Density Functional Theory (DFT) calculations at the B3LYP/3-21G basis set was carried out to determine the stability of intermediates during the pulsed laser polymerization (PLP) of acrylate monomers. The reaction path was determined successfully by calculating Electrostatic Potential Maps (ESP) for the selected systems. For this study, pulsed laser photo-initiated polymerization of methoxyacrylate monomers was carried out via a Q-switched Nd: YAG laser (2rd harmonic at 532nm). The monomers, n-butyl methoxyacrylate (B) and n-octadecyl methoxyacrylate (O) along with the activated initiator, benzoyl peroxide were dissolved in ethanol (EOH) and were exposed to the laser for 50 min. Reaction mixture, B: O in stoichiometry 1:1 for copolymerization and pure ‘B’ and ‘O’ solutions for homo-polymerization were treated with laser in order to study the reaction path based on transition state stabilities. Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (1H-NMR) spectroscopy and elemental analysis were used for the structural elucidation of the products. The computed results were found in good agreement with the experimental findings and the comparisons revealed the effectiveness of the DFT-computed method for predicting mechanisms and path for new reactions.

Asma Batool, Zareen Akhter, Lubna Tabassam, Rumana Qureshi, M. Aslam Khan and Asghari Gul