CHAR FORMATION IN POLYMER BLENDS

A quantitative study on the formation of carbonaceous char at 350, 500 , 650 and 800 degrees C in unplasticized poly(vinyl chloride), acrylon itrile-butadiene-styrene and especially in blends of the two polymers has been carried out. Incorporating iron compounds at varying levels i nto the polymer blends dramatically increases char formation even at 8 00 degrees C. Flammability and smoke data are also presented and the r elationship between char formation and levels of iron present are disc ussed. Crosslinking/char-forming schemes are proposed in an attempt to explain the action of iron compounds in these polymer formulations.