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Anna Pielesz,1 Czesław Ślusarczyk,1 Marta Sieradzka,1 Tomasz Kukulski,1 Dorota Biniaś,1 Ryszard Fryczkowski,1 Rafał Bobiński,2 Wioletta Waksmańska2 1University of Bielsko-Biała, Faculty of Materials, Civil and Environmental Engineering, Bielsko-Biała, 43-300, Poland; 2University of Bielsko-Biała, Faculty of Health Sciences, Bielsko-Biała, 43-300, PolandCorrespondence: Anna PieleszUniversity of Bielsko-Biała, 2 Ulica Willowa, Bielsko-Biała 43-300, Poland, Tel +48 33 827-9114Fax +48 33 8279355Email apielesz@ath.bielsko.plIntroduction: The aim of this interdisciplinary study was to answer the question of whether active antioxidants as graphene oxide (GO), sodium ascorbate, and L-ascorbic acid modify at a molecular and supramolecular level the tissue of pathological amnion and the necrotic eschar degraded in thermal burn. We propose new solutions of modifiers based on GO that will become innovative ingredients to be used in transplants (amnion) and enhance regeneration of epidermis degraded in thermal burn.Methods: A Nicolet 6700 spectrophotometer with Omnic software and the EasiDiff diffusion accessory were used in FTIR spectroscopic analysis. A Nicolet Magna-IR 860 spectrometer with an FT Raman accessory was used to record the Raman spectra of the samples. The surface of the samples was examined using a Phenom ProX scanning electron microscope with an energy-dispersive X-ray spectroscopy detector to diagnose and illustrate morphological effects on skin and amnion samples. SAXS measurements were carried out with a compact Kratky camera equipped with the SWAXS optical system.Results: Characterisation of amide I–III regions, important for molecular structure, on both FTIR and FTR spectra revealed distinct shifts, testifying to organization of protein structure after GO modification. A wide lipid band associated with ester-group vibrations in phospholipids of cell membranes and vibrations of the carbonyl group of GO in the 1,790– 1,720 cm− 1 band were observed in the spectra of thermally degraded and GO-modified epidermis and pathological amnion. SAXS studies revealed that GO caused a significant change in the structure of the burnt skin, but its influence on the structure of the amnion was weak.Conclusion: Modification of burn-damaged epidermis and pathological amnion by means of GO results in stabilization and regeneration of tissue at the level of molecular (FTIR, FTR) and supramolecular (SAXS) interactions.Keywords: amnion, burned skin, graphene oxide, FTIR and FTR, SAXS, SEM

The improvement of poly(ethylene terephthalate) (PET) fibers flame retardancy is usually achieved by using antipyrenes, which may be incorporated into polyester molecules during polycondensation or are physically mixed with polymer in the fiber formation process. In this article we present an alternative method to reduce the flammability of PET fibers and fabrics which is analogous to dyeing them with a dispersed dyes in a high temperature bath. We have tested this method many times using various modifiers so far. This time, we applied a commercial organophilized montmorillonite Cloisite®15A (C15A). In the presented work, using Limited Oxygen Index (LOI) flammability tests and the thermogravimetric analysis (TGA) method, the effectiveness of the modification used was demonstrated and its optimal variant was determined. Based on Fourier Transform-Infrared Spectroscopy (FT-IR) studies, the existence of interactions between PET macromolecules and the C15A modifier in the entire temperature range of the oxidative degradation was confirmed. Using the Wide-Angle X-ray Scattering (WAXS) and Small-Angle X-ray Scattering (SAXS) methods, the basic parameters of the nanostructure of the studied fibers were determined, and their nanocomposite nature was confirmed. The most important goal, which was successfully achieved, was to explain the mechanism of flame inhibition by the applied modifier C15A.

