Synthesis and characterization of ultraviolet-curable fluorinated polydimethylsiloxanes as ultraviolet-transparent coatings for optical fiber gratings
Résumé
Synthesis of photocrosslinkable fluorinated polydimethylsiloxane (PDMS) was carried out through the direct hydrosilylation of allyl 2-(perfluorohexyl)ethyl ether with copoly(dimethyl methyl hydro siloxane). The hydrosilylation of the fluorinated allyl ether allowed the introduction of fluorinated groups onto the polysiloxane backbone. Then, a second hydrosilylation of allyl methacrylate led to PDMS bearing both fluorinated and photocrosslinkable groups. The ratio between fluorinated groups and allyl methacrylate groups allowed us to tune the refractive index of the resin without changing thermal properties. Formulations containing fluorinated PDMS were ultraviolet-cured, and their ultraviolet transparency and Yttrium Aluminium Garnet (YAG) laser resistance were investigated.