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1

The influence of accelerated aging on selected mechanical properties of polypropylene with organic fillers

Szymiczek Małgorzata, Chomiak Monika, Chmielnicki Błażej, Sarraj Sara, Gołuch Paulina

Polimery

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2022

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Vol. 67, nr 7-8

308--316

EN

The aging effect in water atthe temperature of 100±2°C on selected mechanical properties of polypropylene with organic fillers (hemp chaff, a mixture of oak, birch and maple leaves) was investigated. A significant influence of the aging process on the impact strength and elongation at break was observed. The degradation processes were also visible on the surface of the samples.

PL

Zbadano wpływ starzenia w wodzie w temperaturze 100±2°C na wybrane właściwości mechaniczne polipropylenu z napełniaczami organicznymi (plewy konopne, mieszanina liści dębu, brzozy i klonu). Stwierdzono istotny wpływ procesu starzenia na udarność i wydłużenie względne przy zerwaniu. Procesy degradacji widoczne były również na powierzchni próbek.

2

Characterization and Proposal of a Substitute Stone for the Restoration of the Archaeological Site of Lixus (Larache, Morocco)

Chahid Noureddine, Yehdhih Maimouna, Boujamlaoui Zakaria, Bahgdad Bouamar, Zerdeb Mohammed Amine, Moussa Karima, El Hmidi Fatima, Zoraa Noura, El Hadi Hassan, Chakiri Saïd

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 5

124--136

EN

The town of Lixus is the most important archaeological site on the Moroccan Atlantic coast. It is essentially built, from at least 12 centuries BC, by rocks of sedimentary origin. A preliminary diagnosis allowed us to identify the main factors of the physico-chemical degradation observed on the buildings of the monument. The interest of the conservation of this archaeological richness requires an intervention of safeguard, which will go beyond the operation of protection of its perimeter to another desired action of development of its tourist and cultural purposes. The objective of this work mainly concerns a comparative study of the petro-physical characteristics of the sandstones sampled at various levels of the geological formation located to the northwest of the Lixus site, as a substitute stone, which will be used for any eventual rehabilitation operation. On the basis of the definition of the main causes of pathologies observed at the level of the site, the realization of these categories of action are first carried out by an experimental simulation of accelerated aging by "imbibition-drying" cycling. Then the call for petrographic analyzes where the thin sections revealed the mineralogical composition, the proportion of the figured elements and the nature of the bonding phase of the rocks tested; then the chemical characterization carried out by XRF fluorescence (X-Ray Fluorescence) and the quantification of the carbonated fraction by calcimetry. Also and with the help of geotechnical tests, in particular the determination of the porosity, the density and the hydric density as well as the uniaxial compressive strength (RC) and the rebound index (hardness by sclerometer). The confrontation of all the results obtained reveal a valid estimate of the potential for durability and compatibility in the sense of homogeneity with the material to be replaced, in view of their significant mineralogical composition in terms of sufficient quantity of silica and calcite. The tests used allowed the refinement of the discriminating mechanical parameters, they highlighted the relationships between the mechanical resistance and the physical properties of this replacement stone, particularly the high mechanical resistance (50.1–74.9 MPa), the absolute density values (2.54–2.68) and the rebound index (30–34) significant, which evolve inversely proportional to the low porosity values (1.7–2.20). However, all these recorded results have qualified this rock as a resistant lithology according to the classification adopted by the International Society of Rock Mechanics (ISRM), recommended for any possible renovation of Lixus.

3

Influence of air content on thermal degradation of poly(ethylene terephthalate)

Rejmer Wojciech

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2021

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nr 24(1)

183--193

EN

The aim of these research is to investigate the air content on aging of poly-(ethylene terephthalate) (PET) preforms. Three air pressures were selected and in each pressure 5 samples were aged during 21 days in 80°C. Three samples were selected to be cut for determination of density with the use of hydrostatic method. Sample mass, Young modulus and surface roughness were measured for each sample before and after aging and differences between those parameters were presented as results. The changes of parameters may lead to a conclusion that mechanism of polymeric chain oxidation is dominant during thermal aging of PET. However aging process is not the fastest in atmospheric pressure but in lower air contents. This effect may be caused by greater evaporation of small molecule degradation products and shifting of reaction equilibrium in the direction of further decomposition.