The objective of the work was to investigate the possibility of simultaneous application of different types of nanofillers: graphene oxide with carboxylic groups and modified bentonite nanoparticles to carboxylated acrylonitrile–butadiene rubber (XNBR), and to determine the effect on the structural, mechanical and barrier properties of the composites. The composites were designed for use in protective clothing and gloves. Rubber compounds were crosslinked by a hybrid set with simultaneous use of sulphur (1.5 phr) and magnesium oxide (2.5 phr). Graphene oxide and bentonite particles were characterised by BET test method. The XNBR composites with nanofillers were studied in terms of structure (WAXS) and types of chemical bonds (FTIR), barrier properties against chemical substances (mineral oil) and swelling properties, as well as mechanical properties (puncture resistance, tear resistance, cut resistance, abrasion resistance, tensile strength). Simultaneous incorporation into XNBR of two types of nanofillers, bentonite in the amount of 1.0–4.0 phr and graphene oxide with carboxylic groups in the amount of 1.0–2.0 phr, affected positively the mechanical parameters. The most significant improvement was noted for the parameter specifying the puncture resistance, almost threefold improvement from 34 ± 2 N for unfilled XNBR composite to 91 ± 5 N for XNBR composite filled with 2 phr of bentonite (XNBR Bent. 2), or one and a half to 56 ± 5 N for XNBR composite filled with 2 phr of bentonite and 2 phr of graphene oxide (XNBR Bent 2 GO 2). The composites showed equally high resistance to penetration of the selected test chemical—mineral oil. The breakthrough time for XNBR composites without the nanofiller and containing differential amounts of nanofillers was very long and similar to that obtained for the reference sample (480 min).

Proper functioning of living organisms requires controlling the factors which govern the level of oxidative stress in the system, that is presence of free radicals at a given, rather low, level and preventing their excess. In this work it is shown that SA and AA active antioxidants, governing the oxidative stress in the wound, modify standard serum solution as well as burn affected necrotic eschar at the molecular structure level. In the case of incubation of skin fragments in SA and AA, the following findings were reported: modification of serum, that is appearance of low molecular weight oligomer bands in AA and recreation of native serum bands in SA. In frozen serum solutions modified by AA FTIR 1759 and 1420–1053 cm−1 bands are observed, whereas in SA FTIR 1603, 1411–1054 and 536 cm−1 bands appear. In the case of modification of the burn affected necrotic eschar in SA and AA – frequency shifts in the fingerprint region 1780–1000 cm−1 can be biomarkers indicating tissue regeneration process under the influence of antioxidants. 1780–1580 cm−1 and 1418–1250 cm−1 regions on the Raman spectra are particularly rich in spectral information. Modification of samples of skin burnt with AA activates the regions of the β-sheet aggregates whereas treatment of the samples with SA ascorbate demonstrates changes which testify to reconstruction of α-helix structure (SAXS studies).

One of the methods of obtaining reduced graphene oxide (rGO) involves the oxidation of graphite to graphene oxide, which is then exfoliated and reduced. Each of these stages has a decisive influence on the properties of the produced nanoadditive, which determines its subsequent application. The process conditions which are examined during the oxidation stage are related to: The mixing time of the reactants before oxidation, sonication of the reaction mixture, and its composition. During reduction optimization, in turn, the form of the GO sample and the method of its purification, as well as the temperature at which this process took place, are examined. At each stage, the determined structural parameters of the produced materials (GO and rGO) are related to their morphology (SEM&mdash, scanning electron microscope), oxidation state (FTIR&mdash, Fourier transform infrared spectroscopy, EDS&mdash, energy-dispersive spectrometer), structure defect (Raman spectroscopy), as well as the number of layers and crystalline structure (WAXS&mdash, wide-angle X-ray scattering). The obtained results show that the shorter mixing time of the reactants determines the formation of more oxygen functional groups. On the basis of the obtained results, the process conditions that enable the production of multilayer, well-exfoliated reduced graphene oxide, with only a slightly defected structure, are established.

Nanocomposite fibers based on poly(butylene terephthalate) (PBT) and reduced graphene oxide (rGO) were prepared using a method able to disperse graphene in one step into a polymer matrix. The studies were performed for fibers containing four different concentrations of rGO at different take-up velocities. The supermolecular structures of the fibers at the crystallographic and lamellar levels were examined by means of calorimetric and X-ray scattering methods (DSC, WAXS, and SAXS). It was found that the fiber structure is mainly influenced by the take-up velocity. Fibers spun at low and medium take-up velocities contained a crystalline &alpha, form, whereas the fibers spun at a high take-up velocity contained a smectic mesophase. During annealing, the smectic phase transformed into its &alpha, form. The degree of transformation depended on the rGO content. Reduced graphene mainly hindered the crystallization of PBT by introducing steric obstacles confining the ordering of the macromolecules of PBT.

