https://elib.belstu.by/handle/123456789/20520 2026-04-16T10:53:35Z 2026-04-16T10:53:35Z Liubimau, A. G. Yurachka, V. V. https://elib.belstu.by/handle/123456789/21104 2020-10-21T07:37:10Z 2015-01-01T00:00:00Z

Title: Polyethylene antioxidants based on aromatic acid hydrazides Authors: Liubimau, A. G.; Yurachka, V. V. Abstract: Hydrazides of aromatic acids were synthesized and used as stabilizers of polyethylene. The thermal stability of polyethylene compositions was studied by methods thermogravimetry and infrared spectroscopy. The activation energy of thermal oxidative degradation of modified polyethylene was calculated. The optimal concentration of synthetic antioxidants was determined. It was shown that hydrazones of aromatic acids exhibit thermostabilizing properties.

2015-01-01T00:00:00Z Revyako, M. M. Kasperovich, O. M. Khrol, E. Z. Petrushenia, A. F. https://elib.belstu.by/handle/123456789/21103 2020-10-21T07:37:10Z 2015-01-01T00:00:00Z

Title: Research of charactristics of polymeric heat-shrinkable sleeves Authors: Revyako, M. M.; Kasperovich, O. M.; Khrol, E. Z.; Petrushenia, A. F. Abstract: The results of testing of polymeric heat-shrinkable sleeves used for forming the fixed joints of pipe-lines are presented in the article. During the production sleeves of this type are exposed to radiation and orienting drawdown. It was determined the dependence of the performance characteristics of heat-shrinkable sleeves on the technological parameters of their production, in particular on the nature of the used polymer material and the exposure degree after molding. Quality assessment of the obtained sleeves was assessed by such indicators as the degree of crosslinking of the material in the product, the degree of parison swell of products after conducting the orientation (drawing), and the force and pressure of compression of pipe-shells by sleeves. The mode to obtain sleeves with an excellent set of operational characteristics is determined in the work.

2015-01-01T00:00:00Z Emello, G. G. Bondarenko, Zh. V. Gerasimovich, V. A. Kharlan, T. V. https://elib.belstu.by/handle/123456789/21102 2020-10-21T07:37:10Z 2015-01-01T00:00:00Z

Title: Aqueous solution properties of ZETESOL surfactant preparations Authors: Emello, G. G.; Bondarenko, Zh. V.; Gerasimovich, V. A.; Kharlan, T. V. Abstract: Surface-active, optical and electrical proper ties of surfactant specimens ZETESOL ZN and ZETESOL MG water solution were investigated using various analysis methods (stalagmometry, turbidimetry, refractometry, conductometry). The quantitative characteristics of adsorption process such as the Langmuir’s maximum adsorption, the consta nts of Shishkovsky’s equation were calculated. It was determined that the specimens investigated have great surface activity on the frontier between surfactant specimens water solutions and air. The resu lts of obtained by turbidimetric method show that the specimens are colloidal systems and their critical concentration of micelle formation are coequal. The admixture (laureth-3, phenoxyethanol, sulfates of metals) have the positive influence on the effect of aggregation in colloidal solutions of surfactant specimens. The specimen ZETESOL MG has greater effect on micelle formation than the specimen ZETESOL ZN because of larger quantitive constant in its composition. The characteristic curves “electro conductivity – concentration of water solution of surfactant specimens” were carried out by conductometric method. The electrical properties of anionic specimens depend on the ionic qualitative composition of systems. It was established that electro-conductivity of ZETESOL MG water solutions is higher than that of ZETESOL ZN water solutions due to higher electrolyte (MgSO [4]) concentration. The investigations showed that the specimens ZETESOL group could be used in composition of hygienic detergents as foam-producing agents and stabilizers of foams.

2015-01-01T00:00:00Z Vershilovskaya, I. V. Kruk, M. M. https://elib.belstu.by/handle/123456789/21101 2020-10-21T07:37:10Z 2015-01-01T00:00:00Z

Title: Acid-base and photophysical properties of asymmetric dendrimers with porphyrin core Authors: Vershilovskaya, I. V.; Kruk, M. M. Abstract: The spectral and photophysical properties of mixed 5,10,15,20-arylporphyrins with А 2В2 - cis and А 2В2 - trans peripheral substitution and the porphyrin core dendrimers with the same spacer architecture between tetrapyrrolic macrocycle and indolocarbazole dendrons as well as those of their mono- and doubly protonated forms have been studied. Sequential formation of both mono- and doubly protonated forms of all the studied compounds was found during the acid-base titration. However, the concentration of monoprotonated form is small compared to those of the free base and doubly protonated one due to close values of protonation constants р K[a1](Н[2]P ↔Н[3]P{+}) and рK[а2](Н[3]P{+} ↔ Н[4]P{2+}) in both ground singlet S[0] state and first excited singlet S[1] state. Different position of peripheral substituents/spacers of А (phenyls) and В (mesityls) type, which is known to have different sterical hindrances with tetrapyrrolic macrocycle, does not result in any noticeable differences in the acid-base properties. The free bases of all the compounds have similar photophysical properties. Doubly protonated forms of dendrimers and parent porphyrins were found to have different probabilities of lowest singlet S[1] state deactivation. Compared to the free base molecules the fluorescen ce quantum yield value for dendrimers reduces for 50 −1,000 times, whereas the parent porphyrins demonstrate about three fold increase.

2015-01-01T00:00:00Z