Polymer source-based

A Macromolecular Division of lUPAC was created in 1967, and it created a permanent Commission on Macromolecular Nomenclature, parallel to the other nomenclature commissions. The Commission over the years has issued recommendations on basic definitions, stereochemical definitions and notations, stmcture-based nomenclature for regular single-strand organic polymers and regular single-strand and quasisingle-strand inorganic and coordination polymers, source-based nomenclature for copolymers, and abbreviations for polymers. AH of these are coUected in a compendium referred to as the lUPAC Purple Book (99). 

Polymer (source-based name, structure-based name)... 

The nomenclature of macromolecules can be compHcated when there is Httle or no regularity in the molecules for such molecules, the stmctural details may also be uncertain. In cases where the macromolecule is a polymeric chain with some uncertainties about regularity in its stmcture, a simple expedient is to name the polymer after the monomer that gave rise to it. Thus there are source-based names such as poly(vinyl chloride). 

The more familiar source-based names for these polymers are poly(phenylene oxide) (1), poly(ethylene terephthalate) (2), and polycaprolactam (3). 

The principal observation, which the laboratory scientist should not forget, was that most lifetime assessment of polymers is based on experience from service. Many of the respondents to the survey report examining parts taken from service at the end of life, or those that failed during warranty. Service experience is the principal source of information for the definition of insured lifetimes for polymer components in the construction industry. 

Kamarajugadda, S., and Mazumder, S. Numerical investigation of the effect of cathode catalyst layer structure and composition on polymer electrolyte membrane fuel cell performance. Journal of Power Sources 2008 183 629-642. Krishnan, L., Morris, E. A., and Eisman, G. A. Pt black polymer electrolyte-based membrane-based electrode revisited. Journal of the Electrochemical Society 2008 155 B869-B876. 

Generic source-based nomenclature for polymers (lUPAC Recommendations 200 ), Pure Appl. Chem. 73, 1511-1519 (2001). Errata, Pure Appl. Chem. 74, 2019 (2002). Reprinted as Chapter 21, this edition. 

Formerly, the stmcture-based name, poly[oxy(l-methylethylene)], would have heen acceptable for this molecule but longer is (see page 257 for an explanation of traditional names, strueture-based names and source-based names of polymers). 

The formation of a systematic name for a polymer requires the identification and naming of a preferred constitutional repeating unit (CRU). This basic name is then modified by prefixes, which convey precisely the structural identity of the polymer in question. Such names are referred to as structure-based names. However, polymers can also be named as being derived from a monomer (or precursors), named according to lUPAC rules. Such names are referred to as source-based names. Over the years, rules for determining polymer nomenclature under these two systems have developed in parallel. An example of the modification of the lUPAC name of an organic molecule to lUPAC structure-based and source-based names of a polymer is illustrated below. 

In addition to structure-based and source-based names, there are traditional names (or retained names) for polymers which are widely used, particularly in industry but also in academia. When they meet the requirements of utility and when they fit into the general pattern of systematic nomenclature, these traditional names are retained. The following... 

Two systems of polymer nomenclature have been introduced - the source-based and the structure-based. The latter cannot be used for all types of macromolecule, e.g., statistieal copolymer molecules and polymer networks. lUPAC expresses no strong preference for the use of structure-based nomenclature versus source-based nomenclature, but for certain purposes one system of naming may be preferred to the other.. ... 

The principal deficiency of source-based nomenclature is that the chemical structure of the monomeric unit in a polymer is not identical with that of the monomer, e.g., -CHX-CH2- versus CHX=CH2. The structure of the constitutional repeating unit (CRU) may also not be clearly identified in this scheme for example, the name polyacrylaldehyde does not indicate whether (i) the vinyl group or (ii) the aldehyde group was the locus of polymerization. 

Despite these serious deficiencies, source-based nomenclature is still firmly entrenched in the scientific literature. It originated at a time when polymer science was less developed and the structures of most polymers were ill-defined. The significant advances made during the last 50 years in the structure determination of polymers are gradually shifting the emphasis of polymer nomenclature away from starting materials and toward the structure of the synthesized macromolecules. 

Despite the Commission s long-standing position, the scientific community has continued to use source-based nomenclature for homopolymers such as polystyrene and poly(vinyl acetate) because of their simplicity, convenience and obvious relationship with the monomers from which the homopolymers are prepared. The Commission therefore decided to recommend source-based nomenclature as an alternative official nomenclature for homopolymers in a 2001 publication [2]. Consequently, both source-based and structure-based names are now available for most polymers. The names of monomers in the source-based names may be traditional or semi-systematic, if well established by usage, and not necessarily only those retained in the 1993 A Guide to lUPAC Nomenclature of Organic Compounds [3]. 

The same publication [2] recommended a generic source-based nomenclature, which comprises the optional addition of a polymer class name to the source-based name of the polymer. The addition is recommended when it is necessary to avoid ambiguity or to add clarification. 

Table 4. Examples of structure-based and source-based names for some common polymers ...

Structure-based and source-based nomenclature rules have been extended to regular double-strand (ladder and spiro) organic polymers [7]. A double-strand polymer is defined as a polymer the molecules of which are formed by an uninterrupted sequence of rings with adjacent rings having one atom in common (spiro polymer) or two or more atoms in common (ladder polymer). 

Source-based nomenclature identifies the starting monomer(s) from which the doublestrand polymer is prepared with addition of an appropriate prefix "ladder- or "spiro- . Examples are ... 

The Commission recognized that a number of common polymers have semisystematic or trivial source-based names that are well established by usage it is not intended that they be immediately supplanted by the structure-based names. Nevertheless, it is hoped that for scientific communication the use of semisystematic or trivial source-based names for polymers will be kept to a minimum. 

For the following idealized structural representations, the semisystematic or trivial source-based names given are approved for use in scientific work the corresponding structure-based names are given as alternative names. Equivalent names for close analogues of these polymers [e.g. other alkyl ester analogues of poly(methyl acrylate)] are also acceptable. 

In 1985, the Commission also published rules on source-based nomenclature for copolymers [3] which by definition are polymers derived from more than one species of monomer [4]. 

The source-based nomenclature identifies the starting material(s) from which the ladder or spiro polymer is prepared. It is derived from the nomenclature system for copolymers [3]. The system is based on the following principles ... 

Source-based (co)polymer names [2, 6] are given first, followed by structure-based names [2], if these exist, before the proposed formula. 

In principle, a comprehensive structure-based system of naming copolymers would be desirable. However, such a system presupposes a knowledge of the structural identity of all the constitutional units as well as their sequential arrangements within the polymer molecules this information is rarely available for the synthetic polymers encountered in practice. For this reason, the proposals presented in this Report embody an essentially source-based nomenclature system. 

Further applications of generic source-based names of polymers... 

Most trivial names, such as polystyrene, are source-based names. Hitherto, the Commission has not systematically recommended source-based names for homopolymers because it considered that the more rigorous structure-based names were more appropriate for scientific communications. However, since the publication of Nomenclature of Regular Single-Strand Organic Polymers in 1976, scientists, in both industry and academia, have continued to use trivial names. Even the Commission itself adopted (1985) a source-based nomenclature for copolymers because of its simplicity and practicality. Based on these facts, the Commission has now decided to recommend source-based... 

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