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1

Synteza i zastosowanie modyfikowanych nanorurek TiO2

Górzyński Daniel, Nadolna Joanna, Kozak Magda, Mazierski Paweł

Wiadomości Chemiczne

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2024

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[Z] 78, 3-4

171--188

EN

Heterogeneous photocatalysis in the presence of semiconductor materials, especially TiO2, is increasingly studied due to its potential application in hydrogen generation, carbon dioxide conversion, and pollutant degradation. TiO2, known for its cost-effectiveness, stability, and safety, is particularly effective in its nanometric form, with nanotubes standing out for their structure that improves light absorption and charge carrier mobility. One approach to improve the properties of TiO2 for its application in photocatalytic processes involves its modification. Modifications of TiO2 nanotubes aim to reduce the rate of recombination of photogenerated charge carriers, increase photocatalytic activity in the UV range, extend its activity to the visible radiation range, and enhance reaction selectivity. Enhancing TiO2 photocatalytic efficiency involves modifications such as doping, creating heterojunctions, and introducing structural defects. The objective of this mini-review is to present selected methods of modifying TiO2 nanotubes obtained through anodic oxidation, leading to the enhancement of their photocatalytic properties.

2

The tribological characteristics of zirconium diboride particle reinforced composites processed by SPS

Sulima Iwona, Hyjek Paweł

Composites Theory and Practice

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2024

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R. 24, nr 1

2--8

EN

The tribological properties of composites based on 316L steel reinforced with zirconium diboride (5 and 10 wt.%) were described. The composites were fabricated by the spark plasma sintering (SPS) method. Wear resistance tests were carried out using the ball-on-disc method at room temperature under dry friction conditions. Countersamples made of SiC, Si3N4, ZrO2 and AISI52100 steel were used in the tests. The determined parameters included the coefficient of friction μ, mass loss m and specific wear rate Ws(disc). After the tribological tests, the surfaces of the samples were examined under a confocal microscope. The obtained research results showed that the tribological properties depend on the test conditions (the type of countersample) and on the content of the ZrB2 reinforcing phase.

PL

Przedstawiono właściwości tribologiczne kompozytow na osnowie stali 316L wzmocnionych diborkiem cyrkonu (5 i 10% wag.). Kompozyty zostały wytworzone z zastosowaniem metody Spark Plasma Sintering (SPS). Badania odporności na zużycie przeprowadzono, wykorzystując metodę ball-on-disc w temperaturze pokojowej w warunkach tarcia suchego. Testy przeprowadzono, stosując następujące przeciwprobki: SiC, Si3N4, ZrO2 i stal AISI52100. Wyznaczono współczynnik tarcia μ, ubytek masy m i wskaźnik zużycia Ws(disc). Powierzchnie probek po testach tribologicznych obserwowano za pomocą mikroskopu konfokalnego. Uzyskane wyniki badań wykazały, że właściwości tribologiczne zależą od warunkow badań (rodzaju przeciwprobki) i ilość fazy wzmacnianej ZrB2.

3

Analysis of the thermal expansion coefficient of glass- and carbon-fibre-reinforced composites

Fejkiel Romuald, Skwara Krystian

Advances in Mechanical and Materials Engineering

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2024

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Vol. 41, nr 1

17-26

EN

With the development of manufacturing processes, an increase in the importance of metal-fibre composites in materials engineering is observed. These are materials consisting of appropriately arranged layers of metal and various types of fibres. The very wide use of composite materials in the construction of machine and equipment components means they are often exposed to work in variable temperature conditions. The aim of this article was analysis of the thermal expansion of typical composites: carbon fibre-reinforced polymer, glass fibre-reinforced polymer, glass-reinforced aluminium laminate and carbon-fibre reinforced aluminium laminate. EN AW-6060 aluminium alloy was used as the reference material. The aim of the dilatometric tests was to determine the coefficient of thermal expansion and the dimensional stability of composite materials at elevated temperatures up to 100 °C. The EN AW-6060 aluminium alloy was characterized by the highest linear expansion coefficient (20.27×10−6 1/K). Composites containing glass fibres were characterized by the lowest positive linear thermal expansion coefficient. Among the composite materials tested, CARALLs exhibit the lowest thermal expansion coefficient.

