Microstructural and Thermal Characterization of Hyphaene thebaica Fibers from the Far North of Cameroon with a View to Their Incorporation into Polymer Matrices

This work focuses on microstructural and thermal investigations of Hyphaene thebaica fibers. Analyses aimed at understanding their molecular, crystallites, morphological, and thermal behavior are performed in order to control their interactions with polymers. SEM characteristics reveal a crystalline state in the surface areas of the oxidized fibers in particular. The sharp X-ray diffraction (XRD) images are characteristic of cellulose crystals. Fibers retted with water and soda exhibit a crystalline state more than others. This demonstrates the presence of microorganisms acting within the fiber, leaving a certain heterogeneity around these environments caused by these sharp peaks. The vibrational movements observed on the FTIR curves predispose these fibers to physicochemical interactions with organic matter originating from the polymer matrix. Structural infrared analyses revealed the presence of absorption bands concentrated around 1750 cm−1 and 1050 cm−1 on the DOSO, DOROL, and DOROTER samples, indicating that the treatments eliminated hemicelluloses and some of the lignin. This factor impacts the crystallinity of these fibers and the size of the crystallites they contain. This characteristic suggests good performance in the production of composites with these constituents. Specifically, thermal tests showed an overall mass loss ranging from 5.53% to 74.30%. ADT analysis shows that these fibers begin to degrade under thermal effects at 251˚C for the least resistant and 378˚C for the most resistant. It can be concluded that these fibers can withstand thermocompression and yield structural composites.