โ Scribed by T. Sato; M. Yoshioka; T. Otsu
No coin nor oath required. For personal study only.
Binary systems consisting of dimethylaniline-N-oxide (DMOA) and some ~-halo-carbonyl compounds, such as phenacyl halide and ce-halo-acetic acid ester, were found to induce radical polymerzation of vinyl monomers. Bromo-derivatives showed higher initiating activities than chloroderivatives. The polymerization of methyl methacrylate (MMA) with DMAO and phenacyl bromide (PBr) was investigated kinetically. The polymerization rate (Rp) was expressed as follows;
The overall activation energy of the polymerization was calculated to be 42.7 kJ mol -t. No noticeable chain-transfer from the polymer radical to DMAO or PBr was observed. The benzoyl radical was trapped by 2-nitroso-2-methylpropane, a spin trapping reagent, in the reaction of DMAO and PBr. The u.v. spectrum of poly (MMA) obtained suggests that the polymer contains end-groups similar to acetophenone and DMA. From the results, an initiation mechanism for the polymerization has been proposed and discussed.
๐ SIMILAR VOLUMES