316
S. Adeel et al.
C
C
O
O
O
O
CH 2
CH 2
n
Fig. 2 Structure of polyester
4 Chemistry of Polyester
The term polyester is known as many esters, a combination of different acids
and alcohols and represented as –CO–O. The composition of polyester is based on
three main groups such as carbonyl groups (–OCO–), methylene groups (–CH 2 ) and
(
) ester group represent in Fig. 2. The interaction with dye molecules takes
place due to the presence of weak hydrogen bonding and Van der Waal’s forces
which has a prominent role in the world of dyeing [13].
5 Classes of Dyes
Dyes are organic molecules which are divided into two main classes according to
origin i.e. Natural dyes and synthetic dyes
5.1 Natural Dyes
These dyes are extracted from different sources, as shown in Fig. 3.
5.2 Synthetic Dyes
Synthetic dyes are those colorants that are synthesized from petroleum. The colored
organic substances are used to dye textile material like cotton, wool, silk, polyester,
leather, nylon [14] and attach themselves by chemical and physical bonding with
fibers and develop the colored textiles. Synthetic dyes have a property of reproducible
shades and colors due to which the use of natural dyes in textiles is obsolete [15].
S. Adeel et al.
C
C
O
O
O
O
CH 2
CH 2
n
Fig. 2 Structure of polyester
4 Chemistry of Polyester
The term polyester is known as many esters, a combination of different acids
and alcohols and represented as –CO–O. The composition of polyester is based on
three main groups such as carbonyl groups (–OCO–), methylene groups (–CH 2 ) and
(
) ester group represent in Fig. 2. The interaction with dye molecules takes
place due to the presence of weak hydrogen bonding and Van der Waal’s forces
which has a prominent role in the world of dyeing [13].
5 Classes of Dyes
Dyes are organic molecules which are divided into two main classes according to
origin i.e. Natural dyes and synthetic dyes
5.1 Natural Dyes
These dyes are extracted from different sources, as shown in Fig. 3.
5.2 Synthetic Dyes
Synthetic dyes are those colorants that are synthesized from petroleum. The colored
organic substances are used to dye textile material like cotton, wool, silk, polyester,
leather, nylon [14] and attach themselves by chemical and physical bonding with
fibers and develop the colored textiles. Synthetic dyes have a property of reproducible
shades and colors due to which the use of natural dyes in textiles is obsolete [15].