Tamás Bárány

Tamás Bárány
Budapest University of Technology and Economics · Department of Polymer Engineering

PhD

About

72
Publications
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Publications

Publications (72)
Article
Full-text available
We prepared different thermoplastic elastomers (TPEs) using an internal mixer. We investigated the properties of thermoplastic polyurethanes (TPUs) produced from prepolymers with various isocyanate content and two different chain extend-ers to select the most appropriate TPU matrix for preparing thermoplastic vulcanizates (TPVs). Based on the resul...
Article
In this study, we investigated gamma radiation treated ground tire rubber (GTR) at different doses and measured the soluble content and the cross-link density of the samples. These results have been evaluated with Horikx's diagram. The results showed that at low doses, the selective chain-scission of the sulphur cross-links is dominant; however, at...
Article
In this study, we prepared polypropylene sheets with a superhydrophobic surface from extruded sheets with a phase separation method. We investigated the influence of extrusion parameters on the morphological properties of the polypropylene sheet and found that two significantly different structures can be formed in the cross-section of the sheet wh...
Article
The complex structure of tyres makes them hard to recycle economically; hence, it is crucial to minimize the generation of tyre waste. Nano‐reinforcement, such as graphene, has the potential to increase the abrasion resistance of rubber and thus their lifespan as well. In this research, hybrid styrene‐butadiene rubber‐based (SBR) nanocomposites rei...
Article
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 blend...
Article
We thermomechanically devulcanized ground tire rubber (GTR) in a co-rotating twin-screw extruder at different barrel temperatures and screw speeds. We measured the soluble content and the cross-link density of the samples and then evaluated them by Horikx's analysis. The results showed that at lower temperatures, selective cross-link scission is do...
Article
Full-text available
In the present study, we produced and investigated polypropylene-based single-polymer composites (SPCs) using four amorphous poly-alpha-olefin (APAO) grades as matrices and two plain-woven polypropylene fabrics as reinforcement. Our goal was to investigate the applicability of APAOs as matrix materials of SPCs and to widen the processing temperatur...
Article
Full-text available
Fibrous carbon nanotubes (CNTs) and lamellar graphene oxide (GO) exhibit significant advantages for improving the fatigue properties of rubber composites. In this work, the synergistic effect of CNTs and GO on the modification of the microstructure and fatigue properties of natural rubber (NR) was comprehensively investigated. Results showed that C...
Article
Full-text available
We devulcanized ground tire rubber (GTR) in a laboratory microwave oven and an internal mixer, measured the soluble content and the cross-link density of the samples, and then used Horikx’s analysis. The results showed that microwave treatment caused severe degradation of the polymer chains, while in the case of thermomechanical devulcanization, th...
Article
Full-text available
We developed polypropylene-based single-polymer composites (PP-SPC) with blends of amorphous poly-alpha-olefin (APAO) and random polypropylene copolymer (rPP) as matrix material and polypropylene (PP) woven fabric as reinforcement. Our goal was to utilize the lower melting temperature of APAO/rPP blends to increase the consolidation of the composit...
Article
Full-text available
We performed the complex static and dynamic mechanical characterization of cross-linked polyethylene foams; we investigated the effect of foam density on various mechanical properties and the relationship between cell structure and mechanical behavior. The impact damping and energy absorption properties of the foams were determined by falling weigh...
Article
In our current paper the preparation and properties of thermoplastic elastomer produced by dynamic vulcanization is presented and discussed. We dynamically vulcanized natural and styrene butadiene rubber (NR/SBR) phase by continuous extrusion. Dispersion and in-situ vulcanization of the rubber phase occurred simultaneously in a co-rotating twin scr...
Article
Full-text available
In this study, the mechanical properties of ultrasonic welded lap joints of all‐polypropylene composite (APPC) were investigated and compared to the interlaminar properties of the composite sheet itself. The process control parameter was welding time: welded samples were prepared with an ultrasonic welding machine in the 0.1–1.0 second time range....
Article
Full-text available
The aim of this paper was the detailed investigation of the properties of one-shot bulk polymerized thermoplastic polyurethanes (TPUs) produced with different processing temperatures and the properties of thermoplastic dynamic vulcanizates (TDVs) made by utilizing such in situ synthetized TPUs as their matrix polymer. We combined TPUs and conventio...
Article
Full-text available
Rubber recycling is a major environmental challenge, as their covalently crosslinked structure makes it impossible to reprocess via conventional polymer processing technologies. Devulcanization of rubber waste, whereby crosslinks are selectively broken, may provide a solution, as it allows it to be remolded into new shapes. We used two types of gro...
Chapter
The current chapter is dedicated to polypropylene (PP) based composites. The material grouping and presentation in the chapter follows the logic of the reinforcement length gain and covers the areas from nano- to macro-composites. Thus, separate sections are devoted to PP-nanocomposites, discontinuous fiber-reinforced, mat-reinforced, fabric-reinfo...
