A. Patil et al
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high nitrogen content, if the concentration of the cationic agent increases the nitrogen
content on the cotton, it also increases its dyeability considerably [62].
A cationizing agent from soya bean hull was synthesized for eco-friendly saltfree dyeing on cotton substrate. This agent contains amino acid compounds in its
structure which lowers the negative surface of cotton after modification without
affecting its physical property and enhancing the dyeing ability of cationic cotton.
The investigation proved that the soya bean hull was found to be effective cationizing
agent for salt-free dyeing on cotton [63].
The pigments are insoluble in water and they do not have an affinity for cotton.
However, it is observed that cotton can be dyed with pigments if cotton is pretreated with a cationic auxiliary to provide the necessary affinity [64]. The mixture
of chitosan and dendrimer i.e. chitosan-poly(propylene imine) dendrimer hybrid (CSPPI) was found to be more durable and efficient. This CS-PPI hybrid is biocompatible
compound and it can be used for salt-free reactive dyeing to achieve high fixation
and excellent fastness property with zero effluent load [65].
Pigments have no affinity for cotton. Hence, the cationic charge is incorporated
on cotton by applying a cationizing agent. Cotton is first treated with cationizing
agent and dyed with pigment.
In a test, commercial samples of Sandene 2000 and Solidogen NRL were applied
to modify the cotton surface and develop cationic sites for pigment dyeing, the result
obtained was satisfactory to good for rubbing fastness. As the concentration of the
cationizing agent increases, better fixation and level pigment dyeing by exhaust
method was achieved [66].
3.5.3 Finishing
The finishing of textiles is the final process, which depends on consumer requirements. This process is used to enhance the aesthetic and functional properties of
textiles. The variety of finishing agents or textile auxiliaries used in industry are
mostly anionic in nature. The anionic nature of the cotton repelsanionic finishes,
resulting in temporary effect. The cationization of cotton was effectively used to
develop a new approach for durable and improved finishing effects. This process
was studied by many researchers to increase anti-microbial activity, UV-protection
effect and for effluent treatment. The one bath treatment using a mixture of cationizing agents along with other finishing chemicals can give multifunctional finish on
cotton. The chemical surface modification, cationization plays a vital role in finishing as well. If the cationizing agents have multiple reactive sites or inbuilt multiple
properties, then multifunctional finishing is also possible with this treatment. For
instance, chitosan shows cationizing property with an anti-microbial effect on cotton
(Fig. 10).
In conventional finishing treatments, anionic finishes are fixed on cotton with
hydrogen or ionic bonding depending on the type of chemical. In finishing, different
auxiliaries are used as a precursor for fixation of chemical on the cotton surface
(Fig. 11).
303
high nitrogen content, if the concentration of the cationic agent increases the nitrogen
content on the cotton, it also increases its dyeability considerably [62].
A cationizing agent from soya bean hull was synthesized for eco-friendly saltfree dyeing on cotton substrate. This agent contains amino acid compounds in its
structure which lowers the negative surface of cotton after modification without
affecting its physical property and enhancing the dyeing ability of cationic cotton.
The investigation proved that the soya bean hull was found to be effective cationizing
agent for salt-free dyeing on cotton [63].
The pigments are insoluble in water and they do not have an affinity for cotton.
However, it is observed that cotton can be dyed with pigments if cotton is pretreated with a cationic auxiliary to provide the necessary affinity [64]. The mixture
of chitosan and dendrimer i.e. chitosan-poly(propylene imine) dendrimer hybrid (CSPPI) was found to be more durable and efficient. This CS-PPI hybrid is biocompatible
compound and it can be used for salt-free reactive dyeing to achieve high fixation
and excellent fastness property with zero effluent load [65].
Pigments have no affinity for cotton. Hence, the cationic charge is incorporated
on cotton by applying a cationizing agent. Cotton is first treated with cationizing
agent and dyed with pigment.
In a test, commercial samples of Sandene 2000 and Solidogen NRL were applied
to modify the cotton surface and develop cationic sites for pigment dyeing, the result
obtained was satisfactory to good for rubbing fastness. As the concentration of the
cationizing agent increases, better fixation and level pigment dyeing by exhaust
method was achieved [66].
3.5.3 Finishing
The finishing of textiles is the final process, which depends on consumer requirements. This process is used to enhance the aesthetic and functional properties of
textiles. The variety of finishing agents or textile auxiliaries used in industry are
mostly anionic in nature. The anionic nature of the cotton repelsanionic finishes,
resulting in temporary effect. The cationization of cotton was effectively used to
develop a new approach for durable and improved finishing effects. This process
was studied by many researchers to increase anti-microbial activity, UV-protection
effect and for effluent treatment. The one bath treatment using a mixture of cationizing agents along with other finishing chemicals can give multifunctional finish on
cotton. The chemical surface modification, cationization plays a vital role in finishing as well. If the cationizing agents have multiple reactive sites or inbuilt multiple
properties, then multifunctional finishing is also possible with this treatment. For
instance, chitosan shows cationizing property with an anti-microbial effect on cotton
(Fig. 10).
In conventional finishing treatments, anionic finishes are fixed on cotton with
hydrogen or ionic bonding depending on the type of chemical. In finishing, different
auxiliaries are used as a precursor for fixation of chemical on the cotton surface
(Fig. 11).