The effectiveness of an oxidative biomimetic copper-pyridine system (Cu-py-H2O2) was successfully demonstrated on model textile samples of unaged and artificially aged desized cotton inoculated with pure cultures of selected fungi, isolated from historical textile objects (Bjerkandera adusta (Basidiomycota), Cladosporium sp., Chaetomium cochlioides, Aspergillus conicus, and A. montevidensis (Ascomycota)). Colour, structure and mechanical properties of test cotton samples were evaluated. Investigation into bleaching effect against intra- and extracellular fungal pigments, and the influence on textile substrate revealed the 3-day treatment as the most appropriate length of bleaching procedure (bleaching achieved L*>90, a*<1, b*<10). The treatment had some undesirable effects on the structure and properties of the textile fabrics (cuticle flaking, longitudinal cracks, etc.), with mechanical (tensile) properties loss of maximum 60% (specific stress). The undesirable effects differed between test samples, with the least observed in control, uninoculated samples, moderate in samples, inoculated with the strains belonging to the selected ascomycetes, and the highest in the samples inoculated by selected basidiomycete (known to degrade cellulose). This is promising, as the Ascomycota are the fungi that usually cause the most intensive colouration of the textiles. Further optimization of the process may therefore lead to discolouration of the fungal stains with tolerable damage to underlaying textile.

This work presents a unique approach for the preparation of a flame retardant (FR) polyamide 6 (PA6) polymer with chemically bonded 9,10-dihydro-9,10-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as a pendant group bridged to the polymer via an -NH- group. A novel phosphonamidate co-monomer (DOPO-A-CLM) was synthesized from DOPO and alpha-amino-epsilon-caprolactam (A-CLM). This co-monomer was subsequently used in the hydrolytic polymerization with epsilon-caprolactam (CLM) in different weight ratios to prepare DOPO-NH-functionalized PA6 (PA6-xDC, x = 7, 10, and 15 wt% DOPO-A-CLM). Chemical incorporation of DOPO-A-CLM into the PA6 backbone decreased the molecular weight of the polymer from 15387 for neat PA6 to 12375, 10516 and 9316 for PA6-7DC, PA6-10DC and PA6-15DC, respectively. The DOPO-NH- pendant group accelerated start of the PA6 thermal decomposition and increased the char residues at 500 degrees C from 1% for PA6 to 4.6, 4.9, and 5.0% for the PA6-7DC, PA6-10DC, and PA6-15DC samples, respectively, indicating crosslinking reactions in the condensed phase. The evolved phosphorus-active species in the gas phase inhibited the PA6 depolymerization, resulting in increased thermo-oxidative stability and about a fourfold higher residue at 500 degrees C in the case of PA6-15DC compared to PA6. The intrinsically flame retardant PA6 filament yarns with chemically bound FR pendant group were successfully melt spun from PA6-10DC, drawn and wound on bobbin. The DOPO-NH- pendant group decreased filament flammability and inhibited flame propagation, resulting in immediate self-extinguishment after flame removal. Incorporation of DOPO-A-CLM decreased the filament tensile properties compared to the neat PA6, which correlates with the decreased polymer molecular weight.

In this study, the effect of curing applied to jute woven fabric (four-layers) reinforced composite materials in which different proportions of acrylated epoxidized soybean oil (AESO) and epoxy resin are used as matrix material, on the thermal, thermo-mechanical and morphological properties of the composite materials are investigated. Composite material production is carried out by vacuum infusion method, whereas curing at 90 °C is done during production and post-curing at 120 °C is performed using a conditioning oven after production. Dynamic mechanical analysis (DMA) results show that the storage and loss modulus values of composite materials increase with increasing AESO ratio, while tan delta curves display that the bonds between the fiber and matrix of hybrid samples are stronger than composite materials using a single type of resin. This result is also supported by scanning electron microscope (SEM) images. The effect of curing (90 °C) and post-curing (120 °C) temperatures on the thermo-mechanical properties of the composite material is more clearly seen in epoxy composite samples whose glass transition temperature is higher than the room temperature. Besides, the decrease in glass transition temperature of the material with the increase in AESO content is obtained from both DMA and differential scanning calorimetry (DSC) plots.

