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1

Surface and mechanical properties of plasma-modified chitosan/polyvinyl alcohol composite films

Chang Shih-Hang, Chang Yuan-Hsuan

Polimery

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2025

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Vol. 70, nr 3

177--185

EN

The surface and mechanical properties of chitosan/polyvinyl alcohol (CS/PVA) composite films modified with O2 and N2 plasma were investigated. The FT-IR method confirmed the presence of characteristic bands originating from both CS and PVA, the intensity of which significantly increased after plasma modification. Plasma treatment also increased the hydrophilicity of CS/PVA films, with a slight decrease in their surface smoothness. In addition, plasma modification reduced the adhesion of bovine serum albumin. The highest fracture toughness and the lowest adhesion of bovine serum albumin were obtained for CS/PVA films (1/3 wt%/wt%). The conducted studies confirmed the possibility of biomedical applications of chitosan/polyvinyl alcohol composite films.

PL

Zbadano właściwości powierzchniowe i mechaniczne folii kompozytowych chitozan/alkohol poliwinylowy (CS/PVA) modyfikowanych plazmą O2 i N2. Metodą FT-IR potwierdzono obecność charakterystycznych pasm pochodzących zarówno od CS, jak i PVA, których intensywność znacząco zwiększyła się po modyfikacji plazmą. Działanie plazmy zwiększyło również hydrofilowość folii CS/PVA, przy niewielkim zmniejszeniu gładkości ich powierzchni. Ponadto modyfikacja plazmą zmniejszyła adhezję albuminy surowicy bydlęcej. Największą wytrzymałość na pękanie i najmniejszą adhezję albuminy surowicy bydlęcej uzyskano w przypadku folii CS/PVA (1/3 % mas./% mas.). Przeprowadzone badania potwierdziły możliwość biomedycznych zastosowań folii kompozytowych chitozan/alkohol poliwinylowy.

2

Polypropylene composites with natural carbon fillers obtained by rotational molding

Szymańska Joanna, Szostak Marek, Paukszta Dominik

Polimery

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2025

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Vol. 70, nr 5

313--321

EN

PP composites with different contents of natural/waste carbon filler (1, 5, 10 and 25 wt.%) were obtained by rotational molding. Thermal properties (DSC), tensile properties and structure (optical and digital microscopy, WAXS) of PP composites were assessed. It was found that the composites are charac-terized by good surface quality of external walls and usually poorer quality of internal walls. The filler content affects both the degree of crystallinity and the mechanical properties of PP.

PL

Kompozyty PP o różnej zawartości naturalnego/odpadowego napełniacza węglowego (1, 5, 10 oraz 25% mas.) otrzymano metodą formowania rotacyjnego. Dokonano oceny właściwości termicz¬nych (DSC), właściwości mechanicznych przy rozciąganiu i struktury (mikroskopia optyczna i cyfrowa, WAXS) kompozytów PP. Stwierdzono, że kompozyty charakteryzują się dobrą jakością powierzchni ścian zewnętrznych oraz zazwyczaj słabszą ścian wewnętrznych. Zawartość napełniacza ma wpływ zarówno na stopień krystaliczności, jak i na ich właściwości mechaniczne PP.

3

PET composites and their applications in the face of green chemistry challenges - an overview

Ostrowski Krzysztof Adam, Spyrowski Mariusz, Romańska Paulina, Majka Tomasz M., Piech Radosław, Zawadzka Zuzanna, Furtak Kazimierz, Bednarowski Dariusz

Polimery

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2025

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Vol. 70, nr 4

227--239

EN

The review discusses the recycling of PET packaging, highlighting its significance in the circular economy. It presents methods for processing the recovered material and its potential applications in various sectors of the economy. The importance of the 6R principle in integrating the economy and promoting sustainable development is also emphasized.

PL

W artykule omówiono recykling opakowań PET, podkreślając jego znaczenie w gospodarce obiegu zamkniętego. Przedstawiono metody przetwórstwa odzyskanego materiału i jego potencjalne zastosowania w różnych sektorach gospodarki. Wykazano znaczenie zasady 6R w integracji gospodarki i promowaniu zrównoważonego rozwoju.

