Effects of the filler loading and aging time on the mechanical and electrical conductivity properties of carbon black filled natural rubber

• Published in: Journal of applied polymer science Vol. 110; no. 2; pp. 747 - 752
• Main Authors: Azura, A.R, Ghazali, Suriati, Mariatti, M
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-10-2008; Wiley
• Subjects: ageing; Applied sciences; Composites; conducting polymers; Exact sciences and technology; fillers; Forms of application and semi-finished materials; mechanical properties; Polymer industry, paints, wood; rubber; Technology of polymers; Conducting material; ageing; Electrical conductivity; Carbon black; Electrical properties; conducting polymers; Thermal ageing; Mechanical properties; Natural rubber; Dispersion reinforced material; Experimental study; Composite material; Tensile strength; fillers; Morphology; Concentration effect; rubber; Percolation; Tear strength
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.28517

The effects of the filler loading and aging time on the mechanical and electrical conductivity properties of natural rubber were investigated. In this work, carbon black (type N220) was used as a filler, and its loading was varied from 0 to 50 phr. The mechanical properties (e.g., the tensile strength and catastrophic tearing energy) increased with a filler loading up to a certain loading, and a decrease in the mechanical properties was observed with higher filler loadings. The tensile strength and catastrophic tearing energy of the aged samples decreased after 3 and 6 days of aging at 100°C. The results for the electrical conductivity properties of unaged samples showed a percolation threshold at 20 phr, and the values were consistent with further filler loadings. After aging, the percolation threshold was still maintained at 20 phr. The morphologies of unaged and aged samples were significantly different: holes were observed to occur in the aged samples. This might have been due to the movement of fillers when the materials were subjected to heat, and this subsequently influenced the mechanical properties of the natural rubber composites.