Chemical modification of the surface of halloysite nanotubes (HNT) by alkalization (with sodium hydroxide (NaOH)) and grafting with silanes (bis(trimethylsilyl)amine (HMDS)) was carried out. The efficiency of the alkalization and grafting process was evaluated by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and the nitrogen adsorption method were used. XRD and FTIR analysis confirmed the formation of bonds of trimethylsilyl groups to the HNT surface which changed the nature of the surface from hydrophilic to hydrophobic.
View Article and Find Full Text PDFIn this study, new, functional hydroxyapatite-lignin hybrid systems were designed and characterized. The efficacy of the mechanical method utilized to obtain these systems was confirmed by Fourier transform infrared spectroscopy. The hybrid materials were also noted for their good electrokinetic stability and thermal stability.
View Article and Find Full Text PDFA large amount of graphene-related research is its use as a filler for polymer composites, including thin nanocomposite films. However, its use is limited by the need for large-scale methods to obtain high-quality filler, as well as its poor dispersion in the polymer matrix. This work presents polymer thin-film composites based on poly(vinyl chloride) (PVC) and graphene, whose surfaces were modified by curcuminoids.
View Article and Find Full Text PDFIn this work, a method to increase the dispersion of graphene (GN) in the matrix of rigid poly(vinyl chloride) (PVC) by using a natural plant extract from L. (CE) is proposed. Currently, despite the increasing number of reports on the improvement of GN dispersion in PVC blends, still there is a need to find environmentally friendly and economical dispersion stabilizers.
View Article and Find Full Text PDFIn this article, halloysite-lignin hybrid materials (HL) were designed and obtained. The weak hydrogen bonds found between the components were determined based on Fourier transform infrared spectroscopy (FTIR), proving the achievement of class I hybrid systems. The HL systems were characterized by very good thermal stability and relatively good homogeneity, which increased as the proportion of the inorganic part increased.
View Article and Find Full Text PDFThis review addresses the impact of different nanoadditives on the glass transition temperature () of polyvinyl chloride (PVC), which is a widely used industrial polymer. The relatively high limits its temperature-dependent applications. The objective of the review is to present the state-of-the-art knowledge on the influence of nanofillers of various origins and dimensions on the of the PVC.
View Article and Find Full Text PDFThe current work assessed the burning behavior of plasticized poly(vinyl chloride) (PVC-P) modified with a two-component composition, consisting of L-histidinium dihydrogen phosphate-phosphoric acid (LHP) and nanoclay (n). The thermal and thermodynamical properties of the PVC-P containing from 10 to 30 wt% of the fire retardant system (FRS) were determined by thermogravimetric analysis (TG) as well as by dynamic mechanical thermal analysis (DMTA). In contrast, fire behavior and smoke emission were studied with a cone calorimeter (CC) and smoke density chamber.
View Article and Find Full Text PDFThe common applications of poly(vinyl chloride) (PVC) in many industries mean that the topic of recycling and disposal of post-consumer waste is still very important. One of the methods of reducing the negative impact of PVC waste on the natural environment is to use technological or post-consumer waste of this polymer to produce new composite materials with favorable utility properties, with the addition of natural fillers, among which agro-waste, including hop residue, is deserving of special attention. In this study, the effect of the addition of residual hops (H) on the mechanical and physicochemical properties of poly(vinyl chloride) was investigated.
View Article and Find Full Text PDFThe thermal stability of PVC with 1 wt % of spherical porous nanosilica, prepared by roll milling at processing time varied from 1 to 20 min, was investigated by means of visual color changes, Congo red, and thermogravimetric tests (TGA and DTG), as a function of rolling time and composition of PVC matrix. The melt flow rate (MFR) measurements were realized to identify the degradation-induced changes of processing properties. A high level of gelation of the PVC matrix for all samples was verified by DSC (differential scanning calorimetry).
View Article and Find Full Text PDFBackground: Modern technology, which has been getting more and more recognition in the world for the last several years, is the moving bed biofilm reactor (MBBR) technology. Currently, movable biofilters made of basic polymeric materials, polyethylene and polypropylene.
Methods: An innovative solution in the field, mainly because of the large active surface area for biological membrane can be wood polymer composites (WPC).
This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing of poly(vinyl chloride). It was observed that the pomace in this study was used to extract naphtha, thereby permitting the removal of bio-oil as a factor preventing the obtaining of homogeneous composites. Furthermore, adding 20% raspberry pomace filler after extraction extended the thermal stability time for the composites by about 30%.
View Article and Find Full Text PDFMagnetic magnesium-zinc spinel ferrite MgZnFeO (where x = 0.4, 0.6, and 0.
View Article and Find Full Text PDFThis study investigates the effects of the addition of tungsten on the structure, phase composition, textural properties and activities of β-SiC-based catalysts in the aqueous phase hydrogenation of furfural. Carbothermal reduction of SiO₂ in the presence of WO₃ at 1550 °C in argon resulted in the formation of WC-β-SiC nanocomposite powders with significant variations in particle morphology and content of WC-tipped β-SiC nano-whiskers, as revealed by TEM and SEM-EDS. The specific surface area (SSA) of the nanocomposite strongly depended on the amount of tungsten and had a notable impact on its catalytic properties for the production of furfuryl alcohol (FA) and tetrahydrofurfuryl alcohol (THFA).
View Article and Find Full Text PDFThe objective of this study was to develop a method for the thermally-assisted acidic hydrolysis of waste biomass from the sugar industry (sugar beet pulp and leaves) for chemical and biotechnological purposes. The distillates, containing furfural, can be catalytically reduced directly into furfurayl alcohol or tetrahydrofurfuryl alcohol. The sugars present in the hydrolysates can be converted by lactic bacteria into lactic acid, which, by catalytic reduction, leads to propylene glycol.
View Article and Find Full Text PDFA functional magnesium hydroxide/lignin hybrid system was prepared by grinding and mixing the pure precursors using a planetary ball mill. In addition, the thermal stability was assessed based on the total mass loss of the hybrid system within the temperature range of 30⁻1000 °C, which amounted to 38%. Moreover, the average particle size was at 4.
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