Polymorphism of 1,1‐diamino‐2,2‐dinitroethene (FOX‐7, DADNE) has investigated by X‐ray powder diffraction (XRD), differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), IR‐spectroscopy. Two previously unknown polymorph modifications of FOX‐7 ‐ ϵ and ζ were discovered. ϵ‐FOX‐7 has prepared by hydrolysis of 2‐(dinitromethylene)‐5,5‐dinitropyrimidine‐4,6(1H,3H,5H)‐dione in a media with pH up 7–8 to Ho≈−3 and 2‐(dinitromethylene)imidazolidine‐4,5‐dione in aqueous ammonia. ϵ‐FOX‐7 is a stable and exists in temperature range 273–378 K. ζ‐polymorph of FOX‐7 can be obtained at ϵ‐FOX‐7 heating to 378–380 K. ζ→ϵ polymorph transition is a reversible and occurs at 361.7±3.1 K. At 433–453 K ζ‐FOX‐7 transforms to γ‐polymorph. ζ→γ phase transition temperature range was determined using IR‐spectroscopy because it is invisible on DSC curves. IR‐spectra of ϵ and ζ polymorphs are significantly distinct from α‐, β‐ and γ‐FOX‐7. ϵ‐FOX‐7, in contrast to monoclinic α‐polymorph, has orthorhombic type of crystal system (space group P212121). Based on received data, new scheme of FOX‐7 polymorph transition is proposed.

A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and 1,2,3-triazole ring as well as nitramine group in the polymer chain have been described. The developed solvent- and catalyst-free approach is methodologically simple and effective, the comonomers used are easily available, and the resulting polymer does not need any purification. All this makes it a promising tool for the synthesis of energetic polymers. The protocol was utilized to generate multigram quantities of the target polymer, which has been comprehensively investigated. The resulting polymer was fully characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers, thermochemical characteristics, and combustion features indicate the prospects of this polymer as a binder base for energetic materials. The polymer of this study surpasses the benchmark energetic polymer, nitrocellulose (NC), in a number of properties.

No abstract

We discuss the use of differentiated methods in teaching English for specific purposes to students of non-linguistic specialities. Admittedly, within the framework of the Bologna process, foreign language proficiency is regarded as one of the main cross-cultural competences to ensure competitiveness on the global labor market. At the same time, the Bologna system has brought with it a number of challenges with shortage of academic hours being amongst them. On the other hand, university professors have to deal with numerous long-standing school problems, such as lack of academic motivation in learners, their target language knowledge gaps, short-term approach found in learners and their parents, and so on. The teachers in ESP face the necessity of setting priority areas for the development of linguistic competence in students in order to prepare them for professional communication in the chosen field. Although the language classroom is to cover various aspects of the target language, in the meantime, however, teachers need to choose effective activities for developing specific skills in students, the skills which will be successfully put into practice by the young professionals. We teach students of musical, economic, medical and pedagogical specialities. We describe our teaching experience focusing on some specific methods applied to promote linguistic competence in students of other than linguistic fields. They maintain the significance of carefully chosen teaching resources for successful development of professionally related competences in learners; emphasize the vital importance attached to thoughtful arrangement of self-studies for the trainees and insist on developing a well-balanced structure of supervised and independent learner studies. We consider applying information technologies with the aim of shaping and raising the level of students’ linguistic, cross-cultural and communicative competences as one of optimal solutions in the modern academic process. At the same time, the learners’ major will often determine and enhance the choice of activities that develop the particular skills relevant for the students’ future careers. Therefore, this study will consider the types of tasks methodologically relevant for different specialities.

No abstract