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IS0
I NT ERN AT1 ON AL ORGANIZATION FOR STANDARD I Z AT I ON
f'
IS0 RECOMMENDATION
R 896
SURFACE ACTIVE AGENTS
SCI ENT1 F IC C LASSI F ICATl ON
1 st EDITION
December 1968
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of thai country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 896, Surface active agents - Scientific classification, was drawn up by
Technical Committee lSO/TC 91, Surface acriue agents, the Secretariat of which is held by the Association
Française de Normalisation (AFNOR).
Work on this question led, in 1963, to the adoption of a Draft IS0 Recommendation.
In June 1965, this Draft IS0 Recommendation (No. 817) was circulated to all the IS0 Member Bodies
for enquiry. It was approved, subject to a few modifications of an editorial nature, by the following Member
.
Bodies :
Argentina France Portugal
Australia Germany South Africa, Rep. of
Austria
Hungary Spain
Belgium 1 re lan d Switzerland
Brazil Israel U.A.R.
Canada Italy United Kingdom
Chile Korea, Rep. of Yugoslavia
Colombia Netherlands
Czechoslovakia Poland
One Member Body opposed the approval of the Draft :
Romania
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council, which
decided, in December 1968, to accept it as an IS0 RECOMMENDATION.
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ISO/R 896-1%8(E)
CONTENTS
Page
5
Foreword .
6
1 . Scope .
6
2 . Field of application .
6
3 . Terminology .
6
4 . Principle .
1
7
5 . Rules of classification .
9
6 . Classification .
.............. 10
Table . Scientific classification of surface active agents
Annexes
13
A . Principle of classification .
Constitutive diagrams . 14
16
B . Rules of classification .
17
C . Detailed description of the elementsusedin the classification .
D . Considerations regarding the application of the decimal classification system for surface
active agents . 30
E . Reference classification on punched cards . 22
.
Appendix . Examples of the application of the classification . 26
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ISO/R 896-1%8(E)
FORE WO RD
The classification of surface active agents is intended to provide a clear and logical designation of the structural
chemical groups of a surface active agent, in the form of a decimal notation. Its aim is to describe a surface active
agent, considered in isolation, according to its chemical formula.
The classification is based on the polar/non-polar structure of surface active agents, which determines their
hydrophilic and lipophilic properties.
The traditional importance of water-soluble surface active agents leads to separate consideration of the hydrophilic
part and the hydrophobic part of the molecule. A surface active agent can be characterized by indicating these parts;
however, the extremely numerous possibilities of variation in the structure of the hydrophobic part make it necessary
to specify this part in some detail; the hydrophilic part, though structurally simpler, still needs to be defined by
certain of its characteristics, especially those responsible for solubility in water or in organic media.
The subdivision of the classification is, however, not taken far enough to enable one classification index number to
be considered as necessarily corresponding to a specific product (the classification is not a precise chemical nomen-
clature). On the contrary, it may be considered that in general several products, having chemical structures and
practical characteristics that are of necessity closely similar, will be designated by the same classification index
number. Moreover, the classification index number would enable one to reconstruct a molecular structure, which is
approximate but nevertheless sufficiently precise.
The application of the decimal classification is a matter for judgment, which is within the capacity of technicians with
an ordinary knowledge of the chemistry and technology of surface active agents. Rigorous application of the rules of
classification, and detailed study of the classification table are indispensable for establishing the classification index
number of a surface active agent, which should be obtained without any ambiguity.
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ISO/R 896-1%8(E)
IS0 Recommendation R 896 December 1968
SURFACE ACTIVE AGENTS
SCI ENT1 F IC C LASSI FI CATI ON
1. SCOPE
The purpose of this IS0 Recommendation is to set out a scientific classification of surface active agents.
2. FIELD OF APPLICATION
This classification applies both to surface active agents which are preferably used in an aqueous medium and to
those used in organic media.
3. TERMINOLOGY
Key hydrophilicgroup. Group embodying one and only one function which is considered as the most
3.1
important for the hydrophiiic behaviour of the surface active agent.
