
12 Partially Aromatic Poly(amide)s
The earliest commercially utilized poly(amide)
(PA) is silk. Silk is a natural PA. It is produced by
the larvae of the silkworm. Spider silk is a natural PA,
composed from modestamino acids.It canbe regarded
as a natural high performance polymer. The first syn-
thetic PAs were produced in the 1930s, now termed
as nylons, which are pure aliphatic. On the other side
of the product palette of PAs are pure aromatic PAs,
which are addressed as aramids. In aramids, both the
diacid and the diamine moieties are of an aromatic
nature. Whereas nylons are considered as engineering
polymers, aramids are classified as high performance ...