International Union of Pure and Applied Chemistry
Polymer Division
Subcommittee on Polymer Terminology
A Brief Guide to Polymer Nomenclature
Version 1.1 (2012)
1) Introduction
The universal adoption of an agreed nomenclature has never been more
important for the description of chemical structures in publishing and on-line
searching. The International Union of Pure and Applied Chemistry (IUPAC)
1a,b
and Chemical Abstracts Service (CAS)
2
make similar recommendations.
The main points are shown here with hyperlinks to original documents.
Further details can be found in the IUPAC Purple Book.
3
2) Basic Concepts
The terms polymer and macromolecule do not mean the same thing. A polymer
is a substance composed of macromolecules. The latter usually have a range of
molar masses (unit g mol
-1
), the distributions of which are indicated by
dispersity (Đ). It is defined as the ratio of the mass-average molar mass (M
m
) to
the number-average molar mass (M
n
) i.e. Đ = M
m
/M
n
.
4
Symbols for physical
quantities or variables are in italic font but those representing units or labels are
in roman font.
Polymer nomenclature usually applies to idealised representations; minor
structural irregularities are ignored. A polymer can be named in one of two
ways. Source-based nomenclature can be used when the monomer can be
identified. Alternatively, more explicit structure-based nomenclature can be used
when the polymer structure is proven. Where there is no confusion, some
traditional names are also acceptable.
Whatever method is used, all polymer names have the prefix poly, followed by
enclosing marks around the rest of the name. The marks are used in the order:
{[( )]}. Locants indicate the position of structural features, e.g., poly(4-
chlorostyrene). If a source-based name is one word and has no locants, then the
enclosing marks are not essential, but they should be used when there might be
confusion, e.g., poly(chlorostyrene) is a polymer whereas polychlorostyrene
might be a small, multi-substituted molecule. End-groups are described with
α- and ω-, e.g., α-chloro-ω-hydroxy-polystyrene.
3
3) Source-Based Nomenclature
5
3.1 Homopolymers
A homopolymer is named using the name of the real or assumed monomer (the
‘source’) from which it is derived, e.g., poly(methyl methacrylate). Monomers
can be named using IUPAC recommendations, or well-established traditional
names. Should ambiguity arise, class names can be added.
6
For example, the
source-based name poly(vinyloxirane) could correspond to either of the
structures shown below. To clarify,
the polymer is named using the
polymer class name followed by
a colon and the name of the
monomer, i.e., class name:monomer name. Thus on the left and right,
respectively, are polyalkylene:vinyloxirane and polyether:vinyloxirane.
3.2 Copolymers
7
The structure of a copolymer can be described using the most appropriate of the
connectives shown in Table 1. These are written in italic font.
3.3 Non-linear polymers
5
Non-linear polymers and copolymers, and polymer assemblies are named using
the italicized qualifiers in Table 2. The qualifier, such as branch, is used as a
prefix (P) when naming a (co)polymer, or as a connective (C), e.g., comb,
between two polymer names.
Table 1 – Qualifiers for copolymers.
7
Copolymer Qualifier Example
uns
p
ecified co
(
C
)
p
ol
y(
st
y
rene-co-iso
p
rene
)
statistical stat (C) poly[isoprene-stat-(methyl methacrylate)]
random ran (C) poly[(methyl methacrylate)-ran-(butyl acrylate)]
alternatin
g
alt
(
C
)
p
ol
y
[st
y
rene-alt-
(
maleic
anh
y
dride
)
]
periodic per (C) poly[styrene-per-isoprene-per-(4-vinylpyridine)]
block block
(
C
)
p
ol
y(
buta-1,3-diene
)
-block-
p
ol
y(
ethene-co-
p
ro
p
ene
)
g
raft
a
g
ra
f
t
(
C
)
p
ol
y
st
y
rene-
g
ra
f
t-
p
ol
y(
eth
y
lene
oxide
)
a
The first name is that of the main chain.
Table 2 – Qualifiers for non-linear (co)polymers and polymer assemblies.
5
(Co)polymer Qualifier Example
blend blend (C)
poly(3-hexylthiophene)-blend-
polystyrene
comb comb
(
C
)
p
ol
y
st
y
rene-comb-
p
ol
y
iso
p
rene
complex compl (C)
poly(2,3-dihydrothieno[3,4-
b][1,4]dioxine)-compl-
p
ol
y(
vin
y
lbenzenesulfonic
acid
)
a
cyclic cyclo (P) cyclo-polystyrene-graft-polyethylene
branch branch (P)
branch-poly[(1,4-divinylbenzene)-
stat-styrene]
network net (C or P) net-poly(phenol-co-formaldehyde)
interpenetrating network ipn (C)
(net-polystyrene)-ipn-[net-
poly(methyl acrylate)]
semi-interpenetrating
network
sipn (C) (net-polystyrene)-sipn-polyisoprene
star star (P) star-polyisoprene
a
In accordance with IUPAC organic nomenclature, square brackets enclose locants that
refer to the numbering of the components of the fused ring.
