Immortal ring-opening polymerization of β-butyrolactone with zinc catalysts: Catalytic approach to poly(3-hydroxyalkanoate)

✍ Scribed by Clémence Guillaume; Jean-François Carpentier; Sophie M. Guillaume

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 437 KB
• Volume: 50
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2009.10.014

✦ Synopsis

The zinc alkoxide complex prepared in situ from the reaction of (BDI)Zn(N(SiMe 3 ) 2 )

is an efficient catalyst for both the solution and bulk ring-opening polymerization (ROP) of racemic-bbutyrolactone (BBL). The controlled ''immortal'' ROP of BBL using the binary catalytic system (BDI)Zn(N(SiMe 3 ) 2 )/BnOH, where the alcohol acts both as co-initiator and chain transfer agent, proceeds smoothly under mild conditions (solution or bulk, 23-90 C) to produce atactic poly(3-hydroxybutyrate) with moderate to high molar mass. For the first time, PHBs could be prepared from very small loadings of a metallic catalyst (100 ppm) via an ''immortal'' procedure, thereby allowing the growth of as many as 50-200 PHBs chains per metal center. Well-defined a-hydroxy,u-alkoxy ester telechelic PHBs, of molar mass ranging up to Mn ¼ 42; 600 g mol À1 were thus quantitatively obtained and fully characterized by NMR, MALDI-TOF MS and SEC analyses.