Synthesis and Photoinitiated Cationic Polymerization of Polyfunctional 1-Propenyl Ether Monomers and Polymers Containing Phosphonate Linkage in the Main Chain

Polyfunctional 1-propenyl ether monomers (la-c) were synthesized by the regioselective addition reaction of 1-propenyl glycidyl ether (PGE) with certain phosphonic dichlorides using quaternary onium salts as catalysts. The reaction of PGE with phenylphosphonic dichloride (PPDC) gave bis[1-(chloromethyl)-2-(propenyloxy)-ethyl]phenylphosphonate (la) in 82% yield. Polycondensation of la with terephthalic acid (TPC) was also carried out using 1, 8-diazabicyclo[5.4.0]undecene-7 (DBU) as a base to afford the corresponding polymer containing 1-propenyl ether groups (2a). A multifunctional monomer (3a) containing both 1-propenyl ether groups as Vc and methacrylate groups as Vr was prepared by the reaction of la with methacrylic acid (MA) using DBU. Photoinitiated cationic polymerization of these 1-propenyl ether compounds proceeded rapidly using bis[4-(diphenylsulfonio)phenyl]sulfide bis(hexafluorophoshate) (DPSP), as a cationic photoinitiator without solvent upon UV irradiation.