The alternative method of reducing the flammability of polyethylene terephthalate (PET) fibers, analogous to dyeing of PET fibers with dispersed dyes in a high-temperature bath, was proposed. A commercial organophilic montmorillonite Cloisite&reg, 15A (C15A) was applied as a flame retardant. The aim of the presented work was to evaluate the effectiveness of the introduced modifier and the improvement of the flame-retardant properties of PET fibers by limiting oxygen index (LOI) and thermogravimetric analysis (TGA) measurements. Evolved gas analysis (EGA) by spectrometric method (FTIR) during coupled thermogravimetric analysis (TGA) was applied in order to confirm no increase in the toxicity of volatile degradation products released from burning modified fibers. The nanocomposite nature of modified fibers was confirmed based on the structural parameters of the fibers determined using wide-angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS) X-ray diffraction methods.

An effective &beta, nucleating agent for polypropylene crystallization was obtained by the functionalization of reduced graphene oxide with calcium pimelate. The nucleating ability of the modified reduced graphene oxide (rGO-CP) was confirmed during non-isothermal crystallization. In further examinations, the rGO-CP was used as an additive to modify polypropylene fibers. The fibers were extruded in laboratory conditions. Gravity spun fibers containing three different concentrations of the rGO-CP and fibers taken at three different velocities were obtained. The supramolecular structure of the fibers was examined by means of calorimetric and X-Ray Scattering methods (DSC, WAXS, and SAXS). The considerable amount of -iPP was obtained only in the gravity spun fibers. In the fibers extruded at higher velocities, the diminishing impact of the additive on the fibers structure was revealed. The changes observed in the fiber structure in connection with the impact of the additive on polypropylene crystallization was discussed.

The paper presents the results of a study on the preparation of cellulose-based composite fibres (CEL) with graphene oxide addition (GO). Composite fibres (GO/CEL) were prepared via the wet spinning method from CEL solutions in 1-ethyl-3-methylimidazolium acetate (EMIMAc) that contained a nano-addition of GO dispersion in N,N-dimethylformamide (DMF). The GO contents of the composite fibres were 0, 0.21, 0.50, 0.98, and 1.97 % w w. The fibres were coagulated in two solvents: distilled water and methanol. The results demonstrated that the amount of GO additive and the type of coagulant significantly impact the physicochemical, mechanical and structural properties of the CEL and GO/CEL fibres. The use of distilled water in a coagulation bath causes a degree of crystallinity of 31.0-40.8 % (WAXS) and a shift in the thermal decomposition temperature (by approximately 19 °C) towards higher temperatures (TGA). The results demonstrate improvements in the mechanical properties of the GO/CEL fibres, which were at the level of 9.43-14.18 cN/tex. In addition, the GO/CEL fibres exhibit satisfactory GO dispersion throughout their volume.

To improve the process of ethanol dehydration, asymmetric chitosan membranes were prepared and applied in the pervaporation process. A porous structure was obtained by adding absolute ethanol into chitosan solution. Fabricated membranes were comprehensively characterized by means of contact angle measurements, degree of swelling analysis, scanning electron microscopy, positron annihilation lifetime spectroscopy and wide angle X-rays scattering, to provide an extensive analysis of their physicochemical properties. The results showed a strong correlation between structure, amount and size of pores, and separation effectiveness of investigated membranes. Additionally, an interesting phenomenon of changing in membrane structure during pervaporation process was observed and was found to cause a nonlinear time dependence of transport and separation parameters. Consequently, the best performance of PV separation of 96 vol% ethanol (feed) was obtained for a membrane prepared from casting solution containing 0.1 ml of absolute ethanol, for which the values of separation factor and permeate flux reached 599.7 and 3.534 kg∙m−2∙h−1, respectively.

This paper presents the results of studies on the preparation of cellulosic membranes, from a solution in 1-ethyl-3- methylimidazolium acetate (EMIMAc), using the phase inversion method. Initially, the membranes were obtained by coagulation of the polymer film in water and primary alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol), 1-hexanol, 1-octanol) resulting in membranes with significantly differing morphologies. Subsequently, composite membranes were produced, with the support layer being a membrane with the largest pores, and the skin layer a membrane with smaller pores. The resulting membranes were tested for physicochemical and transport properties. The morphology of the membrane surfaces and their cross-sections were investigated by using a scanning electron microscope (SEM). The structure of the membranes, on the other hand, was investigated by FTIR spectroscopy and WAXS structural analysis.

