A synthetic scheme was developed to prepare cationically polymerizable octafunctional monomers with silsesquioxane (T8) cores. Epoxy and 1‐propenoxy functional groups were attached to the core by the hydrosilation of T H8 with an appropriate precursor. The steric constraints and the requirements for the hydrosilation reaction are discussed. The monomers were fully characterized and then polymerized by exposure to ultraviolet irradiation in the presence of onium salt photoinitiators. The polymerization conditions for the monomers were optimized and compared with each other using real‐time infrared spectroscopy. Thermal analysis was also performed on the resulting crosslinked polymers. © 1997 John Wiley & Sons, Inc.

This paper describes the use of high-energy electron beam radiation to fabricate highperformance epoxy resin matrix composites. Employing catalytic amounts of diaryliodonium and triarylsulfonium salt photoinitiators, it was found that graphite fiber reinforced composites based on epoxy monomers could be efficiently e-beam cured at room temperature when exposed to e-beam irradiation. A mechanism involving the reduction of the onium salt initiators by e-beam induced free radicals has been proposed. Strong protonic acids generated during the course of this reaction initiate the cationic ring-opening polymerization of the epoxy resins. This chemistry was employed to fabricate high-performance carbon fiber reinforced composites. The mechanical properties of the composites were measured and effects of blends with other epoxy monomers and additional types of particulate fillers were evaluated using various testing methods.

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A synthetic scheme was developed to prepare cationically polymerizable octafunctional monomers with silsesquioxane (TJ cores. Epoxy and 1-propenoxy functional groups were attached to the core by the hydrosilation of T~with an appropriate precursor. The steric constraintsand the requirementsfor the hydrosilationreaction are discussed.The monomers were fully characterized and then polymerized by exposure to ultraviolet irradiation in the presence of onium salt photoinitiators. The polymerization conditions for the monomers were optimized and compared with each other using real-time infrared spectroscopy. Thermal analysis was also performed on the resulting crosdinked polymers.