Rheological Properties of poly(Lactic acid) Modified by Cellulose Acetate Propionate

The effect of the addition of cellulose acetate propionate (CAP) on the rheological properties of poly(lactic acid) (PLA) was studied. Although the blends of CAP and PLA had phase-separated structures, a small amount of CAP did dissolve in the PLA. Therefore, the oscillatory shear moduli in the low-frequency region were greatly increased by the addition of CAP. Neat CAP exhibited marked strain hardening in transient elongational viscosity. This was attributed to the presence of CAP crystals at the processing temperature. The CAP chains that dissolved in the PLA also provided strain hardening in elongational viscosity for the blends, demonstrating that CAP, as a biomass-based plastic, is a good processing modifier for PLA.

Automated summary

The effect of cellulose acetate propionate (CAP) addition on the rheological properties of poly(lactic acid) (PLA) was studied. It was found that a small amount of CAP dissolved in PLA and greatly increased the oscillatory shear moduli in the low-frequency region. Neat CAP also exhibited strain hardening in transient elongational viscosity, and the CAP chains dissolved in PLA provided strain hardening in elongational viscosity for the blends.