Book
This book extensively reviews Polypropylene (PP), the second most widely produced thermoplastic material, having been produced for over 60 years. Its synthesis, processing and application are still accompanied by vigorous R&D developments because the properties of PP are at the borderline between those of commodity and engineering thermoplastics....
Article
Small angle X-ray scattering (SAXS) and polarized Raman spectroscopy were used to examine the structure of unidirectional all-polypropylene composites prepared at different consolidation temperatures. Analysis of the anisotropy of the X-ray scattering pattern provided a way to quantify the disorientation of the crystallites and a direct correlation...
Article
Full-text available
Because of the chemically crosslinked 3D molecular structure of rubbers, their recycling is a challenging task, especially when cost efficiency is also considered. One of the most straightforward procedures is the grinding of discarded rubber products with subsequent devulcanization. The devulcanized rubber can be used as a feedstock for fresh rubb...
Article
In this work the effect of cyclic butylene terephthalate (CBT) was studied on the curing, rheological, morphological and mechanical properties of styrene butadiene rubber (SBR), oil extended styrene butadiene rubber (oSBR), acrylonitrile butadiene rubbers (NBR) with various acrylonitrile (AN) content and a carboxylated acrylonitrile butadiene rubbe...
Article
A method was elaborated to prepare flame retarded self-reinforced polypropylene composites by injection moulding. The effect of intumescent flame retardant (FR) loading was comprehensively investigated on the morphology, flammability, and mechanical properties of the self-reinforced polypropylene composites and compared with non-reinforced counterp...
Article
Full-text available
In this work, the effect of mixing temperature (Tmix) on the mechanical, rheological, and morphological properties of rubber/cyclic butylene terephthalate (CBT) oligomer compounds was studied. Apolar (styrene butadiene rubber, SBR) and polar (acrylonitrile butadiene rubber, NBR) rubbers were modified by CBT (20 phr) for reinforcement and viscosity...
Article
Full-text available
The flame retardant synergism between highly stretched polymer fibres and intumescent flame retardant systems was investigated in self-reinforced polypropylene composites. It was found that the structure of reinforcement, such as degree of molecular orientation, fibre alignment and weave type, has a particular effect on the fire performance of the...
Article
Impact resistant all-poly(lactic acid) composites were prepared by film-stacking of highly crystalline poly(lactic acid) (PLA) fibres with fully amorphous PLA films. The flammability of the self-reinforced PLA composites (PLA-SRCs) was effectively reduced by incorporating ammonium polyphosphate based flame retardant (FR) additive and montmorillonit...
Article
Graphene nanoplatelets (GnP) reinforced styrene-butadiene rubber (SBR) nanocomposites were produced by two different methods. For reference purpose carbon black (CB) reinforced formulations served. In the first method the components were mixed on a two roll open mill directly. In the second method, GnP was subjected to milling in an attritor mill t...
Article
Water-assisted, or more generally liquid-mediated, melt compounding of nanocomposites is basically a combination of solution-assisted and traditional melt mixing methods. It is an emerging technique to overcome several disadvantages of the above two. Water or aqueous liquids with additives, do not work merely as temporary carrier materials of suita...
Article
Full-text available
In this paper the effect of a novel bifunctional additive [cyclic butylene terephthalate (CBT)] was investigated on the rheological, curing and mechanical properties of natural rubber (NR), styrene butadiene rubber (SBR), oil extended styrene butadiene rubber (oSBR), acrylonitrile butadiene rubber (NBR) and ethylene propylene diene rubber (EPDM). R...
Article
The essential work of fracture (EWF) approach is widely used to determine the plane stress fracture toughness of highly ductile polymers and related systems. To shed light on how the toughness is affected by nanofillers EWF-suited model polymers, viz. amorphous copolyester and polypropylene block copolymer were modified by multiwall carbon nanotube...
Article
Multilayer self-reinforced polypropylene composites, fire retarded with APP based intumescent systems, were found to have surprisingly good fire retardancy. The combination of V-0 classification with excellent mechanical properties could be realized at significantly lower additive levels than expected. Modifying the structure of the composites allo...
Article
Preparation, properties and applications of single-polymer composites (SPCs), representing an emerging family within the polymeric composite materials, have been surveyed. SPCs were classified in respect to their composition (one- and two-constituents), and preforms (non-consolidated and consolidated). SPCs composed of amorphous or semicrystalline...
Article
Full-text available
The essential work of fracture (EWF) approach is widely used to determine the plane stress fracture toughness of highly ductile polymers and related composites. To shed light on how the toughness is affected by nanofillers EWF-suited model polymers, viz. amorphous copolyester and polypropylene block copolymer were modified by multiwall carbon na...
