Fibrous PEBA-graphene nanocomposite filaments and membranes fabricated by extrusion and additive manufacturing

Abstract

Polyether block amide (PEBA) and PEBA based nanocomposites are one of the most promising materials in environmental technology, used for separation and filtration. Applications of Pebax are studied extensively, however, most of the previous studies focused on its use as a dense membrane without giving due attention to fibrous membranes. This research presents a novel approach to prepare fibrous PEBA Nanocomposite (PNC) membranes while giving special attention to achieving uniform nanomaterial dispersion and applicability of the technology on an industrial scale. For that purpose, extrusion process was used to prepare PNC filaments in the presence of 0.2 wt% of Paraffin Liquid (adhesive layer) and 0.05–0.4 wt% of Graphene (nanofiller material with high aspect ratio). The prepared filaments were spun into fibrous membranes using melt electrospinning as environmentally-friendly additive manufacturing technology. The spinning process was performed with a constant collector diameter (150 mm), at different drum rotational speeds (30–60 rpm), and different spinning temperatures (160–180 °C, based on the Graphene concentration) to study the effect of these conditions on the morphology of the formulated PNC membranes. Potential applications of the produced PNC membranes in the cleanup of oil spills were studied. Morphology and dispersion of the obtained PNC filaments and membranes were investigated by SEM and TEM. Chemical, thermal, and mechanical properties were studied using XRD, FTIR, TGA, DSC, and universal testing machine. The results showed that in both cases (PNC filaments and fibrous membranes) at 0.3 wt% of Graphene material with optimum properties, such as uniform dispersion, high tensile strength, elastic modulus, melting temperature, crystallinity degree (65% improvement in filaments and 58% improvement in fibrous membranes compared with pure PEBA), and low plasticity was achieved. Spinning results showed that aligned fibers with an average diameter 5 μm were produced at the highest rotational speeds (such fibers can be used in textiles) while at the lowest speeds cross-linked microfibers in form of membrane with small inter-fiber pores were produced (the membranes can be used in cleanup of oil spills). The developed approach for preparation of nanocomposite filaments can be used to produce raw material for melt spinning or 3D Printing in general.