Graphic representations (chemical formulae) of macromolecules (IUPAC recommendations 1994)

Abstract

The unambiguous graphic representation of molecules is specially important for macromolecules, which often exhibit a larger number of structural features than do molecules of low molecular weight. For example, the formula of a copolymer should immediately imply if it is meant to present a block copolymer or a copolymer with an unspecified sequence of monomeric units. Thus, a two-block copolymer consisting of a block containing p monomeric units A and a block comprising q monomeric units B is represented by the formula -(-A-)p-(- B -)-q whereas the corresponding random copolymer is represented by the formula (-a-/-B—)nwhere p + q = n. Overall, the document provides rules and examples for the graphic representation of constitutional repeating units and monomeric units, regular and irregular polymers of simple as well as complex structures, including organic and inorganic homopolymers, alternating and periodic copolymers, statistical, random and unspecified copolymers, block copolymers and graft copolymers, including star polymers. The proposed graphic representations of chemical formulae for polymers are suitable for presentation through graphics computer programs. © 1994 IUPAC