IUPAC polymer nomenclature

Last updated

IUPAC Polymer Nomenclature are standardized naming conventions for polymers set by the International Union of Pure and Applied Chemistry (IUPAC) and described in their publication "Compendium of Polymer Terminology and Nomenclature", which is also known as the "Purple Book". [1] [2] Both the IUPAC [3] and Chemical Abstracts Service (CAS) make similar naming recommendations for the naming of polymers.

Contents

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 (Mm) to the number-average molar mass (Mn) i.e. Đ = Mm/Mn. [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 idealized representations meaning 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 the 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. [1]

Source-Based Nomenclature

Homopolymers

Homopolymers are named using the name of the real or assumed monomer (the ‘source’) from which it is derived, e.g., poly(methyl methacrylate). [5] Monomers can be named using IUPAC recommendations, or well-established traditional names. [6] Should ambiguity arise, class names can be added.

polyalkylene:vinyloxirane (left) and polyether:vinyloxirane (right) Polyalkylene colon vinyloxirane and polyether colon vinyloxirane.png
polyalkylene:vinyloxirane (left) and polyether:vinyloxirane (right)

For example, the source-based name poly(vinyloxirane) could correspond to either of the structures shown. 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.

Copolymers

The structure of a copolymer can be described using the most appropriate of the connectives shown in Table 1. [7] These are written in italic font.

Qualifiers for copolymers [7]
CopolymerQualifierExample
unspecifiedco (C)poly(styrene-co-isoprene)
statisticalstat (C)poly[isoprene-stat-(methyl methacrylate)]
randomran (C)poly[(methyl methacrylate)-ran-(butyl acrylate)]
alternatingalt (C)poly[styrene-alt-(maleic anhydride)]
periodicper (C)poly[styrene-per-isoprene-per-(4-vinylpyridine)]
blockblock (C)poly(buta-1,3-diene)-block-poly(ethene-co-propene)
graftagraft (C)polystyrene-graft-poly(ethylene oxide)

a The first name is that of the main chain.

Non-linear polymers

Non-linear polymers and copolymers, and polymer assemblies are named using the italicized qualifiers in Table 2. [5] 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.

Qualifiers for non-linear (co)polymers and polymer assemblies [5]
(Co)polymerQualifierExample
blendblend (C)poly(3-hexylthiophene)-blend-polystyrene
combcomb (C)polystyrene-comb-polyisoprene
complexcompl (C)poly(2,3-dihydrothieno[3,4-b][1,4]dioxine)-compl-

poly(vinylbenzenesulfonic acid)a

cycliccyclo (P)cyclo-polystyrene-graft-polyethylene
branchbranch (P)branch-poly[(1,4-divinylbenzene)-stat-styrene]
networknet (C or P)(net-polystyrene)-ipn-[net-poly(methyl acrylate)]
interpenetrating networkipn (C)(net-polystyrene)-ipn-[net-poly(methyl acrylate)]
semi-interpenetrating polymer networksipn (C)(net-polystyrene)-sipn-polyisoprene
starstar (P)star-polyisoprene

a In accordance with IUPAC organic nomenclature, square brackets indicate the nature of the locant sites in fused ring systems. [8]

Structure-Based Nomenclature

Regular single-strand organic polymers

In place of the monomer name used in source-based nomenclature, structure-based nomenclature uses that of the "preferred constitutional repeating unit" (CRU). [9] It can be determined as follows:

  1. A large enough part of the polymer chain is drawn to show the structural repetition.
    Consider as an example:
    IUPAC example polymer for structure based nomenclature.png
  2. The smallest repeating portion is a CRU, so all such possibilities are identified (including multiple directional possibilities for the chain).
    For the preceding polymer, they are:
    IUPAC all CRUs of example polymer for struture based representation.png
  3. The subunits that make up each of these structures are identified, i.e., the largest divalent groups that can be named using IUPAC nomenclature of organic chemistry.
    In the example, the two-carbon ethylidene unit is longer than two separate one-carbon methanediyl units.
    Figure 1. The order of subunit precedence. The subunit with the highest precedence is at the top centre. Subunits of lower precedence 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 arrow to follow. Decision tree for IUPAC polymer nomenclature.png
    Figure 1. The order of subunit precedence. The subunit with the highest precedence is at the top centre. Subunits of lower precedence 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 arrow to follow.
  4. Using the shortest path in order of decreasing precedence of subunits, the correct order of the subunits is determined using Figure 1.
    In the example, the oxy subunits in the CRUs are heteroatom chains. From Figure 1, oxy subunits are take precedence over acyclic carbon chain subunits.
  5. The preferred CRU is chosen as that with the lowest possible locant(s) for substituents.
    In the example, there is a bromo-substituted -CH2-CH2- subunit. 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)].

