The aim of this work was to examine the influence of new curing agents proposed for brominated butyl rubber (BIIR) on the cross-linking process of rubber compounds and the thermal behavior of the vulcanizates. Rubber blends that were filled with carbon black and contained acetylacetonates of different transition metals in the presence of triethanolamine (TEOA) as new cross-linking agents were prepared. The performed studies showed that metal acetylacetonates (Me(acac)) are effective cross-linking agents for BIIR, which was confirmed by high values of the torque increment (∆M) and significant cross-linking degree of the vulcanizates (α (T)). The most active curing agent seems to be iron acetylacetonate (Fe(acac)). Its application results in a shorter optimal vulcanization time, lower onset vulcanization temperature and similar vulcanization enthalpy compared to the BIIR cured with a sulfur curing system. The BIIR vulcanizates cured with Me(acac) reveal good mechanical properties with tensile strengths in the range of 9-14 MPa and better damping properties comparing to the sulfur-cured rubber. The proposed curing agents do not significantly affect the thermal stability of the BIIR vulcanizates.

The influence of new pro-ecological curing agents on the crosslinking process of chloroprene rubber (CR) was examined. The proposed curing system used a simpler recipe (no need to apply harmful products such as zinc oxide and ethylene thiourea) and cost less than standard metal oxides. It was expected that the mechanism of crosslinking would be similar to that of Heck-type reactions. Heck-type reactions are powerful tools for the creation of new C=C bonds. They provide the simplest and most efficient way to synthesize a variety of important compounds used in many areas, such as pharmaceuticals, antioxidants, ultraviolet absorbers, and industrial applications. However, despite their wide application, Heck-type reactions have not been used in the rubber industry so far. Rubber blends containing acetylacetonates with different transition metals as new crosslinking agents were filled with fumed silica Aerosil 380 or carbon black Corax N-550. It was found that metal complexes are active crosslinking agents of the CR composites. The obtained vulcanizates were characterized by a high degree of crosslinking and good mechanical properties. Considering the high tensile strength and degree of crosslinking, iron acetylacetonate was the most effective curing agent of the used metal complexes. Compared with the reference sample cured with metal oxides, the CR samples crosslinked using metal acetylacetonates had a higher activity.

Recently, carbon nanofibers have become an innovative reinforcing filler that has drawn increased attention from researchers. In this work, the reinforcement of acrylonitrile butadiene rubber (NBR) with carbon nanofibers (CNFs) was studied to determine the potential of carbon nanofibers as reinforcing filler in rubber technology. Furthermore, the performance of NBR compounds filled with carbon nanofibers was compared with the composites containing carbon black characterized by spherical particle type. Filler dispersion in elastomer matrix plays an essential role in polymer reinforcement, so we also analyzed the influence of dispersing agents on the performance of NBR composites. We applied several types of dispersing agents: anionic, cationic, nonionic, and ionic liquids. The fillers were characterized by dibutylphtalate absorption analysis, aggregate size, and rheological properties of filler suspensions. The vulcanization kinetics of rubber compounds, crosslink density, mechanical properties, hysteresis, and conductive properties of vulcanizates were also investigated. Moreover, scanning electron microscopy images were used to determine the filler dispersion in the elastomer matrix. The incorporation of the carbon nanofibers has a superior influence on the tensile strength of NBR compared with the samples containing carbon black. It was observed that addition of studied dispersing agents affected the performance of NBR/CNF and NBR/carbon black materials. Especially, the application of nonylphenyl poly(ethylene glycol) ether and 1‐butyl‐3‐methylimidazolium tetrafluoroborate contributed to enhanced mechanical properties and electrical conductivity of NBR/CNF composites.

In this work, cross‐linking at low temperature (90°C) of butadiene rubber (BR) using a vulcanizing system based on a hydroperoxide and ionic liquids (ILs) has been evaluated. Composites of BR with cumene hydroperoxide (CHP) and selected ILs have been prepared and tested. In order to elucidate the influence of novel systems on the cross‐linking as well as on the properties of the final product, BR composites have been characterized by different techniques, that is, rheometrical properties, cross‐linking density determination, as well as mechanical strength and weather aging resistance studies. Herein, the influence of weather aging on the properties of the samples is performed and further discussed. CHP and ILs were found to be an effective peroxide system, which enabled to decrease the energy consumption during vulcanization as well as the amount of applied CHP. Taking into account cross‐linking efficiency, system containing 1,3‐dimethylimidazolium methyl sulfate (IS), or tetrahexylammonium tetrafluoroborate (AB) seems to be the most active.

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