Prepared for publication by A. D. Jenkins (UK), P. Kratochvìl
(Czech Republic), R. F. T. Stepto (UK), and U. W. Suter (Switzerland)
MOLECULES AND MOLECULAR
STRUCTURE
1.1 macromolecule
polymer molecule
A molecule of high relative molecular mass, the structure of which
essentially comprises the multiple repetition of units derived, actually
or conceptually, from molecules of low relative molecular mass.
Notes
1. In many cases,
especially for synthetic polymers, a molecule can be regarded as having
a high relative molecular mass if the addition or removal of one or
a few of the units has a negligible effect on the molecular properties.
This statement fails in the case of certain macromolecules for which
the properties may be critically dependent on fine details of the
molecular structure.
2. If a part or the whole of the molecule has a high relative
molecular mass and essentially comprises the multiple repetition of
units derived, actually or conceptually, from molecules of low relative
molecular mass, it may be described as either macromolecular
or polymeric, or by polymer used adjectivally.
1.2 oligomer molecule
A molecule of intermediate relative molecular mass, the structure
of which essentially comprises a small plurality of units derived,
actually or conceptually, from molecules of lower relative molecular
mass.
Notes
1. A molecule is
regarded as having an intermediate relative molecular mass if it has
properties which do vary significantly with the removal of one or
a few of the units.
2. If a part or the whole of the molecule has an intermediate
relative molecular mass and essentially comprises a small plurality
of units derived, actually or conceptually, from molecules of lower
relative molecular mass, it may be described as oligomeric,
or by oligomer used adjectivally.
1.3 monomer molecule
A molecule which can undergo polymerization (see
Definition 3.1), thereby contributing constitutional units (see
Definition 1.14) to the essential structure of a macromolecule
(see Definition 1.1).
1.4 regular macromolecule
A macromolecule (see Definition 1.1),
the structure of which essentially comprises the repetition of a single
constitutional unit (see Definition
1.14) with all units connected identically with respect to directional
sense.
1.5 irregular macromolecule
A macromolecule (see Definition 1.1),
the structure of which essentially comprises the repetition of more
than one type of constitutional unit (see
Definition 1.14), or a macromolecule the structure of which comprises
constitutional units not all connected identically with respect to
directional sense.
1.6 linear macromolecule
A macromolecule (see Definition 1.1),
the structure of which essentially comprises the multiple repetition
in linear sequence of units derived, actually or conceptually, from
molecules of low relative molecular mass.
1.7 regular oligomer molecule
An oligomer molecule (see Definition
1.2), the structure of which essentially comprises the repetition
of a single constitutional unit (see
Definition 1.14) with all units connected identically with respect
to directional sense.
1.8 monomeric unit
monomer unit
mer
The largest constitutional unit (see
Definition 1.14) contributed by a single monomer molecule (see
Definition 1.3) to the structure of a macromolecule (see
Definition 1.1) or oligomer molecule (see
Definition 1.2).
Note
The largest constitutional unit contributed
by a single monomer molecule to the structure of a macromolecule or
oligomer molecule may be described as either monomeric, or
by monomer used adjectivally.
1.9 macromonomer molecule
A macromolecule (see Definition 1.1)
that has one end-group which enables it to act as a monomer molecule
(see Definition 1.3), contributing
only a single monomeric unit (see Definition
1.8) to a chain of the final macromolecule.
1.10 macroradical
A macromolecule (see Definition 1.1)
which is also a free radical.
1.11 pre-polymer molecule
A macromolecule (see Definition 1.1)
or oligomer molecule (see Definition 1.2)
capable of entering, through reactive groups, into further polymerization
(see Definition 3.1), thereby contributing
more than one monomeric unit (see Definition
1.8) to at least one chain of the final macromolecule.
Note
A pre-polymer molecule capable of entering into
further polymerization through reactive end-groups (see
Definition 1.35), often deliberately introduced, is known as a
telechelic molecule.
1.12 macromonomeric unit
macromonomer unit
The largest constitutional unit (see
Definition 1.14) contributed by a single macromonomer molecule
(see Definition 1.9) to the
structure of a macromolecule (see Definition
1.1).