W artykule przedstawiono role i znaczenie serwisow internetowych dla osob z niepelnosprawnością wzroku oraz zaprezentowano kilka takich serwisow. Na ich przykladzie autor artykulu wyroznil pewne typy serwisow oraz wskazal, ze glownym celem tworzenia spe­cjalnych serwisow internetowych jest wyrownanie szans osob niewidomych i slabowidzących w spoleczenstwie informacyjnym.

Graphene due to its extraordinary properties and a wide range of potential applications, has aroused a great interest. Although there are many ways to obtain graphene, the existing methods still possess certain disadvantages. Numerous attempts are made to scale up a new and efficient production method of this material on an industrial scale. A very popular method to obtain graphene is a two-step process. It is based on the oxidation of graphite and subsequent reduction to graphene. This article presents a new way of low-temperature reduction of graphene oxide (GO) in presence of various solvents. Indeed, using of appropriate organic solvents in a particular stage of graphene preparation affects the reduction process and the exfoliation of graphene oxide. The possibility to reduce GO in the presence of a disperser opens new paths for the preparation of graphene containing composites.

The examinations of the skin flammability, small-angle X-ray scattering (SAXS) and thermogravimetric (TGA) investigations were all carried out in temperature sufficient for simulating a burn incident. Above methods were used to perform assessment of collagen molecular structure changes in conditions of thermal oxidative stress, whereas the scanning electron microscopy analysis (SEM) was used to illustrate skin surface changes. The changes were observed in the presence of active antioxidants such as L-ascorbic acid, sodium ascorbate and hydrogel of orthosilicic acid H4SiO4 • n H2O. Presence of these modifiers of the burn process minimizes external effects of simulated burn incidents for model samples of animal skin and burn wound epidermis extracted from the patients. The examinations of the skin flammability were carried out with the limited oxygen index (LOI) method. In this study, synergy between orthosilicic acid and L-ascorbic acid and sodium ascorbate into animal and human skin has been shown through an increase in LOI values. The treatment by means of L-ascorbic acid affects particular morphological changes in the skin which is visible in SEM method. Skin samples incubated in the solution of the 3.5 %, 5 % L-ascorbic acid, 7 % sodium ascorbate solutions and 7 % orthosilicic acid demonstrate the development of a structure resembling a coherent solid composite. SAXS gives structural information on the assembly of dermal collagen as well as the lamellar organization of stratum corneum (SC) lipids located in the outermost part of the epidermis. Using this technique, two lamellar phases with repeat distance of approximately 4.3 and 6 nm in the SC lipids domains were observed. Moreover, the diameter of the collagen fibrils were extracted. The observed differences in the values of these parameters allowed us to better understand the mechanism of modification of the surface of the burn affected skin and the influence of the modification on the process of skin regeneration.

Two types of cellulose membranes were produced by a classical wet phase inversion method from a solution of the polymer in 1-ethyl-3-methylimidazolium acetate (EMIMAc) by coagulation in water and selected primary alcohols. The first type were membranes made from pure cellulose (CEL). The second type were membranes obtained by adding nanosized graphene oxide (GO) to the cellulose solution. The process of precipitation and selection of the coagulant affected the structure of the membranes, which in turn affected their usability and applicability. The results of the presented studies show that the physicochemical properties of the coagulant used (e.g., molecular mass and dipole moment) play important roles in this process. It was found that both the content and dimensions of the pores depended on the molecular mass of the coagulant used. It was also found that the dipole moment of coagulant molecules had a large influence on the volume content of the pores (e.g., the 1-octanol (Oc) membrane had a dipole moment of 1.71 D, &Phi, = 1.82%). We investigated the effect of the type of coagulant on the porous structure of CEL membranes and how this affected the transport properties of the membranes (e.g., for the distilled water (W) membrane, Jv = 5.24 &plusmn, 0.39 L/m2 h, for the Oc membrane, Jv = 92.19 &plusmn, 1.51 L/m2 h). The paper presents the results of adding GO nanoparticles in terms of the structure, morphology, and transport properties of GO/CEL membranes (e.g., for composite membrane F (containing 20% GO), Jv = 40.20 &plusmn, 2.33 L/m2 h). In particular, it describes their extremely high ability to remove heavy metal ions.