3.2 Secondary hydrophilic groups. Groups embodying functions with solubilizing properties other than those of
the key hydrophilic group; these serve only in a secondary manner to characterize further the surface active
agent.
3.3 Key hydrophobic residue (determining the hydrophobic behaviour of the surface active agent). Residue
comprising a radical of the hydrophobic type considered as a whole, along with direct substitutions. It should
be linked to the key hydrophilic group in a clearly definable way.
3.4 Characteristic hydrophobic residues. Chemical groups which are not more hydrophobic than the key hydro-
phobic residue to which they are functionally linked. They constitute either an intermediate connecting link
within the molecule itself or appear as a secondary hydrophobic residue attached to the rest of the molecule.
3.5 Intermediate functional groups. Groups occurring between the hydrophobic residue(s) and the key hydro-
philic group and joined to the latter either by a hydrocarbon link or a characteristic hydrophobic residue.
They provide supplementary characteristics for the hydrophobic part.
3.6 Supplementay properties of the hydrophilic part. Properties which make it possible to provide a fuller
description of the hydrophilic part and to give details either of its solubilizing properties in an aqueous medium,
or of its preferential behavioür of insolubility in water, for special use in organic media.
4. PRINCIPLE*
The classification of surface active agents enables them to be specified by the following characteristics defined in
section 3 :
(1) the key hydrophilic group;
(2) possibly, secondary hydrophilic groups;
(3) the key hydrophobic residue;
(4) possibly, characteristic hydrophobic residues;
(5) intermediate functional groups;
supplementary properties of the hydrophilie part,
(6)
See in Annex A, diagrams giving practical details of the principle of the classification.
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W
ISO/R 896-1%8(E)
5. RULES OF CLASSIFICATION
5.1 The classification of a surface active agent is governed by the determination of the key hydrophiiic group,
followed by the key hydrophobic residue. In order to avoid any ambiguity, these two elements should be
determined in accordance with the following rules :
Rule 1
THE KEY HYDROPHILIC GROUP IS THE FIRST PART CONSIDERED IN THE PREPARATION OF THE CLASSIFI-
CATION INDEX NUMBER CHARACTERIZING A SURFACE ACTIVE AGENT.
5.2 Hydrophilic groups can be classified in three groups :
-
hydrophilic groups with anionic properties,
-
hydrophilic groups with cationic properties,
-
hydrophilic groups with non-ionic properties.
Rule 2
THE CLASSIFICATION OF A SURFACE ACTIVE AGENT INTO ONE OF THE THREE FOREGOING GROUPS IS
EFFECTED BY MEANS OF THE FIRST THREE FIGURES :
--
the first relating to groups with anionic properties,
~
the second to groups with cationic properties and
-
the third to groups with non-ionic properties.
5.3 Where the surface active agents contain only one hydrophilic group, there is no possibility of ambiguity
Where they contain several of these groups, the following rules should be applied :
Rule 3
If the molecule contains more than one hydrophilic group,
THE KEY HYDROPHILIC GROUP IS THE ONE WHICH APPEARS FIRST. THE ORDER IN WHlCH FUNCTlONS
(1)
SHOULD BE SELECTED IS AS FOLLOWS (see Table, pages 10 and 11) :
A cationic group from column 2, indicated in boxes 5,6, 7, 8 and possibly 9, if the function is
(a)
sufficiently basic;
An anionic group from column 1, indicated in boxes 2, 3,4, 5, 6, 7,8 and possibly 9, if the
(b)
function is sufficiently acidic;
A non-ionic group from column 3, indicated in boxes 3,4, 5 and 6;
(c)
A cationic group from column 2, indicated in boxes 1, 2, 3,4 and possibly 9, if the function is
(d)
slightly basic;
An anionic group from column 1, indicated in box 1, and possibly box 9, if the function is
(e)
slightly acidic;
The other non-ionic groups from column 3, indicated in box 1, 2, 7,8 and 9.
U>
The figure corresponding to the key group should be underlined.
THE SECONDARY HYDROPHILIC GROUP SHOULD BE SELECTED USING THE SAME ORDER OF FUNCTIONS
(2)
The figure chosen for this secondary hydrophiiic group cannot be quoted if it is in the same column as that
of the key hydrophilic group.
