Polypropylene Melt-Blown Fiber Mats and Their Composites

One of the most important developments in polymer engineering and science is, without question, the production of polymeric nano-/micron fibers. In recent years, various techniques such as template synthesis.

This chapter aims to facilitate an outlook on melt-blown fiber mats and related composites by reviewing the recent developments in melt blowing, melt-blown fiber mats and their related applications, nano-/submicron fiber reinforced composites. The chapter also focuses on advancing sustainable fibers and composites via knowledge. The literature overview summarizes the materials used in the melt blowing, the effects of processing parameters on the structure and performance of the fiber mats and their products, thermal and physical properties, mechanical behaviors of fiber mat interleaved and reinforced composites, and related composite manufacturing methods and their potential implementation in polymer and composite science & engineering.

In this chapter, the structure of (polypropylene) PP fibers was evaluated systematically and comparatively using different processing conditions via melt blowing. The influence of four parameters (air pressure, air temperature, die-to-collector distance (DCD), and collector speed) on the fiber morphology (fiber diameter, pore size, porosity) and mechanical and thermal properties were detailed and the fiber formation mechanism was investigated. Melting temperature, melting enthalpy and crystallinity were obtained using the differential scanning calorimetry (DSC) technique as a function of melt-blowing parameters. The crystallite size and crystal phase evaluations were carried out using the peak parameters obtained by the curve fitting of the equatorial wide-angle X-ray diffraction (WAXD) profiles. A new factor, the mat consolidation coefficient, was introduced and used to efficiently summarize melt-blown (MB) PP fiber mats’ process-property-structure relationships. This study details how to control the melt blowing parameters to tailor the PP fiber mat features for the respective application fields. It also gives insight into fiber formation mechanisms during melt blowing to generate self-bonded, defect-free, fine fiber mats.

In this chapter, integrating melt-blown (MB) Polypropylene (PP) fiber mat interleaves into single-polymer composites (SPCs) was demonstrated. SPCs were created by film-stacking using PP film as a matrix, a PP woven fabric as primary reinforcement, and the MB PP fiber mats as an interleaving veil. MB PP fiber mat interleaving improved the SPC’s tensile modulus and interlaminar shear strength by up to 46% and 17%, respectively. The perforation energy of the laminae at impact was also increased by 14% with the PP fiber mat interleaving. Differential scanning calorimetry (DSC) tests showed that MB fibers acted as a nucleating agent in the matrix, resulting in improved crystallinity. Dynamic mechanical analysis (DMA) was conducted, and master curves were constructed based on the time–temperature superposition principle. The storage modulus significantly increased while the tanδ decreased. MB PP fibers created a net-like structure between reinforcing woven and matrix, enhancing interfacial performance. The interleaving concept can promote SPCs utilization in respective engineering applications where high toughness and impact resistance are required.

In this chapter, the method of producing a multiwalled carbon nanotube (MWCNT)-doped Polypropylene (PP) fine fibers via melt-blowing was demonstrated. The MWCNT-doped fiber mats were then applied as an interleaving veil to create hierarchical single-PP composites. The morphological, thermal and mechanical properties of the nanocomposite fibers are discussed. The effect of the nanocomposite fine fiber mat interleaving on the thermal and mechanical properties of the SPCs was systematically and comparatively investigated. Results implied that incorporating MWCNT increased the melt-blowing grade PP resin viscosity. Incorporating MWCNT enhanced the melt-blown (MB) PP fiber mat's specific strength by 78% and improved thermal stability. Hierarchical single-polypropylene composites (SPCs) were produced by film-stacking, for which a PP film was used as a matrix, a PP woven fabric was used as primary reinforcement, and the MB fiber mat was used as interleaves. Interleaving enhanced the SPC's tensile modulus by up to 37%. Interleaving of the MWCNT doped PP fiber mat provided a robust interfacial adhesion and higher damage tolerance under tensile load. Master curves were constructed from dynamic mechanical analysis (DMA) frequency sweep tests based on the time–temperature-superposition (TTS) principle. Results revealed that the SPCs storage modulus increased by 33%, while the tanδ decreased by around 10% with the interleaving PP/MWCNT fiber mat.

This book investigated melt-blown fibers' production methods and applications for sustainable and green composite production. Firstly, the melt-blown fiber formation mechanism was investigated, considering the effect of processing parameters on the fiber mat properties. And then, a new concept of making advanced single-polymer composites with melt-blown fiber mat interleaving was demonstrated. The effect of melt-blown fiber mat interleaving on the composite laminae’s thermal and mechanical behavior was evaluated. The multiwalled carbon nanotube-doped polypropylene melt-blown fiber mats were produced, and the effect of multiwalled carbon nanotube doping on thermal and mechanical properties was analyzed. Carbon nanotube-doped melt-blown fiber mats were also used as an interleaving veil to produce single-polymer composites. The effect of the nanocomposite fiber mat on the single-polymer composite’s thermal and mechanical characteristics was also detailed. In this chapter, results from these experimental studies were summarized, and significant findings were highlighted. Furthermore, the past and future of melt blowing research and development were briefly discussed. New concepts and future directions of melt-blown fibers and their composites were discussed in light of the sustainable industrial revolution goals.