1.13 degree of polymerization
The number of monomeric units ) in a macromolecule (see
Definition 1.1) an oligomer molecule (see
Definition 1.2), a block (see
Definition 1.62), or a chain (see
Definition 1.30).
1.14 constitutional unit
An atom or group of atoms (with pendant atoms or groups, if any)
comprising a part of the essential structure of a macromolecule (see
Definition 1.1), an oligomer molecule (see
Definition 1.2), a block (see
Definition 1.62), or a chain (see
Definition 1.30).
1.15 constitutional repeating unit (CRU)
The smallest constitutional unit (see
Definition 1.14), the repetition of which constitutes a regular
macromolecule (see Definition 1.4),
a regular oligomer molecule (see Definition 1.7),
a regular block (see Definition 1.62),
or a regular chain (see Definition 1.30).
1.16 configurational unit
A constitutional unit (see Definition 1.14)
having at least one site of defined stereoisomerism.
1.17 configurational base unit
A constitutional repeating unit (see
Definition 1.15) in a regular macromolecule (see
Definition 1.4), a regular oligomer molecule (see
Definition 1.7), a regular block (see
Definition 1.62), or a regular chain (see
Definition 1.30), the configuration of which is defined at least
at one site of stereoisomerism in the main chain (see
Definition 1.34).
1.18 configurational repeating unit
The smallest set of successive configurational base units (see
Definition 1.17) that prescribes configurational repetition
at one or more sites of stereoisomerism in the main chain (see
Definition 1.34) of a regular macromolecule (see
Definition 1.4), a regular oligomer molecule (see
Definition 1.7), a regular block (see
Definition 1.62), or a regular chain (see
Definition 1.30).
1.19 stereorepeating unit
A configurational repeating unit (see
Definition 1.18) having defined configuration at all sites of
stereoisomerism in the main chain (see
Definition 1.34) of a regular macromolecule (see
Definition 1.4), a regular oligomer molecule (see
Definition 1.7), a regular block (see
Definition 1.62), or a regular chain (see
Definition 1.30).
1.20 tacticity
The orderliness of the succession of configurational repeating units
(see Definition 1.18) in the main
chain (see Definition 1.34) of a
regular macromolecule (see Definition 1.4),
a regular oligomer molecule (see Definition 1.7),
a regular block (see Definition 1.62),
or a regular chain (see Definition 1.30).
1.21 tactic macromolecule
A regular macromolecule (see Definition
1.4) in which essentially all the configurational (repeating)
units (see Definitions 1.16
and 1.18) are identical.
1.22 stereoregular macromolecule
A regular macromolecule (see Definition
1.4) essentially comprising only one species of stereorepeating
unit (see Definition 1.19).
1.23 isotactic macromolecule
A tactic macromolecule (see Definition
1.21), essentially comprising only one species of configurational
base unit (see Definition 1.17),
which has chiral or prochiral atoms in the main chain (see
Definition 1.34) in a unique arrangement with respect to its adjacent
constitutional units (see Definition
1.14).
Notes
1. In an isotactic macromolecule, the configurational repeating
unit (see Definition 1.16) is identical
with the configurational base unit.
2. An isotactic macromolecule consists of meso diads (see
Definition 1.64).
1.24 syndiotactic macromolecule
A tactic macromolecule (see Definition
1.21), essentially comprising alternating enantiomeric configurational
base units (see Definition 1.17),
which have chiral or prochiral atoms in the main chain (see
Definition 1.34) in a unique arrangement with respect to their
adjacent constitutional units (see Definition
1.14).
Notes
1. In a syndiotactic macromolecule, the configurational
repeating unit consists of two configurational base units that are
enantiomeric.
2. A syndiotactic macromolecule consists of racemo diads (see
Definition 1.64).
1.25 atactic macromolecule
A regular macromolecule (see Definition
1.4) in which the configurational (base) units (see
Definitions 1.16 and 1.17) are
not all identical.
