Influence of NR/EPDM Ratios on the Performance of Pneumatic Fenders in Seawater

Abstract

The performance of pneumatic fenders in seawater is crucial to ensure safety and serviceability. Hence, the objective of this study is to investigate the performance of compound formulations of two different types of carbon black N660 and N220 at various NR/EPDM (Natural Rubber/Ethylene Propylene Diene Monomer) ratios of 100/0; 90/10; 80/20, and 70/30 in artificial seawater at 95°C for 30 days. The mechanical properties of rubber compounds were measured and compared before and after aging in seawater. Comparing two types of carbon black, no significant difference in tensile, elongation, tear strength, and compression set at the same blend ratios after aging in seawater. Nevertheless, the abrasion resistance of N220 is lower than that of N660 before and after aging in seawater due to insufficient dispersion. Adding high crystalline EPDM in the blend results in lower mechanical properties change than pure NR after aging in seawater. In addition, the blend contains EPDM imparts high abrasion resistance in seawater. Using EPDM up to 30 phr in the blend with NR indicates the possibility of utilizing this high oxidation stability of rubber as a pneumatic fender.