Fotodegrada？？o de compósitos de poliestireno/argila montmorilonita: efeito do tipo de argila e presen？a de sal

composites of polystyrene/montmorillonite (ps/mmt) containing 2.5 wt. (%) clay were prepared with two types of clays modified with quaternary ammonium salts. were also prepared samples of ps + quaternary ammonium salt, using the same amount employed in modifying the clay. all samples were exposed to uv radiation for up to 12 weeks, and then tests were conducted to evaluate the changes in molecular weight, mechanical properties (tensile and impact), chemical structure (ftir) and fracture surface (sem) of these samples. the results showed that metal compounds existing in clay catalyzes the photodegradation process of ps and the presence of salt alone does not significantly alter the behavior of ps under uv.