4

Accelerated aging studies of the selected commercial films

Cichecka Magdalena, Pałys Beata, Wilbik-Hałgas Bożena, Struszczyk Marcin H.

Polimery

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2021

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T. 66, nr 6

350--356

EN

The Arrhenius method was used to investigate the effect of accelerated aging conditions on the physical and mechanical properties of polymer films for technical, medical, food and office applications. Temperature and UV radiation were taken into account as environmental factors. It was shown that the tested films are more sensitive to thermal degradation than UV radiation. The reduction in tensile strength after thermal aging does not exceed 40%, and in the case of UV radiation, 14%. The estimated lifetime of the tested films is over 5 years.

PL

Metodą Arrheniusa zbadano wpływ warunków przyspieszonego starzenia na właściwości fizyko-mechaniczne folii polimerowych do zastosowań technicznych, medycznych, spożywczych i biurowych. Jako czynniki środowiskowe uwzględniono temperaturę i promieniowanie UV. Wykazano, że badane folie są bardziej wrażliwe na degradację termiczną niż promieniowanie UV. Zmniejszenie wytrzymałości na rozciąganie po starzeniu termicznym nie przekracza 40%, a w przypadku promieniowania UV, 14%. Oszacowany czas życia badanych folii wynosi ponad 5 lat.

5

The Influence of the Aging Process on the Change of Selected Strength Properties of Polypropylene Compositions with Mineral Fillers

Garbacz Łukasz, Klepka Tomasz, Longwic Filip

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 2

65--74

EN

The goal is to understand the influence of minerals fillers on the course and performance of process of injection molding polypropylene compounds as well as on the mechanical properties of the obtained products. Three types of mineral fillers, derived from post-production waste, were used for testing. It was aluminosilicate (zeolite), fly ash and gypsum powder, all in powder form. The minerals fillers were introduced into the tested PP in a mechanical mixing process prior to the processing. During the injection molding process, inorganic fillers are subject to the same steps as plastic processing, compression, homogenization, transport. Organic fillers used in the injection process were introduced into the processed PP in the amount of 30% by weight. The test stand consists of a screw injection molding machine, Arburg AllRounder 320C. The research on the structure of manufactured materials, mechanical strength, impact resistance and hardness are presented. The laboratory tests of accelerated aging were conducted using an aging chamber. The aging temperature in the heat chamber was set to even amount of 63 oC and irradiance 0,51 W/m2. According to the standard, the aging time has been applied accordingly: 120, 240, 360 h, which conform to degradation at room temperature for 4 month, 8 month and one year. It was found that the type of mineral fillers used did not have a significant influence on the hardness of the surface of the moldings. The changes in hardness shown in the figures are primarily influenced by the properties and type of polymers used during the injection process. During the tests, differences in the mechanical strength of composites for injection molded parts made of PP with mineral fillers were observed. Filling PP with zeolite in the tested value causes a decrease in mechanical strength by an average of 10% from 24 to 21.6 MPa. Different mechanical interactions are shown by flying ash and gypsum powder fillers, increasing mechanical resistance of the composition. Flying ash increases mechanical strength by 30% on average, from 24 to 31.2 MPa. In case of gypsum powder application the resistance of PP composition increases analogically, but on average 20 %, to 29,5 MPa.

6

Impact of Accelerated Aging on the Performance Characteristics of “Green” Packaging Material of Polylactide

Moraczewski Krzysztof, Pawłowska Alona, Karasiewicz Tomasz, Rytlewski Piotr

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 4

1--10

EN

The paper presents the result of the research on the impact of the accelerated aging process on selected operational properties of polylactide films containing natural antioxidants in the form of coffee, cocoa or cinnamon extracts. The research was focused on mechanical properties important for the packaging industry from the point of view of the reliability of the obtained products, i.e. tensile strength, relative deformation at maximum stress, relative deformation at break, Young’s modulus, impact strength and storage module at various temperatures. The extracts have a positive effect on the determined mechanical properties. The obtained results were very often better not only than the values obtained for pure polymer, but also better than the values obtained for the film containing the synthetic anti-aging compound. It can therefore be concluded that the proposed plant extracts will have a positive effect on the stability of the mechanical properties of the manufactured products, which will allow long-term, reliable and safe operation of packaging. Proposed extracts can therefore be an alternative to the previously used synthetic anti-aging additives.

