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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)

REACTIONS

3.1 polymerization

The process of converting a monomer (see Definition 2.1) or a mixture of monomers into a polymer (see Definition 2.2).

3.2 oligomerization

The process of converting a monomer (see Definition 2.1) or a mixture of monomers into an oligomer (see Definition 2.3).

Note
An oligomerization by chain reaction carried out in the presence of a large amount of chain-transfer (see Definition 3.24) agent, so that the end-groups (see Definition 1.35) are essentially fragments of the chain-transfer agent, is termed telomerization.

3.3 homopolymerization

Polymerization (see Definition 3.1) in which a homopolymer (see Definition 2.4) is formed.

3.4 copolymerization

Polymerization (see Definition 3.1) in which a copolymer (see Definition 2.5) is formed.

3.5 co-oligomerization

Oligomerization (see Definition 3.2) in which a co-oligomer (see Definition 2.7) is formed.

 

 

3.6 chain polymerization

A chain reaction in which the growth of a polymer (see Definition 1.1) chain (see Definition 1.30) proceeds exclusively by reaction(s) between monomer(s) (see Definition 2.1) and reactive site(s) on the polymer chain with regeneration of the reactive site(s) at the end of each growth step.

Notes
1. A chain polymerization consists of initiation and propagation reactions, and may also include termination and chain transfer (see Definition 3.24) reactions.
2. The adjective chain in chain polymerization denotes a chain reaction rather than a polymer chain.
3. Propagation in chain polymerization usually occurs without the formation of small molecules. However, cases exist where a low-molar-mass by-product is formed, as in the polymerization of oxazolidine-2,5-diones derived from amino acids (commonly termed amino-acid N-carboxy anhydrides). When a low-molar-mass by-product is formed, the adjective condensative is recommended to give the term condensative chain polymerization.
4. The growth steps are expressed by

Px + M Æ Px+1 (+ L) {x} Œ {1, 2, º }

where Px denotes the growing chain of degree of polymerization x, M a monomer, and L a low-molar- mass by-product formed in the case of condensative chain polymerization.
5. The term chain polymerization may be qualified further, if necessary, to specify the type of chemical reactions involved in the growth step, e.g., ring-opening chain polymerization, cationic chain polymerization.
6. There exist, exceptionally, some polymerizations that proceed via chain reactions that, according to the definition, are not chain polymerizations. For example, the polymerization

HS—X—SH + H2C=CH—Y—CH=CH2 Æ S—X—S—CH2—CH2—Y—CH2—CH2

proceeds via a radical chain reaction with intermolecular transfer of the radical center. The growth step, however, involves reactions between molecules of all degrees of polymerization and, hence, the polymerization is classified as a polyaddition (see Definition 3.8). If required, the classification can be made more precise and the polymerization described as a chain-reaction polyaddition.

3.7 polycondensation

A polymerization (see Definition 3.1) in which the growth of polymer (see Definition 1.1) chains (see Definition 1.30) proceeds by condensation reactions between molecules of all degrees of polymerization (see Definition 1.13).

Notes
1. The growth steps are expressed by

Px + Py Æ Px+y + L {x} Œ {1, 2, º }; {y} Œ {1, 2, º }

where Px and Py denote chains of degree of polymerization x and y, respectively, and L a low-molar- mass by-product.
2. The earlier term polycondensation was synonymous with condensation polymerization. It should be noted that the current definitions of polycondensation and condensative chain polymerization were both embraced by the earlier term polycondensation.

 

 

3.8 polyaddition

A polymerization (see Definition 3.1) in which the growth of polymer (see Definition 1.1) chains (see Definition 1.30) proceeds by addition reactions between molecules of all degrees of polymerization (see Definition 1.13).

Notes
1. The growth steps are expressed by

Px + Py Æ Px+y {x} Œ {1, 2, º }; {y} Œ {1, 2, º }

where Px and Py denote chains of degrees of polymerization x and y, respectively.
2. The earlier term addition polymerization embraced both the current concepts of polyaddition and chain polymerization, but did not include condensative chain polymerization.

3.9 statistical copolymerization

A copolymerization (see Definition 3.4) in which a statistical copolymer (see Definition 2.9) is formed.

3.10 random copolymerization

A copolymerization (see Definition 3.4) in which a random copolymer (see Definition 2.10) is formed.

 

 

3.11 alternating copolymerization

A copolymerization (see Definition 3.4) in which an alternating copolymer (see Definition 2.11) is formed.

3.12 periodic copolymerization

A copolymerization (see Definition 3.4) in which a periodic copolymer (see Definition 2.12) is formed.

3.13 ring-opening polymerization

A polymerization (see Definition 3.1) in which a cyclic monomer (see Definition 2.1) yields a monomeric unit (see Definition 1.8) which is acyclic or contains fewer cycles than the monomer.

Note
If the monomer is polycyclic, the opening of a single ring is sufficient to classify the reaction as a ring-opening polymerization.

3.14 ring-opening copolymerization

A copolymerization (see Definition 3.4) which is a ring-opening polymerization (see Definition 3.13) with respect to at least one monomer (see Definition 2.1).

3.15 radical polymerization

A chain polymerization (see Definition 3.6) in which the kinetic-chain carriers are radicals.

Note
Usually, the growing chain end bears an unpaired electron.

 

3.16 radical copolymerization

A copolymerization (see Definition 3.4) which is a radical polymerization (see Definition 3.15).

3.17 ionic polymerization

A chain polymerization (see Definition 3.6) in which the kinetic-chain carriers are ions or ion-pairs.

Note
Usually, the growing chain ends are ions.

3.18 ionic copolymerization

A copolymerization (see Definition 3.4) which is an ionic polymerization (see Definition 3.17).

3.19 anionic polymerization

An ionic polymerization (see Definition 3.18) in which the kinetic-chain carriers are anions.

3.20 cationic polymerization

An ionic polymerization (see Definition 3.18) in which the kinetic-chain carriers are cations.

3.21 living polymerization

A chain polymerization from which chain transfer and chain termination are absent.

Note
In many cases, the rate of chain initiation is fast compared with the rate of chain propagation, so that the number of kinetic-chain carriers is essentially constant throughout the polymerization.

3.22 living copolymerization

A copolymerization (see Definition 3.4) which is a living polymerization (see Definition 3.21).

3.23 cyclopolymerization

A polymerization (see Definition 3.1) in which the number of cyclic structures in the constitutional units (see Definition 1.14) of the resulting macromolecules (see Definition 1.1) is larger than in the monomer molecules (see Definition 1.3).

3.24 chain scission

A chemical reaction resulting in the breaking of skeletal bonds (see Definition 1.50).

3.25 depolymerization

The process of converting a polymer (see Definition 2.2) into a monomer (see Definition 2.1) or a mixture of monomers.

Note
Unzipping is depolymerization occurring by a sequence of reactions, progressing along a macromolecule (see Definition 1.1) and yielding products, usually monomer molecules (see Definition 1.3), at each reaction step, from which macromolecules similar to the original can be regenerated.



 


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