The Role of C-Black in Improvement of Tribological Properties of Industrial Rubber Materials: Deproteinised Natural Rubber and Polyisoprene

Abstract

This is a part of collaborative project between Multimedia University, Melaka and Malaysia Rubber Board, Sg. Buloh, Selangor. In this work, the tribological properties of Deproteinised Natural Rubber (DPNR) was examined and compared with synthetic cis 1,4 polyisoprene rubber (IR) namely Natsyn 2200. The effect of adding carbon black (CB) (0, 25 and 50 phr) to both DPNR and IR on the friction and wear characteristics was investigated. Dry abrasion tests were carried out using pin-on-ring tribometer with abrasive paper (diamond-50) under different operating test conditions such as applied normal load (5-35N), sliding speed (0.3-1.5 m/s), and sliding distance (90-450m). Experimental results showed that the addition of CB has significantly affected the wear and friction characteristics of both DPNR and IR, i.e. reduces the abrasion weight loss by more than 70% compared to unfilled rubber, depending on the test conditions and the concentration of CB. The friction coefficient of DPNR was improved by about 12.5% upon the addition of 50phr CB, compared to unfilled DPNR. Meanwhile, adding (25-50phr) CB to IR drastically deteriorates the friction coefficient, i.e. an increase in the friction by about 200% at 25phr CB and 300% at 50phr CB compared to unfilled IR. Finally, SEM technique is employed to observe the abrasion pattern of rubber in order to correlate the experimental test results to the wear mechanisms.