Elasticity and recovery are important for clothing comfort, especially in the manufacture of apparel and sportswear. Recently, yarns containing PBT (polybutylene terephthalate), which are able to develop good elastic properties with high recovery after a finishing process (e.g., thermal treatment), have been used for this purpose. The aim of this work is to give a comprehensive overview of the use of PBT yarns in woven structure, with the aim of improving the elastic properties of cotton-like fabrics. The experimental part was divided into three main sequences to investigate the fabric properties (physical, elastic, UPF, comfort) influenced by (1) PBT-containing yarn structure, (2) weave and fabric structure (basic weaves and complex weaves) with PBT in weft direction, and (3) processing sequence-thermal treatment of PBT yarns or fabrics after weaving. According to the results, PBT-containing yarns have great potential for the production of lightweight elastic fabrics. The advantages of improving the elastic properties of fabrics by incorporating a relatively small amount of PBT yarns into the fabric only in certain areas, thereby minimally affecting the production costs, are demonstrated by a product with partially elastic areas obtained after thermal treatment.

The aim of this study was to evaluate the antibacterial and antifungal activity, cytotoxicity, leaching, and ecotoxicity of novel flame retardant polyamide 6 (PA6) textile fibers developed by our research group. The textile fibers were produced by the incorporation of flame-retardant bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative (PHED) in the PA6 matrix during the in situ polymerization process at concentrations equal to 10 and 15 wt% (PA6/10PHED and PA6/15PHED, respectively). Whilst the nanodispersed PHED provided highly efficient flame retardancy, its biological activity led to excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, as well as excellent antifungal activity against Aspergillus niger and Candida albicans. The results confirmed leaching of the PHED, but the tested leachates did not cause any measurable toxic effect to the duckweed Lemna minor. The in vitro cytotoxicity of the leached PHED from the PA6/15PHED sample was confirmed for human cells from adipose tissue in direct and prolonged contact. The targeted biological activity of the organophosphinate flame retardant could be beneficial for the development of PA6 textile materials with multifunctional properties and the low ecotoxicity profile, while the PHED's leaching and cytotoxicity limit their application involving the washing processes and direct contact with the skin.

Studies of the production of fiber-forming polyamide 6 (PA6)/graphene composite material and melt-spun textile fibers are scarce, but research to date reveals that achieving the high dispersion state of graphene is the main challenge to nanocomposite production. Considering the significant progress made in the industrial mass production of graphene nanoplatelets (GnPs), this study explored the feasibility of production of PA6/GnPs composite fibers using the commercially available few-layer GnPs. To this aim, the GnPs were pre-dispersed in molten ε-caprolactam at concentrations equal to 1 and 2 wt %, and incorporated into the PA6 matrix by the in situ water-catalyzed ring-opening polymerization of ε-caprolactam, which was followed by melt spinning. The results showed that the incorporated GnPs did not markedly influence the melting temperature of PA6 but affected the crystallization temperature, fiber bulk structure, crystallinity, and mechanical properties. Furthermore, GnPs increased the PA6 complex viscosity, which resulted in the need to adjust the parameters of melt spinning to enable continuous filament production. Although the incorporation of GnPs did not provide a reinforcing effect of PA6 fibers and reduced fiber tensile properties, the thermal stability of the PA6 fiber increased. The increased melt viscosity and graphene anti-dripping properties postponed melt dripping in the vertical flame spread test, which consequently prolonged burning within the samples.

Polyamide 6 (PA6) composite filament yarns were produced by the simultaneous incorporation of melamine cyanurate (MeCy) with multiwalled carbon nanotubes (CNTs) and carbon black (CB) into a composite matrix in a melt-spinning process. The results show that the simultaneous incorporation of MeCy with CNTs or CB additives provided filaments with a uniform black color. Tensile analysis confirmed that a reinforcing effect was achieved when CB was used, whereas the CNTs induced a reducing effect on the filament tenacity. With regard to the burning behavior, the flame-retardant action of MeCy was preserved in the presence of CB but was significantly hindered when used in combination with CNTs. These results indicate that the mixture of MeCy and CB was much more compatible for the production of reinforced PA6 composite filaments with increased thermal stability and improved flame retardancy over those of the MeCy and CNTs. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47007.

