Functionalization of cellulosic and polyester textiles using reduced Schiff base (RSB) of eco-friendly vanillin

Vanillin is an active ingredient found in the crop 'vanilla' and is traditionally extracted from the 'vanilla pod'. Vanillin intrinsically is not a suitable candidate for imparting durable functional features into textile substate due to its smaller chemical structure which leads to leaching of the same during washing operation. To enlarge the structure, in the present study, vanillin has been converted into 4-(benzylamino) methyl))-2-methoxyphenol vanillin derivative (reduced Schiff base) with considerable amount of yield by using a simple one-step process and the synthesized product has been characterized by 1H, C13 NMR, FTIR, and Raman analysis. Thereafter, the reduced Schiff base of vanillin (RSB) has been integrated on cotton as well as polyethylene terephthalate (PET) fabric using high temperature high pressure (HT-HP) technique for imparting multiple functionalities. FESEM EDX analysis has confirmed the integration of RSB on both the fabrics by revealing uniform presence of the nitrogen (of the synthesized derivative) on the treated textile materials. Both types of functionalized textiles have demonstrated appealing color shades with an excellent antimicrobial activity of about 90% against Escherichia coli (E. coli) bacteria. The treated fabrics could cater pleasing fragrance and exhibit 90% antioxidant properties. Moreover, enlarged vanillin derivative in the form of RSB can retain its properties in the fabrics even after repeated machine launderings. RSB-treated cotton fabric has shown ultra-violet protection factor (UPF) of 38 which drops to 24 after washing whereas in case of PET treated fabric, the observed UPF values are 265 and 164 before and after washing, respectively. The RSB treatment has been found to be cytotoxically secure and biocompatible as tested on the PET fabric. Other required properties of the treated fabrics such as water absorbency, flexibility, etc. have also been found to be intact. Thus, the presented study reveals a new class of safe material that can be derived from eco-friendly vanillin and has the potential to replace hazardous chemicals that are currently used in textile chemical processing industries.

The online version contains supplementary material available at 10.1007/s10570-023-05085-z.