Comprehensive characterization of raw and alkali (NaOH) treated natural fibers from Symphirema involucratum stem.

The present study investigated the effect of alkali treatment on the enhancement of Physico-chemical, tensile, thermal and surface properties of Symphirema involucratum stem fiber (SISF). The investigation of chemical constituents of optimally alkalized SISF revealed that ideal increment of cellulose content (68.69 wt%) and desired modification of other chemical components was accomplished through 60 min immersion period. An increase in the crystallinity index to 33.33% and small crystallite size to 3.21 nm was noted by X-ray diffraction analysis. Moreover, the treated fiber was found suitable for light-weight applications since physical analysis acknowledges that the density of the fiber augmented to 1424 kg/m3after surface treatment that reduces total weight percentage. The enhancements in tensile strength (471.2 ± 19.8 MPa), tensile modulus (5.82 ± 0.77 GPa) and thermal stability (371 °C) were noted that ensures the treated fiber has good mechanical and thermal properties required for composite preparation. These findings validated that the optimally surface-modified SISF is a suitable material for lightweight composite structures, for the time being.

Characterization of novel natural cellulosic fiber extracted from the stem of Cissus vitiginea plant.

In this study, a new natural fiber obtained from the stem of Cissus vitiginea has been studied for the first time. Chemical composition results confirmed that the proposed fiber has a rich amount of cellulose (65.43 wt%) and lower quantity of hemicellulose compounds (14.61 wt%),which in turn leads to better mechanical characteristics. Various chemical groups distributed over the fiber surface were predicted and reported with the help of Fourier transform infrared spectroscope and nuclear magnetic response spectroscopy. The crystalline nature of the fiber surface was examined using X-ray diffraction spectroscopy and the crystallinity index value was calculated to be 30.5% with 12.69 nm crystallite size. Morphological study was conducted on the fiber using a scanning electron microscope. The thermal stability of the fiber was found to be 304 °C with 68.72 kJ/mol kinetic activation energy. Hence C. vitiginea fiber can be suggested as reinforcement for the thermoplastic green composite.