10 results on '"Roland Petrény"'
Search Results
2. Combined effects of plasticizers and D-lactide content on the mechanical and morphological behavior of polylactic acid
- Author
-
Katalin Litauszki, Roland Petrény, Zsófia Haramia, and László Mészáros
- Subjects
Polylactic acid ,Plasticizer ,D-lactic content ,Mechanical properties ,Crystallization ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Nowadays, research into environmentally friendly, renewable materials is the focus of materials science. One of the best candidates for these purposes is polylactic acid (PLA), whose properties are determined mainly by its D-lactide content. PLA is often plasticized to achieve proper toughness. Our aim was to investigate the combined effects of plasticizers and D-lactide content on PLA. We investigated two different plasticizers: oligomeric lactide acid (OLA) and dioctyl adipate (DOA). An internal mixer was used to prepare the compounds, and then sheets were prepared by hot pressing. After mechanical and morphological analyses, we found that tensile strength and modulus of neat PLAs and PLA-OLA compounds decreased almost linearly with increasing D-lactide content. The mechanical properties of PLA-DOA compounds depended far less on D-lactide content than in the case of PLA-OLA compounds. Plasticizers promote the crystallization of crystallizable PLAs by their chain mobilizing effect—we obtained a higher crystalline fraction. The latter effect reduces the impact of the plasticizing effect of plasticizers in the product. The compatibility and dispersibility of plasticizers also have a significant effect on the properties of the materials. OLA is more compatible with PLA than DOA, which resulted in better plasticization, but caused more defects in the crystallites, thus reducing the crystalline melting temperature, and so the processing temperature of the compound containing plasticizers.
- Published
- 2023
- Full Text
- View/download PDF
3. Ground tire rubber filled low-density polyethylene: The effect of particle size
- Author
-
Lóránt Kiss, Dániel Ábel Simon, Roland Petrény, Dávid Kocsis, Tamás Bárány, and László Mészáros
- Subjects
Ground tire rubber ,Particle size ,Polyethylene ,Recycling ,Polymers and polymer manufacture ,TP1080-1185 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In the present study, we investigated the possibility of value-added recycling of ultrafine ground tire rubber (uGTR) produced from water jet milling, with an average particle size of a few tens of microns. Our goal was to compare the properties of blends with different uGTR and conventional fine ground tire rubber (fGTR) contents prepared by blending with low-density polyethylene (LDPE). We also aimed to explore the property changes caused by the larger specific surface area due to the size effect. Samples were prepared with a hydraulic press after internal mixing. In the case of ground tire rubber (GTR) filled mixtures, the tensile properties showed rubber-like characteristics: with a significant decrease in modulus, elongation at break remained high, and tensile strength slightly decreased. The fracture surfaces of the samples were analyzed by scanning electron microscopy (SEM), wherein the case of materials made with uGTR showed better adhesion between the phases. In order to investigate the interfacial adhesion between the GTR and LDPE, we performed dynamic mechanical thermal analysis (DMTA). The glass transition peak of the uGTR shifted to a higher temperature and the storage modulus was higher than in the case of samples containing fGTR. Finally, we determined the Shore D hardness of the materials, which decreased with increasing GTR content, but hardness was greater in the case of uGTR samples. The better mechanical properties of blends containing uGTR were explained by better interfacial adhesion between the two phases due to the significantly higher specific surface area compared to fGTR.