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ISO/R 896-1968(E)
5.4 The hydrophobic part of a surface active agent has a more or less complex chemical structure, as it may
consist of various hydrocarbon residues with hydrophobic properties, intermediate hydrocarbon functions
or substituents.
The choice of a key hydrophobic residue is an essential factor in the classification of a surface active agent.
The following rules should make it possible to make an unambiguous choice :
Rule 4*
THE KEY HYDROPHOBIC RESIDUE IS IN PRINCIPLE THE HYDROCARBON RESIDUE, AS FAR AWAY AS POSSIBLE
FROM THE KEY HYDROPHILIC GROUP.
The need in classifying the key hydrophobic residue as far away as possible from the key hydrophiiic group
is to make it possible to include the maximum amount of information in the supplementary characterization
of the surface active agent.
Substituents occurring on the key hydrophobic residue do not affect the choice of the latter.
IN THE CASE WHERE THE HYDROPHOBIC RESIDUE CHOSEN AS THE KEY RESIDUE COMPRISES STRUCTURAL
ELEMENTS OF BOTH ALIPHATIC AND RING (e.g. AROMATIC) TYPES, ACCOUNT SHOULD BE TAKEN OF THE
LENGTHS OF THE ALIPHATIC CHAINS IN ORDER TO DEFINE THE RING CHARACTER OF THE HYDROPHOBIC
RESIDUE.
Rule 5*
THE ALIPHATIC HYDROCARBON CHAIN SHOULD BE CONSIDERED SUFFICIENTLY LARGE, WITHIN THE
MEANING OF RULE 4, IF IT CONTAINS A CHAIN OF AT LEAST 8 CARBON ATOMS.
Rule 6*
IN THE ABSENCE OF ALIPHATIC HYDROCARBON CHAINS WTH 8 OR MORE CARBON ATOMS, THE RING READUE
WITHIN THE MEANING OF RULE 4 SHOULD BE REGARDED AS THE KEY PART.
Rule 7
IN THE ABSENCE OF AN ALIPHATIC HYDROCARBON CHAIN WITH 8 OR MORE CARBON ATOMS, AND IN THE
ABSENCE OF ANY RING RESIDUE, THE LARGEST HYDROPHOBIC PART SHOULD BE REGARDED AS THE KEY
HYDROPHOBIC RESIDUE.
For example : C6 chain of sodium hexyl sulphate.
5.5 A hydrophobic residue other than the key hydrophobic residue, and functionally linked to it, may affect
the behaviour of a surface active agent, if it is sufficiently hydrophobic; it should then be regarded and
described as a characteristic hydrophobic residue.
Rule 8
A CHARACTERISTIC HYDROPHOBIC RESIDUE SHOULD SATISFY RULES 5 OR 6 DEFINING THE KEY HYDRO-
PHOBIC RESIDUE.
However, a secondary function may make it possible to include in the molecule two radicals which are not
very important when considered separately, but which are linked to each other, for example, the dibutyl-
amide function -CO-N(C4 H9)2. In this case, these secondary radicals should be added together, and the
group should be regarded as a characteristic hydrophobic radical, provided that it contains at least 8 carbon
atoms.
IN ACCORDANCE WITH RULE 6, AN AROMATIC INTERMEDIATE LINK, EVEN WHEN NOT SUBSTITUTED, SHOULD
BE REGARDED AS A CHARACTERISTIC HYDROPHOBIC RESIDUE.
* See Annex B for examples illustrating the application of rules 4, 5 and 6 in the case of surface active agents the hydrophobic
part of which comprises both aliphatic chains and rings.
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ISO/R 896-1%8(E)
6. CLASSIFICATION
This classification system operates on the decimal system, with a minimum of 10 figures divided into 3 groups of
3 figures, with at least 1 additional figure, so that the key hydrophilic groups may be defined.
The groups of figures are arranged in columns, according to the constitutive sequence of relative positions
described above.
Each column contains subdivisions numbered from O to 9, O usually indicating (unless otherwise stated) the absence
of functions, groups or characteristics according to the specific designations of the various columns.
