Few-layer graphene structures synthesized by the plasma electrochemical method are used as modifiers of epoxy binders. It is shown that the obtained structures have the maximum positive...

The effect of low concentration of fullerene, graphene oxide and their combinations at an 85/15 ratio as additives on structure and mechanical properties of cross-linked polyurethanes has been studied at static and dynamic loading. Structure of nanocomposites has been determined from X-ray analysis and scanning electron microscopy. It has been shown that the presence of carbon nanoparticles in a composite results in its lower strength under both static and shock-wave loads. The synergetic effect of carbon nanoparticles mixture is revealed to have 1.25 times higher Young's modulus as compared with native polymer.

Eco-friendly waterborne polyurethanes (WPU) find wide application in agriculture as pesticide carriers, which enhances their efficiency. To provide better control of the retention time and capacity of pesticides, WPU can be modified by cyclodextrin derivatives able to form supramolecular assemblies with bioactive substances. Synthesis of WPU containing up to 15 wt.% of covalently bound β-cyclodextrin partial nitrate (CDPN) is reported in this work. Covalent bonding of CDPN to a polyurethane matrix has been proved by IR spectroscopy and size exclusion chromatography. The particle size and viscosity of the WPU dispersion have been determined. The introduction of CDPN affects molecular weight and thermal properties of WPU films. The presence of CDPN in WPU is shown to provide higher average molecular weight, wider molecular weight distribution, and larger average size of dispersed particles, compared with WPU reference samples containing 1,4-butanediol. The analysis of the rheological behavior of the obtained WPU dispersions shows that they can be classified as pseudoplastic liquids. The analysis of the thermal parameters of WPU films indicates that the introduction of 15.0 wt.% CDPN shifts the value of the glass transition temperature from −63 °C to −48 °C compared with reference samples. We believe that the results of the present study are sufficiently encouraging in terms of using CDPN-modified eco-friendly WPU as potential systems for developing the delivering agents of bioactive compounds. The application of such systems will allow the long-term contact of pesticides with the plant surface and minimize the possibility of their release into the environment.

The results of the study of the mechanisms of the initiation reactions of anionic polymerization of acrylonitrile under the action of a new initiating system with tertiary amine–ethylene (or propylene) oxide are presented. ¹H NMR spectroscopy it was shown that, ethylene oxide slowly and in equilibrium reacts with 1,4-diazabicyclo[2.2.2]octane at room temperature with the formation of zwitterions, which initiate the further polymerization of ethylene oxide. In the presence of acrylonitrile, zwitterions quickly join it causing rapid growth of polyacrylonitrile chains on the formed carbanions. The reaction scheme for the initiation is suggested. The scheme was confirmed by quantum-chemical calculations of thermodynamic parameters for the reversible reactions of addition of ethylene (or propylene) oxide to some tertiary amines with the formation of zwitterions. The relationship between the molecular structure of tertiary amines and their ability to form zwitterions is discussed.

It is shown that the products of interaction of ethylene oxide and bicyclic amines containing tertiary nitrogen atoms at the tops of bicyclic structures efficiently initiate the anionic...