MILLIGRAM-SCALE FLAME CALORIMETER: A NOVEL INSTRUMENT FOR FLAMMABILITY ASSESSMENT USING MG-SIZED SAMPLES

摘要

Brominated flame retardants (BFRs) are widely used in polymers due to their effectiveness at relatively low cost. Recent studies suggest that certain BFRs may present health and environmental hazards, yet obtaining adequate replacements is an ongoing challenge. To develop new additives, it is not only important to better understand the mechanisms governing the action of BFRs, but it’s also critical that screening BFR replacement candidates can be done in a cost effective, highly repeatable manner while reflecting actual performance during realistic fire scenarios. To address this challenge, a novel apparatus, the Milligram-scale Flame Calorimeter (MFC), is proposed. In MFC, the pyrolysis and gas-phase combustion processes are uncoupled. Samples of 30?5 mg are pyrolyzed in anaerobic atmosphere and their pyrolysis products are burned in a laminar diffusion flame under controlled and customizable conditions in a fully enclosed system. Heat release information is obtained through the oxygen consumption calorimetry. The masses of post-combustion char/solid residue and solid combustion products (e.g. soot) are measured. In this work, a description of the design, parametric optimization of test conditions, and overall testing methodology is given. Heat release measurements are presented for polystyrene with increasing amounts of brominated polystyrene as well as polybutylene terephthalate with increasing concentrations of aluminum diethylphosphinate.