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 Task-Specific Ionic Liquids with Lactate Anion Applied to Improve ZnO Dispersibility in the Ethylene-Propylene-Diene Elastomer

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 774
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Laina Guo ◽  
Etienne Delebecq
Keyword(s):  
Zinc Oxide ◽  
Ionic Liquids ◽  
Carboxyl Groups ◽  
Work Task ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
Oxide Particles ◽  
Zinc Oxide Particles ◽  
Elastomer Composites

Task-specific ionic liquids (TSILs) are ionic liquids with structures and, consequently, properties and behaviors designed for particular applications. In this work, task-specific ILs with alkylammonium or benzalkonium cations and carboxyl groups in the form of lactate anions were used to promote the homogeneous dispersion of the curatives in the elastomer matrix. The reaction of carboxyl groups of TSILs with zinc oxide, which acts as a vulcanization activator, was confirmed. This interaction improved the solubility and dispersibility of zinc oxide particles in the ethylene-propylene-diene (EPDM) monomer matrix, which consequently affected the curing characteristics of rubber compounds. Most importantly, TSILs increased the efficiency of vulcanization by shortening the time, lowering the temperature and increasing the enthalpy of this process, while maintaining safe processing of elastomer composites. EPDM vulcanizates containing TSILs with lactate anion were characterized by satisfactory functional properties.

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 Synthesis and Performance of 6FDA-Based Polyimide-Ionenes and Composites with Ionic Liquids as Gas Separation Membranes

Membranes ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 79 ◽  
Author(s):  
Kathryn O’Harra ◽  
Irshad Kammakakam ◽  
Emily Devriese ◽  
Danielle Noll ◽  
Jason Bara ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
Gas Separation ◽  
High Thermal Stability ◽  
Hybrid Membranes ◽  
High Co2 ◽  
Separation Membranes ◽  
Gas Separation Membranes ◽  
And Performance ◽  
Thermal Stability Of

Three new isomeric 6FDA-based polyimide-ionenes, with imidazolium moieties and varying regiochemistry (para-, meta-, and ortho- connectivity), and composites with three different ionic liquids (ILs) have been developed as gas separation membranes. The structural-property relationships and gas separation behaviors of the newly developed 6FDA polyimide-ionene + IL composites have been extensively studied. All the 6FDA-based polyimide-ionenes exhibited good compatibility with the ILs and produced homogeneous hybrid membranes with the high thermal stability of ~380 °C. Particularly, [6FDA I4A pXy][Tf2N] ionene + IL hybrids having [C4mim][Tf2N] and [Bnmim][Tf2N] ILs offered mechanically stable matrixes with high CO2 affinity. The permeability of CO2 was increased by factors of 2 and 3 for C4mim and Bnmim hybrids (2.15 to 6.32 barrers), respectively, compared to the neat [6FDA I4A pXy][Tf2N] without sacrificing their permselectivity for CO2/CH4 and CO2/N2 gas pairs.

scholarly journals Characterization of Ethylene–propylene Composites Filled with Perlite and Vermiculite Minerals: Mechanical, Barrier, and Flammability Properties

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 585 ◽  
Author(s):  
Bolesław Szadkowski ◽  
Anna Marzec ◽  
Przemysław Rybiński ◽  
Witold Żukowski ◽  
Marian Zaborski
Keyword(s):  
Ionic Liquids ◽  
Flame Retardants ◽  
Considerable Effect ◽  
Maximum Heat ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Reinforcing Fillers ◽  
Uniform Dispersion ◽  
Elastomer Composites ◽  
Mineral Fillers

Perlite and vermiculite are naturally occurring minerals, commonly used by industry to obtain highly thermoisolative and/or non-flammable materials. However, there has been little research into the preparation and application of rubber compounds containing these inexpensive mineral fillers. Here, we show the benefits of perlite and vermiculite minerals as fillers for ethylene-propylene rubber (EPM) composites. To obtain more uniform dispersion and improved compatibility between the minerals and the elastomer matrix, 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (AMIMTFSI) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIMTFSI) imidazolium ionic liquids (ILs) were added. The mineral fillers were found to be attractive semi-reinforcing fillers, which also act as flame retardants in the elastomer composites. Furthermore, a higher content of vermiculite mineral significantly reduced the air permeability of the composites. The incorporation of ionic liquids into the EPM-filled systems had a considerable effect on the torque increment, crosslink density, and more importantly the flammability of the studied compounds. The application of 2.5 parts per hundred parts of rubber (phr) BMIMTFSI, in particular, reduced the flammability of the EPM composite, as the maximum heat release rate (HRRmax) decreased from 189.7 kW/m2 to 170.2 kW/m2.

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.

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.

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