This paper is devoted to the analysis of the photochemical behaviour of copolymers with carbazole units exposed to long-wavelength radiation. These copolymers are constituted of two types of carbazolylethyl methacrylate units (CEM) with octyl methacrylate moieties (OMA). The exposure of copolymers and PVK to UV light results in dramatic modifications of the physical and photophysical properties of the polymer. These modifications can be correlated with modifications of the chemical structure of the matrix. The photoageing of copolymers and PVK has been analysed by fluorescence, ESR, UVevis and infrared spectroscopies. The effects of crosslinking and chain scissions were determined by gel fraction measurements and size exclusion chromatography.

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Particle morphology of energetic materials to a great extent defines their sensitivity and reactivity properties. The morphology in its turn strongly depends on the crystallization process. In the present research the thermal crystallization of pentaerythrol tetranitrate (PETN) explosive and ammonium perchlorate (AP) was studied by differential scanning calorimetry (DSC) and FT-IR spectroscopy. DSC test usually included the heating of the sample with the constant rate of 5°C/min to the temperature which was several degrees higher than the melting temperature and then the cooling of the sample with the different cooling rates. The cooling led to the crystallization. The crystallization temperature, heat and rate were measured. The newly crystallized samples were then subjected to microscopic inspection and FT-IR spectroscopy.It was found that the crystallization of AP takes place in two stages. The first high temperature stage proceeds at temperatures higher than the melting temperature and starts just after beginning of cooling. The second low temperature stage occurs at temperature significantly less than the melting temperature, e.g. the crystallization is realized from the overcooled liquid. The relative contributions of these types of crystallization strongly depend on the cooling rate. At low cooling rate (0.2°C/min) the crystallization takes place through the high temperature mechanism solely whereas at high cooling rate (15°C/min) only low temperature process is realized. At intermediate cooling rates both types of crystallization exist. The ratio of the heat of low temperature crystallization to the high temperature one (H lowtemp /H hightemp ) increases exponentially with the cooling rate. FT-IR spectroscopy showed that the AP sample crystallized through the high temperature mechanism has strictly the same spectrum as the initial material. The spectrum of AP crystallized from the overcooled melt demonstrates certain differences (line shapes and frequencies) in the range of NH 4 + stretching (≈3200 cm -1 ) and bending (≈1400 cm -1 ) vibrations and ClO 4 stretching (≈1100 cm -1 ) vibrations. These facts testify perhaps that the different mechanisms of crystallization result in formation of different crystal structures.Crystallization of PETN in all experiments takes place from the overcooled melt and proceeds in one stage. The value of the overcooling depends on the cooling rate. At low cooling rates (up to 4°C/min) the crystallization temperature is approximately constant and concentrates near 120 °C (T melt =141 °C). The further rise of the cooling rate (from 5°C/min and up to 15°C/min) results in the sharp increase of the overcooling (T cryst ≈100 °C). It was found that the rate of crystallization has the same step like dependence upon the cooling rate. The high overcooling leads to the significant increase of the crystallization rate. FT-IR spectra do not show any differences between initial and newly crystallized samples. However visual and microscopic inspection show that in the case of low rate crys...