Addition of 1 wt% EPO significantly improved the tensile strength of PLA/EPO(1) and PLA/EPO(3) blends by approximately 5% and 13% respectively. This suggests that EPO acts as plasticizer, which increases the interaction at the phase boundaries and improves the flexibility of blends. Generally, the compounded EPO is dispersed in the interphase between the PLA chains. This results in strong interphase interaction, which reduces the stress concentration point when tensile load is applied on the blends and consequently produces higher mechanical strength