4

Management of waste fly ash as an epoxy resin filler

Szymańska Joanna, Tomczak Dorota, Przesławski Grzegorz, Borysiak Sławomir

Polimery

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2025

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Vol. 70, nr 1

40--49

EN

Epoxy resin composites with the addition of 20-50 wt.% of ash from municipal waste incineration were obtained. The curing kinetics of the composites (DSC) was determined, and the activation energy was calculated using the Kissinger and Ozawa method. In addition, flexural properties, and impact strength, as well as the structure of the composites (XRD, optical microscopy) were investigated. Brittles of the composites increased with increasing the filler content. The addition of ash also affected the kinetics of the resin cross-linking reaction. A change in the activation energy, degree of conversion and cross-linking time was observed.

PL

Otrzymano kompozyty żywicy epoksydowej z dodatkiem 20-50% mas. popiołu ze spalania odpadów komunalnych. Określono kinetykę utwardzania kompozytów i stopień konwersji (DSC), a energię aktywacji obliczono metodą Kissingera i Ozawy. Ponadto zbadano właściwości mechaniczne przy zginaniu i udarność, a także strukturę kompozytów (XRD, mikroskopia optyczna). Kruchość kompozytów zwiększała się wraz ze wzrostem zawartości napełniacza. Dodatek popiołu wpływał również na kinetykę reakcji sieciowania żywicy. Zaobserwowano zmianę energii aktywacji, stopnia konwersji i czasu sieciowania.

5

Flax fiber reinforced PET-G composites with improved interfacial adhesion

Hartung David, Seidlitz Holger, Osiecki Tomasz, Sztorch Bogna, Przekop Robert E., Kazimierczuk Magdalena

Polimery

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2025

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Vol. 70, nr 2

113--123

EN

Recycled PET-G (rPET-G) composites reinforced with flax fiber were obtained. To improve interfacial adhesion, the fiber was treated by washing and finishing with bio-based epoxidized soybean oil and admixture acid. The effect of fiber surface treatment on its properties and those of the composites was evaluated by TGA, FT-IR and SEM, as well as by contact angle, flexural and tensile measurements. The results indicated delayed degradation of the treated flax fiber with a fiber mass loss of about 4 wt%. The flexural strength and modulus increased for the washed and finished flax fiber compared to the untreated one. While the tensile properties were influenced by structural effects resulting from the fiber treatment. These findings contribute to the development of more sustainable and high-performance natural fiber-reinforced thermoplastic composites.

PL

Otrzymano kompozyty PET-G z recyklingu (rPET-G) wzmocnione włóknem lnianym. Aby poprawić oddziaływania międzyfazowe, włókno poddano obróbce przez mycie i wykończenie na bazie biologicznej epoksydowanym olejem sojowym i kwasem admerginowym. Wpływ obróbki powierzchni włókna na jego właściwości i właściwości kompozytów oceniano za pomocą TGA, FT-IR i SEM, a także pomiarów kąta zwilżania, właściwości mechanicznych przy zginaniu i rozciąganiu. Wyniki wskazały na opóźnioną degradację poddanego obróbce włókna lnianego z utratą masy włókna wynoszącą ok. 4% mas. Wytrzymałość na zginanie i moduł sprężystości wzrosły w przypadku umytego i wykończonego włókna lnianego w porównaniu z niepoddanym obróbce. Natomiast właściwości mechaniczne przy rozciąganiu zależały od efektów strukturalnych wynikających z zastosowanej obróbki włókna.

6

Energy-efficient propeller-driven climbing robot design based on glass-fiber reinforced polymer

Abouhussein Omar Abdelaziz, Fouly Ahmed

Polimery

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2025

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Vol. 70, nr 7-8

455--466

EN

Three techniques were investigated to optimize the performance of a propeller-driven climbing robot: i) materials optimization using glass fiber reinforced polymer (GFRP) laminates with three distinct configurations - symmetric cross-layer (0°/90°), antisymmetric cross-layer (0°/90°), and antisymmetric angle-layer (±45°), ii) optimization of the robot chassis structural topology using density-based methods, and iii) laminate thickness (0.5-3.0 mm) and fiber content (50-70 v%). Optimal performance was achieved for an antisymmetric angle-layer configuration of 2.2 mm with 60 v% fiber content, resulting in a weight reduction (6.8%). Combined with a topologically optimized chassis design (20.1% weight reduction), the entire system achieves a 23.5% weight reduction, which translates into energy savings (23.6% torque reduction and 17.3% thrust reduction) while maintaining structural integrity. These results set a new standard for energy-efficient climbing robot designs, thanks to the synergistic optimization of materials and structures.