PL

Wraz z rozwojem techniki, możemy zaobserwować wzrost znaczenia kompozytów metalowo-włóknistych w inżynierii mechanicznej. Są to materiały składające się z odpowiednio ułożonych warstw metalu oraz różnego rodzaju włókien. Bardzo szerokie zastosowanie materiałów kompozytowych w budowie elementów maszyn i urządzeń powoduje, że niejednokrotnie są one narażone na pracę w warunkach zmiennych temperatur. Celem tego artykułu była analiza rozszerzalności cieplnej typowych materiałów kompozytowych wzmocnionych włóknami węglowymi i szklanymi oraz laminatów typu GLARE i CARALL. Jako materiał referencyjny wykorzystano stop aluminium EN AW-6060. Celem badań dylatometrycznych było określenie rozszerzalności cieplnej i stabilności wymiarowej materiałów kompozytowych w podwyższonych temperaturach do 100°C z szybkością nagrzewania 5°C/min. Największym współczynnikiem rozszerzalności liniowej (20,27×10−61/K) charakteryzował się stop aluminium EN AW-6060. Najmniejszym dodatnim liniowym współczynnikiem rozszerzalności cieplnej charakteryzowały się kompozyty zawierające włókna szklane. Spośród materiałów kompozytowych, najmniejszym współczynnikiem rozszerzalności cieplnej charakteryzował się kompozyt typu CARALL.

4

A study of basalt-composite reinforcement of Georgian production and standard preparation

Khmelidze Tamaz, Kikadze Vladimer, Rajczyk Marlena

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2023

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Z. 29 (179)

48--52

EN

Analyzing the development of the modern construction industry clearly shows the steady increase in the share of load-bearing and enclosing structures made based on building materials obtained by new technology. Polymer-based composites have a special place in this range of materials. The use of composite materials in construction can solve such important issues as reducing operating costs and the mass of buildings, improvement of technical characteristics of structures, serviceability, strength, deformation, thermal insulation, operational properties, etc. The advantage of composites include: the construction of structures, elements and details with predetermined properties that meet working conditions and requirements. The variety of fibers and matrix materials, as well as the optimization of reinforcement schemes used to create the composite structures, give the engineers complete freedom to adjust the properties of the composite material accordingly at the expense of changing the component ratio and macro-structure. Hundreds of thousands of natural (non-composite) and artificial materials are now known. However, they can no longer meet the increased demands.

PL

Analizując rozwoj wspołczesnego budownictwa, wyraźnie widać stały wzrost udziału konstrukcji nośnych i osłonowych wykonywanych w oparciu o materiały budowlane otrzymywane z wykorzystaniem nowej technologii. Kompozyty na bazie polimerow zajmują szczegolne miejsce w tej gamie materiałow. Zastosowanie materiałow kompozytowych w budownictwie może rozwiązać ważne problemy, takie jak: zmniejszenie kosztow eksploatacji i masy budynkow, poprawa właściwości technicznych konstrukcji - użyteczności, wytrzymałości, odkształceń, izolacyjności termicznej, właściwości eksploatacyjnych itp. Zaletą kompozytow jest: swoboda w konstruowaniu elementow i detali o określonych właściwościach, spełniających warunki i wymagania pracy. Rożnorodność włokien i materiałow osnowy, a także optymalizacja schematow zbrojenia stosowanych przy tworzeniu struktur kompozytowych dają inżynierom pełną swobodę w zakresie odpowiedniego dostosowywania właściwości materiału kompozytowego kosztem zmiany proporcji składnikow i makrostruktury. Obecnie znane są setki tysięcy materiałow naturalnych (niekompozytowych) i sztucznych. Nie są one jednak w stanie sprostać rosnącym wymaganiom przemysłu i gospodarki.

