Influence of Ultrasonication on Dual Site Phase Transfer Catalyzed Radical Polymerization of Heterocylic N Alkenyl Monomers A Kinetic Study

Abstract

vii newlineABSTRACT newlinePhase-transfer catalysis (PTC) is a well-established strategy for the promotion of newlinereaction between two immiscible phases [1-2]. This type of catalysis facilitates the newlinereactions between the two phases by through the transfer of an anionic species from the newlineaqueous (or solid) phase to the organic phase. The important advantages of PTC are: i) newlineless dependency of organic solvents ii) good scalability iii) enhancement of reactivity with newlineshort duration and increased yield iv) ability to substitute inconvenient reagents [like newlinelithium diisopropylamide (LDA)] and v) to control enantioselective variants. Further, newlineimportant salient features of PTC are economy, operational simplicity and ecofriendliness. newlinePTC technology was widely used in various domains of pharmaceutical, newlineagrochemical, polymer, organic and material chemistry. The reaction order was found to newlinebe unity for monomer, initiator and catalyst. Generally, the reaction rate was relatively fast newlinein two phase system, when a use of dual-site phase transfer catalyst. The synthesis of newlinedual-site phase transfer catalysts (1,4-bis (triethyl methyl ammonium) benzene newlinedibromide) [TEMABDB] and characterization of the catalysts by FT-IR, 1HNMR, 13CNMR newlineand Elemental analysis (CHN). newlineUltrasound is a kind of high-frequency sound waves exhibits in wide range of newlinefrequencies (i.e. 20 kHz to 10MHz). It was used in the various applications based on the newlinefrequency range or limit. The cavitation phenomenon occurs in an irradiated liquid during newlineultrasound-assisted reactions, which involves the formation, growth and collapse of newlinebubbles in the liquid. This effect enforces high local temperatures and pressures to newlineincrease the rate of reactions. Ultrasonication have been employed in various chemical newlinereactions because of short reaction time, good yields, mild conditions and enhanced newlineproduct purities by reducing unwanted side reactions compared to conventional heating newlinemethods. Polymers were synthesized by solution and emulsion polymerization technique newlineunder ultrasonication newlineviii newlineA compara