4) Structure-Based Nomenclature
4.1 Regular single-strand organic polymers
8
In place of the monomer name used in source-based nomenclature, structure-
based nomenclature uses that of the preferred constitutional repeating unit
(CRU). It can be determined as follows: (i) a large enough part of the polymer
chain is drawn to show the structural repetition, e.g.,
CH
Br
CH
2
OCH
Br
CH
2
OCH
Br
CH
2
O
(ii) the smallest repeating portion is a CRU, so all such possibilities are
identified. In this case:
OCH
Br
CH
2
CH
2
OCH
Br
OCH
2
CH
Br
OCH
Br
CH
2
CH OCH
2
Br
CH
Br
CH
2
O
(iii) the next step is to identify the subunits that make up each of these
structures, i.e., the largest divalent groups that can be named using IUPAC
nomenclature of organic compounds such as the examples that are listed in
Table 3; (iv) using the shortest path from the most senior subunit to the next
senior, the correct order of the subunits is determined using Figure 1; (v) the
preferred CRU is chosen as that with the lowest possible locant(s) for
substituents.
In the above example, the oxy subunits in the CRUs are heteroatom chains.
From Figure 1, oxy subunits are senior to the acyclic carbon chain subunits, the
largest of which are bromo-substituted -CH
2
-CH
2
- subunits. 1-Bromoethane-1,2-
diyl is chosen in preference to 2-bromoethane-1,2-diyl as the former has a lower
locant for the bromo-substituent. The preferred CRU is therefore oxy(1-
bromoethane-1,2-diyl) and the polymer is thus named poly[oxy(1-bromoethane-
1,2-diyl)]. Please note the enclosing marks around the subunit carrying the
substituent.
Polymers that are not made up of regular repetitions of a single CRU are called
irregular polymers. For these, each constitutional unit (CU) is separated by
a slash, e.g., poly(but-1-ene-1,4-diyl/1-vinylethane-1,2-diyl).
9
R. C. Hiorns (France),* R. J. Boucher (UK), R. Duhlev (UK), K.-H. Hellwich (Germany), P. Hodge (UK), A. D. Jenkins (UK), R. G. Jones (UK),
J. Kahovec (Czech Republic), G. Moad (Australia), C. K. Ober (USA), D. W. Smith (USA), R. F. T. Stepto (UK), J.-P. Vairon (France), and J. Vohlídal
(Czech Republic). *E-mail: [email protected]; Sponsoring body: IUPAC Polymer Division, Subcommittee on Polymer Terminology.
1
Freely available on: (a) http://www.iupac.org/publications/pac/;
(b) http://www.chem.qmul.ac.uk/iupac/
2
http://www.cas.org/.
3
IUPAC. The “Purple Book”, RSC Publishing, (2008).
4
IUPAC. Pure Appl. Chem. 81, 351—352 (2009).
5
IUPAC. Pure Appl. Chem. 69, 2511—2521 (1997).
6
IUPAC. Pure Appl. Chem. 73, 1511—1519 (2001).
7
IUPAC. Pure Appl. Chem. 57, 1427—1440 (1985).
8
IUPAC. Pure Appl. Chem. 74, 1921—1956 (2002).
9
IUPAC. Pure Appl. Chem. 66, 873—889 (1994).
CH CH
2
O
n
CH CH
2
n
O
CH
CH
2
International Union of Pure and Applied Chemistry
Polymer Division
Subcommittee on Polymer Terminology
A Brief Guide to Polymer Nomenclature
Version 1.1 (2012)
Table 3 – Representations of divalent groups in polymers.
8
Name Grou
p
a
Name Grou
p
a
oxy
O
propylimino
N
CH
2
CH
2
CH
3
sulfanediyl
S
hydrazine-1,2-diyl
NH NH
21
sulfonyl
SO
2
phthaloyl
CO
CO
diazenediyl
N N
1,4-phenylene
2
5
1
3
6
4
imino
NH
cyclohexane-1,2-diyl
2
5
1
6
4
3
carbonyl
C
O
butane-1,4-diyl
CH
2
CH
2
CH
2
CH
2
321
4
oxalyl
C
O
C
O
1-bromoethane-1,2-diyl
CH
Br
CH
2
12
silanediyl
SiH
2
1-oxopropane-1,3-diyl
C
O
CH
2
CH
2
32
1
ethane-1,2-diyl
CH
2
CH
2
12
ethene-1,2-diyl
CH CH
12
methylene
CH
2
methylmethylene
CH
CH
3
a
To avoid ambiguity, wavy lines drawn perpendicular to the free bond, which are
conventionally used to indicate free valences,
13
are usually omitted from graphical
representations in a polymer context.
