Evaluation of Dynamic Compressive Properties of Pla/Pbat Polymer Alloys Using Split Hopkinson Pressure Bar Method

Poly(lactic acid) (PLA) is a biodegradable biomass polymer. Polymer blends or polymer alloys
have been used to overcome its brittleness. Because poly(butylene/adipate/terephthalate)
(PBAT) is a ductile and biodegradable polymer, PLA/PBAT polymer alloys can potentially
exhibit high impact strengths. Different mixing ratios of PLA/PBAT (80:20, 70:30 and 60:40)
and the addition of dialkylperoxide as compatibilizing agent for each mixing ratio have been
examined. The stress-strain curves of the PLA/PBAT specimens (observed using a scanning
electron microscope) were measured using a split Hopkinson pressure bar (Kolsky bar) and
a universal testing machine. The PBAT ratios and addition of dialkylperoxide affected the
stress-strain curves. Yield stress decreased with increasing PBAT ratios. Addition of dialkylperoxide
did not change the yield stress of specimens when PLA:PBAT = 80:20. At high strain
rates, the addition of dialkylperoxide clearly reduced yield stress and Young’s modulus when
PLA: PBAT = 70:30 and 60:40.