Designing the Organoplastics Based on Aromatic Polyamide, Study of Their Operational Properties and Applicability

Polymeric composite materials that are reinforced with organic fibers are characterized by great possibilities in terms of improving the durability of friction nodes in machines and mechanisms. These composites successfully compete with non-ferrous metals and their alloys and, in some cases, outperform polymeric and metallic analogs by their properties. In this regard, we have studied the influence of the organic fiber lola on operational characteristics of the aromatic polyamide phenylone, brand C-1, and on possibilities to apply the developed polymeric composite materials.Experimental studies have confirmed that the reinforcement of phenylone with the organic fiber lola in the amount of 5–15 % by weight improves its operational characteristics. This is predetermined by the arrangement of the supramolecular structure of the basic polymer due to the introduction of organic fiber. Thus, at the interface " phenylone-filler" one clearly observes the transformation of the binder's globular structure into fibrillar one. That leads to a positive effect: there is an increase in destruction energy (by 1.5 times) and chemical resistance (by 1.1–1.36 at aging in 5 % HCl, and by 1.27–1.6 ‒ in 10 % HCl). It should be noted that the developed organoplastics are stable at a temperature of 673 K, while the starting polymer begins to destroy intensively at 400 K. Specifically, it was determined that at a further increase in the mass fraction of the filler these indicators deteriorate, due to insufficient adhesion between the filler and the binder.Using the organic fiber lola (in the amount of 5–15 % by weight) makes it possible to obtain composites with improved operational characteristics: enhanced thermal and chemical parameters, high resistance to impact loads. Thus, there is reason to argue about the prospects of using the fiber lola as a filler for composites. Organoplastic with an optimum fiber content (15 % by weight) is recommended for manufacturing the components of tribological nodes for modern equipment instead of non-ferrous metals and their alloys due to sufficiently high operational properties

CONTENTS OF CYTOKINES IN BLOOD OF THE PATIENTS WITH LOCAL FROSTBITES

Abstract. Cytokines provide important connecting links between immunity, blood clotting, and nonspecific resistance that become altered in local frostbites. The aim of study was to determine the contents of cytokines in blood of patients with local frostbites at various terms following the lesion. Fifty patients, 17 to 50 years old, with frostbites of extremities (grade II to IV) were under observation. Arterial and venous blood, as well as venous blood from damaged and intact extremities were examined. Cytokine concentrations were determined using ELISA technique. It was shown that blood concentrations of TNFα, IL-1β, IL-4, IL-8 and IL-18 reached their maximum at early reactive period of the trauma (a 2.3- to 19-fold increase). IL-1β concentration exceeded appropriate control values during all the periods of local frostbites. IL 18 levels were increased at early reactive period of the trauma. IL-1β and IL-8 concentration at pre-reactive period proved to be higher in arterial blood of damaged extremities, than in effluent venous blood. Both during early and late reactive periods, the levels of pro-inflammatory cytokines in effluent blood from damaged extremities were 1.2- to 8-fold higher than in venous blood from intact extremities, whereas IL-4 levels were 2- to 5-fold lower