Biodegradable Behavior of Waste Wool and Their Recycled Polyester Preforms in Aqueous and Soil Conditions

Present study deals with the biodegradable behavior of individual components and their preforms of nonwoven biocomposites developed from waste wool fibers including coring wool(CW),dorper wool(DW)and recycled polyester fibers(RPET).A respirometric technique was employed to estimate the production of CO_(2) during the biodegradation experiments under soil and aqueous media conditions.Functional groups of test samples before and after biodegradation were analyzed using Fourier transform infrared spectroscopy(FTIR).Leaching chemicals such as formaldehyde(hydrolyzed)and Chromium VI(Cr VI)was also measured.The CO_(2) emission in wool fibers CW and DW indicated 90%and 60%biodegradation in soil burial and aqueous media conditions respectively,for 100 days incubation.RPET fibers,20%and 10%biodegradation in soil burial and aqueous media conditions was measured respectively while the preforms of waste wool and RPET reflected 30%and 25%biodegradation in soil burial and aqueous media conditions,respectively.The degradation of end functional groups such as carbonyl(keto and ester),aldehyde and hydroxyl were also confirmed by FTIR.The DW and CW wool fibers showed higher Cr(VI)concentration as compared to the RPET.The released formaldehyde results showed higher concentration for RPET preforms as compared to waste wool preforms.These results suggest that waste wool preforms are extremely environment friendly as compared to RPET preforms.Thus,waste wool preforms it can be potentially utilized for preparing biocomposite materials and associated biobased products.

Comparison of Methods for Extraction of Keratin from Waste Wool

The U.S. sheep industry, more than 80,000 producers of 40 million pounds of raw wool per year, is an important component of the meat industry. New methods for the treatment of domestic wool with keratin isolated from the unmarketable fraction of wool, and functionalized for water, oil, or insect repellency are needed. As a first step in the process, we are evaluating the effectiveness of keratin solubilization via relatively benign methods that use thioglycolic acid, bisulfite or sulfide to reduce disulfide bonds, peracetic acid or percarbonate to oxidize disulfides, and urea/thiourea as hydrogen bond disrupters. The procedures are compared in terms of quality of soluble protein, cost effectiveness, potential for upscaling, environmental and operator safety. Successful completion of this project will provide the basis for commercial development of such methods, followed by functional modification of the soluble keratin, and its application to textiles.

Utilization of waste wool fibers for fabrication of wool powders and keratin:a review

Wool fiber contains approximately 95%keratinous proteins,which is one of the most abundant sources of structural protein.However,a large amount of wool waste is underutilized.Developing appropriate approaches to recycle wool waste and produce value-added products is vital for sustainable development and reducing environmental burden.Thus,this paper reviews the mechanical methods of fabricating wool powder,including pan milling,combined wet and air-jet milling,steam explosion,freeze milling,and three-stage milling.The influencing factors of shape and size,structure,and properties are highlighted to overview of the possible controlling methods.Then,this review summarizes various chemical methods for the extraction of wool keratin,underlining the dissolution efficiency and the structure of wool keratin.Furthermore,the application of reused wool particles in textile,biosorbent,and biomaterials are also reported.Finally,several perspectives in terms of future research on the fabrication and application of wool particles are highlighted.

A novel strategy for producing high-performance continuous regenerated fibers with wool-like structure

We proposed a novel approach to prepare high-performance continuous regenerated keratin fibers with wool-like structure by using the cortical cells and linear keratin from wool waste as reinforcement and adhesive,respectively.The spindle-shaped cortical cells were taken from wool waste based on the different responses of cortical cells and mesenchyme in wool to the treatments of H_(2)O_(2) oxidation and ultrasonication.The linear keratin was yielded through dissolving wool waste in the green solution consisting of starch derived dithiothreitol and protein denaturant sodium dodecyl sulfate.The recycled keratin fibers were produced by wet-spinning of the mixture solution comprising of cortical cells,linear keratin and toughener poly(ethylene glycol)diacrylate,and crosslinked by glutaraldehyde and 4,4′-methylenebis-(phenyl isocyanate).The cortical cells were aligned along the regenerated fibers axis and retained quite a fewα-helical crystals of the intermediate filaments,benefitting improvement of mechanical properties.Consequently,the valuable chemical compositions and hierarchical microstructures of wool were largely inherited.Their mechanical properties,thermal stability,dyeing property,moisture absorption capability,and antistatic resistance resembled those of wool.The regenerated fibers contained 93.3 wt.%components of wool,and the amount of synthetic chemicals in the regenerated fibers was controlled to as low as 6.7 wt.%.