The detailed description of the elements used in the classification is given in Annex C.
Some examples of the application of this classification are given in the Appendix, page 26.
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I TABLE ~ Scientific classification of surface active agents
RI - KEY HYDROPHOBIC RESIDUE
FI - KEY HYDROPHILIC GROW
Important descriptive characteristic properties
Characteristic properties
4 5 6
1 2 3
LINKAGE OE KLY
SUBSTITUTION
CATIONIC NON-IONIC CONSTITUTION
ANIONIC
FUNCTION E I
O AA
D AA O AA
O AA O AA
D AA
Non aromatic,
Non-branched
Absence of Absence of
Absence of Absence of
diphatic group primary
1 BB
1 BB 1 BB
1 BB 1 BB I BB
Unraturaiion
Non aromanc.
Aliphatic Branched
c=c
COOH Primary amine
aliphatic group xLondary
hydroxyl group
c=c
2 CC
2 CC 2 cc 2 CC
2 cc 2 cc
Alicyclic or
Non arorndtiL.
Alicydic group. Alkyl group
uomatic
OS0 1 H Secondary amine
terpenes (linked to cyder) tertiary
hydroxyl group
3 DD 3 DD
3 DD 3 DD 3 DD
3 DD
By inlerrnedidte
Non branched
Non-condensd
ihain on ring,
Tertiary amine polyether on Ring group
SO3 H
benzene group
primary
intermediate chain
4 tt
4 EE 4 Et 4 tt
4 EE 4 EE
By interrnedidte
Branched polyether Aromatic group HdlOgenS. nitro.
on intermediaie with condenwd nitroso and similar Lhdin on ring.
S SO,H Amine oxide
5eiond.q
chain cycles substituent\
5 FF 5 FF 5 FF
5 FF 5 FF 5 FF
Derivatives of
SO2 H.
Heterocycli~ group By intermedidtr
including other
sorbitan. mannitan,
Quarternary
with 1 non-carbon tther hydroxyls Lhain on ring.
sulphur functions ammonium carbohydrates
tertiary
atom on tne ring
and similar
- SOl” (r)
6 GC 6 GG
6 GG 6 GG 6 GG 6 GG
Heterocyclic group
Derivatives of Carboxyl function5
Pyridinium, Direct Iinkdgc
with 2 or more non- and derivdtives
Orthophosphorik sorbitan. mannitan.
on droniatic
Quinilinium
dcid esteri OXY dkyl carbo- carbon atoms on COO (I),
ring
and similar
CON (r)*, etL
hydrates the ring
7 HH 7 HH 7 HH 7 HH 7 HH
7 HH
Direct linkage
Sulphide and
Polymer group on non dramatic
Phosphonic acids Sulphoniurn Carbonyl group
sulphate funiiionr
idrbon ring
-
8 KK 8 KK 8 KK
8 KK 8 KK 8 KK
Direct Iinkrlgr
Uress. tiroup containing Primary. wçonddry
through carbon
ureides. other elements in and tertiary ainine
Per acids Phosphonium
atom oi rl hetero
a çhdin functions
polypeptides
ivcle
9 LL 9 LL 9 LL 9 LL
9 LL 9 LL
Other hydrophobic Other substitutions
Other cationic Other non-ionic and substitutions
Other anionic groups
not chemically
functions functions functions
designated
1
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ISO/R 896-1968 (E)
HYDROPHILIC PART
P - HYDROPHOBIC PART
Supplementary chuacteristic properties
Supplementary characteristic properties
-.
