Carbon fibers (CFs) are made mostly from a non-environmentally friendly polyacrylonitrile (PAN) and little from rayon. PAN-based CFs, require huge amount of energy for its production aside its contributions to the global CO₂ emission. Therefore, there is recourse to a more environmentally friendly sources of CFs biomass. Recently lignin has been recognized as a potential renewable raw material for carbon fibers to replace PAN-based. The magnitude and quality of CO₂ emission of lignin-based CFs are dependent on the processing route. On this premise; this review examines the various lignin-based CFs processing route adopted by researcher in the recent past to establish the most viable route with minimum carbon footprint emission. Outcome of the review shows that the major advantages of aromatic polymer (AP) generated precursor over PAN is the presence of higher quantity of guaiacyl units and oxygen content which makes the stabilization phase efficient and faster requiring less energy. Though there are several methods and options for the various stages of conversion of lignocellulosic biomass into CFs as highlighted in the study, establishing an optimum processing route will be a trade-off amongst various issues of concern; carcinogenic risk, carbon footprint emission, CFs Yield and mechanical strength of the CFs. Inferences from the study shows that the L-CF significantly produced reduced climatic impact in terms of CO₂ emission.

A way to avoid or minimize the side effect that could result in drug delivery to cells with increased efficiency and performance in the health rehabilitation process is to use biocompatible and biodegradable drug carriers. These are essentially biomaterials that are metallic, ceramic, or polymeric in nature. The sources of these materials must be biological in its entire ramification. The classification, synthesis, processing, and the applications to which these materials are put are the essential components of having suitable target cell drug carriers. This chapter will be devoted to discussing biomaterials suitable as drug carrier for use in the health-related matters of rehabilitation.

The need for the use of suitable natural alternative materials to oil-derived carbon-based materials, largely because of carbon IV oxide emissions and the attendant global health and environmental impact, has led to the discovery of lignin, a biomass-derived material, as a precursor for carbon fibre (CF) manufacture and as a reinforcement for biologically derived polymers like polylactide (PLA) with a variety of biomedical and industrial applications. This study investigated the thermal, structural, and compositional properties of lignin extracted from the pseudostem of Musa paradisiaca L. (the plantain tree). Dried and milled plantain pseudostem was pretreated using diethyl ether. Lignin was extracted from the untreated and pretreated pseudostem samples using 5M HCl for 1 h at 200 °C and 250 °C (acid hydrolysis). The results revealed that lignin obtained from pretreated pseudostem at 200 °C and 250 °C possesses superior thermal stability, as shown by the thermogram, with a DTG_max of 429.97 °C and 442.62 °C in contrast to 397.22 °C and 382.53 °C for lignin from untreated pseudostem due to the removal of volatile impurities and unwanted constituents after pretreatment. The FTIR spectrum of the extracted lignin samples shows similar absorption bands, like 1703.4 cm⁻¹ (C=O–conjugated carbonyl group), 1606–1602 cm⁻¹ (C=C stretching–aromatic compounds, benzene ring), 1315 cm⁻¹ (C-O stretching–syringyl units), and 1200.2 cm⁻¹ (C-H stretching, guaiacyl units), with the pretreated biomass having higher transmittance (%) values, indicating increased purity after pretreatment. The results presented above showed that lignin has been successfully extracted and can serve as a potential precursor for the production of carbon fibre, thereby reducing dependence on fossil-fuel-based precursors, with a reduction in carbon dioxide emission pollution.

Polylactic acid (PLA) and polyvinyl alcohol (PVA) are promising biocompatible and biodegradable materials for biomedical uses, yet they have limitations. Similarly, lignin is a precursor for carbon fiber but requires plasticizers to be spun into fibers. This hampers their use in areas like carbon fiber production and tissue engineering, thus the reason for this study. Lignin was extracted from the plantain stem, and a lignin blend with PLA and PVA was made and electrospun into fibers. Thereafter, the physiochemical properties of the composite fibers were analyzed. The XRD spectra revealed increased crystallinity in PLA/Lignin fiber. When 0.75 wt.% of lignin was added to PVA, a new peak and peak shift were formed in the composite fiber, indicating strong interaction. The crystallinity of PVA/lignin decreased from 71.5 to 60.1% when 0.25 wt. % of lignin was added. DSC showed miscibility of polymers and improved melting temperatures from 155 to 228 °C, for PLA/lignin (0.5wt.%) fiber, but a reduction in melting temperatures of PVA, with higher lignin content (149–143 °C). FTIR showed notable functional groups, typical of PLA, PVA, and lignin, such as the OH group between 3800 and 3459 cm⁻¹. The minor peak shift in PLA/lignin showed that the level of molecular interaction is less than that of PVA/lignin. PLA/lignin displayed better fiber morphology compared to PVA/lignin, where fibers became sheet-like with higher lignin content. The addition of lignin improved the tensile strength of PVA (0.7 to 2.7 MPa). Conversely, PLA/lignin’s tensile strength decreased, due to reduced load transfer efficiency. Overall, PVA/lignin and PLA/lignin composites exhibit potential as reinforcement materials for biopolymers and carbon fiber precursors, with PVA showing more promise for carbon fiber production due to robust polymer-lignin interaction.

Introduction Electrospun fibre mats have gained tremendous attention in tissue engineering and biomedical applications, owing to their versatile properties. Several researchers have studied PLA/HAP electrospun composite, moreover, the strengthening properties of HAP from Caprine and Bovine have not been fully studied. Method The HAP was varied between 5 and 15 wt.% and was used to reinforce PLA(4 g). The mixture was dissolved in 20 mL of dichloromethane and stirred until homogeneity was achieved before electrospinning. The physicochemical properties of electrospun PLA/HAP fibre were thereafter characterized. Results The morphological analysis revealed that the PLA/HAP fibre exhibited a uniform and interconnected structure with the incorporation of HAP. The functional group study showed characteristic peaks such as the OH group, corresponding to HAP and PLA, indicating their miscibility. Thermal analysis revealed shifts in glass transition temperature (75 °C to 42 °C), suggesting an interaction between PLA and HAP. XRD pattern indicated the presence of HAP crystalline peaks in the PLA/HAP fibre, demonstrating the retention of bioactive features. Conclusion Electrospun PLA/HAP fibre, exhibited, mechanical, structural, and chemical properties essential for tissue regeneration, making it a candidate for tissue engineering use.