Isothermal melt crystallization in the 15/85 (m/m) blend of a high density polyethylene (HDPE) and a homogeneous ethylene copolymer with 5.5 mol% 1-octene was studied by time-resolved SAXS method with synchrotron radiation over a wide-range of crystallization temperatures. The SAXS profile was analyzed by means of the correlation function which allows to elucidate the evolution of the morphological parameters of polyethylene lamellar structure (long period (LP), thicknesses of crystalline ( L C ) and amorphous ( L A ) layers) during a crystallization process. It was found that for the samples crystallized at 100 °C, 120 °C and 122 °C L C increases with time. The lamellar thickening rate strongly depends on crystallization temperature. At 40 °C thickening of the crystalline layers does not occur. The time evolution of the lamellar structure in the blend studied confirms the role of hexyl branches of homogeneous copolymer in the crystallization process of polyethylene. The branches introduce steric constraints which hinder the crystallization of HDPE, thus decreasing the size of the HDPE lamellar crystals.

The purpose of this study was to analyze the changes of the structure of shape memory polymer (SMP) surgical staple made from poly(L-lactide-glycolide-trimethylene carbonate) during in vitro degra- dation. It is crucial to understand the structure and properties of SMP biomedical polymers during the degradation process as their biodegradation rate should match the therapeutic period. It was confirmed that degradation results in a decrease of T g and that degradation at a temperature above T g involves faster dynamics. The hydrolysis of amorphous regions lead to increased crystallinity and erosion of the poly

Isothermal melt crystallisation in high-density polyethylene (HDPE) was studied using the time-resolved SAXS method with synchrotron radiation over a wide range of crystallisation temperatures. The SAXS profile was analysed by an interface distribution function, g 1 ( r ), which is a superposition of three contributions associated with the size distributions of crystalline ( L C ) and amorphous ( L A ) layers and a distribution of long period (LP). The morphological parameters extracted from the g 1 ( r ) functions show that the lamellar thickness increases with time, obeying a logarithmic time dependence. The time evolution of L C observed for the sample crystallised at 122 °C leads to the conclusion that crystallisation proceeds according to the mechanism of thickening growth. For samples crystallised at lower temperatures (116 °C and 118 °C), the lamellar thickening mechanism has been observed. The rate of lamellar thickening in these cases is much lower than that at 122 °C. At 40 °C, thickening of the crystalline layer does not occur. The interface distribution functions were deconvoluted, and the relative standard deviation σ C / L C obtained in this way is an additional parameter that is varied during crystallisation and can be used for analysis of this process. Time-dependent changes in the σ C / L C at large supercooling ( T C =40 °C) indicates that L C presents a broad distribution in which the relative standard deviation increases with time. At lower supercooling ( T C =122 °C), L C shows a much sharper distribution. In this case, the relative standard deviation decreases with time.

The effects of processing conditions on the structure of polypropylene fibrillated fibres were studied using a combination of wide- and small-angle X-ray scattering methods. In particular the impact of selected stages of processing on the crystalline and lamellar structure of PP were analyzed. It was stated that crystalline phase is built from α crystals. The crystallinity index as well as the Herman orientation factor of the crystalline phase is found to have a correlation only with the draw ratio of the PP film. The lamellar structure also changes with the draw ratio.

A method is described for the dispersion of graphene oxide (GO) in dimethyl phthalate that may be used in the production of graphene/polymer composites. Heating the dispersion to 250 °C results in an almost complete reduction of the GO to graphene. The obtained dispersion may be used in further processing of any thermoplastic polymer through melt compounding. Scanning electron microscopy, spectroscopic techniques, thermal analysis and X-ray diffraction confirmed the formation of graphene under low temperature reduction with dimethyl phthalate.

