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dr inż. Krzysztof Formela
Employment
- Profesor uczelni ze stop. nauk. dr at Department of Polymers Technology
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total: 188
Catalog Publications
Year 2018
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Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
PublicationReactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application...
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Rheological properties, oxidative and thermal stability, and potential application of biopolyols prepared via two-step process from crude glycerol
PublicationIn this work, previously synthesized biopolyols were analyzed in terms of their rheological and thermal properties, very important from the technological point of view. For better evaluation of performed synthesis, the influence of its time and temperature on the properties of biopolyols was determined. In the end, obtained materials were used to prepare rigid polyurethane-polyisocyanurate (PUR-PIR) foams, to evaluate their potential...
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Structural and physico-mechanical properties of natural rubber/GTR composites devulcanized by microwaves: Influence of GTR source and irradiation time
PublicationGround tire rubber from car and truck was modified using microwave irradiation at variable time. The irradiated ground tire rubber was used as filler in composites based on natural rubber. The composites, with high content of ground tire rubber, were prepared using an internal batch mixer and subsequently cross-linked at 160℃. The influence of the ground tire rubber source (car/truck) and irradiation time on structure, physico-mechanical...
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Structural, mechanical and thermal behavior assessments of PCL/PHB blends reactively compatibilized with organic peroxides
PublicationThe efficiency of two commercially available organic peroxides, dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB), during reactive processing of poly (ε-caprolactone)/poly (3-hydroxybutyrate) (PCL/PHB) blends was investigated. The changes in chemical structure of PCL/PHB blends, as a function of organic peroxide type (DCP/BIB) and content (in range: 0–1.0 parts by weight - pbw), were characterized by Fourier...
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Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale drill cuttings wastes
PublicationThe potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50...
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Structure-property relationships in peroxide-assisted blends of poly(ε-caprolactone) and poly(3-hydroxybutyrate)
PublicationPoly(ε-caprolactone) and poly(3-hydroxybutyrate) (PCL/PHB) blends in two weight ratios (75/25 and 50/50) were reactively compatibilized in the presence of di-(2-tert-butyl-peroxyisopropyl)-benzene and dicumyl peroxide as free radical initiators. Rheological, mechanical, thermal properties and morphological features, as well as the chemical structure of PCL/PHB blends were investigated. It was found that regardless of PCL/PHB blend...
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Surface Treatment of Rubber Waste
PublicationThis chapter deals with the study of different approaches to improve the compatibility of waste rubber with polymeric matrixes of high density polyethylene (HDPE) by using surface treatments to increase adhesion. Different surface treatments such as etching with sulphuric and nitric acids, the use of a silane as a coupling agent and chlorination with trichloroisocyanuric acid (TCI) have been applied. The modification of waste rubber...
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Synergistic Effects of Bitumen Plasticization and Microwave Treatment on Short-Term Devulcanization of Ground Tire Rubber
PublicationGround tire rubber (GTR) was mechano-chemically modified with road bitumen 160/220 and subsequently treated using a microwave radiation. The combined impact of bitumen 160/220 content and microwave treatment on short-term devulcanization of GTR was studied by thermal camera, wavelength dispersive X-ray fluorescence spectrometry (WD-XRF), static headspace, and gas chromatography-mass spectrometry (SHS-GC-MS), thermogravimetric analysis...
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The study on application of biopolyols obtained by cellulose biomass liquefaction performed with crude glycerol for the synthesis of rigid polyurethane foams
PublicationIn this work rigid polyurethane foams (PUR) were obtained by replacement of 0–70 wt% of petrochemical polyol with bio-polyol obtained via cellulose liquefaction in presence of crude glycerol. The foams with different content of a bio-polyol were prepared by single step method for NCO/OH ratio equals 1.5. The prepared materials were analyzed in terms of their morphology, chemical structure, thermal stability and basic physical and...