7

Effect of environmental and operating conditions on the verification interval for smart electronic electricity meters

Radej Blaž, Drnovšek Janko, Begeš Gaber

Metrology and Measurement Systems

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2019

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Vol. 26, nr 1

171--184

EN

According to metrological guidelines and specific legal requirements, every smart electronic electricity meter has to be constantly verified after pre-defined regular time intervals. The problem is that in most cases these pre-defined time intervals are based on some previous experience or empirical knowledge and rarely on scientifically sound data. Since the verification itself is a costly procedure it would be advantageous to put more effort into defining the required verification periods. Therefore, a fixed verification interval, recommended by various internal documents, standardised evaluation procedures and national legislation, could be technically and scientifically more justified and consequently more appropriate and trustworthy for the end user. This paper describes an experiment to determine the effect of alternating temperature and humidity and constant high current on a smart electronic electricity meter’s measurement accuracy. Based on an analysis of these effects it is proposed that the current fixed verification interval could be revised, taking into account also different climatic influence. The findings of this work could influence a new standardized procedure in respect of a meter’s verification interval.

8

Thermal stability of the elastomeric anti-trauma pad

Olszewska K., Zielinska D., Struszczyk M. H., Wierzbicki Ł., Leonowicz M. K.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 2

93--100

EN

The elastomeric anti-trauma pad (EA-TP) based on shear thickening fluid (STF) has been developed. Dynamic oscillatory shear experiment was conducted at constant strain amplitude of 5%. STF composed of 25% of volume fraction of 7 nm Fumed Silica, dispersed in polypropylene glycol with molar mass 400 gmol−1 shows elastic properties in entire investigated range of the frequency. Ballistic tests of EA-TP with 7.62 mm × 39 mm PS bullets were performed according to the PN-V-87000:2011 standard. The studies revealed about 60% reduction of the average backface signature depth (BSD) for the EA-TP, when compared to the nowadays commonly used soft insert. The ATR-FTIR analysis confirmed slight impact of the elevated temperature and air (oxygen) on the chemical degradation of the EA-TP surface. The UV-VIS spectroscopy has allowed to notice colour deviation of the aged samples towards green and yellow, as well as lack of dye resistance to accelerated aging process. Thermographic analysis has shown no visible changes of the EA-TP surface and sub-surface during accelerated aging process. The aforementioned small changes on the surface of EA-TP did not affect the ballistic properties of composite armour. EA-TP insert maintains ballistic properties after accelerated aging process which was simulating the period of 6 years according to ASTM F1980 – 07:2002 standard.

9

Effect of Accelerated Ageing on Ballistic Textiles Modified By Plasma-Assisted Chemical Vapour Deposition (PACVD)

Struszczyk M. H., Puszkarz A. K., Miklas M., Wilbik-Hałgas B., Cichecka M., Urbaniak–Domagała W., Krucińska I.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 1 (115)

83--88

EN

The functionalisation of textile products and materials using the low temperature plasma technique is increasingly used in industrial practice, mainly because of the many benefits, often unattainable with the use of other techniques. The study focused on the modification of the composite textile materials - sheets of Ultra High Molecular Weight Polyethylene (UHMWPE) fibres (Dyneema® SB51) by applying the surface deposition of silicone-like polymer in an environment of low temperature plasma. The aim of this study was to evaluate changes in the mechanical and physical properties of modified ballistic textiles under simulated storage conditions in accelerated time. Based on experiences in planning the research on accelerated aging, a test programme was developed for the assessment of changes during the aging process in ballistic fibrous materials under various environmental conditions. The process of low temperature plasma modification affected the mechanical properties of the ballistic composite textile materials during the accelerated ageing using temperature or temperature and humidity. The effect of the modification varied with the mechanical properties investigated.

