The Experts below are selected from a list of 723 Experts worldwide ranked by ideXlab platform
Magdalena Maciejewska - One of the best experts on this subject based on the ideXlab platform.
-
ionic liquids and calcium oxide grafted with allylmalonic acid applied to support the peroxide crosslinking of an ethylene propylene copolymer
Materials, 2020Co-Authors: Magdalena MaciejewskaAbstract:Nanosized calcium oxide (CaO) featuring a surface grafted with allylmalonic acid (ALA) was used to increase the efficiency of the peroxide crosslinking of an ethylene–propylene copolymer (EPM) filled with silica nanoparticles. In this study, 1-butyl-3-methylimidazolium ionic liquids (ILs) with different anions were applied to improve the dispersion of CaO/ALA and silica nanoparticles in the EPM copolymer, as well as to catalyze the interfacial crosslinking reactions. In this article, we discuss the effects of CaO/ALA and ILs on the curing characteristics, vulcanization temperature, crosslink density, mechanical properties, and thermal stability of EPM, as well as the resistance of EPM to weather aging. The CaO/ALA with ILs reduced the vulcanization time of the rubber compounds without a significant effect on the vulcanization temperature. Their application resulted in an increased vulcanizate crosslink density, as well as improved tensile strength compared to the pure peroxide system. The influence of 1-butyl-3-methylimidazolium ILs on EPM vulcanization and performance depends on the anion present in the molecules of the ionic liquid. The most active IL seems to be that with the tetrafluoroborate anion.
-
ionic liquids as coagents for sulfur vulcanization of butadiene styrene elastomer filled with carbon black
Polymer Bulletin, 2018Co-Authors: Magdalena Maciejewska, Marian ZaborskiAbstract:The aim of this work was to study the activity of several alkylimidazolium salts of bis(trifluoromethylsulfonyl)imides to obtain a very fast vulcanization of the butadiene–styrene (SBR) elastomer. Ionic liquids (ILs) such as alkylimidazolium salts with ethyl-, propyl-, butyl-, hexyl-, decyl-, dodecyl-, and hexadecyl chains in the cation together with nanosized zinc oxide are used to develop elastomer composites with very short vulcanization time and a reduced amount of vulcanization activator. In this article, we discuss the effect of the ILs with respect to the length of alkyl chain in their cation on the vulcanization kinetics of rubber compounds. The influence of ILs on the crosslink density as well as the mechanical properties of the vulcanizates and their resistance to thermo-oxidative and UV aging were also studied. ILs resulted in a shortened optimal vulcanization time and reduced the onset vulcanization temperature compared to zinc oxide containing rubber compound. This is very important from a technological point of view. A considerable increase in the crosslink density of vulcanizates was also observed.
-
effect of ionic liquids on the dispersion of zinc oxide and silica nanoparticles Vulcanisation behaviour and properties of nbr composites
Express Polymer Letters, 2014Co-Authors: Magdalena Maciejewska, Marian ZaborskiAbstract:The aim of this work was to study the activity of several alkylpyrrolidinium, alkylpyridinium, alkylpiperidinium and benzylimidazolium ionic liquids (ILs) for the purpose of improving the dispersion degree of Vulcanisation activator and filler nanoparticles in the acrylonitrile-butadiene elastomer (NBR). The effect of the ionic liquids on the Vulcanisation kinetics of the rubber compounds, crosslink density and mechanical properties of the vulcanisates and their resistance to thermo-oxidative and UV ageing was studied. The use of ionic liquids allowed for a homogeneous dispersion of nanoparticles in the elastomer without detrimental effects on the Vulcanisation process. The physical properties and the thermal stability of the obtained vulcanisates were signifi- cantly improved. Ionic liquids increased the crosslink density of the vulcanisates and their damping properties. Pirydinium and piperidinium hexafluorophosphates were most effective at increasing the crosslink density and improving the properties of NBR composites.
-
novel ionic liquids as accelerators for the sulfur vulcanization of butadiene styrene elastomer composites
Industrial & Engineering Chemistry Research, 2013Co-Authors: Magdalena Maciejewska, Filip Walkiewicz, Marian ZaborskiAbstract:The aim of this work was to study the activity of novel benzalkonium and ammonium ionic liquids with 2-mercaptobenzothiazolate as accelerators in the sulfur vulcanization of butadiene–styrene elastomer (SBR). In this Article, the effect of the ionic liquids on the vulcanization kinetics of the rubber compounds, the cross-link density, and the mechanical properties of the vulcanizates, as well as their resistance to thermal and UV aging, was studied. The application of novel ionic liquids allowed for the elimination of N-cyclohexyl-2-benzothiazolesulfenamide from SBR compounds and for the considerable reduction of the amount of 2-mercaptobenzothiazole present in rubber products. Synthesized salts seem to be good substitutes for standard accelerators in the sulfur vulcanization of SBR rubber, without the observation of any detrimental effects on the vulcanization process, the physical properties, or the thermal stability of the obtained vulcanizates.