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Thermoplastic Elastomers Filled With GTR
PublicationIn recent years, searching for new and cost-effective methods of recycling waste tires has been a subject of research in many laboratories worldwide. This is due to regulations in the law and environmental factors, which have both stimulated industry to re-use high quality rubber found in ground tire rubber (GTR). One of the most promising solutions in this area seems to be thermoplastic elastomers (TPEs) filled with GTR, which...
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Two-step Conversion of Crude Glycerol Generated by Biodiesel Production into Biopolyols: Synthesis, Structural and Physical Chemical Characterization
PublicationIn this work biopolyols were synthesized via two-step process from crude glycerol and castor oil. For better evaluation of analyzed process, the impact of its time and temperature on the structure and properties of biopolyols was determined. Obtained results fully justified conducting of synthesis in two steps. Prepared materials were characterized by hydroxyl value and water content comparable to polyols industrially applied in...
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Vegetable derived-oil facilitating carbon black migration from waste tire rubbers and its reinforcement effect
PublicationThree dimensional chemically cross-linked polymer networks present a great challenge for recycling and reutilization of waste tire rubber. In this work, the covalently cross-linked networks of ground tire rubber (GTR) were degraded heterogeneously under 150 °C due to the synergistic effects of the soybean oil and controlled oxidation. The degradation mechanism was discussed using Horikx theory and Fourier transformation infrared...
Year 2017
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An investigation on the role of GMA grafting degree on the efficiency of PET/PP-g-GMA reactive blending: morphology and mechanical properties
PublicationGlycidyl methacrylate (GMA) has been grafted on polypropylene (PP) with the aid of styrene (St) comonomer, by changing dicumyl peroxide initiator content, GMA level, and St concentration. The performance of the resulting PP-g-GMA reactive material towards static and dynamic mechanical properties of poly (ethylene terephthalate) (PET) was monitored in terms of grafting reaction variables and compatibilizer content. Fourier transform...
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Biowaste chicken eggshell powder as a potential cure modifier for epoxy/anhydride systems: competitiveness with terpolymer-modified calcium carbonate at low loading levels
PublicationBiowaste chicken eggshell (ES) powder was applied as a potential cure modifier in epoxy/anhydride systems. Cure behaviour and kinetics of composites filled with very low content (0.1 wt% based on epoxy resin) of ES, calcium carbonate (CaCO3), and terpolymer-modified fillers, mES and mCaCO3, were discussed comparatively. Surface analysis was performed by X-ray photoelectron spectroscopy. Cure kinetics was investigated by differential...
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Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach
PublicationExperimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration,...
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Cure kinetics of epoxy/MWCNTs nanocomposites: Isothermal calorimetric and rheological analyses
PublicationA combinatorial route has been applied in cure kinetics study of epoxy nanocomposites containing multi-walled carbon nanotubes (MWCNTs) based on differential scanning calorimetry and rheokinetic analyses under isothermal conditions. Pristine and amine-modified MWCNTs bearing primary and secondary amines were used at very low concentrations (0.1 and 0.3 wt.% based on epoxy weight). Model-free and model-fitting methods were applied...
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Cure kinetics of epoxy/MWCNTs nanocomposites: Nonisothermal calorimetric and rheokinetic techniques
PublicationNonisothermal calorimetric and isothermal rheokinetic analyses were used to study cure kinetics of epoxy/anhydride systems containing very low concentration of pristine and amine-functionalized multiwalled carbon nanotubes (MWCNTs). Isoconversional methods were applied in calorimetric modeling of cure kinetics. Eα vs. α dependency and autocatalytic nature of curing were identified for both types of nanocomposites by isoconversional...
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Evaluation of structural change during fast transformation process of cross-linked NR into liquid NR by light pyrolysis
PublicationThe presence of cross-linked networks in rubber creates a tremendous problem for recycling and reusing of waste rubber. Fast transformation of cross-linked natural rubber (NR) into liquid natural rubber was carried out by light pyrolysis in temperature range from 240 to 300 °C in variable time (in range: 1–30 min). The transformation efficiency was evaluated by measuring the sol fraction and the cross-link density of the gel fraction....
