scholarly journals The Essential Role of 1-Butyl-3-Methylimidazolium-Based Ionic Liquids in the Development of Transparent Silica-Filled Elastomer Systems

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4337
Author(s):  
Małgorzata Kuśmierek ◽  
Bolesław Szadkowski ◽  
Anna Marzec
Keyword(s):  
Ionic Liquids ◽  
Crosslink Density ◽  
Catalytic Effect ◽  
Mechanical Performance ◽  
High Transparency ◽  
Filled Elastomer ◽  
Roll Mill ◽  
Elastomer Composites ◽  
Crosslinking Reactions

In this paper, we present the design of reinforced silica-filled elastomer composites exhibiting a high transparency, high mechanical performance in static and dynamic conditions, and improved electrical conductivity. Two different imidazolium ionic liquids (ILs) were used with increasing loads: 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIMTFSI) and 1-butyl-3-methylimidazolium tetrachloroaluminate (BMIMAlCl4). The composites were prepared in a two-roll mill. The influence of the ILs on the dispersion of the silica in the nitrile rubber (NBR) matrix was assessed by scanning electron microscopy (SEM). The presence of ILs in the NBR/SiO2 systems improved the crosslink density and ionic conductivity of the composites. Their mechanical properties and aging stability remained almost unchanged, at a very satisfactory level. Greater crosslinking was observed for the NBR/SiO2 composites containing BMIMAlCl4, due to its catalytic effect on the efficiency of interface crosslinking reactions. We found the optimal formulation for obtaining transparent reinforced NBR/SiO2 composites. The application of 2.5 phr of BMIMAlCl4 resulted in a high transparency in the case of NBR composites filled with 30 phr of silica.

scholarly journals Ionic Liquids and Calcium Oxide Grafted with Allylmalonic Acid Applied to Support the Peroxide Crosslinking of an Ethylene–Propylene Copolymer

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3260
Author(s):  
Magdalena Maciejewska
Keyword(s):  
Ionic Liquids ◽  
Silica Nanoparticles ◽  
Calcium Oxide ◽  
Crosslink Density ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
And Performance ◽  
Crosslinking Reactions ◽  
Thermal Stability Of

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.

scholarly journals Bis(trifluoromethylsulfonyl)imide Ionic Liquids Applied for Fine-Tuning the Cure Characteristics and Performance of Natural Rubber Composites

2021 ◽  
Vol 22 (7) ◽  
pp. 3678
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Anna Grajewska
Keyword(s):  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
Physico Chemical ◽  
Elastomer Composites ◽  
And Performance

The goal of this work was to apply ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide anion (TFSI) for fine-tuning the cure characteristics and physico-chemical properties of elastomer composites based on a biodegradable natural rubber (NR) matrix. ILs with TFSI anion and different cations, such as alkylpyrrolidinium, alkylammonium, and alkylsulfonium cations, were applied to increase the efficiency of sulfur vulcanization and to improve the performance of NR composites. Thus, the influence of ILs on the vulcanization of NR compounds, as well as crosslink density and physical properties of NR vulcanizates, including tensile properties, thermal stability, and resistance to thermo-oxidative aging was explored. The activity of ILs seems to be strongly dependent on their cation. Pyrrolidinium and ammonium ILs effectively supported the vulcanization, reducing the optimal vulcanization time and temperature of NR compounds and increasing the crosslink density of the vulcanizates. Consequently, vulcanizates with these ILs exhibited higher tensile strength than the benchmark without IL. On the other hand, sulfonium ILs reduced the torque increment owing to the lower crosslinking degree of elastomer but significantly improved the resistance of NR composites to thermo-oxidation. Thus, TFSI ILs can be used to align the curing behavior and performance of NR composites for particular applications.

scholarly journals Influence of Fillers and Ionic Liquids on the Crosslinking and Performance of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1656
Author(s):  
Magdalena Maciejewska ◽  
Anna Sowińska
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Mechanical Performance ◽  
Mechanical And Thermal Properties ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
And Performance ◽  
Surface Silica

