Abstract

The sooting behavior of poly(methyl methacrylate) (PMMA) remains poorly quantified despite its extensive use as a benchmark fuel in fire science. This study presents a systematic characterization of soot production in laminar diffusion flames fueled by clear and black PMMA. Reduced-size samples were burned in an axisymmetric configuration with controlled coflow conditions (20-60 L/min). Temporally and spatially-resolved soot volume fractions were retrieved using line-of-sight attenuation combined with neural network-based Abel inversion. Radiative emission and flame geometry were quantified concurrently. Results showed that pigmentation had a marked influence on soot behavior: black PMMA consistently produced higher soot volume fractions (up to similar to 3 ppm) and sustained radiative output longer than clear PMMA. Power-law correlations between integrated soot observables and flame-scale parameters revealed distinct scaling laws. These correlations provide quantitative targets for calibration of soot yields in fire modeling. The dataset provides a comparative benchmark on the pigmentation effects in PMMA flames, supporting an improved understanding of soot formation pathways in polymer fires.