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

Abstract

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.