The Flammability of Polyacrylonitrile and Its Copolymers I. The Flammability Assessment Using Pressed Powdered Polymer Samples
AbstractThis paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.