PL

Z badano trzy techniki w celu optymalizacji wydajności napędzanego śmigłem robota wspinaczkowego: i) optymalizacja materiałów przy użyciu laminatów na bazie wzmocnionego włóknem szklanym polimeru (GFRP) o trzech konfiguracjach - symetrycznej warstwie poprzecznej (0°/90°), antysymetrycznej warstwie poprzecznej (0°/90°) i antysymetrycznej warstwie kątowej (±45°), ii) optymalizacja topologii strukturalnej podwozia robota przy użyciu metod opartych na gęstości oraz iii) grubości laminatu (0,5-3,0 mm) i zawartości włókien (50-70 v%). Optymalną wydajność uzyskano dla antysymetrycznej konfiguracji warstwy kątowej 2,2 mm z zawartością włókien 60 v%, co skutkowało redukcją masy (6,8%). W połączeniu z topologicznie zoptymalizowaną konstrukcją podwozia (redukcja masy o 20,1%) cały system osiągnął 23,5% redukcję masy, co przekłada się na oszczędność energii (redukcja momentu obrotowego o 23,6% i redukcja ciągu o 17,3%) przy zachowaniu integralności struktury. Wyniki te wyznaczają nowy standard w dziedzinie energooszczędnych konstrukcji robotów wspinaczkowych, dzięki synergicznej optymalizacji materiałów i konstrukcji.

7

Rheological characteristics of composites based on carboxymethyl chitosan

Lewandowska Katarzyna, Lewandowska Sandra

Engineering of Biomaterials

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2025

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vol. 28, no. 173

art. no. 01

EN

Composite formation is a widely used method to modify polymer performance because such systems can combine the advantageous properties of each ingredient. This research evaluates the rheological properties and structure of biopolymer composites based on carboxymethyl chitosan (CMCS), with various additions of an aqueous dispersion of α-chitin (ChA) and glycerin (GLY). Composites containing carboxymethyl chitosan, α-chitin dispersion, and glycerin are designed for potential cosmetic and/or biomedical applications. The rheological properties of carboxymethyl chitosan, α-chitin aqueous dispersion, and their mixtures were determined using a ROTAVISC lo-vi Complete rotational viscometer in the temperature range of 25-40ºC and under various shear rates (1.3-33 s-1). The activation energy of the viscous flow and the rheological parameters from the power law were calculated and analyzed using Arrhenius plots and flow curves, respectively. As part of this investigation, composite films were prepared and characterized using infrared analysis. The studies conducted classified the prepared systems as non-Newtonian liquids that exhibit a shear-thinning effect (i.e. typical pseudoplastic fluids). The results revealed that the introduction of chitin whiskers as an aqueous dispersion into the CMCS matrix significantly altered the rheological properties of the tested composites. These changes were attributed to the mutual interactions between the polymer components and the low-molecular-weight additives.

8

Design and development of multilayered functionalized artificial skin for prosthetic applications: a biomimetic approach

Adamczyk Dominika, Szatkowski Piotr, Grałek Oliwia, Frohlich Martyna, Matysek Justyna

Engineering of Biomaterials

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2025

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vol. 28, no. 173

art. no. 12

EN

The development of artificial skin for prosthetic applications poses a significant engineering challenge due to the need to replicate human skin's multilayered architecture and multifunctionality. Each layer must be engineered to mimic distinct skin functions including mechanical protection, thermal regulation, tactile sensation, and structural support. Additionally, the artificial skin must demonstrate biocompatibility, long-term durability, and seamless integration with prosthetic devices to provide users with enhanced sensory feedback and improved quality of life. This study aims to design and fabricate a low-cost, biomimetic four-layer artificial skin system using functionalized silicon composites to replicate human skin's multilayered architecture and multifunctional properties for prosthetic applications. The four-layer structure includes: a surface biomimetic porous layer for mechanical shielding, a thermal management layer enhanced with boron nitride fillers to improve heat conduction, a conductive sensing layer containing carbon nanotubes for pressure detection, and a base layer providing cushioning and structural integrity. Each layer was specifically engineered to mimic different skin functions: mechanical protection, thermal regulation, tactile sensation, and structural support. The total thickness of the fabricated layers matches the human skin thickness values. Mechanical characterization revealed properties compatible with prosthetic applications, while surface analysis confirmed successful texture modification for enhanced tactile interaction. The thermal layer demonstrated improved heat distribution capabilities, and the conductive layer showed potential for pressure sensing applications. This work presents a complete design approach for artificial skin that meets both appearance and functional needs for prosthetics. The developed system offers promising prospects for enhancing quality of life for amputees through improved sensory feedback and thermal comfort.

