Synergism of the action of some stabilisers against the destruction of polymer materials

Abstract

The process of thermal-oxidative degradation of polymer materials has been studied on the example of polyethylene in the presence of quinones and / or nitroxyl radicals. The synergistic effect of the positive action of a mixture of stabilisers from a number of quinones and nitroxyl radicals on the destructive process of polyethylene has been established. It has been shown that the rate of degradation has significantly slowed down when an equimolecular mixture of 4-acetylamino-2,2,6,6-tetramethylhexahydropyridine-1-oxyl and 2,6-di-tert-amyl-1,4-cyclohexadienone inhibitors has been introduced into the polymer. The kinetics of the initiated thermo-destructive process of polyethylene oxidation in the presence and absence of stabilisers has been studied. A mechanism of joint action of stabilisers based on their interaction with radicals and the breakage of radical chains, as well as a mechanism for the regeneration of stabilisers, has been proposed.

Development of nanocomposite materials for road construction

“…Recently, the material used for the manufacture of the signal cone is plastic with an operating temperature range from -50 to + 600C. Such a material is subject to mechanical destruction, especially in winter, even under low loads [13][14][15].…”

Recent advancements in the use of Bobbitt's salt and 4-acetamidoTEMPO

“…Almost complete transfer of chirality from 161 was observed in the subsequent intramolecular cycloisomerization and Claisen rearrangement that affords seven-membered carbocycle 162 (95% ee). Chiral ketone 162 was advanced to (À)-frondosin B (163), which was completed in 8-steps with an overall yield of 19%. Ovaska and co-worker's synthesis allowed the determination of the absolute configuration of (À)-frondosin B (163), a previously unsettled issue.…”

“…Additives are often used to prevent the destruction of the polymer chains in solution and the synergistic effects of different stabilizing agents were investigated by Zhukova and co-workers. 163 An equimolar mixture of ACT ( 2 ) with a quinone was found to protect polyethylene from thermo-oxidative destruction.…”

Physical and Chemical Prerequisites for Efficient Mechanical Processing of Composite Materials

“…Все эти факторы приводят к тому, что режущее тело, встречая на своем пути армирующее волокно, натягивает его как струну, существенно деформируя и волокно и матрицу. Но разрушение материала происходит только по-сле разрушения связей кристаллической решетки армирующего волокна после значительной упругой деформации всего КМ [26]. Кроме того, возникает такой эффект, что на армирующее волокно, закрепленное в матрице КМ силами адгезии, осуществляется воздействие, как на отдельное тело, нежестко закрепленное в упругой массе.…”