5

Assessment of the applicability of basalt fiber-reinforced epoxy composites in vehicle construction

Ćwiek Janusz, Wierzbicki Łukasz

Transport Problems

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2023

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T. 18, z. 1

43--53

EN

This article presents a description of the properties of basalt fibers and polymer composites containing basalt fibers. Basalt fibers are seen as a potentially beneficial component in composite development, especially for vehicles in transport applications. The article also presents the results of the mechanical properties investigation of the glass-epoxy and basalt-epoxy composites. The composites for testing were prepared using the popular hand lay-up method. The samples were cut from prepared plates using abrasive water jet methods. The obtained samples were tested to evaluate their flexural strength and interlaminar sharing strength. The achieved mechanical properties were compared.

6

Zaprojektowanie materiału kompozytowego przeznaczonego na lekkie konstrukcje w motoryzacji

Suchorowiec Katarzyna, Szatkowski Piotr, Szczepanik Ewa, Twaróg Rafał, Kisilewicz Michał, Gralewski Jacek

Science, Technology and Innovation

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2023

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Vol. 17, no. 1-2

76--84

PL

Artykuł przedstawia koncepcje weryfikacji materiału kompozytowego zbrojonego włóknem szklanym w osnowie epoksydu mogącego znaleźć zastosowanie w nośnej konstrukcji ramy motocyklowej. Poddano analizie występujące typy ram motocyklowych umożliwiających zastosowanie kompozytów. Wytworzono próbki materiału kompozytowego z wykorzystaniem metody trzpieniowej dla wybranej konstrukcji ramy, badając wpływ różnej orientacji włókien szklanych. Próbki kompozytu poddano badaniom fizykochemicznym, określając podstawowe własności wytrzymałościowe, gęstość, pracę zniszczenia oraz przeprowadzono obserwację mikroskopową wykonanych próbek.

EN

The article presents the concept of a glass fiber reinforced composite in an epoxy matrix that can be used in a motorcycle frame. Motorcycle frames types enabling the composites usage were analyzed. Composite material samples with different glass fibers orientations were produced using the pin method. The manufactured composite material was subjected to physicochemical tests to determine basic strength properties, density, work of destruction, and microscopic observation was carried out.

7

Innovative Methods of Terahertz Diagnostics in Selected Key Military and Security Applications

Świderski Waldemar, Dragan Krzysztof, Mielnik Dariusz, Pałka Norbert

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2023

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Vol. 14, Nr 4 (54)

83--90

EN

The article presents the main research directions of the project implemented by the consortium under the National Defence and Security Program: "Development of modern, breakthrough technologies for state security and defence", codename "SZAFIR". During the implementation of the project, the possibilities of using terahertz radiation will be examined for diagnostic tests of components crucial for defence and security, such as solid rocket fuels, aramid fibre-based composites (bulletproof vests, helmets, pyrotechnic suits), and polymer composites reinforced with glass and carbon fibres (aircraft elements). As a result of research, the interaction of tetheric radiation with materials of these components will be analysed, followed by the development of a methodology for determining their defects. This will result in creating innovative dedicated stations for non-destructive testing of these components. Neural network-based advanced signal processing and artificial intelligence algorithms will be used for automatic diagnostics of key components, improve the process of their control and therefore increase the safety of people and military equipment.

PL

W artykule przedstawiono główne kierunki badawcze projektu TeraDiag realizowanego przez konsorcjum (WITU, IOE WAT, ITWL oraz LTT) w ramach programu NCBR na rzecz obronności i bezpieczeństwa państwa pn. "Rozwój nowoczesnych, przełomowych technologii służących bezpieczeństwu i obronności państwa” pk. "SZAFIR". W trakcie realizacji projektu zostaną zbadane możliwości zastosowania promieniowania terahercowego do badań diagnostycznych kluczowych dla obronności i bezpieczeństwa komponentów, takich jak stałe paliwa rakietowe, kompozyty na bazie włókien aramidowych (kamizelki kuloodporne, hełmy, kombinezony pirotechniczne), kompozyty polimerowe wzmacniane włóknami szklanymi i węglowymi (elementy statków powietrznych).W wyniku prac badawczych przeprowadzona będzie analiza oddziaływania promieniowania terahercowego anetz materiałami tych komponentów a następnie opracowana metodyka wyznaczania ich defektów. W rezultacie powstaną nowatorskie dedykowane co najmniej dwa stanowiska do badań nieniszczących tych komponentów. Zaawansowane algorytmy przetwarzania sygnałów i sztucznej inteligencji bazujące na sieciach neuronowych pozwolą na automatyczną diagnostykę kluczowych komponentów, przyczynią się do polepszenia procesu ich kontroli, a przez to poprawią bezpieczeństwo ludzi i sprzętu wojskowego.

