Analytical approaches and advancement in the analysis of natural and synthetic fiber: A comprehensive review

Background: Accurately determining fiber composition is essential for optimizing material properties across diverse applications in textiles, composites, packaging, and other bio-based materials. Fiber performance in textiles, composites, and bio-based materials depends upon their intricate composition. This review explores advanced analytical techniques for the comprehensive characterization of natural (cellulose-hemicellulose-lignin) and synthetic (polymeric) fibers. Natural fibers primarily consist of cellulose, hemicellulose, and lignin, while synthetic fibers are formed by linking small monomer units, such as nylon, polyester, and acrylics. Results: A variety of analytical methods are employed for fiber composition analysis, including microscopy, spectroscopy, chromatography, thermal analysis, and wet chemical methods. A multi-modal approach employing advanced techniques is essential for in-depth fiber analysis. Spectroscopic methods like Fourier Transform Infrared Spectroscopy (FTIR) offer rapid, non-destructive determination of chemical functionalities. Near-infrared spectroscopy (NIR) offers another efficient approach, particularly when integrated with chemometric techniques like Principal Component Regression (PCR) and Partial Least Squares (PLS) for precise quantification of cellulose, hemicellulose, and lignin. Additionally, thermal analysis methods such as Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA) provide insights into thermal stability and mechanical characteristics of fibers. Significance: This review emphasizes the importance of an integrated approach utilizing various analytical methods for comprehensive fiber characterization. While traditional wet chemical methods offer limited advantages, the combined use of advanced techniques provides a more holistic understanding of fiber properties. As technology evolves, this integrated approach is expected to shape the future of fiber analysis and its applications across diverse industries.