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The aim of the study was to design and produce composite packaging using sheep wool fibre. An important aspect was the development of a fully biodegradable and thermally insulated packaging as an ecological alternative to the commonly used packagings for example expanded polystyrene packaging. The samples was produced by injection molding and examined under a digital microscope, goniometer, surface roughness were measured with a Hommel Tester T1000 profile meter using a TH300 sensor and a filter according to ISO 11562; infrared spectroscopy analysis was carried out on a Bruker Tensor 27 spectrometer. To evaluate biodegradability 4 samples (G 2, 3, 4, 5), were put in an aging chamber with two ultraviolet lamps with an intensity of 35 W/cm2 for 48 h. After that time, the samples were taken from the soil and washed with distilled water. One hour in the aging chamber approximates 5645 hours of exposure to natural solar radiation for 30 years. The second type of samples were extruded and then, they were thermoforming (hot pressing). They were examined under a digital microscope, goniometer and were tested for thermal insulation over 20 h. The composite packaging shows similar thermal insulation characteristics to those of the expanded polystyrene packaging. The addition of wool fibre caused the wetting angle value to increase. Surface roughness increased considerably with increasing wool content of the samples. No new chemical bonds are formed in the material. The introduction of wool fibres sped up the biodegradation process.

Composite materials, which can have a wide range of properties, can have an important role in protecting the natural environment. Until now, the most popular fibres used in composites have been those obtained by chemical processes. Natural fibres are much less commonly used, but interest in them is growing due to the principles of eco-development, care for the environment, and their important fact that they are biodegradable. Sheep wool, due to its unique physicochemical properties, such as thermal and sound insulation and the ability to absorb and release moisture, can be used as a fibre in biodegradable composites. Biodegradable polymers are becoming increasingly popular as an alternative to plastics, which have a negative impact on the environment. Although the use of biodegradable polymers is limited by their poor mechanical and thermal properties, a filler in the form of sheep wool fibres increases the mechanical properties of the composite and reduces production costs, while maintaining its biodegradability. Mixed wool is treated as a waste product which is difficult to utilize in the textile industry, but innovative applications in agriculture and medicine provide the opportunity to make use of it. As a fibre with unique physicochemical properties, wool can be used as an element of biocomposites in line with the strategies of bioeconomy and sustainable development.

This study aims to present various forms of cellulose, whose shape depends on the source of origin, and to demonstrate the differences in the influence on the properties of materials produced with its participation. For this purpose, composites with various plant additives have been designed and obtained. Some of them have undergone chemical and pyrolytic modifications. The results of the mechanical, physicochemical and microscopic tests showed differences in cellulose structure, even in the case of very similar sources, and its diversified influence on the characteristics of the obtained materials. The research shows the effect of the use of natural additives and their modified versions on the mechanical properties of the composite based on epoxy resin. It turns out that cellulose modifiers are not only fillers that reduce the price of the final product but can also increase some mechanical properties, e.g., compressive strength, which is an additional advantage and a reason for wider use. The potential of natural resources is not yet fully understood. Relatively recently, people have started to be interested in cellulose on a nanometric scale, as it turns out that it can exist in several different forms with interesting properties.

The present paper analyses the properties of printed polylactic acid (PLA) samples with admixtures of graphene nanopowder (GNP) at wt. 1%, 2% and 4%. The pure polylactide and admixed polylactide printed samples were examined to determine their chemical-physical properties, stiffness, and strength parameters. The tests of tensile, dynamic mechanical analysis (DMA), difference thermogravimetric (TG), and differential scanning calorimetry (DSC) were executed before and after UV (ultraviolet) treatment. The first part of the paper shows the process of manufacturing granulates and filaments mixed with graphene. The second part of the paper concerns the results of the tests made on printed samples. The analysed samples were printed using a Prusa i3 MK3 printer. It transpired that the content of graphene at 1% improved the mechanical parameters of the printed composite by organising its structure. Increasing the amount of graphene caused the values of the measured parameters to drop. This research indicates how important it is to determine the optimal values of nanoadditives in biopolymers.

