Investigation on structure and characteristics of alpaca-based wet-spun polyacrylonitrile composite fibers by utilizing natural textile waste

The composite alpaca/acrylic fibers were auspiciously produced through a wet spinning technique to reduce the consumption of petroleum‐based polyacrylonitrile (PAN) and to enhance the thermal stability and moisture properties of the fibers. The waste alpaca fibers were converted into powder using a mechanical milling method without applying any chemicals. Alpaca powders were then blended with the PAN dope solution in different weight ratios of alpaca: PAN (10:90, 20:80, and 30:70) to wet spin the composite fibers. The Fourier transform infrared spectroscopy showed that all the composite fibers possess the functional groups of both alpaca and PAN. The nuclear magnetic resonance spectroscopy confirmed the presence of typical carbonyl carbon (CO) and nitrile carbon (C≡N) peaks of protein and PAN, respectively. The differential scanning calorimetry and thermogravimetric analysis revealed the enhanced thermal stability of alpaca/PAN composite fibers. The moisture properties of the composite fibers were subsequently found to increase with the incorporation of alpaca, more than three times that of pure PAN fibers. These results revealed a potential green pathway to producing composite acrylic fibers with improved thermal and moisture properties by applying textile waste materials.