PHYSICOCHEMICAL CHANGES OF HYBRID POLYURETHANE INORGANIC THERMAL INSULATION WHEN HEATING IN AIR AND IN AN INERT ATMOSPHERE

Purpose. The article presents the results of a study of physicochemical processes occurring when a hybrid polyurethane inorganic thermal insulation is heated under dynamic conditions up to 800 °C in different atmospheric environments. The object of the study was an industrial sample of thermal insulation “FoamTech 1 550” made in South Korea. Methods. In the course of the work thermo-gravimetric analysis and IR-Fourier spectrometry were used. Samples for spectrometric analysis were prepared in the process of thermogravimetric tests by suspending the experiment. Findings. As the result of the combined studying hybrid thermal insulation material by thermogravimetry and IR-Fourier spectrometry methods, the following was established: – polyisocyanate used for obtaining the material is aliphatic in nature; – the hybrid thermal insulation sample contains about 40 % inorganics, presumably aerogel silica; – there are three main stages of hybrid thermal insulation decomposition, both in air and in an inert atmosphere; – analysis of the changes in IR spectra when heating the hybrid sample showed that at the first stage of decomposition, regardless of the atmospheric environment, the condensation reaction of silanol groups of silica aerogel takes place with the water release; – at the second stage, thickening of the inorganic framework continues, chemical polyurethane bonds with the inorganic are destroyed, and polyurethane component carbonization begins. Research application field. The results give the idea of material decomposition process in a fire. Differences in behavior in oxidizing and inert environments are shown. This is important for comparing a new group of materials with the already known types of polymer thermal insulation in terms of their fire hazard and possible application in building construction. Conclusions. The paper studies the chemical structure and physicochemical changes when heating the new group of materials, namely hybrid organic-inorganic thermal insulation materials. The article is a continuation of a team of authors’ systematic study of a thermal behavior of modern types of polymer thermal insulation.

Engenieering Technology in Plastic Biodegradation by Large Bee Moth Larvae Depends on the Type of Polyethylene

The objective of this research was to evaluate the processes of biodegradation of different types of polyethylene by G. mellonella larvae. The determination of the types of polyethylene samples was carried out by IR Fourier spectrometry. The structure of solid household waste includes polyethylene of different types. When assessing the degree of biodegradation, it was found that holes in the polyethylene samples of different sizes formed 5.3±2.4 - 28.7±9.4 units/day and 54.8±12.6 - 1867.8±38.6 mm2/day, and the mass of polyethylene samples, depending on the type, decreased on average by 1.5±0.5 - 51.0±6.5 μg/day. The obtained results of survival, mobility, weight gain and melanization indicate the absence of negative health effects on larvae when eating polyethylene.

Analysis ofmulticomponent mixture on the example of the drug ”Pentalgin” bythe methods of TLC and IR-Fourier spectrometry

The definition of a qualitative composition of multicomponent drugs ”Pen- talgin” and ”Pentalgin ICN” by TLC and IR-spectrometry is carried out. It is shown that using just TLC or just FT-IR spectrometry does not allow us to identify all the major components. It has been proposed an authentication scheme, which includes the steps of isolating of the test components, their sep- aration by TLC, followed by extraction of components and definition by FTIR spectrometry. The combination of these two techniques allows to separate and identify almost all the most important components of the mixture.

A Study of Perturbations of the A1Σu+ State of Na2

High resolution Fourier spectrometry techniques have been used to study the A1Σ+u state, which is perturbed by the b3Πu state of the Na2 molecule. This study was achieved by means of exciting the B1Πu state from the X1Σ+g ground state by 4880 Å and 4965 Å lines of an Ar+ laser. The excitation is followed by collisional transfer energy produced between B1Πu and (2)1Σ+g states ν, which led to the population of the vibrational levels of the (2)1Σ+g state v. The analysis of the collision-induced system (2)1Σ+g −A1Σ+g enabled us to study, in detail, the perturbations of 11 vibrational levels from v = 0 to v = 10 of the A1Σ+u state.