p-Nitrobenzyltriphenyl phosphonium ylide-initiated radical terpolymerization of Styrene,methyl methacrylate and acrylonitrile: synthesis,characterization and properties

摘要

Solution terpolymerization of styrene (St),methyl methacrylate (MMA) and acrylonitrile (AN) was carried out in dioxane at 65 +- 0.1 deg C for 120 min using p-nitrobenzyltriphenyl phosphonium ylide as radical initiator.The kinetic expression is as follows (R_p is the rate of polymerization): R_p propor.to [ylide]~(0.45)[St]~(0.8)[MMA]~(1.2)[AN]~(1.2).The overall activation energy is 42 kJ mol~(-1) L~(-1).The composition of terpolymer,calculated from ~1H NMR and elemental analysis,was used to evaluate reactivity ratio,as r_1 (MMA + AN) = 0.06 and r_2 (St) = 0.005,employing the Kelen-Tudos method.It confirmed the alternating nature of the terpolymer.The terpolymer was characterized using ~(13)C NMR,gel permeation chromatography and thermogravimetric differential thermal analysis.Electron spin resonance spectroscopy confirmed the presence of the phenyl radical responsible for initiation.