Thermal characterization of the effect of fillers and ionic liquids on the vulcanization and properties of acrylonitrile–butadiene elastomer

Abstract

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.

Properties of Chemically Modified (Selected Silanes) Lignocellulosic Filler and Its Application in Natural Rubber Biocomposites

“…As a result, it may have a positive effect on the cross-linking process. Vulcanization is more effective in an alkaline environment, thereby increasing the efficiency of the cross-linking system [ 33 ]. The silanization of the straw used as an active natural rubber additive contributed to the reduction of the process temperature by another few degrees Celsius.…”

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

“…Therefore, application of pyrrolidinium and ammonium ILs with TFSI anion had a positive impact on the cure characteristics—they acted as coagents of vulcanization, whereas sulfonium ILs did not support the vulcanization of NR compounds, acting rather as vulcanization retarders. The positive impact of pyrrolidinium ILs on t 90 was confirmed by Maciejewska et al for NBR composites with different fillers [ 60 ], whereas Przybyszewska et al reported that alkylammonium salts shortened t 90 of unfilled NBR compounds [ 61 ].…”

Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

“…It is known that the basic environment of this type of reaction accelerates the curing processes and influences the efficiency of cross-linking. In the case of a composite containing a filler, which includes montmorillonite modified with methyl dihydroxyethyl hydrogenated tallow ammonium, the effect of reducing the t 90 value could be the result of the quaternary ammonium compound acting as a surfactant [ 49 ], increasing the filler dispersion degree [ 50 ].…”