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Pure Appl. Chem., Vol. 68, No.12, pp. 2287-2311, 1996

MACROMOLECULAR DIVISION

COMMISSION ON MACROMOLECULAR NOMENCLATURE

Glossary of basic terms in polymer science
(IUPAC Recommendations 1996)

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


> Synopsis
> Preamble
> Entries by topics
  1. Molecules and molecular structure
  2. Substances
  3. Reactions
> Alphabetical Index of Terms

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