Monoaldehydes, due to natural origin and therapeutic activity, have attracted great attention for their ability to crosslink chitosan hydrogels for biomedical applications. However, most studies have focused on single-component hydrogels. In this work, chitosan-based hydrogels, crosslinked for the first time with 2,3,4-trihydroxybenzaldehyde (THBA), were modified with pectin (PC), bioactive glass (BG), and rosmarinic acid (RA). All of these were not only involved in the crosslinking, but also modulated properties or imparted completely new ones. THBA functioned as a crosslinker, resulting in improved mechanical properties, high swelling capacity and delayed degradation and also imparted high antioxidant activity and antiproliferative effect on cancer cells without cytotoxicity for normal cells. Hydrogels containing PC showed enhanced mechanical strength, while the combination with BG gave improved stability in PBS. All hydrogels modified with BG exhibited the ability to mineralise in SBF. The addition of RA enhanced antioxidant and anticancer activities and promoting the mineralisation process.

There is currently a growing demand for more effective thermal insulation materials with the best performance properties. This research paper presents the investigation results on the influence of two types of filler on the structure and properties of rigid polyurethane foam composites. Fly ash as a product of coal combustion in power plants and microspheres of 5, 10, 15, and 20 wt.%, were used as rigid polyurethane foams modifiers. The results of thermal analysis, mechanical properties testing, and cellular structure investigation performed for polyurethane composites show that the addition of fly ash, up to 10 wt.%, significantly improved the majority of the tested parameters. The use of up to 20 wt.% of microspheres improves the mechanical and thermal properties and thermal stability of rigid polyurethane foams.

The aim of this work was to verify the material properties of polylactic acid (PLA) with an addition of carbon nanotubes (CNTs) or graphene nanopowder (GNP). The pure polylactide and admixed polylactide samples were subjected to chemical–physical tests to determine their stiffness and strength parameters. The tensile and impact tests were performed on samples without UV (ultraviolet) treatment and after UV treatment, in a physiological saline solution. The investigations were composed of two stages. The first one was related to the examination of the properties of pure polylactide, denoted as the following: 3001D, 4032D, and 4043D. The second stage was based on an analysis of the properties of PLA 4032D with an admixture of GNP or CNTs, at 0.1 wt.% and 0.5 wt.%. By comparing the strength and the stiffness of pure samples with samples with the considered admixtures, an essential increase was not observed. However, it is stated that the presence of GNP and CNTs in the samples positively influenced the resistance of the materials to the ageing process.

Skin regeneration requires a three-dimensional (3D) scaffold for cell adhesion, growth and proliferation. A type of the scaffold offering a 3D structure is a nonwoven material produced via a melt-blown technique. Process parameters of this technique can be adapted to improve the cellular response. Polylactic acid (PLA) was used to produce a nonwoven scaffold by a melt-blown technique. The key process parameters, i.e., the head and air temperature, were changed in the range from 180–270 °C to obtain eight different materials (MB1–MB8). The relationships between the process parameters, morphology, porosity, thermal properties and the cellular response were explored in this study. The mean fiber diameters ranged from 3 to 120 µm. The average material roughness values were between 47 and 160 µm, whereas the pore diameters ranged from 5 to 400 µm. The calorimetry thermograms revealed a correlation between the temperature parameters and crystallization. The response of keratinocytes and macrophages exhibited a higher cell viability on thicker fibers. The cell-scaffold interaction was observed via SEM after 7 days. This result proved that the features of melt-blown nonwoven scaffolds depended on the processing parameters, such as head temperature and air temperature. Thanks to examinations, the most suitable scaffolds for skin tissue regeneration were selected.

The study was conducted to synthesize self-healing polyurethanes (PUs) in the presence of multiwalled carbon nanotubes (CNTs). Measurements of the self-healing ability of PUs synthesized from N3300 isocyanate and polytetrahydrofuran with various contents of CNTs were taken. The mechanical and thermal properties were studied to analyse healing efficiency in experimentally damaged composite samples. The addition of CNTs results in a slight decrease in the self-healing efficiency of nanocomposites as compared to pure PUs. PU samples containing 40% content of soft segments self-healed much better than the samples with 50% content of soft segments. Functionalized carbon nanotubes CNT-OH due to presence of surface functional groups interact with PU chains, which results in an increase in the healing efficiency of mechanical strength and thermal conductivity of nanocomposites.

