The Mechanical Properties of Kevlar Fabric/Epoxy Composites Containing Aluminosilicates Modified with Quaternary Ammonium and Phosphonium Salts

Abstract

We investigated the effect of modified aluminosilicates, including bentonite from Armenia (BA) modified with quaternary ammonium salts (BAQAS) and phosphonium salts (BAQPS), on the mechanical properties and morphology of Kevlar/epoxy composites. The Kevlar/epoxy composites containing 1.0 or 3.0 wt.% modified bentonites were fabricated using the hand lay-up technique. The mechanical properties, including the tensile, flexural, and in-plane shear strength, were tested. Based on the obtained results, we found that the mechanical properties increased with modified bentonite loading. The best results were obtained for composites containing 3 wt.% BAQAS, as most of the mechanical properties were significantly improved (tensile strength 302.9 MPa (+30%), Young’s modulus 16.3 GPa (+17%), flexural modulus 23.4 GPa (+12.5%), in-plane shear strength 22.8 MPa (+24.5%), and in-plane shear modulus 677.2 MPa (+42%)). The obtained improvements in the mechanical properties are attributed to the uniform dispersion of the filler, which was confirmed by the highest increase in the intergallery spacing, from 28.3 Å for BAQAS to 45.1 Å for the composite with 3 wt.% BAQAS. Scanning electron microscopy (SEM) analysis of the brittle fracture surface indicated that the addition of modified bentonite to the epoxy matrix changed the morphology of the Kevlar/epoxy/organoclay composites and improved the fiber–matrix interfacial adhesion.

Polymer Composites Based on Polycarbonate (PC) Applied to Additive Manufacturing Using Melted and Extruded Manufacturing (MEM) Technology

“…On the other hand, as it is known from the literature [ 47 , 48 ], the morphology presented in Figure 6 c results from the layered structure of the modified bentonite and its organophilic nature, which facilitates good miscibility with the polymer matrix. The addition of lignin modified with silica to the polymer matrix resulted in the formation of finer, jagged plates with small protrusions [ 22 , 25 ]. The introduction of a hybrid system of lignin/bentonite fillers into the matrix did not cause any significant changes.…”

“…PC was filled with: silica (S) containing aluminum oxide (Aerosil MOX 170, Evonic Industries, Hanau, Germany), bentonite (B) (“Specjal” technical product, Zębiec SA Zakłady Górniczo-Metalowe, Zębiec, Poland) modified with quaternary salt ammonium (BARQUAT ® DM80, Lonza, Switzerland), hybrid filler lignin (L) (Sigma-Aldrich, Burlington, MA, USA)/silicon dioxide (Syloid 244, WR Grace & Co., Baltimore, MD, USA) and multiwalled carbon nanotubes (CN) (PlasmaChem, Berlin, Germany). Detailed information on the procedure of preparing bentonite modified with quaternary ammonium salt and nanoparticles of silicon dioxide and lignin was previously patented and described [ 22 , 23 ] and [ 24 , 25 ]. Modified fillers were introduced into the PC to improve the thermal stability and flowability of the composites.…”

Color-Variable Photodynamic Antimicrobial Wool/Acrylic Blended Fabrics

“…Medical textiles, in particular, highlight the need for an antibacterial finishing [3][4][5], as pathogens present on personal protective equipment (PPE), gowns, privacy curtains, or bedding can be easily transferred between the hospital environment, patients and healthcare workers, either directly or indirectly [6]. A number of antimicrobial agents have been incorporated into textiles for infection control, including antibiotics [7,8], quaternary ammonium salts [9,10], silver nanoparticles [11,12], graphene [13,14] and dendrimers [15,16]. However, these all exhibit certain limitations, such as being expensive and/or difficult to dye or finish on textiles, can lead to drug-resistant strains [17], are potentially toxic or lead to undesired side effects (rashes or allergic responses) on the wearer [1], or possess a limited range of antibacterial function (i.e., against a single class of pathogen) [18].…”

Polymer Composites Based on Glycol-Modified Poly(Ethylene Terephthalate) Applied to Additive Manufacturing Using Melted and Extruded Manufacturing Technology

“…PET-G was filled with: silica (S) containing alumina (Aerosil MOX 170, Evonic Industries, Hanau, Germany), bentonite (B) (technical product "Specjal" Zębiec SA Zakłady Górniczo-Metalowe, Zębiec, Poland) modified with quaternary ammonium salt (BARQUAT ® DM80, Lonza, Switzerland) and lignin (L) (Sigma-Aldrich, Burlington, MA, USA)/silicon dioxide (Syloid 244, WR Grace & Co., Columbia, MD, USA) hybrid filler. Detailed information on the procedure of obtaining bentonite modified with quaternary ammonium salt and lignin/silicon dioxide nanoparticles has already been patented and described before [24,25]. Modified fillers were introduced into PET-G in order to improve the flowability of composites (which significantly affects the processing properties of materials) and mechanical properties.…”