GC MS studies of ABS CPVC blends

A detailed GC/MS study, of the products of the pyrolysis in air of suitably chosen samples of CPVC/ABS and PVC/ABS blends with and without the smoke s uppressant basic iron(III) oxide (FeOOH) present, has been undertaken in or der to gain possible insights into the chemical behaviour which results in smoke suppression. Of particular interest is the observation that the prese nce of the iron(III) compound greatly reduced the concentrations as well as the numbers of aromatic and polycyclic aromatic compounds detected. Such c ompounds are well known smoke precursors. Thus the mechanism by which FeOOH functions as a smoke suppressant would appear to be via interference with the reactions leading to production of aromatic species. (C) 1999 Elsevier Science Ltd. All rights reserved.