Structural changes accompanying stabilization and carbonization processes of the two types of polyacrylonitrile (PAN) nanofiber precursors (pure PAN and PAN with carbon nanotubes) were studied using infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The fibrous membranes were preliminary stabilized in air followed by the two-step carbonization process under nitrogen atmosphere. IR absorption spectra showed that the introduction of a small amount of functionalized multiwall carbon nanotubes (MWCNT) into the PAN precursor has a significant impact on its stabilization process. Raman spectroscopy study showed that the structure of carbon nanofibers containing CNT is distinctly more ordered in comparison to pure carbon nanofibers. Based on the XPS analysis the concentration of heteroatoms and the type and amount of functional groups on the surfaces of both types of nanofibers were determined. The results indicate a high potential of functionalized MWCNT as a pyrolysis modifier of polymer precursor leading to the formation of carbon nanofibers with controlled structure and defined chemical state of the surface.

In this work new polyurethane-based phase change materials containing segments of poly(ethylene glycol) with average molar mass of 8000 g/mol with and without chain extender and modified with graphite nano-platelets have been fabricated and characterized. Structure, morphology and phase behaviour of these solid-solid phase change materials were investigated, as well as the thermal stability and conductivity. The heat of phase transition was in the range of 118.0–164.5 J/g for polyurethane without chain extender and 128.0–148.5 J/g for polyurethane with chain extender. The highest heat of phase transition and crystallinity were found for system modified with 0.3% of graphite nano-platelets in polyurethane without chain extender. Modulated differential scanning calorimetry results showed some changes in the phase transition behaviour and the crystallinity of the polyurethane matrix due to graphite nano-platelets confinement effect. Enhancements in the thermal stability in polyurethane modified with graphite nano-platelets, attributed to the barrier effect, were found based on thermogravimetric analysis data. The thermal conductivity increased with an increase of graphite nano-platelets content for both polyurethane systems, with and without chain extender, which is important for modern thermal energy storage applications.

Fly ash (FA) is a waste material having great potential as modifier of mechanical and thermal properties in polyurethane (PUR) technology. There are very few reporting the use of fluidized bed combustion (FBC) FA in the production of PUR foams. In this work, authors have used the as received FBC FA as an additive to PUR rigid foams. The composite materials containing 5, 10, 15, and 20 wt% of FA were obtained by hand mixing and casting method. Microscopic observations of both unmodified and composite foams showed a well formed, cellular structure of the rigid foam. The cell structure was uniform; most of the cells were closed, which was an important parameter influencing thermal insulation properties of PUR materials. FA was uniformly distributed within PUR matrix and placed between cells. When the content of FA in composite foams increased, cells’ dimensions decreased, which suggested that FA particles acted as nucleation sites during the foam formation process. The absorption bands presented in IR spectrum of PUR foam confirmed the presence of urethane bonds in the unmodified foam material. The IR spectrum of as-received FA reconfirmed the crystalline phases recognized by XRD analysis, which were anhydrite, quartz, lime, calcite and aluminosilicate. No additional bands were observed which suggested that no chemical bonding between PUR matrix and FA particles occurred in the composite foam. The incorporation of FA into the PUR matrix, up to 10 wt%, improved the mechanical performance of the composite materials, when compared to unmodified PUR foam. Such a tendency suggested the occurrence of interfacial interactions between polymer matrix and FA particles, as well as the uniform distribution of the filler within PUR material. For all the materials analyzed, the addition of FA to PUR foam reduced both carbon content and the gross calorific value. The addition of FA improved the thermal stability of the PUR foam material (barrier effect of the FA prevented the release of gases from the foam structure).

