Abstract
The effect of the presence of halloysite nanotubes (HNTs) and silane-treated alumina trihydrate (ATH-sil) nanofillers on the mechanical, thermal, and flame retardancy properties of ethylene-vinyl acetate (EVA) copolymer/low-density polyethylene (LDPE) blends was investigated. Different weight percentages of HNT and ATH-sil nanoparticles, as well as the hybrid system of those nanofillers, were melt mixed with the polymer blend (reference sample) using a twin-screw extruder. The morphology of the nanoparticles and polymer compositions was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanical properties, hardness, water absorption, and melt flow index (MFI) of the compositions were assessed. The tensile strength increases as a function of the amount of HNT nanofiller; however, the elongation at break decreases. In the case of the hybrid system of nanofillers, the compositions showed superior mechanical properties. The thermal properties of the reference sample and those of the corresponding sample with nanofiller blends were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Two peaks were observed in the melting and crystallization temperatures. This shows that the EVA/LDPE is an immiscible polymer blend. The thermal stability of the blends was improved by the presence of HNTs and ATH-sil nanoparticles. Thermal degradation temperatures were shifted to higher values by the presence of hybrid nanofillers. Finally, the flammability of the compositions was assessed. Flammability as reflected by the limiting oxygen index (OI) was increased by the presence of HNT and ATH-sil nanofiller and a hybrid system of the nanoparticles.
Highlights
The flammability of polymers has been recognized as a social and scientific problem for the wire and cable industry [1,2]
The results revealed that the nano-kaolin had a synergistic effect with nano-hydroxyl aluminum oxalate (HAO) on flame retardancy in the low-density polyethylene (LDPE)/EPDM system [25]
scanning electron microscopy (SEM) micrographs prepared for the two compositions with the highest proportion of SEM micrographs prepared for the two compositions with the show highest proportion nanofillers, i.e., 8 wt.% halloysite nanotubes (HNTs)
Summary
The flammability of polymers has been recognized as a social and scientific problem for the wire and cable industry [1,2]. There are various types of polymers, which have been applied in the cable industry. Ethylene-vinyl acetate (EVA) copolymers and low-density polyethylene (LDPE) [3,4] have been extensively used in the wire and cable industry as excellent insulating materials owing to good mechanical and thermal properties. Boron compounds, metal hydroxides, melamine (MLM), ammonium polyphosphate (APP), and pentaerythritol (PER) have been applied as flame retardant agents to modify the flame resistance of polymers [9]. Mineral filler fire retardants such as alumina trihydrate (ATH) and magnesium hydroxide (MH) are important fire-safe materials, especially for use in the cable industry [10]. ATH is a non-halogen-based material that can find application in flame retardation and smoke suppression [11]. ATH has been combined with polymers to improve flame retardancy [12,13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
