Thermally induced cationic polymerization of glycidyl phenyl ether using novel xanthenyl phosphonium salts

The present study firstly describes the synthesis of novel, thermo-latent initiators based on xanthenyl phosphonium salts with different counter anions and phosphine moieties and secondly examines their efficiency in the bulk polymerization of glycidyl phenyl ether (GPE). The polymerization was performed with phosphonium salt initiators (ISbF6,IPF6,IAsF6 andIBF4) at ambient temperature to 200 °C for 1 h. The order of initiator activity wasISbF6 >IPF6 >IAsF6 >IBF4. To examine the effect of the phosphine moiety on the initiator activity, polymerization was carried out withISbF6 (Ph3P) andIISbF6 (Bu3P) at ambient temperature to 170 °C for 1 h. The order of reactivity wasISbF6 >IISbF6. In general, the conversion percentage increased with increasing polymerization temperature. The thermal stability of these salts was measured by thermo gravimetric analysis (TGA). The solubility of phosphonium salts in various organic solvents and epoxy monomers was also investigated.