Wyniki wyszukiwania - BazTech

1

Study on thermal stability and degradation kinetics of bio-based low-density polyethylene

Aniśko Joanna, Sałasińska Kamila, Barczewski Mateusz

Polimery

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2023

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Vol. 68, nr 9

451--460

EN

The degradation kinetics of low-density bio-based polyethylene three grades were examined using the TGA method in nitrogen and air atmosphere. An analysis of gases produced during thermal decomposition in air was also performed. The mechanism of thermal degradation processes of bio-based polyethylene was proposed in relation to literature data on the thermal decomposition of polyethylene of petrochemical origin.

PL

Metodą TGA w środowisku obojętnym i utleniającym zbadano kinetykę degradacji trzech odmian biopolietylenu małej gęstości. Dokonano również analizy gazów powstających podczas rozkładu termicznego w powietrzu. Zaproponowano mechanizm procesów termicznej degradacji biopolietylenu w odniesieniu do danych literaturowych dotyczących rozkładu termicznego polietylenu pochodzenia petrochemicznego.

2

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.

3

Limitations of Short Basalt Fibers Use as an Effective Reinforcement of Polyethylene Composites in Rotational Molding Technology

Aniśko Joanna, Bartczak Dawid, Barczewski Mateusz

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

110--123

EN

The rotational molding technology is becoming more popular and even outstanding some of the conventional polymer processing technologies. The production of polymer composites via this technology is still not described thoroughly. This work discusses the possibilities of obtaining polyethylene composites reinforced with short basalt fibers. Two methods of incorporating the fibrous fillers, dry-blending and through preliminary extrusion, are concerned. The application of the extrusion step to mixed polymer matrix with basalt fiber results in better distribution of basalt fibers than the direct dry blending polymer powder with fiber in the mold. The basalt fibers from rotomolded samples prepared from melt mixed plastic powder significantly reduced their length, leading to a substantial limitation in their reinforcing effect on the polymer matrix. The possible reinforcing effect was evaluated in a mechanical test such as a tensile test, impact test, and hardness. Optical microscopy helped in the investigation of the distribution of basalt fibers. Not only the physical structure of composites was examined, but also the chemical composition using the Fourier transform infrared spectroscopy. The spectroscopic analysis confirms a properly realized technological process without degradation caused by rotational molding or additional melt blending. The production of good-quality rotomolded composites reinforced with basalt fibers depends on the method of incorporating the fibrous filler.

4

Polylactide: from Synthesis and Modification to Final Properties

Aniśko Joanna, Barczewski Mateusz

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 3

9--29

EN

The article reports ways and trends in polylactide (PLA) modification methods concerning literature data. The paper consists of two parts and presents the process of polylactide production, and the connection of changes in its properties with the polymer structure obtained thanks to appropriate process conditions and methods of its final polymer properties improvement. Discussing both the most advantageous properties and disadvantages, the possibilities of increasing the scope of its applicability in reference to selected modification methods were presented and discussed. The presented research results related to various modification methods arrange the knowledge from the discussed scope, indicating the best possible effects and limitations. The most considerable emphasis is on the methods and results obtained from heterogeneous nucleation and incorporating various fillers in the PLA matrix. The other methods, like applying chemical interaction methods (crosslinking, using chain extenders), development of polymer blends, copolymerization, and plasticization, are presented synthetically. In summary, the review present and organizes the achievements in the possibility of modifying the most prospective biodegradable polymer, which is PLA.