Production, modification, and characterization of natural bamboo fiber

Abstract

In an effort to extract natural bamboo fiber (NBF) from bamboo for textiles and other uses, four bamboo species Bissetii, Giant Gray, Moso, and Red Margin were chosen for investigation. Conventional fibers such as cotton, polyester, regular rayon, and 12 commercial bamboo viscose were included for comparative study. By using different chemicals and routes, 144 types of NBFs were produced. Assessments on fiber yield percentages (40-77%), average lengths (1.50-37.10 cm), fineness (9.68—93.3 Tex), and overall qualities, determined at least 47 sets were prospective for commercial use. Hand-spinning was executed on three sets of NBFs after blending with cotton fibers. Investigation on moisture regain (M_R) and moisture content (M_C), revealed that bamboo plants and NBFs had M_R=8.0% and M_R=7.5% which was lower than rayon and bamboo viscose fiber (~11% and ~10%) but higher than raw cotton fibers (~5.7% and 5.4%). Among tensile properties, breaking tenacity of longer NBFs (33-37 cm) was 64-140 N/Tex and elongation at break was 2.0-2.5%; these values were 1.50-2.50 N/Tex and 8.0-11.0% respectively for blended yarns. Elemental, chemical, and crystallographic investigations were accomplished by energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infra-Red), Raman spectroscopy (RS) and X-ray diffraction (XRD) techniques. Bamboo plants were estimated to be 70-78% carbon (C) and 20-30% oxygen (O) atoms, and O/C ratio of 0.26-0.33. The NBFs had a higher O/C ratio of 0.58-0.70. Comparisons of the spectra revealed the differences between bamboo-NBF and other fibers. Some distinct lignocellulosic peaks were in NBFs that could be responsible for unique properties. The crystallinity index (CI) of bamboo plants was 63-67% but CI of NBFs was higher 69-73% with crystallite sizes of 35-39 Å (3.5-3.9 nm). Four reflection planes and other properties are also documented. A suitable antibacterial test method was modified for quantitative estimation of bacterial reduction. Results suggest that though 11 out of 12 bamboo viscose products failed to exhibit inhibition against the bacteria, most of the bamboo and NBF specimens successfully showed a bacterial reduction of 8-95% against Klebsiella pneumoniae and 3-50% against Staphylococcus aureus.