8

The use of PLA filled with fibrillar nanocellulose from wastepaper as an expansion joint material

Szafraniec Małgorzata, Grabias-Blicharz Ewelina, Droździel-Jurkiewicz Magda, Tor-Świątek Aneta

Polimery

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2023

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Vol. 68, nr 2

93--98

EN

The effect of nanocellulose (3 or 5 wt%) on the PLA properties was investigated. Moreover, the possibility of using such composites as an expansion joint material was considered. Nanocellulose was obtained from wastepaper by mechano-chemical treatment. The structure, impact strength, tensile strength of the composites and the adhesion to the cement were studied. It was observed that with the increasing nanocellulose content, the impact strength and tensile strength decreased because of weak interactions at the interface and formation of agglomerates.

PL

W pracy zbadano wpływ nanocelulozy (3 oraz 5% mas.) na właściwości PLA. Dodatkowo rozważono możliwość zastosowania tego typu kompozytów jako materiału dylatacyjnego. Nanocelulozę otrzymano z makulatury poprzez obróbkę mechano-chemiczną. Zbadano strukturę, udarność i wytrzymałość kompozytów na rozciąganie oraz adhezję do cementu. Zaobserwowano, że wraz ze wzrostem zawartości nanocelulozy udarność i wytrzymałość na rozciąganie zmniejszały się jako efekt słabych oddziaływań na granicy faz i tworzenia się aglomeratów.

9

The improvement in properties of polyester resin-based composites using a new type of silane coupling agent

Urbaniak Włodzimierz, Bednarek Wojciech Hubert, Paukszta Dominik, Szostak Marek, Szymańska Joanna

Polimery

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2023

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Vol. 68, nr 4

221--225

EN

Adhesion between the polymer matrix and fillers is an important factor influencing the properties of the obtained composites. One way to improve interactions at the interface is to modify the filler with coupling agents, e.g., silanes. The article presents the effect of modifying the surface of the mineral filler with a new type of silane [triethoxy(ketoimino)silane] on the mechanical properties of polyester resin based composites. Composites with triethoxy(ketoimino)silane-modified filler had similar mechanical properties to composites obtained with commercial silanes, with slightly lower water absorption.

PL

Adhezja między osnową polimerową i napełniaczami jest istotnym czynnikiem wpływającym na właściwości otrzymanych kompozytów. Jednym ze sposobów poprawy oddziaływań na granicy faz jest modyfikacja napełniacza środkami sprzęgającymi, np. silanami. W artykule przedstawiono wpływ modyfikacji powierzchni napełniacza mineralnego przy użyciu nowego typu silanu [triethoksy(ketoimino)silan] na właściwości mechaniczne kompozytów na bazie żywicy poliestrowej. Kompozyty z udziałem napełniacza modyfikowanego triethoksy(ketoimino)silanem miały podobne właściwości mechaniczne do kompozytów otrzymanych z udziałem silanów handlowych, przy nieco mniejszej chłonności wody.

10

The effect of funcionalized ethylene-n-octene copolymer on mechanical properties of bioPET with organic waste fillers

Rusin-Żurek Karina, Kuciel Stanisław, Kurańska Maria

Polimery

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2023

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Vol. 68, nr 6

330--336

EN

The effect of compatibilizer – ethylene-n-octene copolymer grafted with maleic anhydride (EOC-g-MAH) used in the amount of 3 wt% on tensile and flexural properties and impact strength of bioPET with the addition of 10 wt% filler derived from organic waste (egg and mollusc shells, coffee grounds) was investigated. EOC-g-MAH slightly decreased tensile strength, flexural strength, and modulus of elasticity, while significantly increasing impact strength (up to 426%). Moreover, ability of bioPET-based composites to dissipate mechanical energy was improved.

