Anna Krzak

Mrs. Anna Krzak

Silesian University of Technology, Gliwice, Śląskie, Poland
orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
26 November 2024 in Science of The Total Environment
Verified
Journal Article
Open access
AKAnna Krzak
Anna Krzak
ANAgnieszka J. Nowak
Agnieszka J. Nowak
MBMagdalena Bogacka
Magdalena Bogacka
Modern societal functioning is intricately intertwined with the omnipresence of plastics. Within industrial domains, composite materials featuring an epoxy matrix have garnered extensive utilization. However, using such glass fiber-reinforced polymer composites poses many environmental problems due to high energy consumption and pollutant emissions during production. This work focuses on analyzing the environmental impact of newly developed resin compositions that will be applied in cryogenic conditions. Composite materials belong to engineering materials that are continuously evolving. As a result, there are imposed requirements for them to have very precise environmental parameters. It is evident that in the future, manufacturers of composite materials will be required to provide declarations of environmental impact. Currently, there are very few comprehensive environmental analyses of such materials in the scientific literature. Based on the calculation of carbon footprint (CF) emissions, it was found that composites that used resin A are less harmful than compositions with resin B. Recipe 2016 Midpoint (H) LCIA methodologies indicated that resin B production has the most significant adverse environmental impacts - global warming, human toxicity (non-carcinogenic), water consumption and marine aquatic ecotoxicity. It is clear that Resin B has a detrimental impact on the environment. The categories of chemical ingredients, electricity, and heat have increased by 22.34 %, 23.36 %, and 89.11 %, respectively, compared to Resin A. The obtained results were compared with literature data. This work is novel due to the provided environmental data from a company producing composite materials in Poland.

20 December 2023 in Materials
Verified
Journal Article
Open access
PDF file
AKAnna Krzak
Anna Krzak
ZAZainab Al-Maqdasi
Zainab Al-Maqdasi
Agnieszka J. NowakAgnieszka J. Nowak
Agnieszka J. Nowak
RJRoberts Joffe
Roberts Joffe
Due to the high interest in the use of glass/epoxy laminates in aerospace applications, aviation, and as cryogenic tanks, it is crucial to understand the behavior of composites under challenging environmental conditions. Polymer composites are exposed to low temperatures, including cryogenic temperatures, which can lead to the initiation of microdamage. This paper investigates damage initiation/accumulation and its influence on the properties of cross-ply woven glass fiber epoxy composites at low temperatures compared to room temperature conditions. To evaluate the influence of a low-temperature environment on the mechanical performance of glass fiber reinforced epoxy composite (GFRP) laminates, three types of test campaigns were carried out: quasi-static tensile tests and stepwise increasing loading/unloading cyclic tensile tests at room temperature and in a low-temperature environment (−50 °C). We demonstrated that the initial stiffness of the laminates increased at low temperatures. On the other hand, there were no observed changes in the type or mechanism of developed damage in the two test conditions. However, the reduction in stiffness due to the accumulated damage was more significant for the laminates tested at low temperatures (~17% vs. ~11%). Exceptions were noted in a few formulations where the extent of damage at low temperatures was insignificant (<1%) compared to that at room temperature. Since some of the studied laminates exhibited a relatively minor decrease in stiffness (~2–3%), we can also conclude that the formulation of matrix material plays an important role in delaying the initiation and formation of damage.

23 February 2024 in Polymers
Verified
Journal Article
Open access
PDF file
AKAnna Krzak
Anna Krzak
Agnieszka J. NowakAgnieszka J. Nowak
Agnieszka J. Nowak
Marcin HeljakMarcin Heljak
Marcin Heljak
JAJerzy Antonowicz
Jerzy Antonowicz
TGTushar Garg
Tushar Garg
MSMichael Sumption
Michael Sumption
It is commonly acknowledged that polymer composites in service are often subjected to not only intricate mechanical loads but also harsh environmental conditions. The mechanical and thermal properties of five particular composites are explored here. The composites are composed of laminates of glass cloth type “E” sheet infilled with a duroplastic matrix. This is a thermoset polymer—epoxy resin with different molecular weights. The composites were fabricated by IZOERG company, which is based in Poland. The final articles were 1.5 mm thick by 60 cm long and 30 cm wide, with the glass layers arranged parallel to the thickness. Young’s modulus and tensile strength were measured at room temperature. Using the thermal analysis of dynamic mechanical properties (DMTA), the values of the storage modulus and the loss modulus were determined, and the damping factor was used to determine the glass transition temperature (Tg). It was revealed that the nature of changes in the storage modulus, loss modulus, and damping factor of composite materials depends on the type of epoxy resin used. Thermal expansion is a crucial parameter when choosing a material for application in cryogenic conditions. Thanks to the TMA method, thermal expansion coefficients for composite materials were determined. The results show that the highest value of the coefficient of thermal expansion leads the laminate EP_4_2 based on brominated epoxy resin cured with novolac P. Duroplastic composites were characterized at cryogenic temperatures, and the results are interesting for developing cryogenic applications, including electric motors, generators, magnets, and other devices.

