Transcript Dyestuffs

Dyestuffs
David S. Seigler
Department of Plant Biology
University of Illinois
Urbana, Illinois 61801 USA
[email protected]
http://www.life.illinois.edu/seigler
Dyestuffs from plants - Outline
Importance
o Former
o Today
Botanical
Chemical
Indigo
Madder
Mordants
Special uses
o Food
o Laboratory use
o Cosmetics
o Tattoos
Reading
• CHAPTER 15 IN THE TEXT, 372 ff.
Introduction
• Dyeing of fibers has been carried out
since antiquity. Virtually every culture
has its own set of dyestuffs, but a few
have emerged and have been
particularly important.
• Although these dyes were once widely used,
the synthesis of synthetic dyestuffs in 1856 by
William Perkin, an English chemist, and the
subsequent manufacture of synthetic dyes
(mainly by the Germans), replaced almost all
of natural dyes with better quality materials.
• Synthetic dyes are more stable, many bind
more effectively to the fabrics, and they are
more reproducible.
• Some purists still use natural dyes, but except
for food and histological uses, few of them
are important.
Silk dress dyed with synthetic mauve
Chemistry in Britain
• Several dyes from animals have also been
used. Cochineal (Coccus cacti) is a scale
insect that feeds on cacti. It was used by the
Aztecs.
• A related insect from the Middle East
produces a similar dye called kermes.
Scale insect on Opuntia species
Scale insect and effects
of mashing them
Adherence of dyes
• Dyes must adhere to the fibers or they will be
washed out. It is easier to dye animal fibers
than plant fibers.
• Although many plant parts are colored, the
components of some of these parts are not
particularly stable and decompose too quickly
to be useful. Some do not bind well to the
fibers.
• In some cases, the dyestuffs bind tightly by
chemical bonding and in others they are only
bound by hydrophobic interactions.
Mordants
• As early as the Egyptians, it was known that other
substances caused some dyes to bind that
normally would not. These are called mordants.
• Many mordants are metal salts that appear to
form metal bridges between the dye and the fiber
molecules.
• Sometimes mordants came from the
container in which the dyeing was being done
and at other times from dung, urine or other
compounds added.
• Some dyestuffs (such as madder) contain
substances that naturally act as mordants.
• Alum is a commonly used mordant. Cream of
tartar, wood ashes, tannic acid (sumac), and
many other substances have been used.
Woad, Isatis tinctoria, Brassicaceae
• Woad (Isatis tinctoria, Brassicaceae or
Cruciferae) was once widely grown and
utilized as a dyestuff in Europe.
• Woad contains a smaller amount of the
same compounds as found in indigo
(actually these compounds are found in
a number of other plants as well).
Woad, Isatis tinctoria,
Brassicaceae
• The odors produced from processing woad
were legendary. The leaves were crushed
and made into balls which were then allowed
to ferment. After fermentation, the product
was allowed to dry and then refermented
before use to make it soluble.
• In the Middle Ages, woad was a common
article of commerce in Europe.
Indigo (Indigofera tinctoria, Fabaceae)
• Indigo (Indigofera tinctoria, Fabaceae) has
been one of the most important dyestuffs; this
dye was used as far back as 6000 years in
China.
• Indigo produces an intense deep blue color.
The leaves and branches of the plant are
harvested, placed in a vat, covered with
water, and permitted to ferment.
Indigo, Indigofera tinctoria, Fabaceae
R. Bentley and H. Trimen, Medicinal Plants, London, Churchill, 1880
Indigo, Indigofera
tinctoria, Fabaceae
Courtesy Dr. David Rembert
• The sludge of partially rotted plant material
which settles to the bottom is collected and
pressed into cakes.
• When dry, these cakes produce a powder that
makes a colorless solution.
• The color only develops when an item is
dipped into the solution, removed and then
exposed to air.
• See p. 375.
Submerging indigo foliage
under water to
manufacture indigo
http://www.indiamart.com/nccagroindustries/
Indigo dye ready to be added to the dye bath
P. C. Cross, The indigo dyers of Amarapura,
http://www.tribaltextiles.info/Galleries/Amarapura_Indigo_Dyers.htm
When the fabric is first removed from the bath of
indigo dye, it is not blue, but turns blue upon
oxidation by air.
• Indigo dyeing and the cultivation of the plant
originated in India. Because of the good
quality of the dye, indigo became an
important item of trade between India and
other parts of the world by 300 B.C.
