove the remaining solvent. The
obtained ether 4a, b had the form of a syrup which was
nearly colourless to yellow–brown, and which solidified at
room temperature.
Fig. 2 GPC chromatogram of 1-O-(2-chloroethyl)glucose 5a
The synthesis of chloroalkyl ethers of glucose has been
described previously [7]. Figure 2 presents the GPC chro-
matogram for ether 4a. The product, apart from glucose
and 2-chloroethanol (about 7% m/m), also contains 1-O-(2-
chloroethyl)glucose oligomers which were formed under
synthesis conditions. The composition of ether 4b was
similar.
Synthesis of Cationic Surfactants (5a, b and 6a, b)
The following components were placed in the reactor:
0.06 mol of ether 4 and 15 mL of water. These were agi-
tated at about 40 ꢁC until a homogeneous solution was
formed. Then, amide 3 was added (0.06 mol) with con-
tinuous mixing. The reactor content quickly became a very
thick paste, hence, the temperature was increased to 50 ꢁC.
After 6 h, complete conversion of ether was confirmed
(by the TLC method). The crude product was washed
twice with acetone to eliminate residual 2-chloroethanol or
3-chloro-1,2-propanediol and it was dried. The product had
the form of a white–grey paste.
These ethers were then subjected to quaternisation with
the use of amides 3, and cationic surfactants 5 and 6 were
obtained in that way.
OH
H
O
HO
HO
H
N
OH
N
R Cl
O
5a R=C15H31
5b R=C17H35
O
OH
H
O
HO
HO
OH
OH
H
N
Results and Discussion
O
N
R Cl
6a R=C15H31
6b R=C17H35
O
3-(N,N-dimethylamino)-1-propylamides were initially
synthesised with the use of triethylamine to absorb
hydrogen chloride which was evolved in the process. The
syntheses were conducted at 20–25 ꢁC and at the diami-
ne:acid chloride molar ratio of 1:0.9/1:1.1, and excess tri-
ethylamine in relation to diamine amounted for 20% m/m.
The yield of amides was 93.5–94.5%, but the product
purity (GC) was never better than 90%. Those amides may
also be produced in the classical Schotten–Baumann
reaction, in the aqueous-alkaline medium. However, that
method presented some difficulties at the stage of produce
recovery. The amide suspension was a fine-grained struc-
ture and its filtration was an onerous task. Another method
for the production of fatty amides is based on the synthesis
with the use of a solvent [6]. That method turned out to be
more efficient. Instead of harmful benzene, safer toluene
was used. The yield of amides was 93.4–94.6%, while the
product purity was over 99%.
The results of the synthesis of new surfactants are shown
in Table 1.
Table 1 Results of the synthesis of novel cationic surfactants
Product
Dry matter
(%)
Content of [Cl-]
(%)
Content of cationic
compoundsa (%)
5a
5a
6b
6b
a
82.1
84.1
82.6
83.8
4.31
5.21
3.24
4.22
96.0
96.5
97.9
98.1
Calculated on a dry weight basis
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J Surfact Deterg (2011) 14:179–184
Surface Active Properties
1. Surface excess:
1
occmc
Ccmc ¼ ꢁ
ꢀ
Determination of Surface Tension Isotherms
2:303RT o log Ccmc
2. Specific surface area:
Figures 3 and 4 show surface tension isotherms for the
novel surfactants. These isotherms were analysed to
establish the cmc values for all compounds. The results are
presented in Table 2.
1020
2
˚
Acmc
¼
ðA Þ;
N ꢀ Ccmc
N:Avogadro’s number ð6:022 ꢂ 1023Þ
Once established, those values made it possible to cal-
culate the following physical–chemical parameters which
describe individual surface active compounds:
3. Free energy of micellisation:
DGcmc ¼ 2:303RT log Ccmc ðkJ/molÞ
The calculation results are shown in Table 3.
75
70
Determination of the Krafft Point
The Krafft point values for novel surfactants were mea-
sured for C = 0.2% m/m, which corresponds to about
7 9 10-6 mol/L, so it is close to cmc. The weighed amount
of sample (content of active component 95–97% m/m) was
placed in 100 ml of distilled water and left to stand over-
night. The obtained suspension was heated up to complete
dissolution and then cooled down to 5 ꢁC. The Krafft point
was found when the sample was heated up at the rate of
4 ꢁC/min. The results are presented in Table 4.
