Number: 2001-081-1-800
Title: Terminology and structure-based
nomenclature of dendritic and hyperbranched polymers
Task Group
Chairman: J. Kahovec
Members: M.
Baron, R.B. Fox,
K. Horie, P.
Kubisa, W.V.
Metanomski, I. Mita,
R.F.T. Stepto, E.S.
Wilks, and J.
Wisniewsski
Objective:
About 15 years ago, a major new class of polymer, the dendrimers,
began to be synthesized. Dendrimers are part of a larger class of
polymer, hyperbranched polymers, which have also become more actively
studied. Industry is very interested in dendritic and hyperbranched
polymers because of their highly branched molecular structures,
leading to their applications, for example, as viscosity controllers,
highly reactive intermediates and release agents for chemicals (drugs,
flavors, dyes, etc.). The need to name such polymers systematically
is widely recognized. However, if even oligomeric dendrimers are
named using organic chemistry nomenclature, very long names result
which obscure the chemical constitution and the Commission for Nomenclature
in Organic Chemistry (CNOC) has aborted its attempt to define their
nomenclature. It is recognized that an approach using the concepts
of structure-based macromolecular nomenclature has much more chance
of success.
A start in naming dendrimers has already
been made in the literature by Newkome et al (J. Polym. Sci.
1993, 31, 641). Unlike that nomenclature, the nomenclature of both
dendrimers and hyperbranched polymers according to the project is
based on priciples of structure-based nomenclature of regular single-strand
organic polymers, but embraces also dendrimers and hyperbranched
polymers of more general, less regular structures. In addition,
an integral part of the work will also be the development of the
basic terminology, enabling different types of branching, or molecular
architecture to be described precisely. Even that does not exist
at present. The project has undergone a thorough feasibility study,
the results of which have been discussed by the Commission.
Progress:
Major progress has been made since the project was launched. Basic
terms pertinent to dendritic and hyperbranched oligomers and polymers
have been defined. The main principles of a new method of naming
them, based on the concept of constitutional repeating unit and
providing for core and end units were elaborated. The method will
now be tuned to meet requirements and checked on the basis of numerous
examples from the literature; if necessary, the rules will be modified
and additional rules added. In addition to defining a structure-based
nomenclature, an attempt will also be made to design a source-based
nomenclature.
Last update: 17 April 2007