9

The influence of areal density of prepreg on crashwor thiness of CFRP composite in quasi-static conditions

Ryzińska Grażyna

Composites Theory and Practice

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2025

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R. 25, nr 2

82-89

EN

In this work, experimental compression tests were performed in quasi-static conditions on composite specimens in the form of tubes of two different diameters (20 mm and 42 mm). The specimens were made of 3k carbon prepregs with a dry fabric areal density of 160 g/m2 and 204 g/m2, plain, and unidirectional (UD) with an areal density of 200 g/m2. The experiment determined the maximum forces (Pmax), average forces (Pi), and the value of absorbed energy (SEA). It was shown that the use of a 21% higher areal density increases the SEA by about 25% for the plain prepreg. Changing the type of prepreg from plain to UD with a similar areal density increases the SEA by 39% - 53%.

10

Microstructure and selected mechanical properties of hot-rolled AA2024/SiC composite manufactured by powder metallurgy

Nikiel Piotr, Kutyła Patrycja

Composites Theory and Practice

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2025

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R. 25, nr 2

102-112

EN

This study investigates the microstructure and mechanical properties of an AA2024/SiC composite produced using powder metallurgy, followed by hot extrusion and multi-pass hot rolling. The composite, containing 5 wt% SiC, was fabricated by hot pressing at 450°C, then extruded and rolled with reductions of up to 66.2%. Microstructural analysis revealed uniform distribution of the SiC particles, grain refinement due to dynamic recrystallization (DRX), and enhanced particle dispersion with increasing rolling reduction. The hardness measurements showed significant improvement, with values increasing from 91 HV1 in the extruded state to 112 HV1 after the final rolling pass, and further grew to 151 HV1 after heat treatment. The tensile tests confirmed a strengthening effect, with the yield stress and ultimate tensile strength rising with rolling reduction from 205 MPa and 304 MPa (after initial rolling) to 236 MPa and 352 MPa (after the final rolling), respectively. Solution treatment and aging of the rolled composite resulted in a sharp increase in yield stress and ultimate tensile strength, reaching 293 MPa and 431 MPa after the first pass, increasing to 375 MPa and 484 MPa after the final pass. The study concludes that hot rolling significantly enhances the mechanical performance of AA2024/SiC composites, with grain refinement and particle fragmentation playing key roles in the strengthening mechanisms.

11

Gradient Al2O3-Ni composites for aggressive substance transport: a novel approach using centrifugal gel casting

Zygmuntowicz Justyna, Tańska Joanna, Wiecińska Paulina, Piotrkiewicz Paulina, Konopka Katarzyna, Szafran Mikołaj, Wachowski Marcin, Michalski Bartosz, Kaszuwara Waldemar

Composites Theory and Practice

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2025

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R. 25, nr 2

144-156

EN

This study focuses on the development and characterization of Al2O3-Ni composite materials designed for use in environments where high corrosion resistance and mechanical strength are critical. The composites were formed using the centrifugal gel casting method to produce pipes with a gradient structure. The inner layer of the pipes consisted mainly of Al2O3, while the outer layer incorporated nickel particles. Rheological, thermogravimetric, and microstructural analyses were conducted to optimize the composite's formulation and processing conditions. The results showed that a monomer content of 3% by weight of 2-hydroxyethyl acrylate (HEA) provided an optimal balance between workability and polymer network formation. Corrosion tests revealed that while the alumina-rich inner layer exhibited good chemical resistance, the presence of nickel particles on the surface led to localized corrosion, particularly in acidic environments. The findings indicate that further refinement of the casting process is necessary to improve the distribution of the nickel particles and enhance the material's overall corrosion resistance.