1.26 block macromolecule
A macromolecule (see Definition 1.1)
which is composed of blocks (see Definition
1.62) in linear sequence.
1.27 junction unit
A non-repeating atom or non-repeating group of atoms between blocks
in a block macromolecule (see Definition
1.26).
1.28 graft macromolecule
A macromolecule (see Definition 1.1)
with one or more species of block (see
Definition 1.62) connected to the main chain (see
Definition 1.34) as side-chains (see
Definition 1.53), these side-chains having constitutional or configurational
features that differ from those in the main chain.
1.29 stereoblock macromolecule
A block macromolecule (see Definition
1.26) composed of stereoregular, and possibly non-stereoregular,
blocks (see Definition 1.62).
1.30 chain
The whole or part of a macromolecule (see
Definition 1.1), an oligomer molecule (see
Definition 1.2), or a block (see
Definition 1.62), comprising a linear or branched sequence of
constitutional units (see Definition
1.14) between two boundary constitutional units, each of which
may be either an end-group (see Definition
1.35), a branch point (see Definition
1.54), or an otherwise-designated characteristic feature of the
macromolecule.
Notes
1. Except in linear single-strand macromolecules (see
Definition 1.39), the definition of a chain may be somewhat arbitrary.
2. A cyclic macromolecule has no end-groups but may nevertheless
be regarded as a chain.
3. Any number of branch points may be present between the boundary
units.
4. Where appropriate, definitions relating to macromolecule
may also be applied to chain.
1.31 subchain
An arbitrarily chosen contiguous sequence of constitutional units
(see Definition 1.14) in a chain
(see Definition 1.30).
Note
The term subchain may be used to define designated subsets
of the constitutional units in a chain.
1.32 linear chain
A chain (see Definition 1.30) with
no branch points (see Definition 1.54)
intermediate between the boundary units.
1.33 branched chain
A chain (see Definition 1.30) with
at least one branch point (see Definition
1.54) intermediate between the boundary units.
1.34 main chain
backbone
That linear chain (see Definition 1.32)
to which all other chains, long (see
Definition 1.36) or short (see Definition 1.37)
or both, may be regarded as being pendant
Note
Where two or more chains could equally be considered to be the
main chain, that one is selected which leads to the simplest representation
of the molecule.
1.35 end-group
A constitutional unit (see Definition
1.14) that is an extremity of a macromolecule (see
Definition 1.1) or oligomer molecule (see
Definition 1.2).
Note
An end-group is attached to only one constitutional unit of a
macromolecule or oligomer molecule.
1.36 long chain
A chain (see Definition 1.30) of
high relative molecular mass.
Note
See Note 1 to Definition 1.1.
1.37 short chain
A chain (see Definition 1.30) of
low relative molecular mass.
Note
See Note 1 to Definition 1.2.
1.38 single-strand chain
A chain (see Definition 1.30) that
comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through two atoms, one on each constitutional
unit.
1.39 single-strand macromolecule
A macromolecule (see Definition 1.1)
that comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through two atoms, one on each constitutional
unit.
1.40 double-strand chain
A chain (see Definition 1.30) that
comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through three or four atoms, two on
one side and either one or two on the other side of each constitutional
unit.
1.41 double-strand macromolecule
A macromolecule (see Definition 1.1)
that comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through three or four atoms, two on
one side and either one or two on the other side of each constitutional
unit.
1.42 spiro chain
A double-strand chain (see Definition
1.40) consisting of an uninterrupted sequence of rings, with adjacent
rings having only one atom in common.
Note
A spiro chain is a double-strand chain (see
Definition 1.40) with adjacent constitutional units (see
Definition 1.14) joined to each other through three atoms, two
on one side and one on the other side of each constitutional unit.
1.43 spiro macromolecule
A double-strand macromolecule (see
Definition 1.41) consisting of an uninterrupted sequence of rings,
with adjacent rings having only one atom in common.
Note
A spiro macromolecule is a double-strand macromolecule (see
Definition 1.41) with adjacent constitutional units (see
Definition 1.14) joined to each other through three atoms, two
on one side and one on the other side of each constitutional unit.
