CATIONIC PHOTOCURING OF POLYDIMETHYL SILO XANE .1. SYNTHESIS AND PHOTOCURING OF POLYDIMETHYL SILOXANE WITH EPOXY NORBORNENE GROUPS

This paper deals with the synthesis of photocurable polysiloxanes bear ing epoxy norbornene groups. Two reactive schemes were used. The first one was an hydrosilylation of 5-vinyl-2-norbornene on hydrogeno chlor osilane followed by a condensation with alpha,omega-dihydroxy polydime thylsiloxane and completed by an epoxydation. The second way was an hy drosilylation of polysiloxane bearing Si-H groups with 2,3-epoxy-5-vin yl norbornene previously prepared by selective epoxydation of 5-vinyl- 2-norobornene. All the compounds were characterized by 2D NMR (H-1-H-1 and H-1-C-13), FTIR, etc., and the first results on cationic photopol ymerization with triaryl sulfonium hexafluoroantimonate as initiator a re reported. As the temperature increases, the yield passes through a maximum at about 50-60 degrees C. (C) 1997 Elsevier Science Ltd.