REX Synthesis of PLA-based Materials via Ring-opening Polymerization

3 REX Synthesis of PLA-based Materials via Ring-opening Polymerization 

Sn(Oct)2 has shown to be an efficient catalyst for REX polymerization of LA as reported by some of However, to get the best processing con- 

In order to achieve enhanced intumescent properties of stereo-complexed PLA, the in situ REX synthesis of PLA was similarly reported for PLA homopolymers in the presence of nanoclays and carhon nanotubes and for stereo-complexed PDLA-A-PLLA diblock copolymers in the presence of a mixture of ammonium polyphosphate, melamine and nanoclay.  

We must mention that intensive research is on-going in the design of metal-free catalysts for the REX ROP of lactide. By comparison with metal-based catalysts like Sn(Oct)2, the advantages of these metal-free catalysts are that they are less harmful for biomedical applications and readily removed during, e.g., extrusion processes. Among the simplest ones, some selected enzymes, tertiary amines, urea- and iodine-based compounds, phosphines and carbenes have proven efficient metal-free catalysts. However, most of these investigations have shown that these metal-free catalysts are less active and may yield intensive side-reactions, such as epimerization, when applied during bulk REX ROP of LA.  

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REX synthesis of PLA-based materials via ring-opening polymerization (ROP) ... 

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