- Author
-
Takahashi, W.
|
Sugawa, O.
|
Ogahara, I.
- Title
- Fire Retardance Mechanism for Ethylene Copolymers Given by Magnesium Hydroxide.
- Coporate
- Science University of Tokyo, Japan
- Journal
-
Bulletin of Japanese Association of Fire Science and Engineering,
Vol. 41,
No. 2,
1-10,
1993
- Keywords
-
copolymers
|
ethylene
|
polyethylenes
|
thermogravity
|
gas chromatography
|
infrared spectroscopy
- Abstract
- [ABSTRACT IN ENGLISH] The fire retardance mechanism of magensium hydroxide for ethylene copolymers were studied experimentally, using low density polyethylene (LDPE), ethylene-ethylacrylate copolymers (EEA) and ethylene-vinylacetate copolymers (EVAc). This study was carried out utilizing a high radiant furnace, thermogravimetry-gas chromatography (TG-GC) and infrared spectroscopy (IR). The results show that magensium hydroxide have little fire retardance on polyethylene and on ethylene-vinylacetate copolymers, but have remarkable fire retardance on ethylene-ethylacrylate copolymers. The differences of the fire retardance effects in these polymer-Mg (OH)₂ systems are due to the thermal stability of char layer formed on the polymer surface. The char formation is due to certain intermolecular reaction forming cross-linked structures in the system. In the case of ethylacrylate copolymers system, particularly, magnesium hydroxide reacts with ethylacrylate groups resulting the cross-links among the polymer chains, and both these reactions and char formation enhance the thermal stability against the burning propagation into the material. The dehydration of magnesium hydroxide gives also important effects for fire retardancy which is given by endothermic effects as well as dilution in gas phase.