Ultraviolet-induced crosslinking of solid poly(ethylene oxide)

Poly(ethylene oxide) (PEO) of molecular weight from 200,000 to 2,000,000 was crosslinked by exposure to ultraviolet radiation with a high-pressure 150 W mercury lamp. Photochemical crosslinking of PEO proceeds in the presence of photoinitiators such as benzophenone and acetophenone which act as a hydrogen-abstracting agent. Gel fraction yield exceeds 90%, and the number-average molecular weight between crosslinks determined by equilibrium swelling in chloroform varies from 3,000 to 100,000. The degree of crosslinking can be controlled by changing the irradiation temperature. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2299–2307, 1997     

Thermosensitive networks based on high molecular weight polyoxyethylene and N-isopropylacrylamide

Summary γ- and UV-irradiation was successfully used for the preparation of mixed networks on the basis of high molecular weight polyoxyethylene (POE) and/or N-isopropylacrylamide and poly(N-isopropylacrylamide) (PNIPAAm). These gels preserve the swelling transition temperature of the pure PNIPAAm and shrink faster above this temperature due to the hydrophilic POE chains. It was found that in a collapsed state these gels retain alkaline organic salts from aqueous solutions. Received: 12 February 1999/Revised version: 18 May 1999/Accepted: 18 May 1999     

UV‐Initiated Crosslinking of Poly(ethylene oxide) with Pentaerythritol Triacrylate in Solid State

A procedure for effective crosslinking of solid films of poly(ethylene oxide) (PEO) by UV irradiation in the presence of pentaerythritol triacrylate (PETA) as a crosslinking agent was developed. UV crosslinking of commercial PEO powder as a hydrocarbon dispersion containing PETA was found to be very effective as well. The polymer gels obtained were free from low molecular aromatic impurities which are inevitable if photoinitiators are used. UV irradiation in the presence of PETA seems to be a simple method for obtaining films or powderlike products of PEO based hydrogels.