PL

Zbadano wpływ kompatybilizatora – kopolimeru etylen-n-okten szczepionego bezwodnikiem maleinowym (EOC-g-MAH) użytego w ilości 3% mas. na właściwości mechaniczne przy rozciąganiu i zginaniu oraz udarność bioPET z dodatkiem 10% mas. napełniacza pochodzącego z odpadów organicznych (skorupki jaj i mięczaków, fusy z kawy). EOC-g-MAH nieznacznie obniżył wytrzymałość na rozciąganie, zginanie i moduł sprężystości, jednocześnie znacznie zwiększył udarność (aż do 426%). Ponadto zwiększyła się zdolność kompozytów na bazie bioPET do rozpraszania energii mechanicznej.

11

Polymer composites used to manufacture Naturacustic acoustic screens

Oliwa Rafał, Bulanda Katarzyna, Molter Łukasz, Markowski Tadeusz, Oleksy Mariusz

Polimery

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2023

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Vol. 68, nr 11-12

652--656

EN

The useful properties of PVC-based composites intended for the production of a new type of pro-ecological acoustic screens for use in road construction as soundproof covers for urban housing estates, bridges and railway tracks were examined. The composites were obtained by melt mixing using a counter-rotating twin-screw extruder. PVC-based composites are characterized by high Charpy notch impact strength (> 12 kJ/m2), high Rockwell hardness (> 78 N/mm2), high oxygen index (50%), good resistance to UV radiation. An important advantage of these composites is the high content of agri-food waste (30 wt%), which makes the materials environmentally friendly.

PL

Zbadano właściwości użytkowe kompozytów na osnowie PVC przeznaczonych do wytwarzania nowego typu proekologicznych ekranów akustycznych do zastosowań w drogownictwie jako osłony dźwiękoszczelne osiedli miejskich, mostów i torów kolejowych. Kompozyty otrzymano metodą mieszania w stanie stopionym przy użyciu przeciwbieżnej wytłaczarki dwuślimakowej. Kompozyty na osnowie PVC charakteryzują się wysoką udarnością z karbem Charpy’ego (> 12 kJ/m2), dużą twardością wg Rockwella (> 78 N/mm2), wysokim indeksem tlenowym (50%), dobrą odpornością na działanie promieniowania UV. Istotną zaletą tych kompozytów jest duża zawartość odpadów rolno-spożywczych (30% mas.), co czyni materiały przyjaznymi dla środowiska.

12

Concept of a technological system for manufacturing the composite products based on impregnated wood waste

Baron Rafał, Friebe Paweł, Kowol Daniel, Matusiak Piotr

Mining Machines

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2023

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vol. 41, iss. 4

248--260

EN

The article presents the results of the research work, which included aqualitative and quantitative analysis of the selected wooden wastesintended for manufacturing thecomposite materials. Additionally, theexisting solutions related to the processing of wooden waste from power poles and railway sleepers were analysed. In the context of theanalysis, the focus was on the methods for removing carcinogenic substances used for preserving thetelecommunications poles, power poles and railway sleepers, with the aim of obtaining thesafe end product. On this basis, the concept of a technological system for recycling the mentioned wasteshas beendeveloped. The recycling process involves reprocessing them and using as components of thecomposite materials.

13

Studying the influence of waste glass and montmorillonite powders on the thermal conductivity and hardness of poly(methyl methacrylate) polymer matrix

Almansoori A., Ghadban R. A., Ali M. H., Sabri M. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 118, nr 2

