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Postępy w badaniach degradacji termicznej materiałów polimerowych. Cz. I. Badania literaturowe

Kaczmarek Halina, Kosmalska Daria, Malinowski Rafał, Bajer Krzysztof

Polimery

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2019

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T. 64, nr 4

241--251

PL

Przedstawiono bieżące kierunki badań stabilności termicznej polimerów, ze szczególnym uwzględnieniem nowatorskich układów polimerowych: kompozytów i nanokompozytów, polimerów biodegradowalnych, biocydowych i do zastosowań specjalnych. Opisano ogólny mechanizm degradacji termicznej zachodzącej podczas przetwórstwa i podstawowe aspekty kinetyczne tego procesu. Omówiono przykłady badań właściwości termicznych wybranych tworzyw na bazie poliuretanów, żywic epoksydowych, kopolimerów kwasu akrylowego i poliestrów.

EN

The article presents current trends in the studies of thermal stability of polymers, with particular emphasis on novel polymeric systems: composites and nanocomposites, biodegradable and biocidal materials as well as polymers for special applications. The general mechanism of thermal degradation occurring during polymer processing and the basic kinetic aspects of this process are briefly described. Exemplary studies of thermal properties of selected plastics based on polyurethanes, epoxy resins, copolymers of acrylic acid and polyesters are also discussed.

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Toward a new approach for passive safety assessment of gymnastic equipment

Costabile G., Schwanitz S., Amodeo G., Martorelli M., Lanzotti A., Odenwald S.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 56, nr 2

59--65

EN

Purpose: Aim of the paper is to propose a new approach for the assessment of passive safety of gymnastic equipment that allows technicians to optimize the choice of protection devices. Design/methodology/approach: According to different standard procedures, EN 913 and EN 1177 with an additional control on the acceleration parameter, experimental tests on polymer foam materials were performed using cylindrical and hemispherical missiles connected to a flexible impact testing apparatus realized at Chemnitz University of Technology. Findings: Impact tests carried out using cylindrical and hemispherical missiles have shown, for the same impact energy, different acceleration peak values, always greater for hemispherical missile than cylindrical one. So considering EN 913 procedure, the severity of head impacts, in term of acceleration peak can be underestimated when a cylindrical missile is used. For this reason to correctly assess the head injuries is necessary to take into account in addition to the acceleration peak value, also HIC parameter. Research limitations/implications: The research described in the paper was carried out taking into account only the human head impacts (the most severe injuries) and not other parts of the human body. Practical implications: The new approach proposed in the paper can be useful for the choice of the protective devices to improve the passive safety of gymnastic equipment. It represents a starting point to define new standards. Originality/value: On the base of experimental tests, the authors show that the safety threshold of peak acceleration defined in the EN913 standard is poor. For this reason it is necessary to modify the current standards, in order to guarantee an adequate passive safety and to allow the technicians to optimize the choice of protection devices on the base of impact absorption properties, that are evaluated using all together the parameters: acceleration peak, drop height and Head Injury Criterion (HIC).

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Multiaspect analyzes of blow moulding process

Szczepański K., Kwiatkowski D., Koszkul J.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

157--160

EN

Purpose: The main purpose of the performed investigations was a multi-aspect analyzes of the blow moulding process in a mould which takes two-stage nature of the process and the occurrence of uncontrolled phenomena which influence the shape, size and quality of the products into consideration. Design/methodology/approach: The value for the Barus number for different dimensions of the nozzle gap and the distribution of the temperature field during blow moulding process have been determined; the product thickness profile has been defined; phenomena which occur during blowing stage have been registered. The investigations have been performed by means of the blow moulding machine of UFP-05 type by IPTS – Metalchem Toruń using the designed and prepared blow mould with the sight-glass made of polycarbonate. Findings: The performed investigations enabled the insight study of uncontrolled phenomena which occur during each individual stage of the process and they showed the dependencies between these phenomena and the process parameters. Moreover, the detailed analyses enabled to determine the influence of these parameters on the physical features and dimensions of the finished goods. Research limitations/implications: The continuation of the investigations with use of extended blow mould design equipped in polycarbonate sight-glass which enabled the determination of the influence of the structure and mould cavity dimensions on the finished product wall thickness seems to be justified. It would be also useful to design the station for the precise non-touch measurements of Barus effect which enabled, except the measurements of the external diameter, the measurements of the finished product wall thickness. Originality/value: The complex analysis of the blow moulding process was possible thanks to innovative and original approach to the experimental tests which enables e.g. the optical registration of the phenomena which occur during blow moulding process.

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Zastosowanie czwartorzędowych soli związków azaaromatycznych

Śliwa W., Dondela B.

Prace Naukowe. Chemia / Wyższa Szkoła Pedagogiczna w Częstochowie

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1998

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Vol. 2

131--144

PL

W artykule przedstawiono przykłady zastosowań czwartorzędowych soli związków azaaromatycznych, jak modyfikowane polimery, barwniki, katalizatory oraz materiały do konstrukcji urządzeń elektronicznych.

EN

In the paper selected examples of applications of quaternary azaaromatics such as modified polymers, dyes, catalysts and materials for optoelectronic devices are presented.