1.44 ladder chain
A double-strand chain (see Definition
1.40) consisting of an uninterrupted sequence of rings, with adjacent
rings having two or more atoms in common.
Note
A ladder chain is a double-strand chain (see
Definition 1.40) with adjacent constitutional units (see
Definition 1.14) joined to each other through four atoms, two
on one side and two on the other side of each constitutional unit.
1.45 ladder macromolecule
A double-strand macromolecule (see
Definition 1.41) consisting of an uninterrupted sequence of rings,
with adjacent rings having two or more atoms in common.
Note
A ladder macromolecule is a double-strand macromolecule (see
Definition 1.41) with adjacent constitutional units (see
Definition 1.14) joined to each other through four atoms, two
on one side and two on the other side of each constitutional unit.
1.46 multi-strand chain
A chain (see Definition 1.30) that
comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through more than four atoms, more
than two on at least one side of each constitutional unit.
Note
A chain that comprises constitutional units joined to each other
through n atoms on at least one side of each constitutional
unit is termed an n-strand chain, e.g., three-strand
chain. If an uncertainty exists in defining n, the highest
possible number is selected.
1.47 multi-strand macromolecule
A macromolecule (see Definition 1.1)
that comprises constitutional units (see
Definition 1.14) connected in such a way that adjacent constitutional
units are joined to each other through more than four atoms, more
than two on at least one side of each constitutional unit.
Note
A macromolecule that comprises constitutional units joined to
each other through n atoms on at least one side of each constitutional
unit is termed an n-strand macromolecule, e.g., three-strand
macromolecule. If an ambiguity exists in defining n, the highest
possible number is selected.
1.48 skeletal structure
The sequence of atoms in the constitutional unit(s) (see
Definition 1.14) of a macromolecule (see
Definition 1.1), an oligomer molecule (see
Definition 1.2), a block (see
Definition 1.62), or a chain (see
Definition 1.30), which defines the essential topological representation.
1.49 skeletal atom
An atom in a skeletal structure (see
Definition 1.48).
1.50 skeletal bond
A bond connecting two skeletal atoms (see
Definition 1.49).
1.51 star macromolecule
A macromolecule (see Definition 1.1)
containing a single branch point (see
Definition 1.54) from which linear chains (see
Definition 1.32) (arms) emanate.
Notes
1. A star macromolecule with n linear chains (arms)
attached to the branch point is termed an n-star macromolecule,
e.g., five-star macromolecule.
2. If the arms of a star macromolecule are identical with respect
to constitution and degree of polymerization, the macromolecule is
termed a regular star macromolecule.
3. If different arms of a star macromolecule are composed of
different monomeric units, the macromolecule is termed a variegated
star macromolecule.
1.52 comb macromolecule
A macromolecule (see Definition 1.1)
comprising a main chain (see Definition
1.34) with multiple trifunctional branch points (see
Definition 1.54) from each of which a linear side-chain (see
Definition 1.53) emanates.
Notes
1. If the subchains between the branch points of the main
chain and the terminal subchains of the main chain are identical with
respect to constitution and degree of polymerization, and the
side chains are identical with respect to constitution and degree
of polymerization (see Definition 1.13),
the macromolecule is termed a regular comb macromolecule.
2. If at least some of the branch points are of functionality
greater than three, the macromolecule may be termed a brush macromolecule.
1.53 branch
side-chain
pendant chain
An oligomeric (see Definition 1.2)
or polymeric (see Definition 1.1)
offshoot from a macromolecular (see Definition
1.1) chain (see Definition 1.30).
Notes
1. An oligomeric branch may be termed a short-chain
branch.
2. A polymeric branch may be termed a long-chain branch.
1.54 branch point
A point on a chain (see Definition
1.30) at which a branch (see Definition
1.53) is attached.
Notes
1. A branch point from which f linear chains emanate
may be termed an f-functional branch point, e.g., five-functional
branch point. Alternatively, the terms trifunctional, tetrafunctional,
pentafunctional, etc. may be used, e.g., pentafunctional branch
point.