49--56

EN

Purpose The present study aims to evaluate the effect of montmorillonite nanoclay (MMT) and waste glass powder (WGP) on the hardness and thermal conductivity of PMMA polymer composites. Thus, this study concentrates on the potential use of MMT and WGP as reinforcements, in different concentrations, in PMMA polymer matrix, with the expectation of improving the performance of PMMA polymer composites in various applications. Design/methodology/approach There is a growing demand for PMMA with increased mechanical properties and thermal stability for applications where inorganic glass would fail. Montmorillonite (MMT) clay and Waste Glass Powder (WGP) have physical and chemical properties compatible with PMMA. Therefore, they could potentially enhance PMMA’s hardness and thermal conductivity. Silicon dioxide in glass silica and MMT and octahedral aluminium hydroxide sheet in MMT can strengthen both covalent and hydrogen bonding architecture in PMMA composite for better mechanical strength and thermal conductivity. Thus, PMMA composites were designed by combining MMT powder and WGP powder in different ratios before being incorporated into the PMMA polymer matrix and tested for hardness and thermal conductivity. Findings The present study measured Brinell Hardness (HB) and electrical conductivity values of four PMMA composites containing different proportions of MMT and WGP. MMT/WGP filler mix had optimal hardiness (HB number = 74) when glass content was 1% (3MMT1G) or better still (HB number = 63) when an equal mix ratio was used (1MMT1G). PMMA composite with 3MMT1G also had the highest thermal conductivity (0.01899W/m.K-1). However, the higher the glass content, the lower the thermal conductivity of the PMMA composite. Thus, the present study has demonstrated that 3MMT1G filler was the best for enhancing the thermal and mechanical properties of PMMA composite. Research limitations/implications The results of this study demonstrate the potential of this new composite material for a variety of applications. Further research is needed to explore the full potential of this material and to develop new and improved versions. Practical implications Reusing waste glass as filler materials in composites requires minimal processing and therefore has lower environmental impacts than synthetic options. Originality/value Experimental data from the present study has provided new insights into Glass/MMT mix design in PMMA composites. The PMMA composite containing 3MMT1G exhibited the best hardness and thermal conductivity characteristics. Thus, the present study has successfully optimised Glass/MMT mix design for PMMA composite for applications requiring these features.

14

The use of recycled carbon fibers (rCF) in production of polymer concrete to improve mechanical properties

Smoleń Jakub

Composites Theory and Practice

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2023

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R. 23, nr 3

167--172

EN

The recycling processes for CFRP waste are difficult due to their complex, and multi-material composition. Consequently, there is a need for new solutions to address this issue. The focus of CFRP composite recycling processes is primarily on recovering costly carbon fibers, which are characterized by exceptional mechanical properties. Pyrolysis has been identified as an effective method for the recovery of carbon fibers without significant damage. In this study, recovered carbon fibers (rCF) were used to produce polymer concrete. The fabricated polymer concretes contained carbon fibers of varying lengths (10, 20, and 30 mm) and volume fractions of 1 and 3%. The results showed that the addition of 3% post-pyrolytic carbon fibers resulted in significant improvement in the mechanical properties of the polymer concrete. Specifically, the flexural strength increased by more than 100% compared to the polymer concrete without carbon fibers, while the compressive strength improved by more than 60%. Overall, the study demonstrates that incorporating post-pyrolytic carbon fibers in the production of polymer concretes offers a promising solution to the challenge of CFRP waste. The use of these fibers not only helps in the recovery of valuable resources but also results in significant improvement in the mechanical strength of the final product.

15

The impact of filler thermomechanical modifications on static and dynamic mechanical performance of flexible foamed polyurethane/ground tire rubber/zinc borate composites

Hejna Aleksander, Kosmela Paulina, Olszewski Adam, Formela Krzysztof, Zedler Łukasz, Piasecki Adam, Skórczewska Katarzyna

