Thermal degradation and ablation energy of poly (methyl methacrylate)

TGA analysis proved that PMMA reduced its thermal decomposition and the glass temperature was not influenced by it. PMMA undergoes very little melting near to the melting temperature. However, the differential scanning calorimetry test revealed that melting does not involve a significant amount of latent heat. At around 160°C the PMMA suffers little melting but swelling (bulging) on the surface of the sample can be identified in the region adjacent to the light interaction. For black PMMA, the decomposition started slowly at 170°C and then accelerated from about 320°C until full decomposition at 395°C with a drop of weight of about 0.008%/°C. But in clear PMMA, the decomposition temperature started at 239°C with minimal mass loss to 320°C then rapid mass loss and was fully decomposed at 404°C with loss of weight of about0.003%/°C.