12

Effect of major alloying elements Zn and Mg on microstructure and microhardness of AA7075 alloys and their composites

Mittal Prachi, Verma Ishu, Tomar Amit, Mahato Jayanta Kumar

Composites Theory and Practice

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2025

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R. 25, nr 2

90-101

EN

The present research work focuses on studying the effect of the major alloying elements on the microstructure and hardness of 7xxx series aluminium alloys and their composites. AA7075 aluminium alloy was used as the base material and different weight percentages of alloying elements zinc (Zn) and magnesium (Mg) were added at ratios 1:1, 2:1 and 3:1 to the base material. Afterwards, the modified aluminium alloys were used as matrix materials for the fabrication of aluminium alloy matrix composites (AAMCs) by adding different weight fractions of silicon carbide (SiC) as reinforcement material. Both the alloys and the AAMCs were fabricated by means of stir casting. XRD, SEM and EDX analysis of the modified aluminium alloys and their composites were carried out. Microstructures of the modified aluminium alloys and AAMCs were observed and the grain sizes were measured according to ASTM standards. Hardness tests of the fabricated specimens were carried out using Vickers microhardness testers and the hardness values were measured utilising the integrated software. It was observed that equiaxed grain structures were formed in both the modified Al alloys and their composites, indicating successful fabrication by means of the casting process; however, the average grain sizes of the fabricated specimens are dependent on the combination of wt% of reinforce ment and the composition of the Al alloys. Interestingly, a positive correlation with the weight percent ratio of Zn and Mg in the AA7075 was observed, indicating the potential for fine-tuning of the mechanical properties through proper selection of the alloying elements. It was also observed that the microhardness of the AAMCs fabricated with the mod ified Al alloys exhibits consistent improvement with an increasing weight fraction of SiC reinforcement, irrespective of the weight percentage ratio of the added Zn and Mg combination.

13

Development of the properties of magnesia alumina spinel-based refractory composites with modifying oxides

Bąk Aleksandra, Surówka Bartosz, Prorok Ryszard, Madej Dominika

Composites Theory and Practice

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2025

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R. 25, nr 3

166--180

EN

The present study investigates the synthesis of MgAl2O4 spinel via one-step sintering, producing a reference sample without additives and four additional samples containing 5 wt% ZrO2, Fe2O3, SiO2, or TiO2, respectively. The MA sample along with the four types of modified spinel-based composites [MA_5T, MA_5Z, MA_5F, MA_5S] were characterized in terms of their phase composition, microstructure, bulk and true densities, as well as open and true porosities of the sintered materials. High-temperature microscopy was employed to evaluate dimensional changes of the samples during their heat treatment process. The presence of phases and the firing behavior of the resulting composite materials were evaluated using thermodynamic simulation (FactSage 8.3). The study demonstrated that the incorporation of specific oxide additives significantly influences the synthesis and properties of MgAl₂O₄ spinel. Iron (Fe³⁺) and titanium (Ti⁴⁺) ions were found to induce structural modifications within the spinel lattice, suggesting partial substitution or incorporation into the crystal framework. XRD analysis showed that the addition of the SiO₂ modifier leads to the formation of Mg₂SiO₄, which can partially dissolve into the spinel phase, while ZrO₂ promoted the extraction of Al³⁺ ions from the spinel structure, as corroborated by the thermochemical simulations using FactSage. The highest microstructural densification was achieved in the samples with TiO₂ and SiO₂, indicating their positive role in enhancing sintering efficiency. Conversely, the addition of Fe₂O₃ did not significantly affect the densification behavior, despite the formation of an Fe-rich spinel phase.

14

Al₂O₃-Ni composites: impact of cooling on composites in centrifugal gel casting

Zygmuntowicz Justyna, Tańska Joanna, Wiecińska Paulina, Piotrkiewicz Paulina, Konopka Katarzyna, Szafran Mikołaj, Wachowski Marcin, Szachogłuchowicz Ireneusz, Kaszuwara Waldemar

Composites Theory and Practice

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2025

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R. 25, nr 2

113-122

EN

This study investigates the influence of polymerization kinetics and the processing sequence on the microstructure and mechanical performance of Al₂O₃-Ni composites fabricated via centrifugal gel casting. Two fabrication approaches were compared, differing in the sequence of component addition and the temperature of the casting mass. The optimized method, involving cooling the suspension to below 5°C prior to the addition of nickel powder and the polymerization initiator, significantly extended the gelation idle time from 225 s to 475 s, allowing improved control over polymerization and particle dispersion. As a result, the microstructure exhibited enhanced phase homogeneity and reduced porosity. Compression tests demonstrated substantial enhancement in mechanical performance: the compres sive strength increased from 22 MPa in the non-optimized series to 185 MPa in the optimized series, representing more than an eightfold improvement. These findings highlight a practical strategy for tuning the polymerization behavior to engineer high-performance ceramic-metal composites with potential applications in structural and functional components.