• Dyers in Europe tried to resist the importation
of indigo into Europe and were able to do so
for a long time. Finally, however, quality won
out.
• Indigo was an early crop in colonial South
Carolina. South Carolina indigo was
considered excellent, but as the economics
were not too good, it was replaced by rice.
• The leaves contain about 3% indigo.
• Synthetic indigo was produced in 1897.
• Although indigo of commerce came
from an Old World plant, another
species of Indigofera was domesticated
and used as a source of a blue dye by
the Precolumbian inhabitants of
Yucatan.
Baptisia leucantha, false
indigo, Fabaceae
In the Eastern U.S., Indians
sometimes used Baptisia
species, which also contain
indigo, as dyestuffs.
Madder (Rubia tinctoria, Rubiaceae)
• Madder (Rubia tinctoria, Rubiaceae) (see p.
372) has been used since ancient times.
• One form of this dye is sometimes called
Turkey red.
• The dyestuff is found in the root of the plant.
• The compound in the plant is ruberythric acid.
• Alizarin (a compound derived from madder) is
usually used with an aluminum mordant.
• Madder is locally important in the Near
East and indigo is still used in Africa and
India.
Madder (Rubia
tinctoria, Rubiaceae)
• This dyestuff is fast to water and light.
• Madder was formerly used to dye mummy
blankets in Egypt.
• Although the dye is fast, the dyeing process is
complicated.
• The fibers were covered with cheap
vegetable oil (called Turkey red oil), were
then degreased and treated with tannic acid,
followed by a aluminum mordant. The fibers
were then steamed.
Wool dyed with madder
• Changing the mordant can give red, pink,
lilac, orange, black, and brown colored
pigments.
• This dye was introduced into Europe in the
late Middle Ages.
• The Dutch selected lines that were of
superior quality.
• The color of the British soldier's uniform in the
Revolutionary War was produced by madder.
• Alizarin is still used as a biological stain.
Henna (Lawsonia inermis, Lythraceae)
• By 3000 B.C., Greek women used
henna (Lawsonia inermis, Lythraceae)
to dye their hair. The leaves are ground
into a paste that has a great affinity for
protein.
• Henna is still used in hair preparations.
Dyeing the skin with
henna is practiced in
many Near Eastern
countries.
Coutesy Dr. Anita Brinker
Swissair Gazette
Safflower (Carthamus tinctorius, Asteraceae
or Compositae)
• Safflower has been used as a dyestuff for
thousands of years in India and other parts of
the Near East.
• Probably native to Afghanistan and Pakistan.
• Makes a red or yellow fugitive dye.
• Today grown mostly as an oilseed.
Safflower (Carthamus tinctorius, Asteraceae
or Compositae)
Logwood (Haematoxylon campechianum,
Fabaceae)
• Logwood (Haematoxylon campechianum,
Fabaceae) came from the New World.
• The wood of this tree permitted dyeing things
black for the first time.
• Although not used today for dyeing,
haematoxylon stain is used as a histological
stain in blood analysis.
Logwood (Haematoxylon
campechianum,
Fabaceae)
Logwood (Haematoxylon campechianum,
Fabaceae)
Achiote or annatto, Bixa orellana, Bixaceae
• Achiote or annatto, Bixa orellana, Bixaceae,
was used by the Aztecs and Mayans for food
preparation.
• The plant is probably native to Brazil.
• The pulp surrounding the seeds contains a
lipid dye that is soluble in grease and dyes
foods a yellow-orange-red color.
• Achiote is widely used in Latin America, but
also in other parts of the world today.
• This substance is also now used to dye
margarine and similar products.
• See p. 374.
• Achiote contains about 2% vitamin A.
Achiote or annatto,
Bixa orellana,
Bixaceae
Achiote or annatto
Litmus dye comes from the lichen Rochella tinctoria.
The pigment from this lichen has been used for pH
measurement.
• Turmeric (Curcurma longa,
Zingiberaceae) is used mostly today to
color foods (such as pickles), but has
been used to dye clothing.
Genipapo, Genipa
americana, Rubiaceae
Genipapo, Genipa americana, Rubiaceae
• Genipapo or genipa was used to paint the
bodies of many Central and South American
Indian groups. The fruit also is eaten.
Batik dyeing in
Indonesia
Stamping designs
on cloth with
lightly colored
wax.
Dyeing the part of
the cloth that is not
waxed.
Heating the cloth to set the dye and to remove the wax
Applying a second or
third coat of wax before
redyeing the cloth.
Making the presses for applying wax.