Preliminary studies on burning behavior of polymethylmethacrylate (PMMA)

The burning behavior and combustion mechanism of polymethylmethacrylate (PMMA) were studied by using cone calorimeter, mass spectrograph and gas chromatograph. Main combustion mechanisms of PMMA were reviewed. Results indicated that PMMA would burn steadily under low radiative heat flux; or with thicker samples. The yields of carbon dioxide and carbon monoxide would not be changed. Under high heating rate, there are three broad stages. Firstly, upon heating by external sources, PMMA would decompose to generate monomer MMA and a small amount of other products. Secondly, monomer MMA would decompose to produce small molecule products. Finally, these small gaseous molecules would undergo oxidation, i.e., burning. The main oxygen consumption reaction, i.e., the heat release reaction, is the burning of small molecule products. Main combustion products are found to be carbon dioxide and water, with a small amount of carbon monoxide. At high temperature, the monomer MMA would react with oxygen directly to produce methyl pyruvate, formaldehyde and acetone. However, these reactions are not important in the combustion process of PMMA.