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). [10]

Representations of divalent groups in polymers [9]
NameGroupaNameGroupa
oxypropylimino IUPAC propylimino divalent group.png
sulfanediylhydrazine-1,2-diyl
sulfonylphthaloyl IUPAC phthaloyl divalent group.png
diazenediyl1,4-phenylene IUPAC 1,4-phenylene divalent group.png
iminocyclohexane-1,2-diyl IUPAC cyclohexane-1,2-diyl divalent group.png
carbonylbutane-1,4-diyl
oxalyl1-bromoethane-1,2-diyl IUPAC 1-bromoethane-1,2-diyl divalent group.png
silanediyl1-oxopropane-1,3-diyl
ethane-1,2-diylethene-1,2-diyl
methylenemethylmethylene IUPAC methylmethylene divalent group.png

a To avoid ambiguity, wavy lines drawn perpendicular to the free bond,
which are conventionally used to indicate free valences, [11]
are usually omitted from graphical representations in a polymer context.

Regular double-strand organic polymers

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. [12]

An example is Regular double-strand organic polymer.png The preferred CRU is an acyclic subunit of 4 carbon atoms with 4 free valences, one at each atom, as shown.

IUPAC Regular double-strand organic polymer CRU.png

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.

Nomenclature of Inorganic and Inorganic-Organic Polymers

Poly[(dimethylsilanediyl)ferrocene-1,1'-diyl IUPAC example Single-Strand Inorganic Polymer.png
Poly[(dimethylsilanediyl)ferrocene-1,1'-diyl

]Some regular single-strand inorganic polymers can be named like organic polymers using the rules given above, e.g., [O−Si(CH3)2]n and [Sn(CH3)2]n are named poly[oxy(dimethylsilanediyl)] and poly(dimethylstannanediyl), respectively. [13] Inorganic polymers can also be named in accordance with inorganic nomenclature, but the seniority of the elements is different from that in organic nomenclature. However, certain inorganic and inorganic-organic polymers, for example those containing metallocene derivatives, are at present best named using organic nomenclature, e.g., the polymer shown can be named poly[(dimethylsilanediyl)ferrocene-1,1'-diyl].

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.

Graphical Representations

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. [11] [14]

Examples graphical representations prepared in accordance with IUPAC recommendations.png

CA Index Names

CAS maintains a registry of substances. [15] 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. [16] [17]

Related Research Articles

<span class="mw-page-title-main">Colloid</span> Mixture of an insoluble substance microscopically dispersed throughout another substance

A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend the definition to include substances like aerosols and gels. The term colloidal suspension refers unambiguously to the overall mixture. A colloid has a dispersed phase and a continuous phase. The dispersed phase particles have a diameter of approximately 1 nanometre to 1 micrometre.

In chemistry, a monomer is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.

<span class="mw-page-title-main">Polymer</span> Substance composed of macromolecules with repeating structural units

A polymer (;) is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals.

<span class="mw-page-title-main">Macromolecule</span> Very large molecule, such as a protein

A macromolecule is a very large molecule important to biological processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. The most common macromolecules in biochemistry are biopolymers and large non-polymeric molecules such as lipids, nanogels and macrocycles. Synthetic fibers and experimental materials such as carbon nanotubes are also examples of macromolecules.

In polymer chemistry, ring-opening polymerization (ROP) is a form of chain-growth polymerization in which the terminus of a polymer chain attacks cyclic monomers to form a longer polymer. The reactive center can be radical, anionic or cationic. Some cyclic monomers such as norbornene or cyclooctadiene can be polymerized to high molecular weight polymers by using metal catalysts. ROP is a versatile method for the synthesis of biopolymers.

<span class="mw-page-title-main">Dispersity</span> Measure of heterogeneity of particle or molecular sizes

In chemistry, the dispersity is a measure of the heterogeneity of sizes of molecules or particles in a mixture. A collection of objects is called uniform if the objects have the same size, shape, or mass. A sample of objects that have an inconsistent size, shape and mass distribution is called non-uniform. The objects can be in any form of chemical dispersion, such as particles in a colloid, droplets in a cloud, crystals in a rock, or polymer macromolecules in a solution or a solid polymer mass. Polymers can be described by molecular mass distribution; a population of particles can be described by size, surface area, and/or mass distribution; and thin films can be described by film thickness distribution.

