Well-defined Syndiotactic Polystyrene-b-Atactic Polystyrene Stereoblock Polymers

✍ Scribed by Liana Annunziata; Yann Sarazin; Michel Duc; Jean-François Carpentier

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 252 KB
• Volume: 32
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.201100072

✦ Synopsis

Abstract

New well‐defined syndiotactic polystyrene–atactic polystyrene (sPS‐b‐aPS) stereoblock polymers were synthesized in a two‐step process using a combination of “pseudo‐living” Ziegler‐Natta and atom transfer radical polymerizations. Under specific conditions, the one‐pot termination with N‐bromosuccinimide of syndioselective styrene polymerization catalyzed by Cp*Ti(CH~2~Ph)~3~/B(C~6~F~5~)~3~/Al(n‐Oct)~3~ (1:1:1) provided sPS‐Br polymers almost perfectly (97%) end‐capped with bromine atoms. These sPS‐Br were used as macroinitiators in the ATRP of styrene affording sPS‐b‐aPS with a broad range of compositions. Characterizations by ^1^H and ^13^C NMR spectroscopy, HT‐GPC and DSC confirmed the formation and identity of the new materials. Preliminary studies on the crystallization behavior under both isothermal and non‐isothermal conditions showed that these sPS‐b‐aPS stereoblock polymers crystallize faster than the corresponding blends made of sPS and aPS with a similar composition; this effect is amplified at high contents (80%) of aPS in the stereoblock materials. magnified image