Enhancement in the mechanical properties of in situ microfibrillar PLA/POE composites

In situ microfibrillar poly(lactic acid) (PLA)/polyolefin elastomer (POE) composites (MFCs) with and without compatibilizer POE-g-GMA were prepared using a multistage stretching equipment. The results showed that the distribution of PLA inside the POE matrix for the MFCs without compatibilizer was in the form of microfibrils, and most of the PLA microfibrils were well-oriented and arranged in the matrix. Further, the high PLA content was more likely to form longer PLA microfibrils in MFCs. With the increase in the amount of POE-g-GMA for (PLA/POE, 20/80) system, the length of PLA microfibrils significantly decreased, whereas the average diameter increased. The addition of 2 wt% POE-g-GMA increased the tensile strength and elongation at the break of POE-20-2 by 52.7% and 53.5%, respectively, and the crystallization temperature increased by about 4 degrees C.