4. CONCLUSION
Toughness of PLA can be improved by blending with NR. Both NR content and particle size of NR
affect to toughness properties. The optimal NR content that could improve the brittleness of PLA was
found to be 10 . At this content the average particle size of NR provided smallest and well disperse in
PLA matrix. However, blending PLA with ENR would reduce mechanical properties of blends. The
crystallization ability of PLA in blends increased with the present of NR or ENR due to small molecules
contained in rubber phase and surface of droplets could act as nucleating agent. Furthermore, the thermal
stability of blends was found to be decreased with addition of NR and ENR. And PLA/ENR blends have
more thermal stability than PLA/NR blends due to migrate of small molecules to surface of NR can lead
to chain scission of PLA while mixing that can be decreased molecular weight of PLA with deceasing of
Thermal stability.