SILVA, D. F.; http://lattes.cnpq.br/2701031112448578; SILVA, Divânia Ferreira da.
Resumen:
The aim of this study was to develop blends of polystyrene/compound of rubber
waste (PS/SBRr) of the shoes industry aiming to tough the PS and to reuse the
SBRr. The blends were prepared in the compositions (70/30; 60/40 and 50/50
wt.%) and with 5 wt.% of styrene-butadiene-styrene compatibilizer (SBS). In order
to study the effect of mixing sequence, the 50/50 wt.% composition, which
presented the best result in impact strength, was selected. The sequences were
PS/SBRr/SBS 47.5/47.5/5%; PS/SBRr + SBS 47.5/47.5 + 5% and PS/SBS + SBRr
47.5/5 + 47.5 wt.%. The blends were prepared by co-rotational twin screw extruder
and molded by injection and characterized by torque rheometer, mechanical
properties, heat deflection temperature (HDT), dynamic mechanical thermal
analysis (DMTA), differential scanning calorimetry (DSC), scanning electron
microscopy (SEM) and transmission electron microscopy (TEM). From the
mechanical tests, a reduction in elastic modulus and tensile strength and a
significant increase in impact strength were observed in relation to PS. The HDT
for all blends was reduced compared to the PS. The mixing sequence showed
good results in mechanical properties, especially in composition PS/SBS + SBRr
47.5/ 5 + 47.5 wt.%. By SEM and TEM it can be seen that the compatibilized
blends presented a better distribution of the rubber particles with a morphology
that was more stable than the one that was not compatibilized. These results were
confirmed by the highest impact strength values, indicating the compatibiliz er
action that improves adhesion among the components of the blend. By DMTA it
was possible to state that these blends are immiscible. Hence, the importance of
the reusing of rubber wastes is evidenced both for toughening of the PS and for
the reduction of problems caused to the environment, when they are discharged
improperly.