- Published
- 2022
- Full Text
- View/download PDF
4. Moisture dependent tensile and creep behaviour of multi-wall carbon nanotube and carbon fibre reinforced, injection moulded polyamide 6 matrix multi-scale composites
- Author
-
Roland Petrény and László Mészáros
- Subjects
Polymer matrix composite ,Hybrid composite ,Polyamide 6 ,Carbon fibre ,Carbon nanotube ,Creep ,Mining engineering. Metallurgy ,TN1-997 - Abstract
abstract: In this study the creep behaviour and its dependence on moisture content in injection moulded hybrid composites reinforced with carbon fibres and carbon nanotubes was investigated. The tensile tests and the scanning electron microscope images confirmed that the presence of carbon fibres helped the uniform distribution of carbon nanotubes in the matrix. In the composites reinforced only with carbon fibres, the creep rate was lower than in any of the composites reinforced with only carbon nanotubes. Synergistic effects were observed when carbon nanotubes were added to the composite besides the carbon fibres: the creep rate was even lower and decreased with the increase in nanotube content. In the composites only reinforced with carbon nanotubes, crystallinity decreased, and moisture absorption increased with increasing nanotube content, but in the hybrid composites, the decrease in crystallinity and moisture absorption was much lower, thus the disadvantageous effect of moisture on the creep rate was much smaller in the hybrid composites.
- Published
- 2022
- Full Text
- View/download PDF
5. Development of electrically conductive hybrid composites with a poly(lactic acid) matrix, with enhanced toughness for injection molding, and material extrusion-based additive manufacturing
- Author
-
Roland Petrény, Csenge Tóth, Aurél Horváth, and László Mészáros
- Subjects
Nanocomposite ,Hybrid composite ,Carbon nanotubes ,Conductive composite ,Fused filament fabrication ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
In this study, we developed electrically conductive nano- and hybrid composites with a poly(lactic acid) (PLA) matrix for different melt processing technologies. We used short carbon fiber and multi-walled carbon nanotube reinforcements to enhance electric conductivity. We prepared the composite compounds with twin-screw extrusion; then the compounds were processed via injection molding and fused filament fabrication. We showed that electric conductivity only slightly increased by when only carbon nanotubes were added to the PLA matrix. However, when carbon fibers were added to the nanocomposites, the higher shear during melt mixing helped the uniform dispersion of the carbon nanotubes, resulting in a highly conductive reinforcement network in the composite. On the other hand, the hybrid reinforcement resulted in higher viscosity, making melt processing difficult and the material also became more brittle. Therefore, we added an oligomeric lactic acid plasticizer to the hybrid composites, and produced specimens by injection molding and 3D printing. The tensile strength increased by 140% and the elongation at break increased by 56%, and at the same time, the electrical conductivity of the material remained at a high level.
- Published
- 2022
- Full Text
- View/download PDF
6. Multi-scale hybrid composites are making their way
- Author
-
Roland Petrény and László Mészáros
- Subjects
polymer composites ,n/a ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Chemical technology ,TP1-1185 - Abstract
editorial
- Published
- 2022
- Full Text
- View/download PDF
7. Ground tire rubber filled low-density polyethylene: The effect of particle size
- Author
-
Dávid Kocsis, Dániel Ábel Simon, Roland Petrény, Tamás Bárány, László Mészáros, and Lóránt Kiss
- Subjects
Materials science ,Polymers and Plastics ,Materials Science (miscellaneous) ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Natural rubber ,Specific surface area ,Ultimate tensile strength ,Chemical Engineering (miscellaneous) ,Shore durometer ,Recycling ,Polymers and polymer manufacture ,Composite material ,Dynamic mechanical analysis ,Particle size ,Polyethylene ,Engineering (General). Civil engineering (General) ,Low-density polyethylene ,TP1080-1185 ,chemistry ,Ground tire rubber ,visual_art ,visual_art.visual_art_medium ,TA1-2040 - Abstract
In the present study, we investigated the possibility of value-added recycling of ultrafine ground tire rubber (uGTR) produced from water jet milling, with an average particle size of a few tens of microns. Our goal was to compare the properties of blends with different uGTR and conventional fine ground tire rubber (fGTR) contents prepared by blending with low-density polyethylene (LDPE). We also aimed to explore the property changes caused by the larger specific surface area due to the size effect. Samples were prepared with a hydraulic press after internal mixing. In the case of ground tire rubber (GTR) filled mixtures, the tensile properties showed rubber-like characteristics: with a significant decrease in modulus, elongation at break remained high, and tensile strength slightly decreased. The fracture surfaces of the samples were analyzed by scanning electron microscopy (SEM), wherein the case of materials made with uGTR showed better adhesion between the phases. In order to investigate the interfacial adhesion between the GTR and LDPE, we performed dynamic mechanical thermal analysis (DMTA). The glass transition peak of the uGTR shifted to a higher temperature and the storage modulus was higher than in the case of samples containing fGTR. Finally, we determined the Shore D hardness of the materials, which decreased with increasing GTR content, but hardness was greater in the case of uGTR samples. The better mechanical properties of blends containing uGTR were explained by better interfacial adhesion between the two phases due to the significantly higher specific surface area compared to fGTR.
