Rheological and Thermal Behavior of High-Density Polyethylene (HDPE) at Different Temperatures

Abstract

In the present work, rheological properties of HDPE samples were measured at temperatures of 150˚C, 190˚C and 230˚C. It was shown, by oscillatory tests, at low frequencies, that, for temperatures of 150˚C and 190˚C, there was a predominance of the viscous behavior over the elastic one. At 230˚C, there was a predominance of the elastic contribution, and there was an increase of the molar mass compared with the ones obtained from the tests at 150˚C and 190˚C. The results obtained from the temperature ramp oscillatory test showed that, up to around 248°C, the viscous behavior prevailed, the opposite being observed at higher temperatures. At 230˚C the sample showed significantly lower values of strain when compared with the ones observed at 150˚C and 190˚C. Oxidative induction time (OIT), melting point and degree of crystallinity were determined by differential scanning calorimetry (DSC).