Elastic melt-blown nonwoven fabrication of styrene‐ethylene/butylene‐styrene copolymer and polypropylene blends: a study of morphology and properties

Fabrics produced by the melt-blown nonwoven process have the advantage over competing materials of possessing an ultrafine fibrous and porous structure. However, their brittleness and poor toughness restrict their wider application. There is increasing demand for nonwovens that have high stretchability and elasticity while maintaining a melt-blown structure. In this study, polypropylene (PP) and styrene‐ethylene/butylene‐styrene copolymer (SEBS) were blended at different ratios and subsequently used in the melt-blowing process. The morphology of the blends displayed a co-continuous structure when the ratio of SEBS to PP in blends was similar. Furthermore, it was found that all the blends had good spinnability from the melt-blowing process during rheological and thermal properties tests. All the elastic melt-blown nonwovens fabricated in this research had elongations higher than 400% and elastic recoveries higher than 50%, which was indicative of good elasticity. Meanwhile, the nonwovens maintained fine fiber diameters and good filtration properties, in keeping with traditional melt-blown nonwovens.

Effect of Hard Plastic Waste on the Quality of Recycled Polypropylene Blends

The recycling of plastic waste is undergoing fast growth due to environmental, health and economic issues, and several blends of post-consumer and post-industrial polymeric materials have been characterized in recent years. However, most of these researches have focused on plastic containers and packaging, neglecting hard plastic waste. This study provides the first experimental characterization of different blends of hard plastic waste and virgin polypropylene in terms of melt index, differential scan calorimetry (DSC), thermogravimetric analysis (TGA), mechanical properties (tensile, impact and Shore hardness) and Vicat softening test. Compared to blends based on packaging plastic waste, significant differences were observed in terms of melt flow index (about 10 points higher for hard plastic waste). Mechanical properties, in particular yield strain, were instead quite similar (between 5 and 9%), despite a higher standard deviation being observed, up to 10%, probably due to incomplete homogenization. Results demonstrate that these worse performances could be mainly attributed to the presence of different additives, as well as to the presence of impurities or traces of other polymers, other than incomplete homogenization. On the other hand, acceptable results were obtained for selected blends; the optimal blending ratio was identified as 78% post-consumer waste and 22% post-industrial waste, meeting the requirement for injection molding and thermoforming.

Why POSS-Type Compounds Should Be Considered Nanomodifiers, Not Nanofillers—A Polypropylene Blends Case Study

In this work, a seriTables of silsesquioxanes (SSQ) and spherosilicates (SS), comprising a group of cage siloxane (CS) compounds, was tested as functional additives for preparation of isotactic polypropylene (iPP)-based nanocomposites and discussed in the aspect of their rationale of applicability as such additives. For this purpose, the compounds were prepared by condensation and olefin hydrosilylation reactions. The effect of these cage siloxane products on properties of obtained CS/iPP nanocomposites was analyzed by means of mechanical, microscopic (scanning electron microscopy-energy dispersive spectroscopy), thermal (differential scanning calorimetry, thermogravimetry), thermomechanical (Vicat softening point) analyses. The results were compared with the previous findings on CS/polyolefin composites. The role of CS compounds was discussed in terms of plastic processing additives.

The Influence of Pressure-Induced-Flow Processing on the Morphology, Thermal and Mechanical Properties of Polypropylene Blends

The pressure-induced-flow (PIF) processing can effectively prepare high-performance polymer materials. This paper studies the influence of pressure-induced-flow processing on the morphology, thermodynamic and mechanical properties of polypropylene (PP)/polyamide 6 (PA6) blends, PP/polyolefin elastomer (POE) blends and PP/thermoplastic urethane (TPU) blends. The results show that pressure-induced-flow processing can significantly improve the thermodynamic and mechanical properties of the blends by regulating internal structure. Research shows that the pressure-induced-flow processing can increase the strength and the toughness of the blends, particularly in PP/TPU blends.