Article
Thermoplastic elastomers were prepared from recycled low density polyethylene [rLDPE] and virgin low density polyethylene (LDPE), respectively, ground tyre rubber (GTR), and ethylene vinyl acetate (EVA) copolymer. The amounts of the rLDPE and GTR were fixed at 40 and 30 wt %, respectively, in the formulations, whereas the LDPE and EVA contents vari...
Article
Multilayered self-reinforced composites were developed from a density-separated light fraction of automotive shredder waste of high polyolefin content, which can fulfil the current technical, safety and environmental requirements of structural materials. The significantly enhanced mechanical properties of the recycled composites were ensured by pol...
Article
The disposal of worn tyres and their economic recycling mean a great challenge nowadays. Material recycling is the preferred way supported by legislative actions and economical/ecological arguments. This paper surveys the recent developments devoted to the reclamation, surface treatments, and to the use of ground tyre rubber (GTR) in thermoplastics...
Article
In this work the creep behavior of self-reinforced polymer composites (SRPC) were investigated. As matrix material olefin based thermoplastic elastomeric (o-TPE), as reinforcement highly oriented polypropylenes were used. The tested self-reinforced composites were prepared by filament winding with subsequent compression molding and injection moldin...
Article
Full-text available
In this study all-poly(ethylene terephthalate) composites were developed and their (fracture)mechanical properties were investigated. Glycol modified poly(ethylene terephthalate) (PETG) and high tenacity PET multifilament were used as matrix material and reinforcement, respectively. The reinforcement was aligned in unidirectional (UD) and crossply...
Article
Full-text available
The fracture behavior of all-PP composites was studied under quasi-static loading conditions. Fracture toughness was evaluated by means of different fracture mechanics approaches depending on materials' behavior. Composites consolidated at low temperature exhibited pop-in features and the failure occurs typically by delamination and tape stretching...
Article
In this work, the fracture and failure behavior of self-reinforced polypropylene composites (SRPPC) was studied. As reinforcement woven fabric, whereas as matrix materials α and β crystal forms of isotactic polypropylene (PP) homopolymer and random PP copolymer (with ethylene) were used. Composite sheets were produced by a film-stacking method and...
Article
The preparation, properties and applications of self-reinforced polymeric materials (SRPMs), representing an emerging family of composite materials, are surveyed. SRPMs are classified according to their constituents (single- or multi-component), their production (in one-step (in situ) or in multi-step (ex situ) procedures) and the spatial alignment...
Article
The essential work of fracture (EWF) concept has become very popular to characterize the plane stress toughness of ductile polymers and related systems. The widespread use of the EWF is due to the simple specimens’ preparation, easy testing and simple data reduction procedure. Though the EWF method is usually used for mode-I type loading, it has be...
Article
In the present work the weldability of self-reinforced composite was investigated. As reinforcement a fabric, woven from highly stretched split PP yarns, whereas as matrix materials of two kinds of random polypropylene copolymer (with ethylene) were used. The composite sheets were produced by film-stacking method and compression molded with differe...
Article
In our present study, the reprocessability of a self-reinforced PP composites (SRPPC) prepared by compression molding was studied. The composite materials (handled separately, based on the related matrix material) were ground, then extruded five times and injection molded after the first and fifth cycle in order to investigate the behaviour of the...
Article
In this study, the properties of polypropylene (PP) homocomposites, prepared by film-stacking followed by hot pressing, were investigated. Alpha- and beta-PP served as matrices, whereas highly oriented PP tapes of the alpha form acted as reinforcement in the homocomposites. Tapes with different draw ratios (DR = 6–12) have been produced and charact...
Article
In the present work self-reinforced polypropylene composites (SRPPC) were developed and investigated. As reinforcement a fabric, woven from highly stretched split PP yarns, whereas as matrix materials α and β crystal forms of isotactic PP homopolymer and random copolymer (with ethylene) were selected and used. The composite sheets were produced by...
Article
All polypropylene (all-PP) composites were manufactured by exploiting the polymorphic forms of PP, in which alpha (α)-PP homopolymer tapes worked as reinforcement and β-nucleated random PP copolymer (β-rPP) as matrix. Both unidirectional (UD) and cross-ply (CP) laminates were prepared by tape winding technology combined with a film stacking method...
Article
The impact behaviour of self-reinforced polypropylene (PP) composites was studied. α and β polymorphs of isotactic PP homopolymer and random copolymer (with ethylene) were used for matrix materials, whereas the reinforcement was a fabric woven from highly stretched split PP yarns. The composite sheets were produced by the film-stacking method and c...
Article
Full-text available
A new technique, that the nanoparticles filled Polypropylene(PP) sheets were stretched under a temperature slightly lower than the melt point of PP, then the sheets were film-stacked with random PP copolymer, was developed in this work. The resultant nanocomposites are much stronger and stiffer than the unfilled PP.