Marian Zaborski - One of the best experts on this subject based on the ideXlab platform.
-
ionic liquids as coagents for sulfur vulcanization of butadiene styrene elastomer filled with carbon black
Polymer Bulletin, 2018Co-Authors: Magdalena Maciejewska, Marian ZaborskiAbstract:The aim of this work was to study the activity of several alkylimidazolium salts of bis(trifluoromethylsulfonyl)imides to obtain a very fast vulcanization of the butadiene–styrene (SBR) elastomer. Ionic liquids (ILs) such as alkylimidazolium salts with ethyl-, propyl-, butyl-, hexyl-, decyl-, dodecyl-, and hexadecyl chains in the cation together with nanosized zinc oxide are used to develop elastomer composites with very short vulcanization time and a reduced amount of vulcanization activator. In this article, we discuss the effect of the ILs with respect to the length of alkyl chain in their cation on the vulcanization kinetics of rubber compounds. The influence of ILs on the crosslink density as well as the mechanical properties of the vulcanizates and their resistance to thermo-oxidative and UV aging were also studied. ILs resulted in a shortened optimal vulcanization time and reduced the onset vulcanization temperature compared to zinc oxide containing rubber compound. This is very important from a technological point of view. A considerable increase in the crosslink density of vulcanizates was also observed.
-
effect of ionic liquids on the dispersion of zinc oxide and silica nanoparticles Vulcanisation behaviour and properties of nbr composites
Express Polymer Letters, 2014Co-Authors: Magdalena Maciejewska, Marian ZaborskiAbstract:The aim of this work was to study the activity of several alkylpyrrolidinium, alkylpyridinium, alkylpiperidinium and benzylimidazolium ionic liquids (ILs) for the purpose of improving the dispersion degree of Vulcanisation activator and filler nanoparticles in the acrylonitrile-butadiene elastomer (NBR). The effect of the ionic liquids on the Vulcanisation kinetics of the rubber compounds, crosslink density and mechanical properties of the vulcanisates and their resistance to thermo-oxidative and UV ageing was studied. The use of ionic liquids allowed for a homogeneous dispersion of nanoparticles in the elastomer without detrimental effects on the Vulcanisation process. The physical properties and the thermal stability of the obtained vulcanisates were signifi- cantly improved. Ionic liquids increased the crosslink density of the vulcanisates and their damping properties. Pirydinium and piperidinium hexafluorophosphates were most effective at increasing the crosslink density and improving the properties of NBR composites.
-
novel ionic liquids as accelerators for the sulfur vulcanization of butadiene styrene elastomer composites
Industrial & Engineering Chemistry Research, 2013Co-Authors: Magdalena Maciejewska, Filip Walkiewicz, Marian ZaborskiAbstract:The aim of this work was to study the activity of novel benzalkonium and ammonium ionic liquids with 2-mercaptobenzothiazolate as accelerators in the sulfur vulcanization of butadiene–styrene elastomer (SBR). In this Article, the effect of the ionic liquids on the vulcanization kinetics of the rubber compounds, the cross-link density, and the mechanical properties of the vulcanizates, as well as their resistance to thermal and UV aging, was studied. The application of novel ionic liquids allowed for the elimination of N-cyclohexyl-2-benzothiazolesulfenamide from SBR compounds and for the considerable reduction of the amount of 2-mercaptobenzothiazole present in rubber products. Synthesized salts seem to be good substitutes for standard accelerators in the sulfur vulcanization of SBR rubber, without the observation of any detrimental effects on the vulcanization process, the physical properties, or the thermal stability of the obtained vulcanizates.
Mehdi Razzaghikashani - One of the best experts on this subject based on the ideXlab platform.
-
vulcanization kinetics of nano silica filled styrene butadiene rubber
Polymer, 2014Co-Authors: Seyed Mostaffa Hosseini, Mehdi RazzaghikashaniAbstract:Abstract It was shown that the physical filler-polymer and filler–filler interactions, apart from the filler surface chemistry, has a substantial role in controlling the vulcanization kinetics of styrene butadiene rubber filled with nano-silica in a sulfur vulcanization system. Kinetic studies by the oscillating disc rheometer, differential scanning calorimeter, and swelling tests revealed that the vulcanization rate goes through a maximum as loading of silica increases, but conversion in crosslinking continuously decreases as the amount of silica increases. The effect of silica loadings on the vulcanization reactions was linked to the immobilization of rubber chains around particles as well as in a polymer-mediated filler network, which were differentiated by the nonlinear viscoelastic behavior of rubber vulcanizates. By surface modification of nano-silica, the accelerating/decelerating effects of nano-silica on the vulcanization reactions were altered corresponding to the non-linear viscoelastic behavior of the vulcanizates. Therefore, a mechanism was proposed which correlates vulcanization kinetics of rubber to the dynamics of chains influenced by the reinforcing fillers.
