Effect of modification of the polymer matrix on the adhesion of highly stressed aramid-rubber-composites

The influence of a modification of the polymer matrix on the adhesion was evaluated for aramide fiber reinforcement elastomer composites. As criterion for the strength of the adhesive bond the maximum yarn pull-out resistance (T-Test) was used. Exchanging the HNBR rubber of a standard model mixture against a highly polar carboxylated XNBR type, the contribution of the ionic clusters in the elastomer leads to an increase of both the filler-filler and the polymer-filler interaction. Therefore, the improved rubber polarity leads to a significant increase of the adhesive bond. Improvements are achieved with the original type of yarn by 44% and with two-step coatings by more than 50 %. Due to a multi-layer structure (core-shell structure), it is sufficient to equip only the inner core having fibre contact.