15

Wybrane metody badań nieniszczących wykorzystywane podczas inspekcji uszkodzonych struktur kompozytowych przed i po naprawie

Szymański Rafał

Badania Nieniszczące i Diagnostyka

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2025

|

nr 1-3

33--45

PL

Artykuł wpisuje się we współczesne zainteresowania firm z branży lotniczej. W artykule wymieniono najczęstsze niezgodności występujące w strukturach kompozytowych powstające na etapie produkcyjnym oraz eksploatacyjnym. W pracy skupiono się na uszkodzeniu wywołanym uderzeniem, które jest najczęstszym typem uszkodzenia podczas eksploatacji samolotów. Przybliżono również ogólne podejście do przeprowadzenia inspekcji w celu identyfikacji uszkodzenia oraz naprawy uszkodzenia. Badania opisane w artykule przeprowadzono na płaskich płytach kompozytowych (polimerowo węglowych) o strukturze monolitycznej i przekładkowej. Zarówno do wykrycia uszkodzeń w kompozycie węglowym oraz weryfikacji naprawy, wykorzystano metodę wizualną, tap-test, termografię oraz ultradźwiękową (Phased Array). Na podstawie otrzymanych wyników określono skuteczność wykrywania uszkodzeń oraz możliwości weryfikacji naprawionych struktur dla każdej z wykorzystanej w badaniach metody nieniszczącej.

EN

The article is in line with the contemporary interests of aerospace companies. The article lists the most common incompatibilities occurring in composite structures arising at the manufacturing and operational stages. The paper focuses on impact damage, which is the most common type of damage during aircraft operations. It also approximates a general approach to conducting an inspection to identify the damage and repair the damage. The tests described in the article were conducted on flat composite (polymer-carbon) plates with monolithic and sandwich structures. Both visual, tap-test, thermography and ultrasonic (Phased Array) methods were used to detect damage in the carbon composite and verify repair. Based on the results obtained, the effectiveness of damage detection and the ability to verify repaired structures were determined for each nondestructive method used in the study.

16

Characterization of EN-AW-6061-O–graphite nanoflake composites for enhanced mechanical properties using multi-pass friction stir processing

Patil Namdev Ashok, Pedapati Srinivasa Rao, Kakkeri Shrishail, Pedapati Santoshi

Advances in Materials Science

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2025

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Vol. 25, nr 3(85)

5--17

EN

In this study, graphite (Gr) nano flakes dispersion with increasing number of passes (1, 2, and 3) inside the resultant aluminium ENAW-6061-O-Gr composites using Friction Stir Processing (FSP) has been accomplished successfully. The objectives were to embed the Gr nanoflakes inside ENAW-6061-O-Gr composites, investigate the effect of number of FSP passes on the mechanical properties of aluminium 6061/graphite composites. The ENAW-6061-O-Gr composite samples were evaluated with tensile tests and elemental analysis through SEM with EDX and mapping. The dispersion and presence of graphite particles is confirmed. Multi-pass FSP improved the tensile strength of the ENAW-6061-O-Gr composites. The UTS of C3-Composite processed with three passes is 153.65 MPa, that is 24% of improvement compared to the unreinforced aluminium ENAW-6061-O base metal alloy.

17

Review of modern methods of timber strengthening

Dygas Justyna

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2024

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Z. 30 (180)

35--45

EN

The aim of this review paper is to present modern methods of strengthening timber structures. The first part of the article discusses the characteristics of timber. It needs to be strengthened for several reasons, as described below. The following points describe the strengthening of the components with the use of steel and composite materials. The focus is placed on composite bars, strips and sheets. The materials industry is particularly interested in composites. The work showed their general characteristics and analysed how to use them to reinforce the structure in the best manner. The analysis of the conducted studies suggests that the application of the aforementioned elements is reasonable, and scientists are planning additional research in this domain.