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In-Situ Processing of Biocomposites via Reactive Extrusion
PublicationLaw regulations, economic and environmental factors are the main causes for the rapidly growing interests in biocomposites’ research, conducted currently in a number of academic and industrial scientific centers. However, weak polymer matrix/filler interactions, common in biocomposites, result in unsatisfactory mechanical properties, which limit their practical applications. From many attempts performed to solve this problem, in-situ...
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Interrelationship between total volatile organic compounds emissions, structure and properties of natural rubber/polycaprolactone bio-blends cross-linked with peroxides
PublicationNatural rubber/polycaprolactone (NR/PCL) bio-based blends with different organic peroxides were prepared using an internal batch mixer and subsequently cross-linked at 170°C. Two types of commonly used organic peroxides, dicumyl peroxide and di(tert-butylperoxyisopropyl)benzene peroxide, were applied as free-radical initiator. Cross-linking efficiency of NR/PCL blends were investigated using oscillating disc rheometer measurements,...
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Liquefaction of macroalgae Enteromorpha biomass for the preparation of biopolyols by using crude glycerol
PublicationThis article describes the liquefaction process of macroalgae Enteromorpha with the use of crude glycerol as a solvent and a reagent, aimed at obtaining of new bio-polyols, which are characterized with respect to their chemical structure, physical and thermal properties. Six different biopolyols were prepared. In order to optimize the liquefaction of algal biomass for the best bio-polyol properties, two catalysts (sulfuric or orthophosphoric...
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Modification of thermal and rheological characteristics of bitumen by waste PET/GTR blends
PublicationWaste poly(ethylene terephthalate) (wPET)/ground tire rubber (GTR) blends with variable compositions were applied as low-cost modifiers into bitumen and their performance has been evaluated via morphological, thermal and rheological analyses. Depending on the weight ratio of wPET/GTR, dispersion of single/composite domains of waste polymers in the bitumen has promoted the interaction between bitumen and blend components. Fourier...
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Performance properties of rigid polyurethane-polyisocyanurate/brewers’ spent grain foamed composites as function of isocyanate index
PublicationIn the presented work, rigid polyurethane-polyisocyanurate (PUR-PIR) foams filled with brewers’ spent grain (BSG) were prepared. The influence of the isocyanate index (II) on its performance was investigated. Foams obtained with higher isocyanate index required a higher amount of hydrofluorocarbon physical blowing agent to provide the same apparent density of material. An increase of isocyanate index resulted in a slight decrease...
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Processing, physico-mechanical and thermal properties of reclaimed GTR and NBR/reclaimed GTR blends as function of various additives
PublicationIn this work, ground tire rubber (GTR) was mechano-chemically reclaimed in the presence of bitumen and various additives. During studies three types of processing and curing additives: (i) peptizer P300; (ii) vulcanization accelerator tetramethylthiuram disulfide (TMTD) and (iii) organic peroxide di(2-tert-butyl-peroxyisopropyl)benzene (BIB1) were applied to enhance reclaiming of GTR. Reclaiming process was evaluated by oscillating...
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PU Polymers, Their Composites, and Nanocomposites: State of the Art and New Challenges
PublicationThe chapter is a review of the polyurethane(PU)-based composites and nanocomposites. The chapter details different components in the manufacturing of PU polymers, composites, and nanocomposites. The different types of glycols, isocyanates, and catalysts that are used for the synthesis of different polyurethanes are discussed. The applications and specialties of polyurethane composites and nanocomposites are also elaborated on.
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Renewable Resources for Polyurethanes and Polyurethane Composites: A Review
PublicationEach year, more than two million tons of polyurethane is produced in the EU by reacting isocyanates with polyols made from fossil fuel. In addition, there are appreciable quantities of petroleum based functional additives applied in the industry nowadays for both polyols and polyurethane materials. It is therefore of key importance to develop sustainable economically viable polyols with enhanced functionalities, and thereby reducing...