In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry. Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.

<span class="mw-page-title-main">Copolymer</span> Polymer derived from more than one species of monomer

In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are sometimes called bipolymers. Those obtained from three and four monomers are called terpolymers and quaterpolymers, respectively. Copolymers can be characterized by a variety of techniques such as NMR spectroscopy and size-exclusion chromatography to determine the molecular size, weight, properties, and composition of the material.

<span class="mw-page-title-main">Oligomer</span> Molecule composed of copies of a small unit

In chemistry and biochemistry, an oligomer is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers. The name is composed of Greek elements oligo-, "a few" and -mer, "parts". An adjective form is oligomeric.

In organic chemistry, a substituent is one or a group of atoms that replaces atoms, thereby becoming a moiety in the resultant (new) molecule.

Barrelene is a bicyclic organic compound with chemical formula C8H8 and systematic name bicyclo[2.2.2]octa-2,5,7-triene. First synthesized and described by Howard Zimmerman in 1960, the name derives from the resemblance to a barrel, with the staves being three ethylene units attached to two methine groups. It is the formal Diels–Alder adduct of benzene and acetylene. Due to its unusual molecular geometry, the compound is of considerable interest to theoretical chemists.

<span class="mw-page-title-main">Suspension polymerization</span> Polymerization reaction among monomers suspended in a liquid

In polymer chemistry, suspension polymerization is a heterogeneous radical polymerization process that uses mechanical agitation to mix a monomer or mixture of monomers in a liquid phase, such as water, while the monomers polymerize, forming spheres of polymer. The monomer droplets are suspended in the liquid phase. The individual monomer droplets can be considered as undergoing bulk polymerization. The liquid phase outside these droplets help in better conduction of heat and thus tempering the increase in temperature.

In polymer chemistry, an inorganic polymer is a polymer with a skeletal structure that does not include carbon atoms in the backbone. Polymers containing inorganic and organic components are sometimes called hybrid polymers, and most so-called inorganic polymers are hybrid polymers. One of the best known examples is polydimethylsiloxane, otherwise known commonly as silicone rubber. Inorganic polymers offer some properties not found in organic materials including low-temperature flexibility, electrical conductivity, and nonflammability. The term inorganic polymer refers generally to one-dimensional polymers, rather than to heavily crosslinked materials such as silicate minerals. Inorganic polymers with tunable or responsive properties are sometimes called smart inorganic polymers. A special class of inorganic polymers are geopolymers, which may be anthropogenic or naturally occurring.

In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among all possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choosing between multiple possibilities in situations where it is important to decide on a unique name. It is intended for use in legal and regulatory situations.

<span class="mw-page-title-main">Interpenetrating polymer network</span>

An Interpenetrating polymer network (IPN) is a polymer comprising two or more networks which are at least partially interlaced on a polymer scale but not covalently bonded to each other. The network cannot be separated unless chemical bonds are broken. The two or more networks can be envisioned to be entangled in such a way that they are concatenated and cannot be pulled apart, but not bonded to each other by any chemical bond.

In organic chemistry, Hantzsch–Widman nomenclature, also called the extended Hantzsch–Widman system, is a type of systematic chemical nomenclature used for naming heterocyclic parent hydrides having no more than ten ring members. Some common heterocyclic compounds have retained names that do not follow the Hantzsch–Widman pattern.

The International Union of Pure and Applied Chemistry (IUPAC) publishes many books which contain its complete list of definitions. The definitions are divided initially into seven IUPAC Colour Books: Gold, Green, Blue, Purple, Orange, White, and Red. There is also an eighth book, the "Silver Book".

In polymer chemistry, ionic polymerization is a chain-growth polymerization in which active centers are ions or ion pairs. It can be considered as an alternative to radical polymerization, and may refer to anionic polymerization or cationic polymerization.

<span class="mw-page-title-main">Star-shaped polymer</span> Polymer structure with linear chains connected to a central core

In polymer science, star-shaped polymers are the simplest class of branched polymers with a general structure consisting of several linear chains connected to a central core. The core, or the center, of the polymer can be an atom, molecule, or macromolecule; the chains, or "arms", consist of variable-length organic chains. Star-shaped polymers in which the arms are all equivalent in length and structure are considered homogeneous, and ones with variable lengths and structures are considered heterogeneous.

In chemistry, a ladder polymer is a type of double stranded polymer with the connectivity of a ladder. In a typical one-dimensional polymer, e.g. polyethylene and polysiloxanes, the monomers form two bonds, giving a chain. In a ladder polymer the monomers are interconnected by four bonds. Inorganic ladder polymers are found in synthetic and natural settings. Ladder polymers are a special case of cross-linked polymers because the crosslinks exist only with pairs of chains.