PL

Funkcjonalizacja tekstylnych produktów i materiałów, przy zastosowaniu techniki plazmy niskotemperaturowej, jest coraz częściej stosowana w praktyce przemysłowej, głownie ze względu na wiele korzyści, często nieosiągalnych dla innych technik modyfikacji. W prezentowanych badaniach skupiono się na modyfikacji kompozytowych materiałów tekstylnych wykonanych z włókien polietylenowych o znaczącej masie cząsteczkowej (Dyneema® SB51) poprzez depozycję powierzchniową polimerów silanowych w środowisku plazmy niskotemperaturowej. Celem pracy była ocena zmian w właściwościach mechanicznych i fizycznych zmodyfikowanych tekstyliów balistycznych pod wpływem symulowanych warunków przechowywania w badaniach przyspieszonego starzenia. Program badań został opracowany na podstawie doświadczeń w planowaniu badań przyspieszonego starzenia, celem określenia zmian w włókienniczym materiale balistycznym zachodzących w czasie starzenia, w różnych warunkach środowiskowych. Proces modyfikacji plazmą niskotemperaturową wywoływał zmiany w właściwościach mechanicznych kompozytowych materiałach balistycznych podczas przyspieszonego starzenia przy zastosowaniu jako czynnika starzeniowego: temperatury lub temperatury i wilgotności. Obserwowane tendencje zmian w właściwościach różniły się w zależności od badanej cechy materiału.

10

Badanie odporności wybranych pigmentów na kompleksowe działanie składników powietrza w mieście przemysłowym

Tomaszkiewicz-Potępa A., Wróbel A.

Przemysł Chemiczny

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2006

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T. 85, nr 7

492-496

PL

Badano wpływ warunków atmosferycznych na trwałość (stabilność) organicznych pigmentów ftalocyjaninowych, nitrozowych kompleksów metalicznych, diketopirolopirolowych i tetrachloroizoindolinowych w standardowym spoiwie winylowo-akrylowym, w ciągu 12 tygodni. Zmiany barwy określano przy użyciu spektrofotometru X-Rite Master Color oraz reflektografu UV-Vis. Dla porównania testowane pigmenty poddano przyspieszonemu starzeniu w komorze ksenonowej, kontrolując spektroskopowo (IR) zmiany ich struktury. Stwierdzono zróżnicowaną podatność pigmentów stosowanych do wewnętrznych i zewnętrznych wymalowań na kompleksowe działanie światła słonecznego i zanieczyszczeń atmosfery (polutantów).

EN

Stability of phthalocyanine, 1-nitroso-2-naphthol Fe, Co, and Mn complexes, diketopyrrolopyrrole, and tetrachloroisoindolinone used alone and as pigments (0.5 or 1%) in a standard vinyl-acrylic paint, was examd. on a 12-week (June– Sept. 2003) outdoor and indoor exposures in terms of color change detd. by an X-Rite spectrophotometer and pigment’s structure change detd. by UV-VIS and IR spectroscopy. Coatings applied to glass conditioned 14 days at 23±2°C, RH 50±2%, were exposed to the atm. at Oświęcim, PL. Nondispersed pigments were lit for 168 hrs. with a 280-nm Xe lamp at 55°C and then IR analyzed. In IR terms, the Fe complex was most resistant, and the other pigments were fully resistant, to accelerated aging. The Co and Mn complexes were least resistant to the 12-week outdoor exposure. Most fading were the diketo and the tetrachloro pigments, but the Xe lamp irradiation produced no major structure changes. The color changes in the tetrachloro pigments produced in the12-week test were invisible to the human eye.

11

Badania wybranych parametrów fizyko-chemicznych stałych homogenicznych i heterogenicznych paliw rakietowych w aspekcie oceny ich trwałości

Florczak B., Jasińska-Guzik H., Marzec A., Szymczak J., Błachnio B., Milewski E., Miszczak M., Szymanowski J.

Problemy Techniki Uzbrojenia

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1999

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R. 28, z. 69

111--123

PL

Badano wpływ przyspieszonego starzenia w temperaturach 75ºC i 120ºC na niektóre parametry fizykochemiczne i balistyczne paliw rakietowych. Po 60 cyklach starzenia stwierdzono ok. 0,5-0,8 % ubytek masy paliw, zaobserwowano zmiany liniowej szybkości palenia i charakterystyk termicznego rozkładu. Zmiany np. kaloryczności, czy współczynnika termicznego były mało znaczące, mieściły się w granicach błędu pomiaru.