Abstract
Thermoreversible crosslinking rubber (TRC-IR) was easily synthesized by modification of isoprene rubber (IR) with maleic anhydride followed by the addition of 3-amino-1, 2, 4-triazole(ATA), in solid phase. The mechanical properties of the resulting rubber were more similar to the sulfur-vulcanized rubber than general thermoplastic elastomers (ex. SEBS). Although the tensile strength and elongation at break were lower than those of a corresponding sulfurcured rubber, the moduli were as high as those of sulfur-cured rubber. Re-forming of TRC-IR could be repeated more than 10 times without significantly changing its mechanical properties. Differential scanning calorimetry (DSC) and infrared analyses revealed that the superior mechanical properties and good recyclability are attributable to the strong hydrogen bonding. The TRC-IR showed an endothermic transition peak at around 185°C on the DSC chart, indicating cleavage of the hydrogen bonding. A hypothetical model which comprises strong crosslinking moiety formed by the seven-points hydrogen bonding was suggested. The thermoreversible crosslinking system was also applied to IIR and EPM. These rubbers also showed superior mechanical properties as well as excellent recyclability and fluidity.
