Evaluation of thermoforming potential of polystyrene/perlite composites.

In this work, the thermoforming potential of PS/perlite composites was investigated. Compositions with amounts of 10% and 20% of the mineral filler were processed in a twin-screw extruder with two different screw configuration profiles, followed by compression molding. The influence of perlite content and screw configuration profiles on the flow behavior and heat capacity of the composites was evaluated through morphological, rheological, and thermal properties. The micrographs indicated that most of the perlite broke during the processing and the ones that remained intact were not bigger than 50 µm. The rheological assessment and the evaluation were decisive for the thermoforming properties characterization. The most pronounced elastic behavior identified for the composite processed in low shear conditions and with higher perlite content (P(20%wt)2:2), even in the fragments form, indicated that this composite was the one with the highest potential thermoforming. The low heat capacity value identified for P(20%wt)2:2 composite when compared to the neat-PS:2:2 reinforced that this was the most suitable composite for thermoforming considering its rapid cooling capability after molded. [ABSTRACT FROM AUTHOR]