Transcatheter implantation of balloon expandable valves in high-risk patients with degenerated tricuspid bioprostheses has been reported since 2010 [1, 2]. Although there have been cases where the SAPIEN valve was implanted in the tricuspid position without rapid pacing [3, 4], invasive rapid ventricular pacing is usually applied during valve deployment. We present a case report documenting for the first time the use of noninvasive, external rapid pacing delivered through defibrillation sticker-pads during transfemoral implantation of the Edwards SAPIEN XT valve for tricuspid valve bioprosthesis stenosis.

In this paper polyurethane-based phase change materials (PCMs) modified with graphene for thermal energy storage were obtained in situ using a one-step bulk polymerization method. Polyurethanes (PUs) have been synthesized with 1,4-butanediol as a chain extender or without a chain extender. FTIR-ATR, DSC, TGA, SEM, OM and ultrasonic techniques were used for characterization of the obtained composites containing up to 4 wt.% of graphene. FTIR-ATR analysis confirmed PU structure and proved that there was no chemical reaction between polyurethane and graphene. The highest heat of phase transition and crystallinity were found for PU system synthesized without the chain extender and modified with 1.0 wt.% of graphene. Microscopic observation results indicated spherulite structures typical for poly(ethylene glycol) (PEG) which was used to form soft segments, with regions of lamellar crystal bundles radiating from the center of a spherulite. Thermal cycling tests were done by 50 and 100 heating/cooling cyclings in air and nitrogen atmosphere for verification of the thermal reliability and chemical stability – it has been found the heat of phase transition was generally not diminished. Importantly, the thermal conductivity of the PCMs was improved after modification with graphene. Generally, PUPEG without chain extender exhibited higher heat of phase transition, higher thermal stability and better thermal reliability.

The aim of this work is to develop a composite material containing a regeneration system and to demonstrate its self-healing properties. For this purpose, we will study the self-healing behavior of composites that are fabricated with a regeneration system consisting of two-sized capillaries filled with epoxy resin and hardener. Composites with restorative systems containing identical microtube diameters can be found in the literature, but until now no comparative studies with multiple diameter structures have been published. We will prove that a regeneration system containing two types of capillaries with diameters of 100 and 50 μm is more efficient (68% recovery of bending strength and Young's modulus after third regeneration) than a regeneration system containing capillaries with the same diameter (44% recovery of bending strength and 44% recovery of Young's modulus after third regeneration). POLYM. COMPOS., 2014. © 2014 Society of Plastics Engineers

Antimony species was chemically anchored on graphene oxide using antimony (III) chloride precursor and then converted to the reduced graphene oxide-antimony species composite by a well-established polyol method. The resultant composite was successfully used as supercapacitor electrodes in a two-electrode symmetric system with aqueous electrolyte. The specific capacitance calculated from the galvanostatic charge/discharge curves obtained for this composite was 289 F/g. The enhanced capacitance results were confirmed by the electrochemical impedance spectroscopy and cyclic voltammetry. The high capacitance of the reduced graphene oxide-antimony species composite arises from the combination of double-layer charging and pseudocapacitance caused by the Faradaic reactions of the intercalated antimony species and residual surface-bonded functional groups.

New polyurethane-based materials (PUs) have been fabricated via a two-step bulk polymerization method with starch as a crosslinker, and 1,4-butanediol as a chain extender. Hydroxyapatite (HAp) was used as a bioactive compound. The structure, morphology and thermal properties of the PUs were investigated. The chemical structure of the obtained materials was confirmed by FTIR. The SEM-EDX analysis confirmed the incorporation of starch and HAp into the PU matrix. Thermogravimetric analysis of PUs indicated enhancement of the thermal stability of PU with an increase in the starch and HAp content. Based on DSC, the introduction of starch into the PU matrix, in the amount of 0,5% wt., was found to lead to an increase in the glass transition temperature (Tg) of soft segments and an increase in the value of the specific heat capacity of the soft phase. In addition, it was found that Tg decreases with an increase of the HAp content. In this paper, multi-frequency temperature modulation differential scanning calorimetry was employed to investigate the glass transition region of PU materials. The obtained composite PUs are characterized by promising properties that reveal their potential for future use in surgery as multifunctional bone cement.