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Structural, thermal and physico-mechanical properties of polyurethane/brewers’ spent grain composite foams modified with ground tire rubber
PublicationIn this work, brewers’ spent grain (BSG) and ground tire rubber (GTR) waste fillers were applied as low-cost reinforcement phase in rigid polyurethane foam (PUR). PUR/BSG/GTR composites were prepared by a single step method, using polyglycerol as partial substitute of commercially available petrochemical polyols. Foaming parameters, chemical structure, dynamic mechanical properties, thermal stability, physico-mechanical properties...
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To what extent can hyperelastic models make sense the effect of clay surface treatment on the mechanical properties of elastomeric nanocomposites?
PublicationThe poor knowledge about nonlinear mechanical behavior of elastomer nanocomposites arises from the incomplete information on the interface. Application of hyperelastic models provides more insights into the nature and the situation of interaction between the elastomeric matrix and nanofillers. The current work seeks to address the effect of interphase strength on tensile properties of the elastomer nanocomposites under large deformations....
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Transparent nanocomposite coatings based on epoxy and layered double hydroxide: Nonisothermal cure kinetics and viscoelastic behavior assessments
PublicationLayered double hydroxide (LDH) has a particular place in clay family because of its flame retardant action. The nanoplatelet-like structure of LDH makes possible development of polymer composites with cationic or anionic nature structures in which macromolecules are positioned in between nanoplatelet galleries. In this work, neat epoxy and its transparent nanocomposite coatings with sodium dodecylbenzene sulfonate (SDBS)-modified...
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Wytłaczanie reaktywne jako proekologiczna metoda wytwarzania nowych biodegradowalnych mieszanin i kompozytów polimerowych.
PublicationBiodegradowalne materiały polimerowe stosowane są obecnie w wielu gałęziach przemysłu, stanowiąc przyjazną środowisku alternatywę dla konwencjonalnych tworzyw sztucznych wytwarzanych z paliw kopalnych. Wzrost liczby zagranicznych i krajowych prac badawczo-rozwojowych nad nowymi iodegradowalnymi materiałami polimerowymi potwierdza dynamiczny rozwój tej grupy materiałów. W artykule pokrótce omówiono wybrane przykłady zastosowania...
Year 2016
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A recent developments in polyurethane foams containing a low-cost and pro-ecological modifiers
PublicationDiversity of the polyurethane (PU) foams applications cause that investigation of the relationships between their structure and properties is currently very popular topic among the many research institutions and companies. At the turn of the last years many scientific papers about PU foams and their composites were published. The one of the main research trends in this field is related to the reduction of production costs of...
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Assessment of microstructure, physical and thermal properties of bitumen modified with LDPE/GTR/elastomer ternary blends
PublicationLDPE/GTR/elastomer ternary blends with variable LDPE/GTR ratio and constant elastomer content were prepared via melt-compounding. Obtained LDPE/GTR/elastomer blends were applied as thermoplastic modifiers into bitumen. Microstructure, physical and thermal properties of the modified bitumen were determined. It was observed that chemical composition of LDPE/GTR/elastomer blends has significant influence on their density and rheological...
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Badania próbek płyt podeszwowych dostarczonych przez Zamawiającego
PublicationPrzedmiotem umowy jest przeprowadzenie badań mających na celu określenie czy dostarczone przez Zamawiającego próbki płyt podeszwowych zostały wykonane z tworzywa termoplastycznego.
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Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization
PublicationIn this work lignocellulose biomass liquefaction was used to produce biopolyols suitable for the manufacturing of rigid polyurethane foams. In order to better evaluate the mechanism of the process, pure cellulose was applied as a raw material. The effect of time and temperature on the effectiveness of liquefaction and the parameters of resulting biopolyols were characterized. The prepared materials were analyzed in terms of their...
