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U ovom radu ispitivan je potencijal korišćenja akril-funkcionalizovanog kraft lignina (AKL) u smanjenju zapaljivosti polimernih kompozita na bazi recikliranih nezasićenih poliesterskih smola (NZPS). Akrilna funkcionalizacija kraft lignina je izvedena direktnom esterifikacijom slobodnih polifenolnih grupa sa akriloil hloridom, nakon čega je AKL umešan u NZP smolu sintetizovanu od poliola dobijenih katalitičkom depolimerizacijom otpadnog poli(etilen tereftalata). AKL je homogenizovan sa NZPS pri različitim masenim udelima: 2,5, 5,0, 7,5 i 12,5 mas.%. Strukturne i dinamičko-mehaničke karakteristike akril-funkcionalizovanog kraft lignina i kompozita određene su primenom FTIR spektroskopije, dinamičkomehaničke analize (DMA) i testova jednoosnog zatezanja. Proučavan je uticaj funkcionalizacije i masenog udela AKL na zatezna i termička svojstva NZPS. Vatrootporna svojstva kompozita su ispitivana prema standardnoj UL-94V metodi, na osnovu koje je kompozit sa 12,5 tež. % akril-funkcionalizovanog lignina dostigao najvišu kategorija toplotno otpornih materijala., This paper investigates the using potential of acryl-functionalized kraft lignin (AKL) in reducing the flammability of polymer composites based on recycled unsaturated polyester resins (UPR). Acryl functionalization of kraft lignin was performed by direct esterification of free polyphenolic groups with acryloyl chloride, after what, the AKL was blended in UPR resin synthesized from the polyols obtained by catalytic depolymerization of waste poly(ethylene terephthalate). The AKL was homogenized in UPR resin in different weight ratios: 2.5, 5.0, 7.5, and 12.5 wt.%. Structural and dynamic-mechanical characteristics of acryl-functionalized kraft lignin and composites were determined using FTIR spectroscopy, dynamicmechanical analysis (DMA), and tensile tests. The influence of functionalization and mass fraction of AKL on tensile and thermal properties of UPR resin was studied. The thermal properties of the composite were tested according to the standard UL-94 method, based on which the highest category of heat-resistant materials is a composite with 12.5 wt.% acylfunctionalized lignin.

U ovom radu ispitivan je potencijal korišćenja akril-funkcionalizovanog kraft lignina (AKL) u smanjenju zapaljivosti polimernih kompozita na bazi recikliranih nezasićenih poliesterskih smola (NZPS). Akrilna funkcionalizacija kraft lignina je izvedena direktnom esterifikacijom slobodnih polifenolnih grupa sa akriloil hloridom, nakon čega je AKL umešan u NZP smolu sintetizovanu od poliola dobijenih katalitičkom depolimerizacijom otpadnog poli(etilen tereftalata). AKL je homogenizovan sa NZPS pri različitim masenim udelima: 2,5, 5,0, 7,5 i 12,5 mas.%. Strukturne i dinamičko-mehaničke karakteristike akril-funkcionalizovanog kraft lignina i kompozita određene su primenom FTIR spektroskopije, dinamičkomehaničke analize (DMA) i testova jednoosnog zatezanja. Proučavan je uticaj funkcionalizacije i masenog udela AKL na zatezna i termička svojstva NZPS. Vatrootporna svojstva kompozita su ispitivana prema standardnoj UL-94V metodi, na osnovu koje je kompozit sa 12,5 tež. % akril-funkcionalizovanog lignina dostigao najvišu kategorija toplotno otpornih materijala., This paper investigates the using potential of acryl-functionalized kraft lignin (AKL) in reducing the flammability of polymer composites based on recycled unsaturated polyester resins (UPR). Acryl functionalization of kraft lignin was performed by direct esterification of free polyphenolic groups with acryloyl chloride, after what, the AKL was blended in UPR resin synthesized from the polyols obtained by catalytic depolymerization of waste poly(ethylene terephthalate). The AKL was homogenized in UPR resin in different weight ratios: 2.5, 5.0, 7.5, and 12.5 wt.%. Structural and dynamic-mechanical characteristics of acryl-functionalized kraft lignin and composites were determined using FTIR spectroscopy, dynamicmechanical analysis (DMA), and tensile tests. The influence of functionalization and mass fraction of AKL on tensile and thermal properties of UPR resin was studied. The thermal properties of the composite were tested according to the standard UL-94 method, based on which the highest category of heat-resistant materials is a composite with 12.5 wt.% acylfunctionalized lignin.

This study consisted to determine a discreet order by sliding method that was applied on a regulation procedure of a formed level by communicating reservoirs. The model that represents the system is determined by parametric identification based on the algorithm of the recursive least square with forgetfulness factor. Problem statement: The purpose is to develop a robust order that assuring the stability of the system autonomously of his initial state or of his environment. Approach: The first step consist to model the process, afterward, we developed the order. Results: We developed a command which permit to conduct the system towards a desired state (chosen state, an equilibrium point in our case) and ensured its stability in this zone whatever the conditions on the system. Conclusions: the hardiness of the order has been proved as a result of the introduction of an external perturbation on the process. But this order will be able again to improve also the non-controllable defects.

The use of organoclays as adsorbents in the remediation of polluted water has been the subject of many recent studies. In this work, a Tunisian smectite modified with 2 cationic surfactants was used as an adsorbent to examine the adsorption kinetics, isotherms and thermodynamic parameters of fluoride ions from aqueous solution. Various pH values, initial concentrations and temperatures have been tested. Two simplified kinetic models, first-order and pseudo-second-order, were used to predict the adsorption rate constants. The pseudo-second-order model was found to be the best choice for describing the adsorption kinetics of fluoride on modified smectites at different operating conditions. Adsorption isotherms and equilibrium adsorption capacities were determined by the fitting of experimental data to well known isotherm models, such as Langmuir and Freundlich. The Langmuir model appeared to fit the adsorption better than the Freundlich model according to the results. The equilibrium constants were used to calculate thermodynamic parameters, such as the change of free energy, enthalpy and entropy. Results of this study demonstrated the effectiveness and feasibility of organoclays for the removal of fluoride ions from aqueous solution., The use of organoclays as adsorbents in the remediation of polluted water has been the subject of many recent studies. In this work, a Tunisian smectite modified with 2 cationic surfactants was used as an adsorbent to examine the adsorption kinetics, isotherms and thermodynamic parameters of fluoride ions from aqueous solution. Various pH values, initial concentrations and temperatures have been tested. Two simplified kinetic models, first-order and pseudo-second-order, were used to predict the adsorption rate constants. The pseudo-second-order model was found to be the best choice for describing the adsorption kinetics of fluoride on modified smectites at different operating conditions. Adsorption isotherms and equilibrium adsorption capacities were determined by the fitting of experimental data to well known isotherm models, such as Langmuir and Freundlich. The Langmuir model appeared to fit the adsorption better than the Freundlich model according to the results. The equilibrium constants were used to calculate thermodynamic parameters, such as the change of free energy, enthalpy and entropy. Results of this study demonstrated the effectiveness and feasibility of organoclays for the removal of fluoride ions from aqueous solution.