Article
To improve the properties of polypropylene (PP), a new route that combines nanoparticles filling with self-reinforced technique was applied in this work. That is, nano-silica particles were firstly modified by graft polymerization to increase interfacial interaction between nanoparticles and matrix. Then the grafted nanoparticles were melt-compound...
Article
Full-text available
In this work, thermoplastic elastomers were prepared based on low-density polyethylene (LDPE) and ground tire rubber (GTR). To improve the adhesion and achieve better rubber-like properties, ethylene vinyl acetate copolymer (EVA) was selected and used as a compatibilizer. The GTR and EVA content were varied between 0–45 and 0–20 wt%, respectively....
Article
Full-text available
Self-reinforced polypropylene composites (SRPPC) were hot pressed from textile layers (carded mat, knitted fabrics) at three different temperatures (160, 165 and 170°C) by setting a constant pressure (6 MPa) and constant holding time (2 min). Both textiles consist of two kinds of isotactic polypropylene (iPP) fibers differing in their orientation....
Article
Full-text available
The in-plane (plane stress) fracture toughness of two polyester (PET, PETG) sheets were assessed using the essential work of fracture (EWF) method after thermal and hygrothermal aging performed just below glass temperature. This ensured that physical aging takes place. On the aged sheets the yield stress (σy), enthalpy relaxation (ΔH) and EWF param...
Article
The in-plane static fracture of a fabric reinforced all-poly(propylene) (all-PP, Curv®) composite was studied at ambient temperature using the concept of the linear elastic fracture mechanics. The apparent fracture toughness was determined on single-edge notched tensile specimens (SEN-T) considering the maximum load. The related values did not diff...
Article
Highly oriented polypropylene fiber reinforced random PP copolymer composites were produced by film-stacking method. The reinforcing fibers were carded and needle punched and the film-stacked packages were compression molded at different processing temperatures (T=150...170°C) and holding times (t=90...600 s). For characterization of the consolidat...
Article
Self-reinforced poly(propylene) (PP) composites were produced by film-stacking using carded mats of α-isotactic PP fibers and films of β-isotactic PP. Composite sheets were produced at various consolidation temperatures (T = 150–170°C) and constant holding time (t = 2 min). In a test series the holding time was varied (t = 2–20 min) by keeping the...
Article
The essential work of fracture (EWF) method was used to assess the in‐plane toughness of a paper containing poly(ethylene terephthalate) (PET) and cellulose fibers before and after ultraviolet (UV) aging. It was found that this paper meets the basic requirements of the EWF method, at least in the yielding/blunting‐related stage. The related EWF ter...
Article
The in-plane (mode I) and out-of-plane (mode III) fracture behavior of amorphous (co)polyester sheets are studied as a function of physical aging using the essential work of fracture (EWF) concept. Physical aging was followed by measuring the yield stress and enthalpy relaxation of the (co)polyesters. The specific essential work of fracture term di...
Article
Syndiotactic polypropylene (sPP) sheets of various crystallinities were subjected to accelerated ultraviolet (UV) aging. The chemical modification of the polymer was followed by FTIR spectroscopy measuring the carbonyl index in transmittance (film) and diffuse reflectance (powder) modes. Both the tensile stress and strain, suitable indicators of th...
Article
The toughness of amorphous poly(ethylene terephthalate) (PET) sheets before and after hygrothermal aging was determined by the essential work of fracture (EWF) concept. Hygrothermal aging at 60 °C for 100 h of the specimens was performed in hot water and soft drink (Coca-Cola), respectively. The EWF parameters were determined using the energy parti...
Article
The plane stress fracture toughness of amorphous copolyester (PETG) sheets plasticized by various amount of neopentylglycol dibenzoate (NPGDB in 0, 5, 10 and 20wt%) was studied in as-received (AR) and rejuvenated (RJ) states by adopting the essential work of fracture (EWF) method. EWF tests were performed on deeply double-edge notched tensile loade...
Article
Plane-stress fracture toughness of amorphous copolyester (COP) sheets of different composition and molecular mass characteristics was determined by the essential work of fracture (EWF) concept using tensile-loaded deeply double-edge notched (DDEN-T) specimens. It was determined that these COPs meet the basic requirement of the EWF concept since the...
Article
A projekt során önerősítéses polipropilén (PP) kompozitot (SRPPC) fejlesztettünk ki. A szükséges feldolgozási hőmérséklet tartományt random PP kopolimer alkalmazásával (mátrix) és/vagy a PP polimorfizmusában rejlő lehetőségek kihasználásával biztosítottuk. A kompozitokat film-stacking módszerrel állítottuk elő. Erősítőszerkezetként általunk előállí...