Role of radiolytically generated species in polymerization of [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETC) in aqueous medium: Steady state and pulse radiolysis study

• Radiation induced polymerization of [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETC), a promising monomer for antibacterial grafting applications, in aqueous solution has been studied for the first time.
• Viscosity, a measure of polymerization, of radiation-induced polymerization of AETC under various conditions has been studied.
• Kinetics of transients of AETC formed on radiolysis and their reactions have been studied by pulse radiolysis technique.

Radiation induced polymerization of [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETC) in aqueous solution has been studied by steady state and pulse radiolysis techniques. The effect of absorbed dose, dose rate, monomer concentration and ambient conditions were investigated by measuring the relative viscosity of monomer solution. AETC has been found to react with OH and e−aq with bimolecular rate constants of 7.6×109 M−1 s−1 and 3.7×1010 M−1 s−1, respectively. The bimolecular rate constants for the reaction of AETC− and AETC-OH with the monomer molecule AETC have been found to be 1.7×107 M−1 s−1 and 2.2×106 M−1 s−1, respectively. Further, AETC− and AETC-OH have been found to react with oxygen with k=3.2×109 M−1 s−1 and 2.2×109 M−1 s−1, respectively. The monomer underwent polymerization upto an absorbed dose of 0.14 and 0.42 kGy in N2O and N2 saturated solutions and later the radiolytic degradation of the polymer was predominant. The reaction of AETC transients with oxygen was also established by decrease in polymerization extent in aerated and oxygenated solution.