Synthesis and characterization of new soluble multisite phase transfer catalysts and their catalysis in free radical polymerization of methyl methacrylate aided by ultrasound-A kinetic study

摘要

Four different soluble phase transfer catalysts (PTCs) containing single, di, tri, and tetra active sites have been prepared and proved by FT-IR, ~1H NMR, ~(13)C NMR, mass, elemental analysis, and conductivity measurement. The presence of the number of active sites in each catalyst was also been confirmed by determining their rate of polymerization of methyl methacrylate (MMA) using potassium peroxydisulfate (PDS) as a water soluble initiator in biphase medium. The comparative study reveals that the R _p of MMA determined in the presence of PTC combined with ultrasound has shown twofold enhancement in the activity than PTC alone. The observed order of activity was found to be of single-site < di-site < tri-site < tetra-site. Further, the thorough kinetic study of free radical polymerization of MMA has been investigated using superior tetra site viz., HBTAMPDTC and by varying the experimental parameters such as MMA, K _2S _2O _8, MPTC, and the temperature. Based on the observed kinetic results and activation parameters, a suitable mechanism was proposed.