PL

Celem tej pracy przeglądowej było przedstawienie nowoczesnych sposobów wzmacniania konstrukcji drewnianych. W pierwszej części artykułu skupiono się na charakterystyce drewna. Jego wzmacnianie jest konieczne ze względu na szereg przyczyn, które omówiono w niniejszej pracy. W kolejnych punktach opisano wzmacnianie elementów za pomocą stali oraz kompozytów. Szczególną uwagę poświęcono prętom, taśmom i matom kompozytowym. Widoczne jest duże zainteresowanie kompozytami w branży materiałowej. Przedstawiono ich ogólną charakterystykę oraz przeanalizowano ich użyteczność we wzmacnianiu konstrukcji. Z badań wynika, że zastosowanie wyżej wymienionych elementów jest zasadne, a naukowcy planują dalsze badania w tym zakresie.

18

Synteza i zastosowanie modyfikowanych nanorurek TiO2

Górzyński Daniel, Nadolna Joanna, Kozak Magda, Mazierski Paweł

Wiadomości Chemiczne

|

2024

|

[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.

19

Resistance of low-emission geopolymer binders with fibers to aggressive external factors

Łach Michał, Przybek Agnieszka, Setlak Kinga, Bazan Patrycja, Hebdowska-Krupa Maria

Structure and Environment

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2024

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Vol. 16, no. 3

134--140

EN

Materials called geopolymers are considered an alternative to common hydraulic binders, but they have certain limitations in many applications due to their brittleness. The use of fibers to reinforce geopolymers can bring the expected results by increasing their compressive strength. This paper presents the results of accelerated durability tests of geopolymers based on coal shale and fly ash reinforced with natural fibers (1% by mass). The results of testing the resistance of such composites to UV radiation, variable temperature cycles and the results of the thermal conductivity coefficient are presented.

PL

Materiały zwane geopolimerami uznawane są za alternatywę dla powszechnych spoiw hydraulicznych jednak posiadają one pewne ograniczenia w wielu zastosowaniach ze względu na ich kruchość. Zastosowanie włókien do zbrojenia geopolimerów może przynieść oczekiwane rezultaty zwiększając ich wytrzymałość na zginanie. W niniejszej pracy zaprezentowano wyniki przyspieszonych badań trwałości geopolimerów na bazie łupków węglowych i popiołu lotnego wzmocnionych włóknami naturalnymi (1% mas.). Przedstawiono wyniki badań odporności takich kompozytów na działanie promieniowania UV, zmiennych cykli temperaturowych oraz przedstawiono wyniki badań współczynnika przewodzenia ciepła.

20

Otrzymywanie i degradacja kompozytów na bazie polilaktydu i paździerzy konopnych modyfikowanych stearyną

Biniaś Dorota, Drabek Weronika

Polish Journal of Materials and Environmental Engineering

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2024

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Vol. 7 (27)

63--73

EN

As a result of the work carried out, composites were obtained whose matrix was polylactide (PLA) and the filler was hemp shives with the addition of stearin. Using a heating press, composites with different shares of both PLA and hemp shives were obtained. The amount of stearin was always 15% in relation to the mass of hemp shives used. Samples were prepared from the obtained composites to test the biodegradation process, which were measured and weighed. The biodegradation process was carried out in the environment, placing the appropriately prepared batches of composites in compost derived from grass. Samples were taken at monthly intervals to analyze changes in mass and thickness and morphological assessment. The degradation process of the obtained composites was carried out for 3 months. The mass of the samples after the first month of biodegradation did not change significantly, however, with the biodegradation time, the masses of the tested composite samples decrease. The thickness of composite samples after the first month of biodegradation increased in relation to the initial value, which may be caused by the adsorption of water from the substrate. However, after three months of biodegradation, a decrease in thickness was observed for all samples in comparison to the initial value. Analysis of the surface morphology of the composite samples carried out using a stereoscopic microscope and a scanning electron microscope confirmed the biodegradation process for the obtained composites. Stearin, which is a mixture of fatty acids, used as a composite modifying additive turned out to be a nutrient for microorganisms present in the compost, which accelerated the decomposition of the samples. As a result of the conducted research, it can be stated that the obtained composite has properties that support ecological processing, which is in line with the assumptions of a circular economy.