Poly(lactic acid) (PLA)/starch/montmorillonite (MMT) biodegradable blends were prepared in a twin-screw extruder. The effect of MMT content on the mechanical and thermal properties of the blends was studied. The microstructure of the composites was observed by wide-angle X-ray diffraction and transmission electron microscopy, and the results showed that there was a stacked and intercalated-and-flocculated structure in the blends. The blends of PLA/starch with MMT had a lower crystallisation temperature (Tc) than without MMT. This means that MMT made the crystallisation of PLA easier. The melting temperature of PLA (Tm) was not significantly affected by the addition of MMT. These blends had a high tensile strength of approximately 40 MPa and a high flexural strength of approximately 80 MPa. The maximum tensile and flexural strengths were obtained when the MMT content was 2 wt.%. The water absorption of the blends with MMT was lower than without it.
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