Microencapsulation of curcumin dye with beta-cyclodextrin embedded in Ioncell® fibres by means of dry jet wet spinning

Abstract

Development of regenerated cellulosic fibres (RCFs) opened up new ventures into the world of sustainable textiles. IONCELL® is a sustainable process which utilizes the IL, [DBNH][OAc] to dissolve cellulose. Through dry-jet wet spinning RCFs with great properties are generated which might be turned into functional textiles. Various spin solutions were prepared by mixing 1% curcumin and/or 2% ß-CDs with standard kraft bleached pulp dissolved in [DBNH][OAc]. Fibers were produced through the IONCELL® process and analysed in detail. All the properties were compared with IONCELL® standard fibers. The properties of all dopes were tested by rheology. The complex viscosity and dynamic moduli of the viscoelastic solutions were close to the standard IONCELL® dope. The presence of microcapsules of ß-CD with curcumin were confirmed by FTIR, XRD, DSC and TGA techniques. The mechanical properties of the generated fibres such as orientation was as high as 0.80 ± 0.12 with an average dry tenacity of 43.6 ± 5.4 cN/dtex. The colour stability of the spin-dyed fibres was compared with fibres dyed by post spinning through 30% ethanol solution. Washing fastness values for spin-dyed fibres was as high as 5 for both colour change and staining. The fibers showed a crystallite size of 41.4 ± 1.0, 35.5 ± 0.1 and 35.8 ± 0.2 Å for (1 ̅10), (110) and (020) regions for the cellulose-II polymorph, respectively. CRI was as high as 79.1 ± 0.7% which is very close to standard IONCELL® fibre. The amount of fixed ß-CD onto the fibres was quantified. With a 2 % addition of ß-CD on pulp 0.1 ± 0.03% ß-CD was fixed onto the regenerated fibres.