Thermal Degradation Behavior of PLA Stereocomplex scPLA

An equivalent mixture of optically pure PLLA and poly(D-lactic acid) (PD LA) having the same melting point of about 175°C [49] forms a stereocomplex (scPLA), which has a melting point (T ) 50°C higher than those of pure PLLA and PD LA [50, 51]. It is well known that the scPLA has some properties that are superior to PLAs. However, since PLAs can easily be hydrolyzed and have poor thermal and photo-stability, the characteristic degradabilities of such PLAs are important in determining how molten scPLA should be processed without causing serious thermal decomposition. 

PLLA and PDLA are considered to be due to differences in both residual Sn contents and numbers of terminal groups acting as starting points of the degradation. 

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