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Characterization of volatile compounds, structural, thermal and physico-mechanical properties of cross-linked polyethylene foams degraded thermo-mechanically at variable times
PublicationWaste cross-linked polyethylene foam (wXLPE) was thermo-mechanically degraded at variable time using internal batch mixer. The progress of wXLPE degradation has been investigated by using a simultaneous thermogravimetric/differential scanning calorimetry analyzer coupled with Fourier transform infrared spectroscopy, swelling measurements, tensile tests and scanning electron microscopy. Volatile organic compounds generated during...
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FTIR spectroscopic and thermogravimetric characterization of ground tyre rubber devulcanized by microwave treatment
PublicationIn this work, the phenomena involved in the microwave devulcanization of ground tyre rubber (GTR) were investigated. Three types of GTR with different content of organic compounds (elastomers, plasticizers, etc.), carbon black and ash have been studied. The chemical structure of GTR before and after a microwave devulcanization process was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)...
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Interfacial adhesion evaluation in (low-density polyethylene)/elastomer blends
PublicationLow-density polyethylene (LDPE) with different elastomers at a ratio of 50/50 wt% blends was prepared by using a co-rotating twin-screw extruder. Three kinds of elastomers were used: ground tire rubber (GTR), partially crosslinked butyl rubber (KalarVR ), and styrenebutadiene- rubber block copolymer (SBS; KratonVR ). For better characterization of interaction between polyethylene and elastomer, influence of the type of elastomer on...
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Investigating the combined impact of plasticizer and shear force on the efficiency of low temperature reclaiming of ground tire rubber (GTR)
PublicationIn the present work, ground tire rubber (GTR) was mechano-chemically reclaimed at ambient temperature using two-roll mills. Road bitumen and styrene-butadiene-styrene (SBS)-modified bitumen at variable content (in range: 2.5–20 phr) were applied as reactive plasticizers to enhance reclaiming of GTR. For better understanding the plasticizing effect of bitumen on the quality of obtained reclaimed rubber, mechano-chemically reclaimed...
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Microstructure, mechanical properties, and flame retardancy of nanoclay-incorporated polyurethane flexible foam composites
PublicationThe present work seeks to investigate microstructure, mechanical properties, and flame retardancy of polyurethane/nanoclay flexible foam composites. In this regard, we prepared various nanocomposites with and without nanoclay and observed the resulting morphologies to correlate them with the other corresponding characteristics. The results provided support for the fact that tensile strength and compression set will increase with...
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Morfologia, właściwości mechaniczne oraz palność spienionych materiałów poliuretanowo-poliglicerynowych modyfikowanych grafitem ekspandowanym
PublicationSpienione kompozyty poliuretanowo-glicerynowe modyfikowane grafitem ekspandowanymotrzymano metodą jednostopniową z układu dwukomponentowego, gdzie jako składnik poliolowyzastosowano odpadową poliglicerynę. Scharakteryzowano morfologię, właściwościmechaniczne oraz klasę palności otrzymanych materiałów. Uzyskane wyniki wskazują, żewprowadzenie poligliceryny do matrycy poliuretanowej umożliwia otrzymanie materiałówcharakteryzujących...
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Morphology and mechanical properties of polyamide/clay nanocomposites toughened with NBR/NBR-g-GMA: A comparative study
PublicationThis work highlights the importance of nanoclay dispersion state in the nanocomposites containing polyamide 6 (PA6), nanoclay and elastomers as well as clay localization at the interface of thermoplastic/elastomer. Morphology and mechanical properties of a series of nanocomposites containing acrylonitrile butadiene rubber (NBR), glycidyl methacrylate-grafted NBR (NBR-g-GMA), and combined NBR/NBR-g-GMA were compared and discussed...
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Potential applications of crude glycerol in polymer technology–Current state and perspectives
PublicationThe increasing use of bio-based fuels and fuel additives, among them biodiesel, causes significant surplus of crude glycerol on the market which creates new challenges in terms of its sustainable utilization. A lot of ways for the incorporation of this by-product into different branches of industry requires purification by expensive and complicated processes. Therefore, researchers are seeking for applications of untreated crude...
