Abstract
This paper describes experiments and results that have been ob tained from a pyrolysis/gas chromatography/mass spectroscopy study on chlori nated polyvinyl chloride (CPVC-65\% Cl) containing two commercially available plasticisers, namely, DOP and Santicizer 2148 with and without modest amounts of an iron (III) smoke suppressing compound. Careful analysis of the mass spectra obtained from the pyrolysis products has shown that the smoke suppressing effect of basic iron (III) oxide (FeOOH) is essentially the result of two sets of chemical reactions. This iron compound reacts with the CPVC poly mer and the plasticisers present. Increased amounts of char formed from the CPVC combined with changes in the path of decomposition during pyrolysis of both plasticisers to give fewer smoke precursor molecules resulted in a signifi cant reduction in smoke formation.