R. Vabrik et al., A STUDY OF EPOXY RESIN-ACRYLATED POLYURETHANE SEMIINTERPENETRATING POLYMER NETWORKS, Journal of applied polymer science, 68(1), 1998, pp. 111-119
Epoxy resin-acrylated polyurethane semi-interpenetrating polymer netwo
rks (semi-IPNs) were synthesized containing various ratios of the digl
ycidyl ether of bisphenol-A (DGEBA)-based epoxy resin and an acrylated
aliphatic urethane oligomer. The synthesis was carried out in the pre
sence of a mixture of triarylsulfonium hexafluoroantimonate salts as a
dual photoinitiator that initiates both the cationic polymerization o
f the epoxy resin and the free-radical polymerization of the acrylated
urethane oligomer simultaneously, upon irradiation with ultraviolet l
ight. The simultaneous photopolymerization, followed by isothermal dif
ferential scanning calorimetry measurements, gave rise to simultaneous
semi-interpenetrating polymer networks (semi-SINs). During polymeriza
tion, partial inhibition of the cationic polymerization was noticed. T
his was investigated by determination of the gel content and the infra
red spectroscopy of the soluble fraction, after extraction of the synt
hesized polymer films in a Soxhlet apparatus, and by determination of
the network density of investigated systems with thermal mechanical an
alysis. The compatibility of the components in the semi-IPNs was inves
tigated by dynamic mechanical thermal analysis. It was found that glas
s transition temperatures are shifted inwardly, which indicated that t
he epoxy resin-acrylated polyurethane semi-IPNs were compatible. (C) 1
998 John Wiley & Sons, Inc.