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The flame retardant mechanism of polyolefins modified with chalk and silicone elastomer
Author(s) -
Hermansson Anna,
Hjertberg Thomas,
Sultan BerntÅke
Publication year - 2003
Publication title -
fire and materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.482
H-Index - 58
eISSN - 1099-1018
pISSN - 0308-0501
DOI - 10.1002/fam.817
Subject(s) - intumescent , fire retardant , acrylate , char , polymer chemistry , silicone , elastomer , materials science , calcium hydroxide , pyrolysis , composite material , chemistry , chemical engineering , copolymer , organic chemistry , polymer , engineering
This paper presents the current understanding of the flame retardant mechanism of Casico™. The study includes the flame retardant effect of each individual component: ethylene–acrylate copolymer, chalk and silicone elastomer, as well as the formation of an intumescent structure during heating. The flame retardant properties were investigated by cone calorimetry and oxygen index tests. To obtain insight into the flame retardant mechanism, heat treatment under different conditions has also been performed. The results indicate that the flame retardant mechanism of Casico is complex and is related to a number of reactions, e.g. ester pyrolysis of acrylate groups, formation of carbon dioxide by reaction between carboxylic acid and chalk, ionomer formation and formation of an intumescent structure stabilized by a protecting char. Special emphasis is given to the formation of the intumescent structure and its molecular structure as evaluated from 13 C MAS‐NMR and 29 Si MAS‐NMR, ESCA and XRD analysis. After treatment at 500°C the intumescent structure consists mainly of silicon oxides and calcium carbonate and after treatment at 1000°C the intumescent structure consists of calcium silicate, calcium oxide and calcium hydroxide. Copyright © 2003 John Wiley & Sons, Ltd.