- Published
- 2022
8. Investigation of the interphase structure in polyamide 6–matrix, multi-scale composites
- Author
-
Roland Petrény, László Almásy, and László Mészáros
- Subjects
General Engineering ,Ceramics and Composites - Published
- 2022
9. Crystalline properties of melt-processed polyamide 6 matrix multiscale hybrid composites
- Author
-
Roland Petrény, József Szakács, and László Mészáros
- Subjects
Materials science ,Nucleation ,02 engineering and technology ,Carbon nanotube ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,010406 physical chemistry ,0104 chemical sciences ,law.invention ,Condensed Matter::Materials Science ,Crystallinity ,Differential scanning calorimetry ,law ,Basalt fiber ,Polyamide ,Crystallite ,Physical and Theoretical Chemistry ,Composite material ,Crystallization ,0210 nano-technology - Abstract
We investigated the crystalline properties of injection-molded polyamide 6 matrix composites containing carbon nanotubes and microfibers (basalt and carbon). We showed with differential scanning calorimetry tests that microfibers affect crystalline properties differently. Basalt fibers do not have a nucleating effect, while carbon fibers do, to a small extent. Carbon nanotubes acted as nucleating agents themselves, but in composites reinforced with microfibers they increased the crystallinity even more. Due to the nucleating effect of the nanotubes, crystallization started at a higher temperature in each composite. We observed synergistic effects concerning nucleation in hybrid composites. We decomposed the crystalline melting curves to determine the characteristics of the crystallite types and proved that the presence of nanotubes facilitated the formation of α-type crystallites. We showed that nanotubes have a double effect: They have a nucleating effect regarding crystallinity, and they inhibit the movement of polyamide molecules relative to each other, which decreases the tendency to crystallize. Therefore, nanotube content has an optimum concerning crystallization. This is in accordance with tensile mechanic properties.
- Published
- 2018
10. Characterization of polylactic acid-based nanocomposite foams with supercritical CO2
- Author
-
Roland Petrény, Ákos Kmetty, Katalin Litauszki, Bálint Morlin, and László Mészáros
- Subjects
Materials science ,02 engineering and technology ,Carbon nanotube ,engineering.material ,01 natural sciences ,Halloysite ,law.invention ,Crystallinity ,chemistry.chemical_compound ,Polylactic acid ,law ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Composite material ,Instrumentation ,chemistry.chemical_classification ,Nanocomposite ,Applied Mathematics ,020208 electrical & electronic engineering ,010401 analytical chemistry ,Polymer ,Condensed Matter Physics ,0104 chemical sciences ,Compressive strength ,Montmorillonite ,chemistry ,engineering - Abstract
In this research, we physically foamed semicrystalline polylactic acid filled with montmorillonite, carbon nanotubes, and halloysite nanoparticles. In the case of polymer foams, their density and compressive strength are important parameters. Although the specific compressive strength calculated as the ratio of the two is a good indicator of the use of polymeric foams, few researchers use this ratio for classification. We have shown that the presence of nanoparticles has a positive effect on this parameter, especially with the use of 3 wt% halloysite, when this value increased from 12.07 ± 7.5 [MPa/(g/cm3)] to 20.89 ± 1.75 [MPa/(g/cm3)], i.e., by more than 70%. In general, the presence of nanoparticles reduced the standard deviation of this ratio. Regardless of the nanoparticles used, the average cell diameter decreased compared to that of the reference material. The results were explained with the cell nucleating ability of halloysite.
- Published
- 2021
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.