Mechanical properties of carboxylato-telechelic polyisoprene

The mechanical properties of carboxylato-telechelic polyisoprenes neutralized with barium, aluminium and zirconium have been studied. In addition to the variable of neutralizing cation valence, the effect of molecular weight was also investigated. It was found that, for those cations studied, increasing cation valence at an approximately constant molecular weight results in increased stresses during a stress-strain experiment. For the barium-neutralized materials, both modulus and observed stresses increase with molecular weight due to entanglement effects. For the zirconium-neutralized materials, this trend is reversed due to the formation of a more well developed network induced by different chemistry.