4.2 Regular double-strand organic polymers
10
Double-strand polymers consist of uninterrupted chains of rings. In
a spiro polymer, each ring has one atom in common with adjacent rings. In a
ladder polymer, adjacent rings have two or more atoms in common. To identify
the preferred CRU, the chain is broken so that the senior ring is retained with the
maximum number of heteroatoms and the minimum number of free valences.
An example is
. The preferred CRU is an acyclic subunit of 4
carbon atoms with 4 free valences, one at each atom, as shown below. It is
oriented so that the lower left atom has the lowest number. The free-
valence locants are written before the suffix, and they are cited
clockwise from the lower left position as: lower-left, upper-
left:upper-right, lower-right. This example is thus named
poly(butane-1,4:3,2-tetrayl). For more complex structures, the order of seniority
again follows Figure 1.
5) Nomenclature of Inorganic and Inorganic-Organic Polymers
11
Some regular single-strand inorganic polymers can be named like organic
polymers using the rules given above, e.g., [O-Si(CH
3
)
2
]
n
and [Sn(CH
3
)
2
]
n
are named poly[oxy(dimethylsilanediyl)] and poly(dimethylstannanediyl),
respectively. Inorganic polymers can also be named in
accordance with inorganic nomenclature, but it should be
noted that the seniority of the elements is different to that
in organic nomenclature. However, certain inorganic-
organic polymers, for example those containing
metallocene derivatives, are at present best named using
organic nomenclature, e.g., the polymer on the left can be
named poly[(dimethylsilanediyl)ferrocene-1,1'-diyl].
6) Traditional Names
When they fit into the general pattern of systematic nomenclature, some
traditional and trivial names for polymers in common usage, such as
polyethylene, polypropylene, and polystyrene, are retained.
7) Graphical Representations
12,13
The bonds between atoms can be omitted, but dashes should be drawn for
chain-ends. The seniority of the subunits does not need to be followed.
For single-strand (co)polymers, a dash is drawn through the enclosing marks,
e.g., poly[oxy(ethane-1,2-diyl)] shown below left. For irregular polymers, the
CUs are separated by slashes, and the dashes are drawn inside the enclosing
marks. End-groups are connected using additional dashes outside of the
enclosing marks, e.g., α-methyl-ω-hydroxy-poly[oxirane-co-(methyloxirane)],
shown below right.
8) CA Index Names
2
CAS maintains a registry of substances. In the CAS system, the CRU is called a
structural repeating unit (SRU). There are minor differences in the placements of
locants, e.g., poly(pyridine-3,5-diylthiophene-2,5-diyl) is poly(3,5-pyridinediyl-
2,5-thiophenediyl) in the CAS registry, but otherwise polymers are named using
similar methods to those of IUPAC.
14,15
Figure 1 The order of subunit seniority. The senior subunit is at the top centre. Subunits of
lower seniority are found by following the arrows. The type of subunit, be it a heterocycle,
a heteroatom chain, a carbocycle, or a carbon chain, determines the colour of the arrow
to follow.
a
Other heteroatoms may be placed in these orders as indicated by their positions
in the periodic table.
8
10
IUPAC. Pure Appl. Chem. 65, 1561—1580 (1993).
11
IUPAC. Pure Appl. Chem. 57, 149—168 (1985).
12
IUPAC. Pure Appl. Chem. 66, 2469—2482 (1994).
13
IUPAC. Pure Appl. Chem. 80, 277—410 (2008).
14
Macromolecules, 1, 193—198 (1968).
15
Polym. Prepr. 41(1), 6a—11a (2000).
To cite, please use: IUPAC. Pure Appl. Chem. 84, 2167—2169 (2012). Publicatio
n
of this document by any means is permitted on condition that it is whole and
unchanged. Copyright © IUPAC 2012.
heterocyclics
heteroatom chains
carbocyclics
carbon chains
y
es no
no
y
es
no yes
yes
largest number of substituents
lowest locant for substituent
alphabetical order of
substituents
most unsaturated
lowest locant for double bond
lowest locant for
ring attachment
N > O > S >
P > Si > B
a
greatest number
of rings
greatest
number of
atoms common
to rings
largest rings
O > S > N >
P > Si > B
a
longest chain
2
4
1
3
n
4
1
2
3
Fe
Si
CH
3
CH
3
n