10/3
9 lop 10/2
8
7
CHARACTERISTIC
INTERMEDIATE INTERMEDIATE
CATIONIC NON.IONIC
ANIONIC
FUNCTIONAL HYDROPHOBIC
FUNCTIONAL
GROUP X2 PART R1
GROUP Xi
_____~~
AA
O AA O AA0
D AA O AA
D AA
Absence of Absence of
Absence of Absence of
Absence of Absence of
1 BB 1 1 BB
1 BB 1 BB
1 BB 1 BB
one or two
Alkaline metal
Charac teristic
Pari R2 identical
rplts : Li, Na, K, etc .
coo __ R
coo- Fi
with put Ri
Inorganic anion
(Group I a)
~~
2 cc 2 cc
2 cc 2 cc
Alkaline earth
One or two characteristic
Aliphatic
ooc ~ R netai saits : Mg, Ca, Sr.
hydrophobic groups. ester function
branched or not
Organic anion
Ba, etc . (Group il a)
-
3 DD 3
3 DD 3 DD
3 DD
Precious and vola- One or two
CON (r) FI CON(r) ~ R Saturated cyclic
tile metai dts : CU, hydrophobic groups. Characteristic
N(1)CO- R hydrocarbons, olefi-
N (r)CO --Fi
ether function
nic cyclic or alicyctic Ag, Zn, Cd, Hg lenzyl radical and umilar.
One And iuo inter- One and two inter
(Groups I band II bi Inorganic anion
mediate funLtion\ mediate functions hydrocarbons
4 tE
4 EE 4 EE 4 EE
4 tE 4 EE
Transition One or tn o
hydrophobic groups. CharaL teristic
Aromatic metai raits : CI, Mn,
S02N(r)-FI - SO~N(I)--R
similu. amide function
Fe, Co, Ni (Groups Vi a, Benzylradical and
- N(r)SOZ---R heterocyclic
N (r) SO2 -F I
VI1 a and VIH) Organic anion
5 FF 15 FF
5 FF
5 FF 5 FF
5 FF
-0 R Salts of metals
O- Fi Charac teristic
Three hydrophobic
Group substituted
with p valencies
One, tu0 dnd three One, two and three
iulpharnide function
groups Inorganic
by hydroxyl or
Al, In, Sn, Pb, Bi
intermediate intermediate
anion - SO2N(rh .
- OR2
(Groups 111 b to V b)
tunclion\ functions
6 GG
6 GC 6 GG 6 GG
6 GG
Lnnthanium and
Three hydrophobic
s- Fi
actinium group
Group substituted
groups OrganiL
so ~ FI
metal salts
by N(r)2 or NH(r)
anion
so2 ~ FI
La, Ce, Th, U, etc
7 HH
7 HH 7 HH 7 HH
7 HH
Groups with
-- COOH
Metallic complekes
Ammonium salts
functions and
derived functions
8 KK
8 KK 8 KK 8 KK
8 KK 8 KK
Groups with
Orpano-metaiiic
Others functions such as Organic base
Others
Beminer
&rivativer
salts
-x R ~ S03H, - ûSû3H,
X- Fi
and similar
9 LL
9 LL 9 LL
Supplementary sub iution characteristic 9 LL
properties, in the absence of
Functlon XI Function X2
Polymer group or
Salts of complex
group containing
Other specialized Other characterirtic
Supplementary Substitutions of
Si, B,and metals. Organe
characteristics functions
. unsdturation column 5 on
other hydrophobic meîaiüc bases
c=c- mtermediate
groups
1
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ISO/R 896-1%8(E) I
ANNEX A
ANNEX A
A.l PRINCIPLE OF CLASSIFICATION
The following diagrams in which the notation below has been used allow a more practical presentation of the
principle of classification.
In general :
F indicates a group with hydropiulic structure
R indicates a group with hydrophobic structure
X indicates an intermediate functional group
In particular :
indicates the key hydrophilic group
indicates a secondary hydrophilic group
indicates the key hydrophobic residue
indicates a characteristic hydrophobic residue
indicates the intermediate functional group closest to F1
indicates another intermediate functional group
indicates an intermediate hydrocarbon link
indicates a substitution of a general nature, but without solubilizing properties
(including unsaturation regarded as a substitution of II electrons on the chain)
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m
ISO/R 896-1%8(E)
ANNEX A
CONSTITUTIVE DIAGRAMS
30
L
,I_
L
O
-.14 -
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I
ISO/R 896 - 1 %8(E)
ANNEX A
p
C
R2
i
-
1
1
R1
J
- 15 -
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ISO/R 896-1%8(E)
ANNEX B
ANNEX B
RULES OF CLASSIFICATION
The case of surface active agents whose hydrophobic part comprises both aliphatic chain structures and rings is
particularly important. The following examples illustrate the application of rules 4, 5 and 6, O designating a ring
residue :
For the substances
O - (CH,)* - Fi
O - (CH2)3 - CH - Fi
I
(CHz)3 - CH3
O - (CH,), - CH - CH2 - FI
(AH? 13 - CH 3
CH3 - (CH2)S - CH - CH2 - FI
I
O
the aliphatic chain with 8 carbon atoms constitutes the key hydrophobic residue, while the ring residue O is
regarded as a substitution on this key hydrophobic residue.
