Varshney A.,Dayanand Girls College |
Prajapati K.,Dayanand Girls College |
Jain N.,Dayanand Girls College
Asian Journal of Chemistry | Year: 2012
Free radical polymerization of methyl methacrylate initiated by α,α'-azobisisobutyronitrile and anthracene iodine charge transfer complex as novel chain transfer agent was studied in DMSO at 60 ± 0.1 ° for 2 h under oxygen free condition. The system followed ideal kinetics. The overall activation energy is 43.5 kJ/mol. The average molecular weight is in between 32608-62662. The FTIR spectra shows band at 3020 and 1725 cm -1 due to phenyl protons of anthracene charge transfer complex and ester stretching of methyl methacrylate, respectively. The 1H NMR spectra confirms the methoxy protons at 3.7 d ppm. Thermogravimetric analysis shows the stability of polymer upto 230 °.
Prajapati K.,Gg Inter College |
Varshney A.,Dayanand Girls College
Asian Journal of Chemistry | Year: 2011
1,2-Dipolar compound containing phosphorus ylide (p-NBTPY) initiated radical polymerization of ethylacrylate in dioxane yielding syndiotactic polyethylacrylate, as evidenced by FTIR and 1H NMR. It was investigated dilatometrically at 65 ± 0.1 °C for 1 h under nitrogen atmosphere. The kinetic expression is Rp ∞ [I]0.4 [M] 1.2. The system follows non-ideal kinetics because of primary radical termination. The activation energy and kp 2/kt were calculated as 53 kJ/mol and 0.15×10-2 mol L-1 s-1, respectively. Thermal properties of polymer have been established with the help of DSC and TGA technique. The polymer has been characterized by MALDI-TOF. The absence of phosphorus in polymer matrix is confirmed from the scanning electron microscopy. The initiation is brought about by phenyl radical as evidenced from six hyperfine lines in electron spin resonance spectrum.