A novel flame retardant polyamide 6 (PA6)/bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-derivative (PHED) nanocomposite textile filament yarns were developed. The scalable production approach includes in situ water-catalyzed ring-opening polymerization of e-caprolactam in the presence of the flame retardant PHED followed by melt-spinning of nanocomposite filament yarns and production of knitted fabrics: The specific chemical structure of the PHED additive enabled its excellent miscibility with molten e-caprolactam and the uninterrupted polymerization of e-caprolactam. The produced PA6/PHED nanocomposite was characterized by the preserved molecular structure of the polyamide 6 and uniformly distributed nano-dispersed FR at concentrations of 10 and 15 wt %. The PA6/PHED nanocomposite structure was successfully preserved after the melt-spinning processing. The PA6 nanocomposite filament yarns at the applied 15 wt %. loading of PHED showed (a) increased thermooxidative stability compared to neat PA6 up to 500 degrees C, with a 43% higher residue at 500 degrees C and (b) self-extinguishment of fiber strand and knitted samples within 1 s in standard vertical flame spread tests (ASTM D6413), followed by the significant reduction of the melt-dripping and the melt-drop flammability. Additionally, 1.2 mm-tick PA6/PHED bar samples achieved a V0 rating in UL94 vertical burning test at the applied 10 wt % concentration of PHED. This innovative and scalable approach could pave the way for the production of new-generation nanocomposite PA6 filament yarns with self-extinguishing properties at the macro-scale, which would be highly beneficial for increasing fire safety, whilst maintaining the use of a DOPO derivative at the minimum level. (C) 2019 Elsevier Ltd. All rights reserved.

It is well-known fact that the supermolecular structure of museum textiles changes during aging and biodeterioration.These structural changes can be observed by diff erent spectroscopic methods such as FT-IR, FT-Raman, and dispersive Raman spectroscopy.The purpose of the presented research is to present the usability of FT-Raman spectroscopy method for the analysis of the cellulose structure of the biodeteriorated historical textile fi bers.Although historical textiles have already been analyzed using FT-Raman spectroscopy the method has been rarely used to analyze the changes of supermolecular structure of the biodeteriorated historical textiles attacked by microorganisms.In the research, cellulose textile samples from diff erent museums and religious institutions were analyzed.Contemporary and historical cellulose textiles were scanned by FT-Raman spectra of reference and compared to determine the supermolecular cellulose fi ber structure of each material.It has been shown that structural changes such as depolymerization and crystallinity changes can be detected using FT-Raman spectroscopy.The supermolecular changes of the cellulose fi ber structure have been detected in biodeteriorated as well as in historical objects not infected by microorganisms.In the spectra of biodeteriorated objects, more intensive changes of spectral features were observed compared to spectra of non-infected samples.The changes were more pronounced at the museum objects made of fl ax.It can be concluded that biodeterioration causes more intensive structural changes than aging.On the basis of the research work, it has been shown that FT-Raman spectroscopy method can be used for the analysis of supermolecular structure changes of cellulose textiles.

The finding of heavily damaged historic silks prompted this study to answer the title question on possible unwanted effects of fungal decontamination by gamma-irradiation. Although silk fiber constitutes of relatively stable protein fibroin heritage silk textiles need protection from biodegradation. Low-dose (0.5 - 2 kGy) gamma irradiation is already recognized as a fast, temperature independent method of insect eradication. For fungal decontamination, somewhat higher absorbed doses are needed. Since possible unwanted side effects to already damaged material must be excluded, model samples were prepared by aging contemporary silk. Some of the imaged and aged samples were irradiated to 6 kGy and other to a much higher dose of 120 kGy to identify radiation-specific damage, if any. In order to achieve detectable damage selected irradiated and non-irradiated model samples were subjected to further artificial aging. None of the assessment methods used (ATR-FTIR, SEM thermal analysis) revealed any radiation-specific change. Provided that the fibroin conformations are identified and analyzed separately, FTIR is the method of choice for monitoring the effects caused by any treatment of silk. An increase in the amide I/II absorption intensity ratio is a sensitive though ambiguous indicator of silk degradation. Transformation of more stable beta-sheet to alpha/random coil fibroin conformation is a definite proof of degradation. It occurred exclusively on artificial aging of model silks and was accompanied by pronounced morphology changes confirming the role of conformation on silk stability. In non-treated historic silks the fraction of more stable beta-sheet conformation was unexpectedly high as was the iron content that likely protected silk structure. Since irradiation produced insignificant and likely partially reversible effects radiation treatment of silk textile is deemed safe beyond the absorbed dose proposed as an upper limit for fungal decontamination, 8 +/- 2 kGy.