On the other hand, for the substances
O - (CH2)7 - FI
CH3 - (CH,), - O - FI
the ring residue O constitutes the key hydrophobic residue, and the aliphatic chain is regarded as an intermediate
chain in the first case, and as a substituent in the second.
Moreover, in order to ensure the best possible designation for products of the following types,
CH3 - (CH,), - O - Fi
CH3 - (CH?), - O - (CH,), - FI
the nng residue O should be chosen as the key hydrophobic residue, whatever the values of n and p. The presence
of intermediate functional groups has the following effect in the cast of these compounds :
for the substances
CH3 - (CH,), - XI - Q - FI
I
R
CH3 -- (CH,), - CH - XI - O - FI
I I
CH2 - CH3 R
the aliphatic chain constitutes the key hydrophobic residue, whatever R may be. On the other hand, for the
substance
CH3 - (CH,)6 - xi -
- FI
I
R
the key hydrophobic residue is the structural unit O - R, or O, when R is not present.
In the two cases below,
R
R
the key hydrophobic residue is the group
R
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II
ISO/R 896-1%8(E)
ANNEX C
ANNEX C
DETAILED DESCRIPTION OF THE ELEMENTS USED IN THE CLASSIFICATION*
C.l FIRST GROUP OF 3 COLUMNS : COLUMNS I, 2, 3
“Key hydrophiiic group : properties”
This group of figures provides an identification of the polar group in the classification, i.e. the key hydrophilic
function or the group of hydrophilic functions. On the first figure depends the order in which the reniaining parts
of the molecule are to be classified.
Column 1 designates the acid functions (anionic type), or functions classified as such, in the case of salts.
Column 2 designates the basic functions (cationic type), or functions classified as such, in the case of salts.
Column 3 designates those functions or functional groups which have no ionic properties, or those classified as
such, in the case of functional groups of a non-ionic type. For example, a simple ether derived from an alcohol
function.
The designation of key functions by means of figures in columns 1, 2 arid 3 should be limited to a strict minimum,
and those indicated should be given in the order of their relative importance as laid down in the rules already given
The designation of supplementary functions of lesser importance should be found in co1uinii 5 of the classification.
For example the hydroxyl group of ncinoleic acid should not be designated as a key function, but as a substituent
in column 5.
C.2 SECOND GROUP OF 3 COLUMhS : COLUMNS 4. 5, 6
“Key hydrophobic residue : important descriptive properties”
This group is intended to classify elements of the key hydrophobic residue (generally that farthest away from the
key hydrophiiic function) and the linkage of the key functional group determining the polar/non-polar structural
relations of the molecule.
Column 4 describes the constitution of the key hydrophobic radical or residue K, It is arranged in such a way that
it shows constitutive elements of the hydrophobic radicals, carefully distinguished one froni the other so that the
clearest possible classification is obtained.
Column 4, although taken as a key, is more often a factor deciding the entire character of the hydrophobic residue
in question. An isododecyl benzene sulphonate is Classified under subdivision 3 of column 4 : “non-condensed
benzene residue”. Alkylbenzimidazol derivatives are classified under subdivision 6 of column 4 : “Hetero-cyclic
residue with 2 or more non-carbon atoms in the ring”.
Column 5 describes the substitution which may occur in the hydrophobic part, and in particular in the key hydro-
phobicresidue designated in column 4.
