RETRACTED: Evaluation of the potential of Yushina alpina bamboo fibers from Cameroon for the manufacture of biocomposites

Abstract

The Cameroon has two bamboo species indigenous to Africa (the <i>alpine bamboo, Yushina alpina</i> and the <i>savannah bamboo, Oxytenanthera abyssinica</i>), and one largely exotic species, <i>Bambusa vulgaris</i>. However, little on their physical characteristics and strength for the composites materials applications is known for these two indigenous bamboos species in Cameroon. Therefore, in this study, emphasis was laid on the alpine bamboo <i>Y. alpina</i>, to evaluate its potential for biocomposites applications. <i>Y. alpina</i> with ages ranging from 1 to 3 years, 4-5 years, and 7 years were characterized. The mechanical and physical properties of these three age ranges were compared. In the first place, the surface texture of the fibers was examined by scanning electron microscopy. Afterwards, chemical treatment was performed on the fibers with 1 % NaOH. In addition, the chemical bonds of the molecules (functional groups) were identified by Fourier transform infrared spectra (FTIR) and the thermal properties of the fibers were examined with a thermogravimetric analyzer. Furthermore, the fibers density was assessed using the Rilem protocol and a tensile testing machine was used to determine the mechanical properties of the treated fibers with 1 % of NaOH. Finally, a dynamic mechanical analysis of 7-year-old <i>Y. alpina</i> fibers was carry out. The results indicate that the Young's modulus of treated fibers with ages ranging from 1 to 3 years, 4-5 years, and 7 years were around 18 GPa, 10 GPa, and 14 GPa, respectively. In summary, this study underlines two primary points: (1) providing a platform for researchers to better understand the influence of age on the physical and mechanical properties of indigenous bamboo <i>Y. alpina</i>; and (2) providing a platform to validate suitable designs of biocomposites materials with <i>Y. alpina</i>.