Synthesis, Kinetics and Mechanism of Terpolymerization of Styrene, Vinyl Acetate with Acrylonitrile Initiated by P-Nitrobenzyl Triphenyl Phosphonium Ylide

摘要

Synthesis of terpolymers consisting of two electron-donating monomers, viz. styrene and vinyl acetate with one electron-accepting monomer, i.e. acrylonitrile, initiated by p-nitrobenzyl triphenyl phosphonim ylide in dioxane as diluent at 65°C for 150 min has been studied. The kinetic expression is Rpα[I]0.8[Sty] 1.2[VA] 1.4 [AN]1.2. The terpolymer composition was determined by the Kelen-Tüdos method. The values of reactivity ratios using r1 (Sty + VA) = 0.1 and r2 (AN) = 0.005. The overall activation energy is 46 kJ●mol●L–1. The formation of terpolymer is confirmed by the FTIR spectra showing bands at 3030 cm–1, 1598 cm–1, and 2362 cm–1, confirming the presence of phenyl, acetoxy and nitrile group respectively. The terpolymer has been characterized by 1H-Nuclear Magnetic Resonance, 13C-Nuclear Magnetic Resonance. The Differential Scanning Calorimetric curve shows the Tg of the polymer as 149.5°C. A scanning electron microscope confirms the polymer to be phosphorus free. Electron.Spin.Resonance spectra confirms phenyl radical responsible for initiation.