Fibers are materials that exist in the form of continuous filaments or are cut into specific lengths and have a very high length-to-diameter ratio. Based on diameter, fibers are classified into three groups: conventional fibers, microfibers, and nanofibers. Due to their various applications in different industries, such as composite manufacturing, there is a need for cost-effective and high-production-rate manufacture techniques. Rotary jet spinning (RJS) is a relatively new technique for making nano/ micro fibers from both polymer solutions and melt. RJS is high throughput, low cost, and environmentally friendly nano/ micro fiber production method. Melt RJS uses molten polymer in the RJS apparatus to form micro and nanofibers without using solvents. The fibers produced using this method can be used as a matrix phase or a reinforcing phase in the construction of various composites. Composites are classified by the matrix material into polymeric composites, metallic composite, and ceramic composites. Polypropylene (PP) and polyester resin are well-known polymers that form the matrix phase of polymer-based composites. Reinforcements or fillers are neutral materials that can be in the form of fibers, sheets, or particles, and they are primarily added to enhance the strength of the matrix. Due to the various applications of composites in different fields, including production of respiratory masks, filters, wound dressing, sensors, and battery separators, in the current study, advanced research conducted using the melt RJS method to produce pure PP fibers and PP fibers reinforced with TiO2, nanoclay, and carbon black at weight percentages of 1, 5, and 8. After being converted into nonwoven fabrics, fabrics were subjected to structural characterization tests, including SEM, XRD, and mechanical tests, including tensile and water contact angle test, as well as antibacterial test. Additionally, produced pure PP fibers at weight percentages of 5, 10, and 20 were used as reinforcing phase in the construction of composites based on unsaturated polyester resin, and their mechanical properties were eva‎luated using various mechanical tests, including tensile, flexural, and impact tests. The results of this research showed that the melt RJS method is a fast and easy technique for producing pure and reinforced PP fibers. In nonwoven fabrics depending on the type, weight percentage, and the distribution and dispersion of the reinforcements, the structural and mechanical properties of the resulting composites improved. Moreover, hydrophobic pure polypropylene nonwoven fabrics became hydrophilic structure in the presence of TiO2 and carbon black. Meanwhile nonwoven fabrics reinforced with nanoclay was hydrophobic. Additionally, the results of present study indicated that pure PP fiber at weight percentages 5 could improve the mechanical properties of polyester resin. In conclusion, the obtained structures of current study could be suggested for use in various products such as respiratory masks, water and gas pollutant filters, and wound healing dresses.

محسن صفوي

مهدي كاروان

محمود فرزين , عليرضا فدائي تهراني