Characterization of high-impact polystyrene by catalytic pyrolysis over Al-MCM-41: Study of the influence of the contact between polymer and catalyst

In this work, the particular behaviour of a commercial high-impact polystyrene (HIPS) during the catalytic pyrolysis over Al-MCM-41 has been studied. The results obtained in a thermobalance showed differences in the number and/or the relative importance of the reaction steps involved in the pyrolysis, depending on the polymer particle size, which can be related to the differences in the nature of the polymeric phase being decomposed in each stage. Moreover, the relative importance of each step is very dependent on the particle size, revealing differences in the distribution of the different copolymer domains (i.e., styrene and butadiene domains) when the different particle size samples are mixed with the catalyst. The type of contact of the pure PS and PB polymers has also been studied revealing that, contrary to other results in literature, the catalyst may have an important effect both on the PS and PB pyrolysis. The results obtained showed that catalytic pyrolysis of these polymers could be a powerful tool for providing a fast and simple method for the characterization of copolymers of styrene and butadiene units.