Vol 475, No 1 (2017)

The effect of a number of quinoid compounds on methyl methacrylate polymerization initiated by azo-bis(isobutyronitrile) has been studied. It has been revealed that N-aryl-o-iminobenzoquinones, in contrast to o-benzoquinones, can provide radical polymerization of methyl methacrylate in controllable mode. The efficiency of the compounds as chain growth regulators has been found to depend on their composition and reaction conditions. It has been established that 4,6-di-tert-butyl-N-(2,6-diethylphenyl)-o-iminobenzoquinone and 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone under radical initiation conditions provide the synthesis of poly(methyl methacrylate) with wide-range molecular weight, retaining polydispersity indices about ~1.4–1.8 up to deep conversions.

It was found that the catalytic effect of modified nanodiamonds (MND) in the H₂O₂–4-aminoantipyrine–phenol oxidative azo coupling reaction is due to microimpurities of iron and copper ions on the surface of nanoparticles. The efficiency of MND as a catalyst is determined by the amount of surface impurities of these ions and can be doubled by their additional adsorption on nanoparticles. Using MND for phenol indication ensures a linear yield of the colored product of the azo coupling reaction over an analyte concentration range of 0.05–10 μg/mL. The possibility of reusing MND for phenol testing in aqueous samples was demonstrated.