Kinetic patterns for thermal oxidation of binary and ternary blends based on polylactide and polyethylene

Russian Chemical Bulletin - The effect of introduced aged low density polyethylene (LDPE-A) on structure and properties of mixed blends based on polylactide (PLA) and low density polyethylene...     

X-ray Diffraction Study of Structural Changes in High-Strength Ceramics Based on Zirconium Oxide with Additions of Ytterbium and Neodymium Oxides after Hydrothermal Treatment

Crystallography Reports - A surface structural analysis of two ceramic samples of zirconium oxide (ZrO2) sintered at 1550°C, stabilized in the tetragonal form, before and after hydrothermal...     

Environmentally friendly films based on poly(3-hydroxybutyrate) and poly(lactic acid): A review

A review of data on the thermo, photo-, and biodegradation of compositions of synthetic polymers with poly-3-hydroxybutyrate and poly(lactic acid) is presented. The influence of these polymers on the thermal, microstructural, and rheological properties of mixtures is examined. The destruction of pure biopolymers, as well as compositions thereof with polyethylene, poly-(3-hydroxybutyrate-co-3-hydroxyvalerate), and polycaprolactone is studied.     

Sensory neuron response to emission from a CO<Subscript>2</Subscript> laser

We have built a wavelength-tunable CO₂ laser meeting the requirements for low-intensity laser therapy. At λ = 10.57 μm and 9.24 μm, we observe a physiological effect detectable from the change in the extent of neurite outgrowth from sensory neurons. This makes it possible to study molecular mechanisms for interaction of low-intensity radiation with tissues in a living body. The ATP molecule is considered as the specific molecular target for the action of the radiation.     

Thermal oxidation and structure of polylactide–polyethylene blends

The thermal oxidation of polylactide–low-density polyethylene mixtures with additives of oxidized polyethylene as an analogue of recyclable materials is studied. It is found that the polylactide is oxidized more slowly than polyethylene, whereas the introduction of up to 30 wt % of oxidized polyethylene accelerates the thermal oxidation of the mixtures, with the physical and mechanical properties of the resultant materials remaining suitable for practical use. It is established that the presence of oxidized polyethylene has virtually no effect on the melting point of polylactide and polyethylene, somewhat increasing, however, the degree of crystallinity of the components of the blend.     

Composite Materials Based on Polylactide and Poly-3-hydroxybutyrate “Green” Polymers

Blends of polylactide with low-density polyethylene and of poly-3-hydroxybutyrate with synthetic ethylene–propylene rubber with the component weight ratios of 30 : 70, 50 : 50, and 70 : 30 were prepared and studied in comparison with the pure components. The thermal characteristics of these blends were determined by differential scanning calorimetry. The melting point of polyhydroxybutyrate and polylactide in the blends changes insignificantly, by 1–2°C. The dependence of the morphology on the composition for both polymer systems was examined by scanning electron microscopy. The physicomechanical properties of the samples are determined by the major phase. The blends undergo biodegradation in soil at 20 ± 3°С. The process occurs faster for blends of polyhydroxybutyrate with ethylene–propylene rubber of all the compositions studied.     

Possible molecular effect related to the reception of low-intensity IR radiation: Role of Src-kinase

The patch-clamp technique has been used to demonstrate that low-intensity IR irradiation affects the effective charge of the activation gating system of slow sodium channels in the nociceptive neuron membrane. IR photons are absorbed by ATP molecules bound to Na⁺,K⁺-ATPase at their hydrolysis site. Na⁺,K⁺-ATPase is a transducer of signal that is further delivered to slow sodium channels and cell genome. It is demonstrated that the irradiation does not modulate the response of a sensory neuron in the presence of PP2, an inhibitor of Src-kinase. The results show that Src-kinase is a series unit involved in the intracellular cascade processes triggered by low-intensity radiation of CO₂ laser.     

Degradation of Polylactide—Polyethylene Binary Blends in Soil

Russian Journal of Applied Chemistry - Binary polylactide-low-density polyethylene blends of various compositions were prepared, and their biodegradability in soil and water absorption kinetics at...     

Radiation-Chemical Purification of Water from Petroleum Products as Studied by Gas Chromatography–Mass Spectrometry

The radiation-chemical purification of water from petroleum products (diesel oil, motor oil, and residual fuel oil) was studied by gas chromatography–mass spectrometry. The removal of -radiolysis products with molecular weights from 40 to 500 amu was examined. Organic compounds (toluene, ethylbenzene, xylenes, other alkylbenzenes, C₁₄–C₁₈ n-alkanes, naphthalene, methylnaphthalenes, and tetralin) were virtually completely removed at a dose of 25 kGy. An interpretation of the data was presented.