This work concerns the effect of fillers and ionic liquids on the cure characteristics of natural rubber (NR) compounds, as well as the mechanical and thermal properties of the vulcanizates. Three types of white filler were applied, such as cellulose, nanosized silica and hydrotalcite, to modify the performance of NR composites. Additionally, ionic liquids (ILs) with bromide anion and different cations, i.e., 1-butyl-3-methylimidazolium (Bmi) and 1-butyl-3-methylpyrrolidinium (Bmpyr), were used to improve the cure characteristics of NR compounds and functional properties of the vulcanizates. The type of filler and the structure of ILs were proved to affect the rheometric properties and cure characteristics of NR compounds as well as the performance of the NR vulcanizates. Owing to the adsorption of curatives onto the surface, silica reduced the activity of the crosslinking system, prolonging the optimal vulcanization time of NR compounds and reducing the crosslinking degree of the elastomer. However, silica-filled NR exhibited the highest thermal stability. Hydrotalcite increased the crosslink density and, consequently, the mechanical properties of the vulcanizates, but deteriorated their thermal stability. ILs beneficially influenced the cure characteristics of NR compounds, as well as the crosslink density and mechanical performance of the vulcanizates, particularly those filled with silica. Cellulose did not significantly affect the vulcanization of NR compounds and crosslink density of the vulcanizates compared to the unfilled elastomer, but deteriorated their tensile strength. On the other hand, cellulose improved the thermal stability and did not considerably alter the damping properties of the vulcanizates.

The Mechanical Performance of Carbon Fibres- Addressing the Role of Microstructure

2019 ◽  
Author(s):  
Peter Peter ◽  
Claudia Creighton ◽  
David Fox ◽  
Pablo Mota Santiago ◽  
Adrian Hawley ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Carbon Fibres

scholarly journals Current trends in leather science

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Anthony D. Covington ◽  
William R. Wise
Keyword(s):  
Ionic Liquids ◽  
Potential Role ◽  
Solid Medium ◽  
Leather Industry ◽  
Chromium Vi ◽  
Current Trends ◽  
New Findings ◽  
Vegetable Tanning ◽  
Sulfide Species

Abstract In preparing the second edition of ‘Tanning Chemistry. The Science of Leather.’, the literature was updated and the content was revised and reviewed. Here, the new findings are presented and discussed. Notable developments include the necessary rethinking of the mechanism of sulfide unhairing because of new understanding of the aqueous chemistry of sulfide species. Revision upwards of the value of the second pKa for sulfide species ionisation means that S2− cannot exist in an aqueous medium, so the unhairing species in hair burn reactions is HS−. Although the technology remains the same, this means the mechanisms of associated reactions such as immunisation must be revised. Rawstock preservation has benefitted from studies of the potential role of materials from plants which accumulate salt, but which also contribute terpene compounds. There is also further discussion on the continuing issue of chromium (VI) in the leather industry. The application to processing of new solvents, ionic liquids and deep eutectics, is the coming technology, which offers transforming options for new chemistries and products. Renewed interest in vegetable tanning and methods of wet white processing are current trends. Also, within the topic of reagent delivery is processing in a solid medium of plastic beads. Graphical abstract

scholarly journals Protic Ionic Liquids as Reagent, Catalyst, and Solvent: Triple Role of 1‐Methylimidazolium Thiocyanate

2021 ◽  
Author(s):  
Daniel B. Werz ◽  
Ivan A. Andreev ◽  
Nina K. Ratmanova ◽  
André U. Augustin ◽  
Olga A. Ivanova ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Protic Ionic Liquids

Copper ionic liquids: Examining the role of the anion in determining physical and electrochemical properties

2013 ◽  
Vol 396 ◽  
pp. 78-83 ◽  
Author(s):  
Harry D. Pratt ◽  
Jonathan C. Leonard ◽  
Leigh Anna M. Steele ◽  
Chad L. Staiger ◽  
Travis M. Anderson
Keyword(s):  
Ionic Liquids ◽  
Electrochemical Properties
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