A MECHANISTIC STUDY OF DOPO-MeOH AS FLAME RETARDANT FOR UHMWPE AND LDPE USING THE COUNTERFLOW DIFFUSION FLAME AND THERMAL ANALYSIS METHODS

摘要

The structure of the counterflow diffusion flame of UHMWPE and LDPE with and without DOPO-MeOH additive, as well as burning of these compositions in the candle-like burning mode was studied.In addition, the methods of conventional thermal analysis and differential mass spectrometric thermal analysis were used to study the thermal degradation of DOPO-MeOH,as well as of UHMWPE and LDPE with DOPO-MeOH as a flame retardant additive in inert and oxidative environment.Adding the DOPO-MeOH flame retardant (FR) to the polymers was found to significantly raise their dripping rate during the polymer's burning.Adding DOPO-MeOH was shown practically not to reduce the concentrations of OH radicals in the flame.The ratio of the concentrations of HOPO2/HOPO, the main products of FR transformation in flame, responsible for the retardancy of chain reactions in flame, was shown to be much less than unity.At the same time, in burning of UHMWPE and LDPE with TPP additive, which essentially reduce the concentrations of OH radicals in flame, this ratio was greater than unity.These facts are likely to be related to the specific features of the flame retardancy of DOPO-MeOH in oxidizing the pyrolysis products of the polymer with DOPO-MeOH additives.