References

  1. 1 2 IUPAC. “The Purple Book”, RSC Publishing, (2008). Retrieved 2012-06-06.
  2. 'Hiorns, R. C.; Boucher, R. J.; Duhlev, R.; Hellwich, K. -H.; Hodge, P.; Jenkins, A. D.; Jones, R. G.; Kahovec, J.; Moad, G.; Ober, C. K.; Smith, D. W.; Stepto, R. F. T.; Vairon, J. -P.; Vohlídal, J.; 'A Brief Guide to Polymer Nomenclature' (retrieved 2013-03-03.; and Pure Appl. Chem.84 (10): 2167–2169. DOI:10.1351/PAC-REP-12-03-05.
  3. IUPAC Nomenclature of Organic Chemistry. Retrieved 2012-06-06.
  4. Stepto, R. F. T.; Gilbert, R. G.; Hess, M.; Jenkins, A. D.; Jones, R. G.; Kratochvíl P. (2009). "Dispersity in Polymer Science" Pure Appl. Chem.81 (2): 351–353. DOI:10.1351/PAC-REC-08-05-02.
  5. 1 2 3 Kahovec, J.; Kratochvíl P.; Jenkins, A. D.; Mita, I.; Papisov, I. M.; Sperling, L. H.; Stepto, R. F. T. (1997). "Source-Based Nomenclature for Non-linear Macromolecules and Macromolecular Assemblies" Pure Appl. Chem.69 (12): 2511–2521.
  6. Bareiss, R. E.; Fox, R. B.; Hatada, K.; Horie, K.; Jenkins, A. D.; Kahovec, J.;Kubisa, P.; Maréchal, E.; Meisel, I.; Metanomski, W. V.; Mita, I.; Stepto, R. F. T.; Wilks, E. S. (2001). "Generic Source-Based Nomenclature for Polymers" Pure Appl. Chem.73 (9): 1511–1519.
  7. 1 2 Ring, W.; Mita, I.; Jenkins, A. D.; Bikales, N. M.; (1985). "Source-Based Nomenclature for Copolymers" Pure Appl. Chem.57 (10): 1427–1440.
  8. "The Blue Book", Introduction, R-0.1.5 Enclosing Marks Retrieved 2012-06-06.
  9. 1 2 3 Kahovec, J.; Fox, R. B.; Hatada, K. (2002). "Nomenclature of Regular Single-Strand Organic Polymers" Pure Appl. Chem.74 (10): 1921–1956.
  10. Fox, R. B.; Bikales, N. M.; Hatada, K.; Kahovec, J. (1994). "Structure-Based Nomenclature for Irregular Single-Strand Organic Polymers" Pure Appl. Chem.66 (4): 873–889.
  11. 1 2 Brecher, J. (2008). "Graphical Representation Standards for Chemical Structure Diagrams" Pure Appl. Chem.80 (2): 277–410.
  12. Metanomski, W. V.; Bareiss, R. E.; Kahovec, J.; Loening, K. L.; Shi, L.; Shibaev, V. P. (1993). "Nomenclature of Regular Double-Strand (Ladder and Spiro) Organic Polymers" Pure Appl. Chem.65 (7): 1561–1580.
  13. Donaruma, L. G.; Block, B. P.; Loening, K. L.; Platé, Tsuruta, T.; Buschbeck, K. Ch.; Powell, W. H.; Reedijk, J. (1985). "Nomenclature for Regular Single-Strand and Quasi-Single-Strand Inorganic and Coordination Polymers" Pure Appl. Chem.57 (1): 149–168.
  14. Bareiss, R. E.; Kahovec, J.; Kratochvíl P. (1994). "Graphic Representations (Chemical Formulae) of Macromolecules" Pure Appl. Chem.66 (12): 2469–2482.
  15. www.cas.org http://www.cas.org/ . Retrieved 2012-06-06.{{cite web}}: Missing or empty |title= (help)[ title missing ]
  16. (1968). "A Structure-Based Nomenclature for Linear Polymers" Macromolecules1 (3): 193–198. DOI: 10.1021/ma60003a001
  17. Wilks, E. S. (1997). "Polymer Nomenclature and Structure:  A Comparison of Systems Used by CAS, IUPAC, MDL, and DuPont. 1. Regular Single-Strand Organic Polymer" J. Chem. Inf. Comput. Sci.37 (2): 171–192.