Since several different substitutions may occur on the same hydrophobic residue, it is advisable, in the decimal
classification, to designate one single substituent, i.e. the one which will niost clearly differentiate the molecule which
is being classified. Failing any decisive observation to this effect. the following should be designated, in order of their
importance : the main carbon substituent(chain or ring); then a substituent secondary funztion F2, the most polar
substituent; and lastly the degree of unsaturation (substitution by n electrons).
Column 6 indicates the way in which the key hydrophilic group FI is linked with the rest of the molecule; this
column can be arranged in such a way that it provides additional information about the molecular constitution.
For example, the use of a figure in column 4 corresponding to ring constitutive elemer,ts, in combination with a
designation for a functional bond not directly linked to the ring, indicates the existence of a carbon chain separating
the ring from the function.
*
See Table, pages 1 O and 11.
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ISO/R 896-1%8(E)
ANNEX C
THIRD GROUP OF 3 COLUMNS : COLUMNS 7, 8 AND 9
C.3
’
“Hydrophobic part : supplementary properties”
In subdivisions O to 8, columns 7 and 8 describe the intermediate functions which may separate the key hydro-
philic function F1 either from the key hydrophobic residue or from a characteristic hydrophobic residue. These
separations also imply the existence of intermediate carbon links C (or X).
Column 7 designates (from O to 8) the intemediutefunction XI closest to the key hydrophilic function FI.
Column 8 designates (from O to 8) a second intermediate function Xz which may either separate the key hydro-
phobic radical R1 from the function F, by means of an extra link C (or X), or introduce a supplementary charac-
teristic hydrophobic radical Rz .
In complex cases, where several intermediate functions X2 may exist together in the same molecule, column 8 should
first show the function which introduces a supplementary characteristic hydrophobic radical R2. If no such radical
is present, the intermediate function Xz designated should be the one closest to the key residue R1.
In connection with the functional specifications of columns 7 and 8, special mention should be made of the
indications given in subdivisions 3 and 5.
in these cases, provision has been made for groups of intermediate polyfunctional links, which may comprise up to
3 intermediate similar functions and grouped as such. The number 3 is the maximum, as above this number functional
groups of this kind become hydrophilic groups, which is sufficient to justify the designation of non-ionic hydrophilic
group in column 3 of the first group of 3 columns.
NOTE. - The foregoing is applicable only in the case of simple intermediate links, such as O - CHz-CH2 -0 of polyethylene oxides.
The figures 9 of columns 7 and 8 provide further supplementary characteristics of the hydrophobic part P; these
caracteristics are included here to increase the flexibility of the classification and greatly extend (as is necessary)
the possibility of combinations :
In the absence of an intermediate function XI (i.e. an intermediate connecting link C), figure 9 of
column 7 makes provision for the possibility of designating a supplementary unsaturation in the carbon
chain of the key hydrophobic residue; this information is important for the classification of linoleic or
ricinoleic derivatives. This supplementary information can also be extended to cover the case of deriva-
tives comprising the intermediate functions X and the intermediate links C, on the assumption that the
designations of column 8, which generally represent the intermediate functions Xz, are now being used
to designate the intermediate functions X1.
Figure 9 of column 8 is used only in the absence of an intermediate function X2 ; the use of figure 9 in
the classification then means that the indications of substitutions found in column 5 of the second group
of 3 columns refer exclusively to substitutions occurring on, and more characteristic of, the intermediate
link C. This arrangement makes it possible to classify clearly such products as sulphated glycerol laurate.
Column 9 of the group describes a characteristic hydrophobic residue R2, appearing by functional bonds in the
molecule, or functionally linked, as a secondary hydrophobic residue, to the rest of the molecule.
A characteristic hydrophobic residue R2 of this kind is included in the molecule by functional bonds X1 and Xz.
It is then characteristic, in the sense that it designates in particular an aromatic or aliphatic supplementary property
of the molecule, which will become apparent a priori.
On the other hand, column 9 also designates a characteristic hydrophobic residue R2, which appears as an adequate,
hydrophobic, supplementary, radical. A functionally linked residue of this kind can be attached to the whole
molecule by an intermediate function X2, (as in the case of sulphonated succinic diesters), by a substituent function
Fz , o
...