This research investigated the influence of two flame retardant (FR) mixtures consisting melamine cyanurate (MeCy) and aluminum diethylphosphinate (AlPi), and MeCy and sodium aluminosilicate (SASi) at different weight ratios, on the flammability, thermal behavior and mechanical properties of polyamide 6 (PA6) composite yarns produced by meltspinning. The morphological and chemical properties of PA6/FR filaments were investigated by scanning electron microscopy and Fourier-transform infrared spectroscopy, flame retardancy by vertical burning test UL-94, thermal behavior by thermogravimetric and differential scanning calorimetric analyses, and mechanical properties by tensile tests. The results indicate that within the UL 94 V2 rating, the composite yarns differed significantly from each other in their burning and dripping behavior. The incorporation of both mixtures, MeCy+AlPi and MeCy+SASi, into the PA6/FR yarns significantly decreased the afterflame time relative to pristine PA6, confirming a lower production of flammable volatiles. This phenomenon was attributed mainly to MeCy, which caused an immediate extinguishment of the flame after the withdrawal of the igniting flame. Compared to one component MeCy, the incorporation of the MeCy+SASi mixture enhanced the thermooxidative stability of the PA6/FR yarns because of their additive effect at higher concentrations. In contrast, an antagonistic effect was obtained for the MeCy+AlPi mixture, irrespective of the concentration. Since the incorporation of MeCy+SASi did not drastically reduce the tensile properties of filaments, this mixture enables the production of the PA6/MeCy+SASi composite yarns with the enhanced flame retardancy and thermo-oxidative stability.

Owing to growing demand for comfortable clothes, elastane filament yarns are being used in fabrics for several garments. In this study, core spun yarns were produced with cotton fibres and PBT/elastane filament yarns (cotton as sheath material, PBT yarn and elastane as core yarns). Twill woven (1/3 Z) fabrics were produced by using core spun yarns (30 tex) and cotton yarns (30 tex) as weft, and 100% cotton yarn (59 tex) as warp yarns. The fabrics consisting of PBT were washed at 100°C for 30 minutes to gain the elasticity. The woven fabrics’ weight, thickness, elongation, permanent elongation, dimensional stability, air permeability, thermal conductivity, thermal absorptivity characteristics were tested and statistically evaluated. According to the results, the fabrics containing PBT and elastane filaments had similar elongation and shrinkage values. PBT filament yarns have a great potential to produce lightweight elastic fabrics.

The article focuses on the novelties that were presented at the trade fair ITMA 2015, more specifically in the field of hardware used in the production of chemical fibres. According to the number of visitors, ITMA 2015 superseded ITMA 2011, however, the number of exhibitors offering complete solutions in the production of synthetic fibres decreased due to recent company acquisitions and mergers. The main theme of the fair and consequently of manufacturers of hardware used in the production of chemical fibres was "focus on sustainability" that should also be the main objective (vision) of the technological development. The article shows the development of hardware used in the production of synthetic fibres, which is still evolutionary, with no revolutionary changes. The novelties can be found in compactness, modularity, use of sustainable materials, reduction of consumption, in increased utilisation of hardware and space, as well as in the use of internet/intranet hardware and software to connect devices, their management, control and data acquisition. Companies are introducing an intelligent network of the production process and management "Industry 4.0". They have been establishing technological centres where they in cooperation with their customers develop new systems, implementing their ideas and concepts.

This paper refers to the formation and properties of polypropylene/stearic acid (PP/SA) composite fibers. For the investigation, commercial metallocene-catalyzed PP polymer and SA were used. The fibers were produced in laboratory conditions using the single screw spin draw device. The textile-mechanical properties, surface composition, morphology and supermolecular structure of as-spun fibers were studied. Moreover, the nonisothermal crystallization of the PP/SA blend and melting behavior of fibers were analyzed. In the investigation Fourier transform infrared–attenuated total reflectance, scanning electron microscopy, differential scanning calorimetry and wide-angle X-ray analytical methods were used. The research showed that the PP/SA blend has lower viscosity compared to the pure polymer and that during the PP crystallization phase, separation is induced. SA delays crystallization of PP, and interaction between SA and PP is observed. The as-spun PP/SA fibers have higher linear density, higher elongation at break and slightly lower tenacity compared to fibers produced from pure PP. The fibers contain a structure with high content of mesophase. During fiber formation, SA migrates towards the fiber surface and forms droplets located beneath the surface of the fiber or crystallizes outside in the form of flake-like crystals.

This work presents a study of the influence of diethyl aluminum phosphinate (EOP) and sodium alumino silicate (ZP) as the novel green flame retardant spinning additives on the thermal properties of polyamide 6 (PA6) fibres. The PA6/additive composite filaments were prepared at 4 wt% concentration of additives and their mixture by melt spinning. The results show that the additives were physically incorporated into the PA6 filament, resulting in an insignificant change of the melting temperature. The presence of EOP decreased T-onset and increased T-max2 compared to pure PA6, which indicates that the degradation process started at lower temperature, whereas the thermo-oxidative stability in the second decomposition step increased. Contrary to EOP, ZP did not cause any noticeable changes in the decomposition temperatures comparing to pure PA6, but significantly increased the final char amount. Both phenomena were also observed when the additives were used in combination. Whereas EOP did not significantly affect the mechanical filament properties, the incorporation of ZP resulted in the reinforcement of fibres.