65
5a
5b
60
55
50
45
40
35
30
Table 2 Results for cmc values
Compound
C (mol/L)
ccmc (mN/m)
-9
-8
-7
-6
-5
-4
-3
-2
-1
5.01 9 10-6
5.25 9 10-6
4.78 9 10-7
5.01 9 10-7
51.5
47.8
46.1
35.9
log C
5a
5b
6a
6b
Fig. 3 Surface tension vs. –log c (concentration) of compounds 5a
and 5b
75
70
65
60
Table 3 Surface properties of novel surfactants
2
Acmc (A )
˚
Compound
106 Ucmc (mol/m2)
DGcmc (kJ/mol)
5a
5b
6a
6b
1.17
1.05
4.25
2.15
141
157
39
29.93
29.82
35.70
35.58
55
50
45
40
35
30
6a
6b
76
Table 4 Krafft point values
Compound
C (mol/L)
Krafft point ( ꢁC)
5a
5b
6a
6b
7.1 9 10-6
6.9 9 10-6
7.0 9 10-6
7.4 9 10-6
30–32
[65
-9
-8
-7
-6
-5
-4
-3
-2
-1
log C
50–52
[65
Fig. 4 Surface tension vs. –log c (concentration) of compounds 6a
and 6b
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J Surfact Deterg (2011) 14:179–184
183
100
90
80
70
60
50
40
The following structural elements may be distinguished
in the novel surfactants:
•
Respectively big fragment with hydrophilic perfor-
mance which comes from glucose
Quaternary ammonium group
•
•
Hydrophobic fatty segment
Those compounds may be classified as cationic surfac-
tants with the extended hydrophilic constituent. The study
of the literature sources indicates that few compounds of
that type have been described. Based on the available
source reports, one may only draw some general conclu-
sions on the properties and potential applicability of such
compounds. Compounds with similar structures were
described in the patent [8] 7 and in the review [9].
2
4
6
8 10 12 14 16 18 20 22 24 26 28 30
days
Fig. 5 Biodegradability of surfactant 6a
OH
O
Moreover, the presence of a quaternary ammonium
group adds good germicidal and preservative properties to
such compounds [9]. Those features are essential in the
case of carbohydrate surface active compounds, for which
the addition of a preservative is required in many instances.
The obtained new surface active compounds also appear
to be favourable from the viewpoint of biodegradability.
Their biodegradability is compared with that of selected
carbohydrate surfactants below:
HO
HO
OH
O
Cl
N
N
7
CO - R
OH
O
HO
HO
CH3
OH
Cl
O-X-CH2NCH2CH2CH2NCOR
5a,b
6a,b
Biodegradability (%)
CH3
Esters of saccharose
Aldonamide C18
Aldonamide C12
Compound 5a
99–100
83 [9]
90 [9]
89
The patent, however, does not comment on the surface
active properties, but it only states that those compounds
offer some specific properties which make them recom-
mended for the hair conditioning formulations as well as
flocculants and pigment dispersants. The obtained new
compounds may also be taken as the saponin-type surfac-
tants [9].
Compound 6a
93
Figure 5 provides the biodegradation profile for the
surfactant 6a (aqueous solution with the concentration of
1% m/m) versus time. As can be seen, its maximum bio-
degradability can be achieved as soon as after only 14 days.
References
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surfactants: annual surfactants review, vol 2. CRC Press/Sheffield
Academic Press, Sheffield, UK
The saponin surfactants are used as components in hair
care products and as emulsifiers. The addition of a carbo-
hydrate radical may bring a number of advantageous
properties to such products, such as:
3. Donges R, Ehrler R (1986) Cationic unsaturated saccharides and
polymers prepared therefrom, and their use. European Patent
EP0166089
•
•
Better skin tolerance
Superior emulsifying performance etc.
123

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J Surfact Deterg (2011) 14:179–184
´ ´
obtained a Ph.D. at the Technical University of Łodz. His field of
research covers the organic synthesis of specialty organic chemicals
and heterogenous catalysis.
4. Papenfuhs B (1996) Acid addition compounds of fatty acid
polyhydroxy alkyl amides. German Patent 19 622 981.2
5. Kirk O, Pedersen FD, Fuglsang CC (1998) Preparation and
properties of a new type of carbohydrate-based cationic surfactant.
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United States Patent 4128485
7. Nowicki J, Poskrobko J (2004) Chemiczna modyfikacja glukozy
Adam Sokołowski (born 1941) studied chemistry from 1966 to 1971
at Wrocław University of Technology and received his Ph.D. at the
same university in 1977. He is presently a professor of chemistry in
the Department of Chemical Engineering. His work focuses on the
surface properties of binary phases, microemulsions and the engi-
neering of dispersed phases.
´
przy uz_yciu alifatycznych zwia˛zkow chlorohydroksylowych.
Przem Chem 83:84–86
8. Petit S (1999) Quaternary ammonium derivatives of amido
alditols, their preparation, compositions containing them and their
uses. European Patent application 895979
9. Malinka W (1999) Zarys chemii kosmetycznej. Volumed, Wrocław,
Poland
Dagmara Reksa (born 1983) graduated in 2008 from Wrocław
University of Technology, Faculty of Chemistry, where she is now a
Ph.D. student in the Department of Chemical Engineering. Her
research interests include the surface properties of binary phases,
microemulsions and ionic liquids as solvents.
Author Biographies
Janusz Nowicki (born 1954) graduated in 1978 from the Faculty of
Chemistry, Wrocław University of Technology, Poland. Since 1980,
he has worked at the Institute of Heavy Organic Synthesis
‘‘Blachownia’’ as a specialist in organic synthesis. In 1992, he
123