Miscibility and Crystallization Behaviors of PEO and PLA, PLLA or PLLA/PDLA Stereocomplex Blends

摘要

Polylactide (PLA) is of growing interest in the field of biomedical applications, such as drug delivery systems, surgical sutures, osteosynthesis devices, etc., due to their outstanding biodegradability and biocompatibility. Especially, its di- or triblock copolymers are widely investigated as a carrier of drug delivery. The introduction of hydrophilic segments into degradable PLA can improve its hydrophilicity, and then can be used in the delivery of hydrophilic macromolecules, such as proteins. Poly(ethylene glycol) (PEG) or poly(ethylene oxide) (PEO) has been widely used as a hydrophilic component because of its excellent biological and physicochemical properties. The physicochemical and biological properties of PEO and PLA have been widely studied by numerous researchers. Particularly, Ikada et al. founded that equimolecular blends of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) formed a stereocomplex (SC), which results in a higher melting point (ca. 50 °C higher), higher mechanical strength and better hydrolytic stability. However, there have been limited studies on miscibility between PEO and PLLA/PDLA SCs, which may help us better understand their morphology and properties. In this work, we have investigated the miscibility and crystallization behaviors in PEO and PLA, PLLA, or PLLA/PDLA blends.