4 December 2024 in Cryogenics
Verified
Journal Article
Open access
AKAnna Krzak
Anna Krzak
ANA.J. Nowak
A.J. Nowak
JFJ. Frolec
J. Frolec
TKT. Králík
T. Králík
DBD. Boroński
D. Boroński
MKM. Kotyk
M. Kotyk

1 August 2023 in Archives of Materials Science and Engineering
Verified
Journal Article
Closed access
AKAnna Krzak
Anna Krzak
Agnieszka J. NowakAgnieszka J. Nowak
Agnieszka J. Nowak
Cryogenic engineering is gaining more and more interest in various industry sectors, which leads to an intensive search for effective solutions. The article presents the findings of mechanical testing conducted on glass-epoxy laminates at room temperature and after long-term contact with liquid nitrogen.To compare the impact properties and flexural strength, the samples were tested under cryogenic and room conditions, and then the fracture locations were identified using the Leica DVM6 microscope. The study brings value to the emerging field of cryogenic engineering by providing valuable information on the mechanical properties of glass-epoxy composites under cryogenic conditions.It has been found out that immersing the glass-epoxy composites into the Dewar had minimal influence on impact and flexural strength properties. The most noticeable changes were observed in the case of the EP_4_2 composite. The material consists of a solution of brominated epoxy resin in an organic solvent. It is used to produce laminates in electrical engineering and printed circuits in electronics, where it should exhibit excellent impact properties.One of the prospective research directions is a thorough analysis of the mechanical properties of the developed composite materials during cryogenic cycles.The study aims to determine the effect of different compositions of glass fabric-reinforced resin with a weight of 205 g/m2 on the mechanical properties of the developed composite materials at both room temperature and after long-term exposure to liquid nitrogen. Those investigations serve as surveillance for developing of new material solutions directed towards cryogenic applications and are essential for subsequent stages of research.

6 November 2024 in Materials
Verified
Journal Article
Open access
PDF file
AKAnna Krzak
Anna Krzak
Agnieszka J. NowakAgnieszka J. Nowak
Agnieszka J. Nowak
JFJiří Frolec
Jiří Frolec
TKTomas Kralik
Tomas Kralik
MKMaciej Kotyk
Maciej Kotyk
GMGrzegorz Matula
Grzegorz Matula
It is widely known that glass–epoxy laminates are renowned for their high stiffness, good thermal properties, and economic qualities. For this reason, composite materials find successful applications in various industrial sectors such as aerospace, astronautics, the storage sector, and energy. The aim of this study was to investigate the mechanical and thermal properties of composite materials comprising two different types of epoxy resin and three different hardeners, both at room temperature and under cryogenic conditions. The samples were produced at IZOERG (Gliwice, Poland) using a laboratory hot-hydraulic-press technique. During cyclic loading–unloading tests, degradation up to a strain level of 0.6% was observed both at room temperature (RT) and at 77 K. For a glass-reinforced composite with YDPN resin (EP_1_1), the highest degradation was recorded at 18.84% at RT and 33.63% at 77 K. We have also investigated the temperature dependence of thermal conductivity for all samples in a wide temperature range down to 5 K. The thermal conductivity was found to be low and had a relative difference of up to 20% among the composites. The experimental results indicated that composites under cryogenic conditions exhibited less damage and were stiffer. It was confirmed that the choice of hardener significantly influenced both properties.