The mechanical properties and biodegradability of retted kenaf and modified starch composites fabricated by adding enzyme-retted kenaf as a filler and poly(vinyl alcohol) (PVA), poly(ethylene glycol), or glycerol as a plasticizer are compared with those of the NaOH-retted counterparts fabricated under identical conditions. In the case of enzyme retting, the composite treated with the PVA plasticizer was deemed the most appropriate for achieving optimal tensile strength, flexural strength, and flexural modulus. Further, the retting treatment, the length of the kenaf fiber, the type of treatment (single- or double-sided), and the adhesion force at the interface significantly affect the mechanical properties of the composites. According to the aerobic biodegradability assessment in natural reclamation conditions, the modified starch composite fabricated using 50-mm-long enzyme-retted kenaf fibers as the filler and double-side treated with PVA plasticizer showed a biodegradation rate of 80% or higher after 80 days.

Waste recycling is a necessary step for environmental conservation. To this end, polyester can be easily collected and recycled into end products. To promote the use of recycled polyester, it is important to expand its range of applications. We earlier reported the fabrication of recycled polyester thermal-bonded nonwovens. In this study, recycled nonwoven fabrics were dyed with Terminalia chebula dye without the use of additional mordants. To optimize the dyeing conditions, the dyeing time, dyeing temperature, and liquor concentration were varied, and the color strength, color changes, fastness properties, thermal stability, and morphology were evaluated. Further, the antibacterial activity of the dyed nonwoven was also estimated. T. chebula dyed the colored recycled rapid melting PET fiber (R-RM) nonwoven brown via the dyeing process, and the dyeablity was improved by increasing the dyeing temperature, time, and liquor concentration. The rubbing and sweat fastness properties were found to be excellent. T. chebula dye imparted efficient antibacterial properties to the R-RM nonwovens against Staphylococcus aureus and Klebsiella pneumonia. The results obtained in this study are expected to broaden the range of natural dyed recycled polyester fabric applications.

A novel smectite post-treatment is developed for enhancement of both washing fastness and light fastness by simultaneous intercalation of pre-dyed cationic dyes.