Time-resolved synchrotron wide- and small-angle X-ray scattering experiments were used to investigate the crystallization behavior and microstructure development of neat poly(ethylene oxide) (PEO) and its 50/50 blend with ionomer containing 6.4 mol% of sodium acrylate. The apparent lateral crystal sizes D (1 2 0) and D (1 1 2)/(0 0 4) were derived from the WAXS profiles. It was found that D (1 2 0) and D (1 1 2)/(0 0 4) of PEO in the blend are almost independent of temperature and are smaller when compared to those of neat PEO sample. The evolution of morphological parameters extracted from time-resolved SAXS profiles such as the long period L , the lamellar crystal thickness l C and the amorphous layer thickness l A , shows that the crystallization process of neat PEO follows the nucleation theory. The lamellar crystal thickness l C shows a single linear dependence on inverse supercooling, over the whole temperature range investigated. In contrast, the crystallization process of PEO in the blend (i.e. in the presence of interactions with the ionomer) follows the nucleation theory only in the narrow supercooling range. It was found also that the morphology of the blend consists of a broad population of lamellar crystal thicknesses. During heating lamellae melt in the reversed sequence of their formation.

Wide-angle X-ray diffraction (WAXD) and the scanning electron microscopy (SEM) were used to determine the morphology of crystalline phase of blends of poly(ethylene-oxide) (PEO) and styrene-acrylic acid (S-AA) copolymers neutralized with sodium ions (Na+). In this study, we investigated the effects of blend composition and the content of ionic groups in amorphous ionomers on the degree of crystallinity and the crystallite sizes. It was found that the degree of crystallinity of PEO in the blends decreases both with increasing S-ANa(6.4) content and with increasing ANa content. The sizes of PEO crystallites, measured both in the direction perpendicular and parallel to the polymer axis, are almost independent of ionic groups content in the amorphous component of the blends but they decrease with increasing S-ANa(6.4) content. For the blends containing small amounts of PEO the confined crystallization of this polymer were observed. The final crystalline morphology of these blends, observed by SEM method, is different in comparison to that formed without spatial confinement.

Samples of polyamide 6 (PA6) of different morphology were studied with use of WAXS, SAXS and PALS technique. The determined ortho-positronium characteristics reflect variations in morphology and particularly the presence of defects at the interface between the crystalline and amorphous region as well as the interaction between the crystalline and the amorphous phases existing in the polyamide samples.

The paper presents results of studies on composites made from polypropylene (PP) modified with polyaniline (PANI) doped with phenylophosphonic acid (PPA). For better miscibility of the components, lauryl gallate (LG) was added. Obtained results show that the amount of PPA and LG affect the thermal and structural properties of the composites. Changes of thermal properties, and particularly of structure, caused by addition of PPA and LG, affect the conductivity of the composites. The results discussed in the paper were obtained using differential scanning calorimetry (DSC) and optical microscopy as well as wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS).

In this paper, results of morphological studies on the 15/85 (m/m) blend of a high-density polyethylene (HDPE) and a homogeneous ethylene copolymer with 5.2 mol% 1-octene are presented. Morphological changes in the blend during cooling and subsequent heating at 10 °C/min were monitored via synchrotron small-angle X-ray scattering (SAXS). SAXS data were analyzed by means of the correlation function. An appropriate procedure of the correlation function treatment was described to obtain a local volume fraction crystallinity (ΦL) of the sample. Owing to this a real progress of morphological parameters was obtained. It was found that crystallization by slow cooling of the investigated blend leads to an extensive separation of its components according to their ethylene sequence length. The semicrystalline morphology of the blend is best described by the lamellar insertion model. The thin lamellae of crystallizing copolymer are formed between the thicker primary lamellae of HDPE yielding a drastic decrease of the long period. During subsequent heating lamellae melt in the reversed sequence of their formation.

Changes in the supermolecular structure of wool fibers, particularly those on the level of the microfibril-matrix complex, are analyzed using the small-angle x-ray scattering method (SAXS). The interfibrillar distances increase after dyeing; conformation changes within disulfide bonds are also suggested, caused by a chemical reduction of the fiber. Internbrillar distances decrease in dyed fibers treated with a solution of natural sweat.

Small-angle X-ray scattering results for ionomers containing alkali metals based on copolymers of styrene–acrylic acid and styrene–methacrylic acid obtained in emulsion are presented. A study has been conducted on the influence of content, the type of salt and the type of alkali metal in styrene-based ionomers on the state of ion aggregation. In all the cases, the state of ion aggregation is dependent on the content of an introduced acrylate or methacrylate and the type of the introduced alkali metal. The obtained results indicated that, in the case of ionomers containing cesium acrylate, aggregates of larger sizes are formed than when containing cesium methacrylate. For all the investigated ionomers, the increase of temperature causes the increase of sizes and number of clusters.These results also indicate that, in the case of ionomers containing lithium and sodium ions at this content of acrylate at room temperature, the scattering maximum is absent. In the case of potassium and cesium ionomers, the scattering maximum appears, which may be attributed to the larger ionic aggregate clusters. For all the investigated ionomers, the increase of temperature causes the increase in sizes and number of ionic aggregates.

