Chemistry Reference
In-Depth Information
1.10
Polymer Nomenclature
Custom then is the great guide of human life.
—David Hume, Concerning Human Understanding
A systematic IUPAC nomenclature exists for polymers just as it does for organic
and inorganic chemicals. This polymer nomenclature is rarely used, however,
because a trivial naming system is deeply entrenched through the force of usage.
A similar situation prevails with all chemical species that are commercially
important commodities. Thus, large-scale users of the compound 1-40
CH
3
C
O
CH
2
CH
3
1-40
will know it as MEK (methyl ethyl ketone) rather than 2-butanone. The com-
mon polymer nomenclature prevails in the scientific as well as the technological
literature. (It is not used in Chemical Abstracts and reference should be made to
Volume 76 [1972] of that journal for the indexing of polymers.)
Reference
[4]
gives details of the systematic IUPAC nomenclature. The
remainder of this section is devoted to a review of the common naming system, a
knowledge of which is needed in order to read current literature.
Although the common naming system applies to most important polymers, the
system does break down in some cases. When inconsistencies occur resort is
made to generally accepted conventions for assignment of names to particular
polymers. The nomenclature is thus arbitrary in the final analysis. It usually
works quite smoothly because there are probably no more than a few dozen poly-
mers that are of continuing interest to the average worker in the field, and the bur-
den of memorization is thus not excessive. The number of polymeric species that
require frequent naming will eventually become too large for convenience in the
present system, and a more formal nomenclature will probably be adopted in
time.
Although there are no codified rules for the common nomenclature,
the
following practice is quite general.
Polymers are usually named according to their source, and the generic term is
“polymonomer” whether or not the monomer is real. Thus we have polystyrene
(1-1) and poly(vinyl alcohol) (1-7). Similarly, polyethylene is written as 1-3
although the representation (CH
2
)
2n
and the corresponding name “polymethylene”
could have been chosen equally well to reflect the nature of the repeating unit.
The monomer name is usually placed in parentheses following the prefix
“poly” whenever it includes a substituted parent name like poly(1-butene) (1-41)
or a multiword name like poly(vinyl chloride) (1-4):