The work presents results on the manufacture and comparative assessment of the structure and microstructure parameters of polyacrylonitrile polymer (PAN)-based carbon nano- and micro-fibers. Using the same polymer solution, PAN nano- and microfibers were obtained. The PAN nanofibers were obtained by electrospinning, and microfibers were spun using the conventional solution-spinning method. The PAN-based fiber precursors were annealed to 1000 °C, 2000 °C and to 2800 °C. Using X-ray diffraction and Raman spectroscopy, the structural and microstructural parameters of both types of carbon fibers were examined. The morphology of PAN nanofibers and carbon nanofibers (CNF) were studied by SEM. Both types of ex-PAN carbon fibers (nano and micro) have similar the c -axis spacing ( d 002 ) values and crystallite sizes after heat treatment to 2000 °C presenting turbostratic structure. HR-TEM images of low temperature CNF show uniform microstructure with the misoriented small carbon crystallites along the fiber axis. The ratio of the integrated intensities of the D and G peaks for carbon nanofibers after heat treatment at 2000 °C was distinctly higher in comparison to carbon microfibers (CF). After additional annealing the fibers to 2800 °C a better structural ordering show CNF. The crystallite sizes ( L c , L a ) in CNF were distinctly higher in comparison to the crystallites in CF. CF consist of two carbon components, whereas CNF contain three carbon components varying in structural and microstructural parameters. One of carbon phases in CNF was found to have the interlayer spacing close to graphite, i.e. d 002 =0.335 nm.

In this work polyurethane/graphene nanocomposites containing segments of poly(ethylene glycol) with defined molecular weight were obtained as new phase change materials for thermal energy storage. The prepared materials were investigated by means of DSC, TG, SEM and ultrasonic non-destructive methods. Enhancements in the thermal stability and thermal conductivity in polyurethane systems modified with graphene were found which is important for thermal energy storage applications. Additionally materials modified with graphene showed lower supercooling in comparison to samples without graphene.

Chronic thromboembolic pulmonary hypertension (CTEPH) is an ominous disease leading to progressive right heart failure. Selected patients can be treated by pulmonary endarterectomy (PEA). We assessed long-term clinical outcome of patients with CTEPH who underwent PEA and patients who remained on medical treatment alone. A total of 112 consecutive patients with CTEPH referred between 1998 and 2008 to one center were followed for a mean of 35 (range 0-128) months after diagnosis. All the patients had advanced pulmonary hypertension at baseline. The operated group had higher World Health Organization functional class compared to the nonoperated group. No other differences in hemodynamic, echocardiographic, or biochemical parameters were observed at baseline. Despite the perioperative mortality rate of 9.1%, patients who underwent PEA had significantly lower long-term mortality compared to nonoperated patients (12.7% vs 34.8%; P = .003), and PEA survivors showed sustained clinical improvement. All efforts should be undertaken to perform PEA in all patients with operable CTEPH.

We present a case of 39-year old female with Klippel-Trenaunay syndrome (KTS) complicated by chronic thromboembolic pulmonary hypertension (CTEPH). Our patient was operated in adolescence by vascular surgeons and severe varicosities of her leg were excised. After second pregnancy she manifested pulmonary embolism (PE) and was treated with vitamin K antagonists (VKA) and implantation of vena cava filter. Despite chronic VKA therapy she developed pulmonary embolism again. We present our TTE studies, X-ray and CT scans confirming diagnosis of pulmonary hypertension. Because of worsening of her cardiopulmonary status she was send to Cardiac Surgery Department and underwent pulmonary thromboendarterectomy. Extensive quantities of chronic thromboembolic material were cut out from both pulmonary arteries. At one year follow-up her functional status returned to NYHA class I. Control TTE demonstrated normal diameter and function of her right cardiac chambers. We conclude that vascular anomalies existing in KTS although present locally are responsible for general hypercoagulability. We also wonder what should be proper treatment and which diagnostic tests should be perform to prevent from severe thromboembolic pulmonary hypertension. JRCD 2013 ; 1 (2): 25–32 Key words: Klippel–Trenaunay syndrome, chronic thromboembolic pulmonary hypertension, pulmonary endartherectomy