Investigations of supermolecular structure and tensile properties of colored heat-stabilized fibers were carried out. For fiber coloring, chosen organic pigments with differentiated nucleating properties were used. It was stated that during the fiber formation, a fibrillar–lamellar structure with α-crystals is formed. In fibers colored with a quinacridone pigment, the minimal number of β-crystals was observed. During heat-stabilization, perfecting of the supermolecular structure of the fiber occurs. Because of pigments, the process of rebuilding occurs more intensively and leads to formation of a more stable structure with higher crystallinity. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 477–488, 1999

Blends of ethylene-propylene-diene rubber (EPDM) and low density polyethylene (PE ld ) or isotactic polypropylene (iPP) crosslinked by dicumyl peroxide (DCP) have been prepared. Their morphology, reactivity of the components and crystallinity have been studied. The blends are microheterogeneous. Both plastomers, but particularly iPP, decrease the crosslinking efficiency of EPDM by DCP. It was found that they also influence the mechanical properties of the blends. The effect of iPP is far more pronounced than that of PE ld , because of an increase in crystalline phase content. iPP particles play a role as nuclei for propylene monomer units in EPDM, whereas PE ld a particles are solvated by the elastomer matrix

The effect of organic pigments on the supermolecular structure of mass coloured PA fibres has been investigated by means of small-angle and wide-angle X-ray scattering methods. It has been found that the dye molecules introduced in polymer melt before the fibre is formed take part in the formation of the supermolecular structure of the fibres. The presence of these molecules causes changes of the weight fractions of the polymorphic forms of the polyamide, the increase of the crystallinity index of the fibres and the increase of the thickness of the transition layers between crystalline and amorphous regions. Changes which have been observed are dependent both on the content of pigments and on their chemical nature. Der Einflus organischer Pigmente auf die Uberstruktur von massegefarbten PA-Fasern wurde mittels Rontgenstreuung (Kleinwinkel- und Weitwinkelstreuung) untersucht. Es wurde festgestellt, das die vor der Faserbildung in die Schmelze eingefuhrten Farbstoffmolekule an der Bildung der Uberstruktur der Faser beteiligt sind. Die Anwesenheit dieser Molekule verursacht Veranderungen der polymorphen Formen des Polyamids, einen Anstieg des Kristallinitats-Index der Fasern und eine Zunahme der Ubergangsschichten zwischen kristallinen und amorphen Bereichen. Diese Veranderungen hangen sowohl vom Farbstoffgehalt als auch vom chemischen Aufbau der Pigmente ab.

In this study, flame-retardant poly(ethylene terephthalate) (PET) fibres were produced using a high-temperature bath method similar to dyeing fibres with disperse dyes. A mixture of aqueous solutions of silicon and phosphorus compounds was used as the flame retardant. Samples of the modified fibres were examined by thermogravimetric analysis. The residue left after limited oxygen index test was analysed by scanning electron microscopy. Effect of the flame retardant on changing the supermolecular structure of PET fibres was evaluated using wide-angle X-ray diffraction. Mechanical properties of the modified PET fibres as compared with standard fibres were also examined.

Crystallization of isotactic polypropylene (iPP) in an ethylenepropylene diene rubber matrix (EPDM), crosslinked with dicumyl peroxide (DCP), has been studied. A discrepancy concerning the degree of crystallinity of the blends determined using different experimental techniques, has been discovered and an effort to explain it is made. iPP was found to recrystallize in EPDM in a manner, depending on the amount of plastomer added. Nucleation, being predominantly homogeneous for 'pure'iPP, becomes predominantly heterogeneous for its blends with EPDM. The smaller the polypropylene content the more a defect crystalline phase is formed. The defects, as well as an orientation were shown to be responsible for the higher, in comparison with other methods, degree of crystallinity determined by wide-angle X-ray scattering.