Organocatalytic polymerization of ethylene oxide and the controlled synthesis of PEO-based hydrogel networks

POLY 612

Andrew F. Mason, andymas@us.ibm.com1, Bas G. G. Lohmeijer, basloh@us.ibm.com1, Hongbo Li, hongbo@lanl.gov2, Russell C. Pratt, rcpratt@us.ibm.com1, Qi Liao3, Curtis W. Frank, curt.frank@stanford.edu3, Kevin Kingsbury, kkingsbu@calpoly.edu4, Robert M. Waymouth, waymouth@stanford.edu5, and James L. Hedrick, hedrick@almaden.ibm.com1. (1) IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120, (2) Inorganic, Isotopes and Actinide Chemistry, Los Alamos National Laboratory, Chemistry Division, MS J514, Los Alamos, NM 87545, (3) Department of Chemical Engineering, Stanford University, Stanford, CA 94305, (4) Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407, (5) Department of Chemistry, Stanford University, Stanford, CA 94305
Poly(ethylene oxide) (PEO) is a biocompatible material frequently used in biomedical applications. PEO formed by traditional anionic polymerization requires extensive purification to remove alkali metal counterions. We have investigated metal-free organocatalytic polymerization of ethylene oxide using N-heterocyclic carbene catalysts. Ring-opening polymerization using 1,3-bis(mesityl)imidazol-2-ylidene catalyst and a primary alcohol initiator produces PEO having controlled molecular weights and narrow molecular weight distributions (Mw/Mn < 1.10). Dihydroxy-terminated PEO formed by this method is used to synthesize swollen hydrogel networks using Click chemistry to crosslink polymer chain-ends. Use of monodisperse PEO chains and a controlled crosslinking reaction results in model hydrogel networks, where gel properties can be related to network structure.
 

7th International Biorelated Polymers Symposium
1:30 PM-5:20 PM, Wednesday, 13 September 2006 San Francisco Marriott -- Salon 14/15, Oral

Division of Polymer Chemistry

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