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In this work, physical, chemical and morphological modifications of three different polyamide 6.6 (PA6.6) fabrics were investigated using double barrier dielectric (DBD) plasma treatment. Several techniques of characterization were used to study the effects caused by the interaction between plasma discharge and polyamide fabrics, such as: contact angle, water drop adsorption, Energy Dispersive Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), whiteness by Berger degree and tensile strength. All analyses performed in this study showed that DBD plasma discharge, when applied on PA6.6 fiber, produces significant modifications on the surface of this substrate, without altering its intrinsic properties, thus proving the effectiveness of this important technology to the textile industry.

Abstract

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The objective of this study is to analyze the impact behavior on the basis of energy approach of weft knitted structures, namely a jersey composite and an auxetic composite using high performance yarns. Weft knitted fabrics were produced with the same structural and machine parameters, using 100% para-aramid and hybrid (47% para-aramid and 53% polyamide) structure. Composite fabrication was achieved through hand lay-up using epoxy resin. Negative Poisson ratio of the reinforcing auxetic fabric was transferred from the fabric to the composite developed. Results obtained by drop weight dart impact test show that the impact experiment with different impact loads confirmed the auxetic composites, regardless de material composition, have an increase in the total energy absorption compared to jersey reinforced composite, approximately 2.5 and 4 times more for para-aramid and hybrid composite, respectively. Auxetic composites developed within this work present great potential for applications in different areas, mainly where energy absorption is a key factor to be considered, such as in protection, sports among others.