Junying Zhang - One of the best experts on this subject based on the ideXlab platform.
-
insights into the vulcanization mechanism through a simple and facile approach to the sulfur cleavage behavior
Macromolecules, 2017Co-Authors: Qingsong Lian, Jue Cheng, Junying ZhangAbstract:The vulcanization mechanism remains unclear due to the difficulty of characterization and the complexity of the vulcanization systems. In this work, a series of epoxy model systems were used to study the sulfur cleavage behavior, from which the study process of the vulcanization mechanism was significantly simplified and a brand new sulfur-only vulcanization mechanism was revealed by the FTIR and DSC analysis. Our studies suggest that thiyl radicals derived from the homolytic cleavage of sulfur play the dominant role in the vulcanization, while the heterolytic fission of sulfur cannot occur as expected because this reaction needs 200 °C. Nevertheless, sulfur anions, which are easy to be understood derived from the heterolytic cleavage of sulfur, are actually transformed from the thiol groups that are produced through the reaction of thiyl radicals abstracting α-H atoms of allyl groups in rubber, and this maybe the reason that vulcanization mechanism remains controversial for centuries.
-
Insights into the Vulcanization Mechanism through a Simple and Facile Approach to the Sulfur Cleavage Behavior
2017Co-Authors: Qingsong Lian, Jue Cheng, Junying ZhangAbstract:The vulcanization mechanism remains unclear due to the difficulty of characterization and the complexity of the vulcanization systems. In this work, a series of epoxy model systems were used to study the sulfur cleavage behavior, from which the study process of the vulcanization mechanism was significantly simplified and a brand new sulfur-only vulcanization mechanism was revealed by the FTIR and DSC analysis. Our studies suggest that thiyl radicals derived from the homolytic cleavage of sulfur play the dominant role in the vulcanization, while the heterolytic fission of sulfur cannot occur as expected because this reaction needs 200 °C. Nevertheless, sulfur anions, which are easy to be understood derived from the heterolytic cleavage of sulfur, are actually transformed from the thiol groups that are produced through the reaction of thiyl radicals abstracting α-H atoms of allyl groups in rubber, and this maybe the reason that vulcanization mechanism remains controversial for centuries
B Herrero - One of the best experts on this subject based on the ideXlab platform.
-
vulcanization kinetics of natural rubber organoclay nanocomposites
Journal of Applied Polymer Science, 2003Co-Authors: Miguel A Lopezmanchado, M Arroyo, B Herrero, J BiagiottiAbstract:The effect of the incorporation of a bentonite on the vulcanization kinetics of natural rubber was investigated by means of both cure-meter testing and differential scanning calorimetry (DSC) under dynamic and isothermal conditions. The vulcanization curves showed that the modified clay behaved as an effective vulcanizing agent, accelerating the vulcanization reaction of the elastomer. A marked decrease in the induction time and optimum cure time of the elastomer were observed in the presence of the organoclay. Although the octadecylamine itself accelerated the vulcanization process, the octadecylamine-modified clay gave rise to a further noticeable increase in the vulcanization rate, which could be attributed to a synergetic effect between the filler and the amine. Moreover, in the presence of the organoclay, a dramatic increase in the torque value was obtained because of the formation of a higher number of crosslinks, which could be attributed to the confinement of the elastomer chains within the silicate galleries and, consequently, to better interactions between the filler and the rubber. However, no significant changes were observed in the unmodified clay composite. These results were in concordance with those obtained by DSC. In addition, the activation energy of the vulcanization process was also calculated by means of both techniques. A clear decrease in the activation energy was observed when the organoclay was added to the nanocomposite, which indicated that the layered silicate favored the processing of the elastomer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1–15, 2003
-
organo montmorillonite as substitute of carbon black in natural rubber compounds
Polymer, 2003Co-Authors: M Arroyo, Miguel A Lopezmanchado, B HerreroAbstract:Abstract The use of octadecylamine modified montmorillonite as substitute of carbon black in natural rubber (NR) compounds is studied. Rubber with 10 parts per hundred resin (phr) of pristine (clay) and octadecylamine modified montmorillonite (organoclay) were compared with 10 and 40 phr carbon black as filler. The modified silicate is analysed by X-ray, FTIR and thermogravimetric analysis. Vulcametric curves show that the organoclay and carbon black accelerate the vulcanization reaction and, furthermore, give rise to a marked increase in the torque, indicating a higher degree of crosslinking as was also confirmed by swelling measurements and DSC. The Vulcanisation rate and torque value of the organoclay compound are sensibly higher than the carbon black compound even at high contents (40 phr). Mechanical characterization shows the strong reinforcing effect of both fillers up to 350% in the strength in relation to NR. The mechanical properties of NR with 10 phr organoclay are comparable to the compound with 40 phr carbon black. Moreover, the organoclay improves the strength of the NR without hardly any reduction in the elasticity of the material.
