magnetical nanocomposite based on sawdust, magnetic nanoparticles, and polyethylenimine was prepared to remove Pb(II), Cd(II) and Cu(II) ions from an aqueous solution. Adsorption on nanocomposite exhibited a maximum removal of 97% for Pb(II). The adsorption capacity in the pseudo-second-order model for Pb(II) was studied and the value of 1.48 mg/g was obtained.
Thermomechanical studies of polamide 6 compositions, modified with (MPM) montmorillonite-polyvinylpyrrolidone mixture, were performed. Polyamide 6 nanocomposites were obtained by the solution deposition. The influence of nanocomposite production conditions on morphological features of polymer blends were researched. Determination of thermomechanical properties makes it possible to define the optimal content of MPM in polyamide 6 blends.
The influence of additional thermal and thermomechanical treatment of PA6/MMT nanocomposites obtained from the formic acid solution on their heat resistance and technological properties was investigated. Thermal analysis established that heating the nanocomposite to a temperature of 250 ºС and treating it on a capillary plastometer IIRT at a temperature of 230 ºС increases the degree of crystallinity and heat resistance of the samples.
The efficiency of surface modified nanoscale zerovalent iron (nZVI) composite by cashew nut shell (CNS) was tested for the removal of cadmium ions from the aqueous solutions. 2 g/l CNS-nZVI was efficient for 98% removal. The adsorption capacity was 35.58 mg/g. The Freundlich isotherm (R2 = 0.9769) and the pseudo-second order adsorption kinetics data fitted well. This proved CNS-nZVI has a high removal efficiency for Cd(II) from aqueous solutions.
The method of obtaining nanocomposites based on polyamide-6 and montmorillonite intercalated by polyvinylpyrrolidone by precipitation from a solution in formic acid was developed in the work. The structure and physical interaction between the components of nanocomposites were studied by the methods of XRD, IR spectroscopic, and microscopic analyzes. The presence of polyvinylpyrrolidone in the structure of nanocomposites obtained from the solution was confirmed by IR spectroscopic analysis.
Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross-linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character.
The interrelation of physico-mechanical and technological characteristics of newly created nanocomposites on the basis of polypropylene (PP)/polyamide (PA-6) mixture with PVP-modified montmorillonite has been investigated. The significant impact of modified polyamide on technological, physical and mechanical properties and heat resistance of polypropylene has been determined. It has been established that the melt flow index of the resulting composites increases by more than 2 times, compared with pure PP.
Mixtures based on polypropylene (PP) and polyamide (PA) are of great importance as structural materials, the mixing of which reduces the negative characteristics of the original polymers. Non-polar PP significantly reduces water absorption of the material during mixing with polar high hydrophilic PA. As a result, the effect of moisture on the mechanical and thermal properties of the composites decreases. On the other hand, mixing PP with PA can extend the temperature range of material exploitation at negative temperatures.
Creation of polymeric nanocomposites based on the polymers of structural designation is a relevant task at present. Of great interest in obtaining the polymeric nanocomposites is montmorillonite, as a nanoscale heterophase.
The paper describes some approaches for thermal analysis of nano-composites by finite element method.