The synthesis, physical properties, and antimicrobial activity of imidazolium, benzalkonium, and phosphonium ionic liquids with 2-mercaptobenzothiazolate has been studied. Synthesized ionic liquids were used as acceleration agents in the vulcanization of rubber. Use of synthesized salts allows to reduce amount of 2-mercaptobenzothiazole, which is commonly used in vulcanization but is an allergenic agent. We obtain in our research shorter vulcanization time, no loss of mechanical properties of rubber, and reduction of the allergen from 56 to 87% in comparison with the vulcanization without ILs.

The aim of this work was to study the activity of novel benzalkonium and ammonium ionic liquids with 2mercaptobenzothiazolate 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.

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.

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Abstract. 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 significantly 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.

Different thermal analysis techniques were used to study the effect of fillers and ionic liquids (ILs) on the vulcanization process, thermal and dynamic mechanical properties of acrylonitrile-butadiene elastomer (NBR). The products of the studies were composites of NBR filled with hydrotalcite, nanosized silica or carbon black. ILs such as 1-butyl-1-methylpyrrolidinium (BMpyrrolBF 4), 1-butyl-4-methylpyridinium (BMpyrBF 4) or 1-butyl-1-methylpiperidinium (BMpipBF 4) tetrafluoroborates were applied to improve the dispersion degree of the curatives and filler particles in the elastomer and to increase the efficiency of vulcanization. The differential scanning calorimetry results indicated that ILs reduced the vulcanization temperature of NBR compounds and increased the homogeneity of cross-link distribution in the elastomer network. NBRs filled with carbon black or silica exhibited similar thermal stabilities, whereas hydrotalcite reduced the temperature of thermal decomposition. The lowest mechanical loss factors were determined for vulcanizates filled with nanosized 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.

Organic zinc salts and complexes were applied as activators for sulfur vulcanization of styrene–butadiene elastomer (SBR) in order to reduce the content of zinc ions in rubber compounds as compared with conventionally used zinc oxide. In this article, the effects of different organic zinc activators on the curing characteristics, crosslink densities, and mechanical properties of SBR as well as the aging resistance and thermal behavior of vulcanizates are discussed. Organic zinc salts seem to be good substitutes for zinc oxide as activators for sulfur vulcanization of SBR rubber, without detrimental effects to the vulcanization time and temperature. Moreover, vulcanizates containing organic zinc salts exhibit higher tensile strength and better damping properties than vulcanizate crosslinked with zinc oxide. The application of organic zinc activators allows the amount of zinc ions in SBR compounds to be reduced by 70–90 wt % compared to vulcanizate with zinc oxide. This is very important for ecological reasons, since zinc oxide is classified as being toxic to aquatic species.