Antimicrobial and aroma finishing of organic cotton knits using natural colourants and Palmarosa oil microcapsules

Abstract

AbstractOrganic cotton SAHANA variety spun into 30s single yarn dyed with four natural colorants (Arecanut slurry, Eucalyptus leaves, Pomegranate rind and Indigo) and further used for development of single jersy knits. Palmarosa oil was used for the preparation of microcapsules through interfacial polymerization technique and finished on organic knitted fabric by exhaust and pad dry cure methods. The finished organic knit was assessed for effect of laundering on antimicrobial efficiency and aroma intensity. The TGA of Palmarosa microcapsules was found to be better with minimum weight loss at higher temperature than the pure oil, and the morphology of microcapsules was fairly irregular due to preparation conditions. Among the natural colourants, cotton yarn dyed with indigo dye possessed greater colour strength and lesser reflectance than the other dyed samples. The fastness properties of cotton yarn dyed with arecanut slurry exhibited good to excellent colour fastness to washing and sunlight. Irrespective of methods of application, organic cotton knits finished with microcapsules by pad dry cure method showed maximum zone of inhibition compared to knits finished by exhaust method against Staphylococcus aureus and Escherichia coli. The antimicrobial activity of the finished samples was subjected to multiple washing which indicated that knits finished with pad dry cure method showed a zone of inhibition even after 20th wash and better aroma retention compared to knits finished with exhaust method of application. Thus, the Palmarosa microencapsulated organic cotton knits are free from hazardous chemicals and have multi functional properties which can be suitable for medical and healthcare textiles.