An increasingly intimate combination of textile technology and material science has made natural polymers like starch an emerging multidisciplinary field of research with tremendous potential. Starch is seen as a cheap, renewable and biodegradable raw material for the textile industry as an ecofriendly alternative of petroleum based polymers.
However natural starch polymer can not be directly processed to textile products. Natural starch consists of a large number of hydroxyl groups, leading to intensive hydrogen bonding, which results in cross linking. This phenomenon counteracts the melting behavior of the starch and makes the product development through melt processing of the native starch approx. impossible, proves starch as non-thermoplastic polymer. On heating the starch polymer, degradation takes place prior to melting.
To improve the thermoplastic nature of starch various physical and chemical methods of starch modification have been used. Physical methods of starch modification are applied mainly through the modification in the starch granulate structure, which results in partial dissolution of starch in water for exa. Heat moisture treatment, annealing, Retrogradation, freezing, pressure treatment, glow discharge plasma treatment, thermal inhibitation, gelatinization etc.
Chemical modification is an effective way to alter the inherent properties of starches and to improve functionality. An inline modification of the starch with the twin screw extruder and development of an industrial process is a key point to develop the starch based textile products.
The project “Star-Tex” provides the opportunity to establish a process from native starch polymer to a variety of textile products. A consortium with research and industrial partners, coordinated by Institut fuer Textiltechnik of RWTH Aachen University provides the opportunity of the chemical modification of starch and blending of thermoplastic starch in continuous process, followed by filament production and development of textile demonstrator in form of knitted pullover, nonwoven geo- and agrotextiles.
Acknowledgement of financial support – We are very thankful to the “Fachagentur Nachwachende Rohstoffe” for their financial support and appreciation.