Over the last two decades, bio-polymer fibers have attracted attention for their uses in gene therapy, tissue engineering, wound-healing, and controlled drug delivery. The most commonly used bio-polymers are bio-sourced synthetic polymers such as poly (glycolic acid), poly (lactic acid), poly (e-caprolactone), copolymers of polyglycolide and poly (3-hydroxybutyrate), and natural polymers such as chitosan, soy protein, and alginate. Among all of the bio-polymer fibers, alginate is endowed with its ease of sol–gel transformation, remarkable ion exchange properties, and acid stability. Blending alginate fibers with a wide range of other materials has certainly opened many new opportunities for applications. This paper presents an overview on the modification of alginate fibers with nano-particles, adhesive peptides, and natural or synthetic polymers, in order to enhance their properties. The application of alginate fibers in several areas such as cosmetics, sensors, drug delivery, tissue engineering, and water treatment are investigated. The first section is a brief theoretical background regarding the definition, the source, and the structure of alginate. The second part deals with the physico-chemical, structural, and biological properties of alginate bio-polymers. The third part presents the spinning techniques and the effects of the process and solution parameters on the thermo-mechanical and physico-chemical properties of alginate fibers. Then, the fourth part presents the additives used as fillers in order to improve the properties of alginate fibers. Finally, the last section covers the practical applications of alginate composite fibers.

Recycling process seems to be the most efficient way to reduce ecological impacts of used polymers. Nevertheless, the properties of the recycled PP polymer are proved to be insufficient during its reuse, particularly with regard to its thermo-mechanical and rheological behaviors. The incorporation of nanoparticles as fillers into polymer matrix seems to be one of the most successful solutions to upgrade recycled PP polymer. This paper presents an overview on the application of different nanofillers such as clay, calcium carbonate (CaCO₃), Silica (SiO₂), Zinc Oxide (ZnO), carbon black (CB), carbon nanotubes (CNT), antioxidizers and others into recycled PP matrix. Literature works on the effects of nanofillers on obtained nanocomposites are extensively studied. The first section deals with PP recycling and its impact on thermal, mechanical and rheological properties of the polymer. Then, the second part summarizes recent studies on the effects of nanoparticles incorporation on thermo-mechanical and rheological properties of recycled PP. Finally, recyclability of PP-based nanocomposites is discussed. GRAPHICAL ABSTRACT

Chitosan is a biopolymer obtained from deacetylation of the abundant natural chitin polymer. It has found its use in many applications due to its unique solubility as well as chemical and biological properties. In addition to its biodegradability and biocompatibility, it has many reactive amino side groups that offer the possibilities of chemical modification and formation of a large variety of beneficial derivatives. Numerous researchers have published works outlining the physical and chemical properties of chitosan, as well as its use in several industries, such as medical, environmental and food. Due to its excellent absorption and biological properties, chitosan present a myriad of opportunities in eco-friendly textile processes. Chitosan is able to confer antimicrobial, antiviral, anti-odor and other biological activities to textile fibers and fabrics. In this review, the first part is dedicated to developing the physio-chemical and biological characteristics of chitosan. Then, we present chitosan applications in the textile industry over the past decade. Literature works on chitosan usage along with different textile production steps (fiber formation, functional treatments, dyeing and effluent treatment) are extensively discussed.

This study investigates the influence of clay nanofiller on morphological, thermal, and mechanical behaviors of post-consumer polypropylene (PCPP)-based nanocomposites. Waste polypropylene was mixed with 1%, 3%, 5%, and 7% of Tunisian clay nanoparticles using twin-screw extruder. The structure and morphology of raw, purified, and organo-modified clays were characterized by Fourier-transform infrared spectroscopy and X-ray diffraction (XRD). The influence of clay nanoparticles content on the thermal behavior of waste polypropylene was studied by means of thermogravimetric analysis. The effect of nanoclay on morphology and properties of PCPP/clay nanocomposites was also studied. It was found from transmission electron microscopy and XRD analysis that clay nanoparticles are well dispersed into PCPP matrix and the addition of organo-modified Tunisian clay did not change the crystal structure of the PCPP polymer. Thus, organically modified Tunisian clay can be used for preparing organic–inorganic hybrids by melt processing with waste PP polymers. In dead, by varying the nanofiller loading, mechanical properties (Young’s modulus, tensile strength, and elongation at break) and thermal stability of filled PCPP showed an increase as compared to unfilled polymer. Optimal mechanical performances were obtained with 5% clay loading.