COLL 223 |
| Joseph V. Nguyen and Christopher W. Jones. School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr NW, Atlanta, GA 30332-0100 |
| Atom Transfer Radical Polymerization (ATRP) has been a widely studied polymerization method since 1995; however one of the main challenges in ATRP is the removal and recycling of the catalyst. In a typical ATRP recipe, the initiator-to-catalyst ratio is usually 1:1 (typically 0.1-1% w/w); consequently the residual catalyst remaining in the recovered polymer deeply colors the product. Immobilizing these catalysts is a common solution to this problem. Unfortunately, the studies carried out to date have not focused on how the synthetic method for catalyst preparation influences the catalyst’s behavior and ultimately the overall performance. In the work presented, CuBr/pyridylmethanimine (PMI) complexes were immobilized via four different synthetic routes: multi-step grafting (M1), two-step grafting (M2), one-pot (M3) and pre-assembled complex (M4) methods. Each synthetic method was evaluated on three different silica supports (mesoporous SBA-15 with 50 and 100 Å pores and non-porous Cab-O-Sil EH5). Their performance in the polymerization of methylmethacrylate (i.e. rates, level of conversion and control) was used to study the role of synthetic method and support porosity on the resulting catalyst structure and efficacy. Characterization techniques such as 1H and 13C NMR, 13C and 29Si CP-MAS NMR, FT-Raman, elemental analysis and TG analysis have been performed to demonstrate a supported CuBr/PMI complex. |
|
Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, March 29, 2004 Disneyland -- North Exhibit Hall, Poster
Division of Colloid and Surface Chemistry |