Synergetic Effect on PP/mEPDM Blends Under Vibration Force Field in Tri-Screw Dynamic Mixing Extruder

摘要

Vibration force field was introduced into plastics processing in tri-screw dynamic mixing extruders, so as to intensify mixability and dispersion. The effects of vibration force field on toughened PP by mEPDM during plastics processing in tri-screw dynamic mixing extruders were investigated experimentally and synergism on polymer blends under vibration force field was discussed by using PP/mEPDM blends as a sample. The results showed a synergism effect on mechanical properties of PP/mEPDM blends under dynamic conditions and it was found that the vibration force field enhanced impact strength of PP/mEPDM blends, the amplitude of enhancement varied as mEPDM content varied, and the impact strength of PP/mEPDM blends basically presented a rising tendency followed by a fall with the increase of frequency and amplitude. The impact strength had a maximum value of 54.4 kJ/m~2 which was much larger than that under steady conditions as amplitude and frequency were 0.6 mm and 20 Hz, respectively, and the mEPDM content was 25%. Therefore, good synergism would be caused and the mechanical properties of PP/mEPDM blends would be modified due to the vibration force field.