This investigation into fungal growth on historical textiles, including the canvases of easel paintings stored in museums and religious institutions (churches and cloisters) in Slovenia, initially indicated relatively widespread fungal contamination. Closer investigation revealed that only 21 objects out of 38 were positive for fungal contamination, with the other objects being discoloured or stained due to other factors. On the objects that were stored at low humidity and temperature, fungal growth remained restricted for several years, even if the objects were contaminated before storage. Although most of the textile specimens contaminated by fungi were from those institutions without any control of internal environmental conditions, the rate of textile degradation due to fungal growth was generally low. The dominant contaminant fungal species, detected by culture-dependent techniques and identified by the use of current molecular genus-specific barcodes, belonged to the genus Penicillium, followed by Aspergillus and Cladosporium. Microscopy analyses of the fungal growth revealed that on most of these objects fungal growth was limited to the surface. The enzymatic profile of selected isolates was determined. Most of the fungi were isolated from the flax of the linen objects, confirmed also by their enzyme activities, particularly by strong beta-glucosidase activity. Amylase activity of selected isolates was also evident; this is important since starch can be added as filling or glue to textile materials. Examination of the structural and physical changes to the fibres on contaminated and non-contaminated objects showed the most pronounced structural changes on flax and other cellulosic fibres, while proteinaceous fibres (e.g., wool and silk) were generally not affected.

The scope of this study was an analysis of the deterioration of cotton fibres caused by selected strains of fungal species from historical cotton textile objects. Aged and non-aged cotton fabric specimens were inoculated with representative strains of the six highest frequency fungal species isolated from museum textile objects from different Slovene museums. The selected fungi were Aspergillus clavatus, Cladosporium cladosporoides, Fomes fomentarius, Hypoxylon fragiforme, Penicillium chrysogenum and Penicillium corylophilum. Their effects on contemporary and artificially aged cotton was examined by Raman spectroscopy, infrared spectroscopy, scanning electron microscopy, and tensile behaviour. These fungal species affected the cellulose structure and fabric properties differently. Among the fungi analysed, P. chrysogenum was least harmful to cotton-cellulose samples, while C. cladosporoides, F. fomentarius and H. fragiforme showed the greatest effects. The main structural changes were hydrolysis, depolymerisation, and decreased molecular order. Although not all of these fungal species are dangerous to cotton fibres, and hence to museum objects, they all cause visible changes that can lead to disintegration of these objects. Another important factor that accelerates the depolymerisation of cellulose macromolecules in cotton fibre is inappropriate storage conditions, which should be avoided at all costs, to preserve historical objects and artefacts.

This paper deals with the characterization of a polymer-matrix composite support beam designed for the automotive industry. The discussed composite polymer-matrix material was characterized using light microscopy (LM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Vickers hardness (HV) measurements and mechanical testing under tensile loads. Using these characterization methods the diameter, distribution and arrangement of the fibres in the composite material were determined. The type of fibres used in this composite material was also established from the chemical composition determined by EDS. The mechanical properties of the discussed composite material under a tensile load were determined on proportional, sub-sized, tensile specimens prepared from the support beam.

The aim of the research was to study the influence of the preparation procedure of a colloidal silver solution on the properties of fibres from polylactic acid (PLA fibres). Colloidal silver solutions were prepared in two solvents, i.e. water and ethanol, under appropriate conditions and applied to the PM fibres with the exhaustion method in order to achieve their antimicrobial activity. The shape, size and chemical composition of silver nanoparticles (Ag ND) in the colloidal solution were determined with UV-Vis spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy (EDS). The morphological properties of treated fibres were studied with scanning electron microscopy, whereas the presence of Ag ND on their surface was proved with the EDS analysis. The concentration of Ag on the treated fibres was determined with inductively coupled plasma mass spectroscopy. The bactericidal properties of treated PLA fibres were studied in terms of bacterial reduction for the bacterium Escherichia coli according to the ASTM E 2149-01 standard method. The research results showed that mostly monomers of Ag ND were formed in water as well in ethanol colloidal solution, which were spherical in shape and the size of which did not exceed 15 nm. The used solvent greatly influenced the amount of adsorbed Ag on the PLA fibres. The concentration of the adsorbed Ag was higher on the fibres treated in water than in ethanol. The application of Ag ND from both solvents provided excellent antibacterial protection of PLA fibres. Unlike water, the treatment of fibres in ethanol caused morphological changes of fibres.