Number: 2000-006-1-400
Title: Terminology of polymers with ionizable groups and polymers
containing ions
Task Group
Chairman: P. Kubisa
Members: J.V. Aleman,
D. Jones, M.
Hess, T. Kitayama,
G. Swift, J.
Vohlidal, E. S. Wilks
Completion Date: 2006 - project completed
Objective:
To prepare definitions of terms related to general class of ion-containing
polymers i.e. polymers containing ionic or ionizable groups within a
macromolecule as well as polymeric systems composed of non-ionic macromolecules
and ionic admixtures. The present lack of clarity of terminology in
the field results in confusion and difficulties in proper scientific
and technological understanding.
Description:
Properties of several polymeric materials are related to the presence
of ionic groups being either an inherent fragments of polymer molecules
or present in low molecular weight components of composite polymeric
materials. Ionic polymers contain both covalent and ionic bonds which
together form a chain or network structure. In majority of cases the
covalent bonds form the chain and ionic bonds are additional to this
structure modifying its properties. The presence of both ionic and covalent
bonds makes the ionic polymers a very diverse group of materials and
their physical properties can vary from soft, pliable thermoplastic
materials (e.g. ionomers) via rubbery elastomers reversibly cross-linked
by ionic bonds or ionic aggregates to rigid, highly cross-linked materials
(e.g. ion-exchange resins). Polymers with high content of ionic (or
ionizable) groups are water soluble and are classified as polyelectrolytes.
In principle any macromolecular structure can be transformed into polyelectrolyte
by covalently attaching sufficient number of ionic groups to a polymer
backbone. The importance of this class of ionic polymers stems from
their widespread application in many areas of everyday life and industrial
production as well as the close affiliation of polyelectrolytes with
the processes of living matter (some essential biopolymers, like nucleic
acids and proteins, are polyelectrolytes).
The presence of ionic (or ionizable) groups in polymers may affect
also other properties (e.g. electrical properties) of resulting materials.
Incorporation of ionic groups (by process known as doping) into polymers
containing sequences of coniugated multiple bonds (e.g. polyacetylene)
leads to the increase of the conductivity to the level which is of practical
interest. The electric conductivity may also be imposed by blending
the conducting low molecular weight material (frequently ionic) into
non-conducting polymer matrix. These two groups of systems are structurally
different which is not always reflected in commonly used terminology.
The aim of the project is to formulate clear concepts and definition
of terms related to the structure and properties of polymeric materials
containing ionic or ionizable groups.
Progress:
A manuscript has been prepared for publication in Pure Appl.
Chem. A final document was submitted to public review
comments until 31 May 2005. > see
provisional recommendations
Project completed - IUPAC Recommendations published in Pure
Appl. Chem.
78(11), 2067-2074, 2006.
Last update: 25 October 2006
<project announcement published in
Chem.
Int.
22(5) 2000>