2. A branch point in a network may be termed a junction
point.
1.55 branch unit
A constitutional unit (see Definition
1.14) containing a branch point (see
Definition 1.54).
Note
A branch unit from which f linear chains emanate may be
termed an f-functional branch unit, e.g., five-functional
branch unit. Alternatively, the terms trifunctional, tetrafunctional,
pentafunctional, etc. may be used, e.g., pentafunctional branch
unit.
1.56 pendant group
side-group
An offshoot, neither oligomeric (see
Definition 1.2) nor polymeric (see
Definition 1.1), from a chain (see
Definition 1.30).
1.57 macrocycle
A cyclic macromolecule (see Definition
1.1) or a macromolecular cyclic portion of a macromolecule.
Notes
1. See Note 2 to
Definition 1.30.
2. In the literature, the term macrocycle is sometimes
used for molecules of low relative molecular mass that would not be
considered macromolecules as specified in Definition
1.1.
1.58 network
A highly ramified macromolecule (see
Definition 1.1) in which essentially each constitutional unit
(see Definition 1.14) is connected
to each other constitutional unit and to the macroscopic phase boundary
by many permanent paths through the macromolecule, the number of such
paths increasing with the average number of intervening bonds; the
paths must on the average be co-extensive with the macromolecule.
Notes
1. Usually, and in all systems that
exhibit rubber elasticity, the number of distinct paths is very high,
but, in most cases, some constitutional units exist which are connected
by a single path only.
2. If the permanent paths through the structure of a network
are all formed by covalent bonds, the term covalent network
may be used.
3. The term physical network may be used if the permanent
paths through the structure of a network are not all formed by covalent
bonds but, at least in part, by physical interactions, such that removal
of the interactions leaves individual macromolecules or a macromolecule
that is not a network.
1.59 crosslink
A small region in a macromolecule (see
Definition 1.1) from which at least four chains (see
Definition 1.30) emanate, and formed by reactions involving sites
or groups on existing macromolecules or by interactions between existing
macromolecules.
Notes
1. The small region may be an atom,
a group of atoms, or a number of branch points connected by bonds,
groups of atoms, or oligomeric chains.
2. In the majority of cases, a crosslink is a covalent structure
but the term is also used to describe sites of weaker chemical interactions,
portions of crystallites, and even physical interactions and entanglements.
1.60 micronetwork
A highly ramified macromolecule (see
Definition 1.1) that contains cyclic structures and is of colloidal
dimensions.
1.61 loose end
A chain (see Definition 1.30),
only one point of which is attached to a network (see
Definition 1.58).
1.62 block
A portion of a macromolecule (see Definition
1.1), comprising many constitutional units (see
Definition 1.14), that has at least one feature which is not present
in the adjacent portions.
Note
Where appropriate, definitions relating
to macromolecule may also be applied to block.
1.63 constitutional sequence
The whole or part of a chain (see Definition
1.30) comprising one or more species of constitutional unit(s)
(see Definition 1.14) in defined
sequence.
Note
Constitutional sequences comprising two
constitutional units are termed diads, those comprising three
constitutional units triads, and so on. In order of increasing
sequence lengths they are called tetrads, pentads, hexads,
heptads, octads, nonads, decads, undecads,
etc.
1.64 configurational sequence
The whole or part of a chain (see Definition
1.30) comprising one or more species of configurational unit(s)
(see Definition 1.16) in defined
sequence.
Note
Configurational sequences comprising two
configurational units are termed diads, those with three such
configurational units triads, and so on. In order of increasing
sequence lengths they are called tetrads, pentads, hexads,
heptads, octads, nonads, decads, undecads,
etc.
1.65 polyelectrolyte molecule
A macromolecule (see Definition 1.1)
in which a substantial portion of the constitutional units (see
Definition 1.14) have ionizable or ionic groups, or both.
1.66 ionomer molecule
A macromolecule (see Definition 1.1)
in which a small but significant proportion of the constitutional
units (see Definition 1.14) have
ionizable or ionic groups, or both.
Note
Some protein molecules may be classified
as ionomer molecules