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Processing and structure–property relationships of natural rubber/wheat bran biocomposites
PublicationIn this work, wheat bran was used as cellulosic filler in biocomposites based on natural rubber. The impact of wheat bran content [ranging from 10 to 50 parts per hundred rubber (phr)] on processing, structure, dynamic mechanical properties, thermal properties, physico-mechanical properties and morphology of resulting biocomposites was investigated. For better characterization of interfacial interactions between natural rubber...
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Recycled Polyethylene terephthalate (PET) as Construction Material in Civil Engineering: A Review
PublicationIn general, the quantity of plastics of all types consumed annually all over the world has been growing in a phenomenal way. The manufacturing processes, service industries and municipal solid wastes (MSW) generate numerous waste plastic materials. The increasing awareness about the environment has tremendously contributed to the concerns related with disposal of the generated wastes. It is believed that the management of solid...
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Styrene-Butadiene Rubber/Modified Ground Tire Rubber Blends Co-Vulcanization: Effect of Accelerator Type
PublicationGround tire rubber was thermo-mechanically modified with using a co-rotating twin screw extruder. Modification of GTR was conducted in autothermal conditions. Styrene-butadiene rubber and modified ground tire rubber blends were prepared via two-roll milling. Obtained compounds were cured with conventional system (sulfur/vulcanization accelerator ratio was 2:1). During this research three commonly vulcanization accelerators (MBT,...
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The estimation of total volatile organic compounds emissions generated from peroxide cured natural rubber/polycaprolactone blends
PublicationNatural rubber (NR)/polycaprolactone (PCL) blends at the ratio of 90/10% wt. (NR/PCL90/10) and 70/30% wt. (NR/PCL70/30), with a constant amount of dicumyl peroxide, were prepared by compounding in an internal mixer. Obtained NR/PCL bio-based blends were cured at three different temperatures (150 °C, 160 °C and 170 °C). The total content of volatile organic compounds (TVOC) as a function of the NR/PCL blends ratio, and their curing...
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Thermo-mechanical reclaiming of ground tire rubber via extrusion at low temperature: Efficiency and limits
PublicationThermomechanical reclaiming of ground tire rubber (GTR) was performed at different temperatures (60, 120, and 180°C) using a co-rotating twin-screw extruder. Obtained samples were used in styrene-butadiene rubber (SBR) blends. As reference samples, SBR compounds containing untreated GTR were used. Curing characteristics, static and dynamic mechanical properties, and morphology of the obtained blends were determined. The results...
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Weldability of pipe grade polyethylenes as realized from thermal and mechanical properties assessments
PublicationSince polyethylene (PE) has been widely accepted for the production of high-pressure fluid conveying pipelines, studies devoted to weldability of PE connections were always of major importance. In this study, two industrial PE grades designed for pipe production, namely PE80 and PE100, were injection molded, cut, and then welded as PE100-PE100, PE100-PE80, and PE80-PE80. The heat-welded joints were assessed by differential scanning...
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Wpływ temperatury na efektywność termomechanicznej regeneracji odpadów gumowych
PublicationTermo-mechaniczną regenerację miału gumowego w zmiennych warunkach temperaturowych prowadzono przy użyciu współbieżnej wytłaczarki dwuślimakowej. Następnie otrzymane regeneraty gumowe mieszano z zespołem sieciującym i wulkanizowano. Scharakteryzowano właściwości przetwórcze oraz mechaniczne regeneratów gumowych w funkcji temperatury ich wytwarzania.
Year 2015
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Charakterystyka właściwości kompozytów termoplastycznych napełnianych miałem gumowym
PublicationKompozyty termoplastyczne napełniane miałem gumowym otrzymano przy użyciu współbieżnej wytłaczarki dwuślimakowej. Scharakteryzowano właściwości mechaniczne oraz morfologię badanych kompozytów. Uzyskane wyniki wskazują że kompozyty typu termoplast/miał gumowy stanowią proekologiczną formę recyklingu zużytych opon samochodowych stanowiąc tym samym ciekawą alternatywę dla powszechnie stosowanego odzysku energetycznego.
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