We present a case of a 35-year old man with a history of an acute pulmonary embolism and ischaemic stroke, who after several weeks of adequate antithrombotic treatment experienced functional deterioration with severe dyspnea and haemoptysis. Detailed evaluation reveled chronic thromboembolic pulmonary hypertension, deep vein thrombosis of his right thigh and patent foramen ovale. No laboratory signs of a hypercoagulable conditions were found. After through assessment the patient was referred for pulmonary endarterectomy and patent foramen ovale closure. Both procedures were performed successfully with the significant improvement in patient’s clinical status. Patient remained clinically stable with no signs of right ventricle dysfunction in the follow-up. This article provides details regarding etiopathogenesis, clinical features and diagnostic evaluation of chronic thromboembolic pulmonary hypertension related to an acute pulmonary embolism. It covers the latest guidelines for screening and therapy as well as information regarding innovations in health care, and social care. JRCD 2012; 1: 24–29 Key words: Pulmonary embolism; Chronic thromboembolic pulmonary hypertension; Pulmonary endarterectomy

We have reported a new reduced graphene oxide–bismuth oxide composite that can be used as a supercapacitor electrode. Bi2O3 was synthesized from bismuth nitrate pentahydrate and oxalic acid as a precipitating agent using a hydrothermal process in an aqueous graphene oxide suspension. Instead of mixing graphene oxide with bismuth oxide, we have developed a bismuth oxalate precipitation between the layers. As prepared, composite of hydrated bismuth oxalate and graphene oxide was converted to bismuth oxide and reduced graphene oxide by thermal decomposition in a muffle stove. The material exhibited the specific capacitance of 94 F/g at current density 0.2 A/g. Using the cyclic voltammetry, the specific capacitance was as high as 55 F/g at scan rate 5 mV/s over the potential range 0–1 V. The material exhibited long-term cycle stability retaining 90 % specific capacitance after 3,000 cycles. Except Bi3+ ions present in Bi2O3, some amount of higher energy Bi5+ was confirmed.

Carbon materials are among the most commonly used components of supercapacitor electrodes. Particularly, active carbons are recognized as cheap, available, and easily tailored materials. However, the carbon family, i.e. carbon products and carbon precursors, consists of many members. In this manuscript some of these materials, including laboratory scale-produced carbon gels, carbon nanotubes and carbonized materials, as well as industrial scale-produced graphites, pitches, coke and coal, were compared. Discussion was preceded by a short history of supercapacitors and review of each type of tested material, from early beginning to state-of-the-art. Morphology and structure of the materials were analyzed (specific surface area, pore volume and interlayer spacing determination), to evaluate their applicability in energy storage. Thermal analysis was used to determine the stability and purity. Finally, electrochemical evaluation using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy was performed. Outcomes of each analytical technique were summarized in different sections.

Problemy związane z przetwarzaniem termoplastycznych tworzyw sztucznych po zakończeniu okresu ich użytkowania lub odpadów poprodukcyjnych są bardzo istotne, głównie ze względu na ochronę środowiska naturalnego. Corocznie na rynek wprowadzane są olbrzymie ilości nowych termoplastów, w tym poliwęglanu (PC). Znaczna część wprowadzanych na rynek polimerów termoplastycznych po okresie użytkowania trafia na wysypiska śmieci. Dzieje się tak, chociaż istnieją możliwości powtórnego przetwarzania i ponownego wykorzystania termoplastów. Zaobserwowano jednak, że recyklaty z poliwęglanu nie są popularne. W opracowaniu przebadano i przedstawiono zależność i zmiany parametrów właściwości mechanicznych w funkcji wielokrotności przetwarzania poprodukcyjnych odpadów płyt poliwęglanowych. Analizie poddano sposób przetwórstwa oraz metodę otrzymywania granulatu z kolejno przetworzonych próbek poliwęglanu. Uwzględniono wpływ możliwych rodzajów degradacji tworzywa sztucznego w trakcie przetwórstwa i jego wpływ na spadek parametrów mechanicznych.