Nanoscale structure of SAN-PEO-SAN triblock copolymers synthesized by ATRP

PMSE 100

Michael S. Silverstein, michaels@tx.technion.ac.il1, Michal Shach-Caplan1, Havazelet Bianco-Peled, bianco@techunix.technion.ac.il2, Nicolay V. Tsarevsky3, Beth M. Cooper3, and Krzysztof Matyjaszewski, km3b@andrew.cmu.edu3. (1) Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel, (2) Department of Chemical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, 32000, Israel, (3) Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
Controlled radical polymerization techniques such as atom transfer radical polymerization (ATRP) can be used to synthesize well-defined polymeric materials with novel compositions, macromolecular architectures and functional end groups. The effects of molecular weight (Mn) and relative block size on the nanoscale architectures and properties of well-defined triblock copolymers (TBC) with poly(styrene-co-acrylonitrile) (SAN) end-blocks and poly(ethylene oxide) (PEO) mid-blocks were investigated. The presence of SAN end-blocks reduces the ability of the PEO mid-blocks to crystallize. As the Mn of the PEO mid-blocks increases so does its mobility and its ability to crystallize. The TBC with PEO mid-block mole fractions of greater than 0.5 exhibit higher crystallinity and a structure with a low level of nanoscale lamellar order. The TCB with PEO mid-block mole fractions of less than 0.5 exhibit lower crystallinity and a random two-phase nanoscale structure.
 

Block Copolymers as Nanoscale Materials
8:00 AM-11:20 AM, Monday, 11 September 2006 San Francisco Marriott -- Salon 7, Oral

Division of Polymeric Materials: Science & Engineering

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006