COMPLEX CHAR FORMATION IN FLAME RETARDED FIBER-INTUMESCENT COMBINATIONS .1. SCANNING ELECTRON-MICROSCOPIC STUDIES

Citation
Ar. Horrocks et al., COMPLEX CHAR FORMATION IN FLAME RETARDED FIBER-INTUMESCENT COMBINATIONS .1. SCANNING ELECTRON-MICROSCOPIC STUDIES, Polymer, 37(15), 1996, pp. 3197-3206
Citations number
19
Categorie Soggetti
Polymer Sciences
Journal title
ISSN journal
00323861
Volume
37
Issue
15
Year of publication
1996
Pages
3197 - 3206
Database
ISI
SICI code
0032-3861(1996)37:15<3197:CCFIFR>2.0.ZU;2-7
Abstract
A recently disclosed development(1-3) comprising a composite of flame retardant cellulose fibres and an intumescent has shown unusually high flame and heat resistance with a char structure that can withstand ai r exposure temperatures up to 1200 degrees C. Char structures of selec ted flame retardant cellulose fibres when alone and blended with inert E-glass and aromatic char-forming novoloid fibres in the presence of an ammonium polyphosphate-based intumescent have been studied using sc anning electron microscopy. Evidence suggests that a 'char-bonded' str ucture is formed in which flame retardant cellulose fibrous chars have interacted with intumescent char during its formation. Similar intera ctions are not seen with E-glass and novoloid fibre residues. The char -bonded structure is considered to have reduced air permeability and s o has considerably enhanced surface oxidative resistance at high tempe ratures. An outline mechanism is proposed and is based on known pyroly sis mechanisms for the flame retarded cellulose fibre and intumescent components. Copyright (C) 1996 Elsevier Science Ltd.