ULTRAVIOLET-INDUCED CROSS-LINKING OF SOLID POLY(ETHYLENE OXIDE)

Poly(ethylene oxide) (PEO) of molecular weight from 200,000 to 2,000,0 00 was crosslinked by exposure to ultraviolet radiation with a high-pr essure 150 W mercury lamp. Photochemical crosslinking of PEO proceeds in the presence of photoinitiators such as benzophenone and acetopheno ne which act as a hydrogen-abstracting agent. Gel fraction yield excee ds 90%, and the number-average molecular weight between crosslinks det ermined by equilibrium swelling in chloroform varies from 3,000 to 100 ,000. The degree of crosslinking can be controlled by changing the irr adiation temperature. (C) 1997 John Wiley & Sons, Inc.