In order to improved the abrasion resistane of rubber, The BR/NR/ silicone nano fiber/ N-339 CB composites were prepared. Untreated silicone nano fiber (USF) normally were in the form of seprated fiber that have 50-80 nm diameter with hydrophilic surface . In order to investigated reinforcing effect of silicon nano fiber the series of the BR/NR/ silicone nano fiber composite were prepared with various silicone nano fiber content loading from 1.0 to 5.0 phr. The results of mechanical properties measurement showed that tensile strength and elongation at break of rubber were improved significantly when USF content was less than 3 phr. The tensile strength and elongation at break of composite with only 3 phr of USF were improved by 100% compared to pure rubber (without USF and CB). It showed silicon nano fiber has good reinforcment effect with low content. SEM characterization of these samples showed that USF was agglomerated in rubber matrix because of their hydrophilic surface. These agglomerates had spherical shape with 20-40 Mm stimated diameter. The series of samples filled with 3 phr USF and various CB content loading from 40 to 60 phr were prepared and were compared with similar samples without USF. The results of mechanical properties measurement showed that abrasion resistance of BR/NR/USF/CB composites compared to BR/NR/CB composites ,15% were improved . In order to create chemical bond between hydrophilic surface of USF and hydrophobic BR/NR rubber , surface modification of USF was done with silane coupling agent (TESPT) via two step method .The sample that filled with 3 phr treated silicone nano fiber (TSF) was prepared . Tensile strength and elongation at break of the rubber only filled with 3 phr TSF were improved by 60% and 200%, respectivity compared to pure rubber. Bonding between silicone nano fiber and polymer chain by TESPT, caused improvement in rubber elongation. Finally samples filled with TSF and 40-60 phr CB was made and 10% improvement in abrasion resistance was observed because of the increase in the elongation of samples compared to the similar USF samples . Keywords: abrasion resistance, silicone nano fiber, TESPT, carbon black, BR/NR
