NASCIMENTO, Uédson Alexandre do.
Resumo:
Blends of high density polyethylene with metallocene linear low density polyethylene, HDPE/m-LLDPE, were prepared by melt compounding in a twin-screw extruder. The m-LLDPE type and content effects on impact and tensile properties were studied. According to the results, these parameters influenced the properties of m-LLDPE. The blend prepared with m-LLDPE Flexus 7200 with the 17% concentration (7217 blend) showed the best properties. However, their hardness was lower than the HDPE Dowlex IP-10262 resin, used for dangerous chemicals transport containers manufacture. The 7217 blend was modified with organophilic montmorillonite (Cloisite 20A organoclay). The diffraction X-ray data (XRD) showed that the 7217 blend modification, with organoclay, on all studied concentrations, did not result in nanocomposites. Nevertheless, the crystallinity properties (determined by differential scanning calorimetry – DSC) and thermal stability (determined by thermogravimetric analysis – TGA) of the 7217 blend, modified with 10 phr of organoclay (7217AO-10) were higher than the pure blend. In addition, the modified blend showed decreased impact resistance, increased elastic modulus and the same tensile strength. As compared to Dowlex IP-10262 HDPE, the tensile strength of 7217AO-10 hybrid was 8% higher, the impact strength was 12% lower and the elastic modulus was 7% lower. In general, the processability and mechanical properties of 7217 blend, modified with 10phr of Cloisite 20A, were similar to that HDPE Dowlex IP-10262. Therefore, this hybrid has great use potencial for dangerous chemicals transport containers manufacture, replacing the HDPE Dowlex IP-10262 resin.