Composites Theory and Practice

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2023

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R. 23, nr 2

76--83

EN

The rapid development of the automotive industry is very beneficial to many aspects of human life, but it is also a very significant environmental burden. The most straightforward impact is related to the generation of exhaust, but the management of post-consumer car parts is also a major challenge. Among them, waste tires are very burdensome due to their enormous numbers. Therefore, it is essential to develop novel, environmentally friendly methods for their disposal, which would reduce their environmental impacts. One of the most promising approaches is shredding, resulting in the generation of ground tire rubber (GTR), which can be introduced into polymeric materials as a filler. The presented work is related to the thermomechanical treatment of GTR in a twin-screw extruder assisted by zinc borate (ZB), whose incorporation is aimed to increase interparticle friction within the extruder barrel. The impact of the treatment conditions on the particle size and Surface development of the GTR/ZB compositions was evaluated. Modified GTR was introduced into flexible polyurethane (PU) foams, and the impact on the static and dynamic mechanical performance of the resulting composites was investigated. Increasing the treatment temperature occurred to have an adverse effect on the tensile performance of the composites due to the agglomeration of GTR particles limiting the efficiency of stress transfer, which was also confirmed by dynamic mechanical analysis. On the other hand, increasing the ZB share in the GTR/ZB compositions limited PU disruptions related to the reactivity of the GTR functional groups with isocyanates, which enhanced the mechanical performance of the composites. It was proven that the proposed method of GTR thermomechanical treatment assisted by ZB might benefit the performance of flexible PU foamed composites, which could broaden the application range of GTR and provide novel ways for its efficient utilization.

16

Mathematical model of modified classical lamination theory for foam core sandwich composites

Kumar S.J. Amith, Kumar Ajith S.J.

Composites Theory and Practice

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2023

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R. 23, nr 4

220--225

EN

Elastic properties are important quantities in the modelling and analysis of sandwich composite structures. The stability of sandwich composites mainly depends on their elastic properties, which in turn depend on the elastic properties of its constituents namely, the core and face skin. Several models have been proposed to predict the elastic constants of core materials such as honeycomb and foam. A foam core may be open-cell foam or closed-cell foam. The present work is focused on the hexagonal cells of a honeycomb grid core and closed-cell polymer syntactic foam core. The honeycomb is considered to be orthotropic with nine independent elastic properties. However, the overall structural performance of the honeycomb core is mainly influenced only by out-of-plane elastic properties. On the other hand, the syntactic foam is considered to beisotropic with two independent elastic constants namely, the modulus of elasticity and Poisson’s ratio. The face skin material may be isotropic with two independent elastic constants or orthotropic with nine elastic constants under three-dimensional loading. The present work is focused on predicting the elastic properties of a honeycomb core, syntactic foam and a glass/epoxy composite using existing theoretical models. Thereafter, the elastic properties of the syntactic foam and glass/epoxy composite are later used to establish the elastic constants for syntactic foam core sandwich composites using modified classical lamination theory (MCLT). The results reveal that the reviewed theoretical models for the honeycomb core, syntactic foam, fiber-reinforced polymeric (FRP) glass/epoxy face skins and sandwich composites are validated by the experimental results.

17

Assessment of mechanical and thermomechanical properties of epoxy-basalt composites modified with halogen-free intumescent flame retardants

Barczewski Mateusz, Matykiewicz Danuta, Andrzejewski Jacek, Sałasińska Kamila, Paszkiewicz Sandra, Piasecki Adam, Aniśko Joanna, Hejna Aleksander, Przestacki Damian

Composites Theory and Practice

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2023

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R. 23, nr 4

239--246

EN

This study aims to examine the effect of flame retardants (FRs) on the mechanical and thermomechanical properties of epoxy composites reinforced with basalt fibers. To effectively modify fire behavior, it is usually necessary to introduce significant amounts of FRs, which raises many concerns due to the potential deterioration of other functional properties, including mechanical performance. In this work, 30 wt.% halogen-free FRs, including a two-component FR (ammonium polyphosphate with pentaerythritol) and melamine cyanurate, were introduced into the polymer matrix. The unmodified and intumescent FR-modified epoxy resin composites reinforced with basalt fibers were subjected to static flexural test and thermomechanical properties assessment. The research results were correlated with the analysis of changes in the chemical composition assessed using Fourier transform infrared spectroscopy. As a result, the saturation of the reinforcing fabrics by the modified epoxy resin was limited, which caused a different failure mechanism under static bending and impact test conditions. Both FR systems reduced the flammability of the modified epoxy laminates along with also acceptable deterioration of the mechanical properties. The most beneficial effects considering the combination of all the analyzed features were noted for the two-component FR system containing ammonium polyphosphate and pentaerythritol.

