A Systematic Investigation on the Influence of Intumescent Flame Retardants on the Properties of Ethylene Vinyl Acetate (EVA)/Liner Low Density Polyethylene (LLDPE) Blends

Abstract

Because of their high filler loadings, commercial-grade clean flame-retardant materials have unstable mechanical properties. To address this issue, intumescent polymers can be used to develop clean flame retardants with very low levels of smoke and toxicity generation. An intumescent flame retardant (IFR) system composed of red phosphorus (RP), zinc borate (ZB), and a terpolymer of ethylene, butyl acrylate, and maleic anhydride (EBM) was used to prepare EVA (ethylene-vinyl acetate) and EVA/LLDPE (linear low-density polyethylene) composites; their mechanical and flammability properties were systematically investigated. The limiting oxygen index (LOI) of the EVA/LLDPE (as base material) composite containing RP and ZB mixed with nonhalogenated flame retardant, mainly magnesium hydroxide (MH) and coadditives, including processing aids and thermal stabilizers, was established. RP was found to have little effect on the tensile properties of EVA/LLDPE 118W/120 phr flame-retardant (MH + RP) composites. There was a minute difference in the effective trend of RP between tensile strength and elongation at break. Following the addition of ZB, the elongation at break of the composites gradually decreased with increasing RP content and then leveled off when the RP content was over 10 phr. Mechanical properties (elongation at break and tensile strength) can be best maintained at below 10 phr content of RP. The mechanical properties decreased with lower amounts of EBM content. In addition, flame retardancy increased when the EBM content decreased. The findings further revealed that MH and RP have poor compatibility, yielding poor mechanical properties. The LOI greatly increased with RP content, even though the total content of flame retardants (main + intumescent flame retardant) was the same in all formulations. Only over 5 phr RP content formulations passed V-0 of the UL-94 test. When under 5 phr, the RP content formulations did not pass V-0 of the UL-94 test.

A Systematic Investigation on the Effect of Carbon Nanotubes and Carbon Black on the Mechanical and Flame Retardancy Properties of Polyolefin Blends

“…PE is flammable but produces less toxic gases during burning, while PVC generates high levels of poisonous gases. Researchers are exploring flame-retardant materials like halogen-free compounds, clean flame-retardant materials, and nontoxic materials [1][2][3][4][5]. Pure materials contain halogen and toxicity-free chemicals but have poor mechanical properties.…”

Experimental study on combustion characteristics of billboard materials

“…That is the electronic components in the light box, the light box piece, or the light box cloth, in which the electronic components mainly include the light source, the connecting line, the power supply, and the control board. According to the analysis of the internal composition of billboards, scholars have studied the fire caused by light sources, connecting lines, and power supply combustion [8][9][10][11]. However, in comparison, the material of advertising materials is thinner [12], and the contact area with the outside air is large, once the fire source appears, the advertising material must be ignited first.…”

Preparation and characterization of poly(ethylene‐co‐vinyl acetate)/high‐density polyethylene/aluminum hydroxide/clay composites by electron beam irradiation

“…Guo et al achieved an impressive limiting oxygen index (LOI) value of 33.2% for HDPE/EVA flame retardant composites by incorporating modified graphite, zinc borate, and MDH/ATH (90 phr), although the tensile properties showed some deterioration 18 . Alosime et al improved flame retardancy of EVA/linear low‐density polyethylene (LLDPE) composites by incorporating red phosphorus, zinc borate, and MDH (114 phr), resulting in enhanced LOI value (~35%) and a V‐0 rating (UL‐94) 19 …”

“…18 Alosime et al improved flame retardancy of EVA/linear low-density polyethylene (LLDPE) composites by incorporating red phosphorus, zinc borate, and MDH (114 phr), resulting in enhanced LOI value ($35%) and a V-0 rating (UL-94). 19 Clays with a two-dimensional layered silicate structure are widely used as mineral fillers to improve the mechanical properties, gas barrier properties, thermal stability, and flame retardancy of PETP-based composites through the exfoliation and/or intercalation of clays in the PETPs structures. 20 Moreover, the addition of a small amount of clay in the presence of a compatibilizer can further improve the welldispersion of clay in the PETPs matrix due to the enhancement of the interfacial interaction between PETPs and clay.…”