EVA-layered double hydroxide (nano)composites: Mechanism of fire retardancy

Abstract

Abstract:Composites of ethylene-vinyl acetate copolymer with two different layered double hydroxides have been obtained by melt blending and these have been characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, thermogravimetric analysis connected to mass spectroscopy and cone calorimetry. There is some small difference in dispersion between the zinc-containing and the magnesiumcontaining layered double hydroxides in EVA, but both these are microcomposites with good dispersion at the micrometer level and relatively poor dispersion at the nanometer level. There is a good reduction in the peak heat release rate at 10% LDH loading. In addition to chain stripping, which involves the simultaneous loss of both acetate and a hydrogen atom, forming acetic acid, and the formation of poly(ethylene-co-acetylene), side chain fragmentation of the acetate group also occurs and may be the dominant pathway of thermal degradation in the first step. The presence of the LDH causes acetone, rather than acetic acid, to be evolved in the initial step of the degradation.

Synthesis and properties of a novel bio‐based benzoxazine resin with excellent low‐temperature curing ability

“…MCC experiments were used to further analyze the correlation between the crosslinked structure and flammability for the cured benzoxazine resins . The key combustion parameters, including heat release capacity (HRC), total heat release (THR), peak heat release rate (PHRR) and the temperature for the PHRR ( T max ), were obtained.…”

An experimental and numerical model for the release of acetone from decomposing EVA containing aluminium, magnesium or calcium hydroxide fire retardants

“…Several recent studies have reported the somewhat unexpected detection of acetone as a pyrolysis product of EVA-MHs. This was initially described by Witkowski et al in 2012 and has since been corroborated by other research [8,9,10].…”

Poly (Ethylene–Co–Vinyl Acetate)/Clay Nanocomposites: Effect of Clay Nature and Compatibilising Agents on Morphological Thermal and Mechanical Properties

“…The use of LDH particles as nanofiller represents an emerging field of application, which may present advantages in comparison to montmorillonite, due to its versatility in chemical composition and charge density and allowing multiple interactions with the polymer [20]. Besides, the structure of these particles presents hydrox-ide groups in great number, making them attractive to enhance thermal stability and to improve fire resistant properties in polymer systems [21,22].…”