18

Treatment of Municipal Wastewater Using Electrocoagulation Process

Abshishek H., Vijayakumar H., Mahesh Kumar C L, Shwetha Kotagi Girisha

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 4

1--13

EN

Treatment of Municipal wastewater by Electrocoagulation (EC) process using punched aluminium and zinc electrodes was studied in a batch EC cell reactor. Response surface methodology (RSM) based on Central Composite Design (CCD) was utilized to optimize the operating parameters for the removal of % Total Suspended Solids (TSS) and % Chemical Oxygen Demand (COD) from Municipal Sewage. Effect of operating parameters such as Electrode Distance (x1), Electrolysis Time (x2) and Voltage (x3) has been optimized for the removal of TSS and COD. The prediction of removal percentage of TSS and COD in various Operational circumstances is done by using Quadratic model. The significance of each operating parameter was computed by Analysis of variance (ANOVA). To achieve the maximum removal of % TSS and % COD, the optimum conditions were Electrode distance(x1)-3 cm, Electrolysis Time (x2)-70.299 minute and Voltage (x3)-6.5V. It was observed that the performance of electrocoagulation process increased up to 61.45% for COD removal, and 73.73% for TSS removal using punched electrode compared to plane electrodes.

19

Badania nieniszczące materiałów kompozytowych metodą termografii laserowej

Hyla Bartosz, Sobczak Michał, Roemer Jakub

Badania Nieniszczące i Diagnostyka

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2023

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nr 1-4

62--66

PL

Termografia jest jedną z metod badań nieniszczących, która wykorzystuje termowizję do wnioskowania o stanie technicznym materiału. Termografia laserowa jest rodzajem termografii aktywnej w której źródłem wymuszenia jest promieniowanie laserowe. Metoda ta pozwala na bardzo precyzyjne kontrolowanie ilości energii dostarczanej do próbki. Istotną zaletą w badaniach laserowych jest możliwość wykrywania zarówno delaminacji jak i pęknięć będącymi głównymi rodzajami uszkodzeń strukturach kompozytowych. W pracy przedstawione zostanie stanowisko do badań, którego prototyp jest opracowywany na AGH oraz wyniki skanowania na przykładzie próbki z włókna węglowego w osnowie polimerowej.

EN

Thermography is a non-destructive testing method that utilizes infrared camera to infer the technical condition of a material. Laser thermography is a type of active thermography in which laser radiation serves as the excitation source. This method allows for highly precise control of the amount of energy delivered to the sample. An important advantage of laser testing is the capability to detect both delamination and cracks, which are the main types of damage in composite structures. This paper presents a test setup developed at AGH University of Krakow and the results of scanning a sample made of carbon fiber reinforced polymer.

20

Effect of Corrosion on Wear Resistance of the Composite Based on GX120Mn13 Cast Steel Zonally Reinforced with Particles (Al2O3+ZrO2)

Medyński Daniel

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 3

133--139

EN

The subject of the work are modern composite materials with increased wear resistance intended for elements of machines operating in difficult conditions in the construction and mining industries. The study determined the effect of zone reinforcement of GX120Mn13 cast steel with macroparticles (Al2O3+ZrO2) on the corrosion resistance and abrasion wear of the composite thus obtained. SEM studies have shown that at interface between two phases, and more precisely on the surface of particles (Al2O3+ZrO2) a durable diffusion layers are formed. During the corrosion tests, no significant differences were found between the obtained parameters defining the corrosion processes of GX120Mn13 cast steel and GX120Mn13 with particles (Al2O3+ZrO2) composite. No intergranular corrosion was observed in the matrix of the composite material, nor traces of pitting corrosion at both phases interface. This is very important in terms of tested material’s service life. Reinforcement of cast steel with particles (Al2O3+ZrO2) resulted in a very significant improvement in the abrasion resistance of the composite – by about 70%. After corrosion tests, both materials were subjected to further operational investigations. These examinations consisted in determining the impact of corrosion processes on the durability of the composite in terms of abrasion. The obtained results indicate that corrosion processes did not significantly deteriorate the wear resistance of both the cast steel and the composite.