novel Method for Preparation of Carboxylated Nitrile Rubber-Natural Rubber Blends Using Bis(diisopropyl)Thiophosphoryl Polysulfides

摘要

Bis(diisOpropyl)thiOPhoSPhorYl trisulfide (DIPTRI) and bis(diisopropyl) thiophosphoryl tetrasulfide (DIPTET) are successfully used as a novel coupling agent and accelerator, respectively, to covulcanize an elastomer blend comprising polar car-boxylated nitrile rubber (XNBR) and nonpolar natural rubber (NR). These compounds are capable of forming a chemical link between these dissimilar rubbers to produce a technologically compatible blend as judged by a swelling experiment. The blend vulca-nizates thus produced exhibit enhanced physical properties that can further be im-proved by adopting the two-stage vulcanization technique and also by judicious selec-tion of the NR:XNBR ratio. The blend morphology assessed by scanning electron microcroscopy micrographs accounts for significant improvement in the physical prop-erties of the blend vulcanizates, particularly in two-stage vulcanization.