Study of rheological characteristics and mechanical strength properties of natural rubber vulcanizates varying the type and content of carbon black

Abstract

This paper presents a study about the influence of the size and content of two types of carbon black N220 and N550 with loading of 10–100 phr on the properties of the vulcanized natural rubber (NR). The mechanical characteristics such as the tensile strength, the tensile modulus, the elongation at break, the hardness, the abrasion resistance, and rheological properties of NR reinforced with carbon black were investigated. By analyzing the results of an N220 reinforced NR, the reinforcement gives improvement in tensile strengths when fillers are added up to 70 phr. However, and by referring to elongation at break, a fall of product elasticity is observed. The increase of filler loading results a decrease in rheological properties; optimum cure time, scorch time, cure rate index (CRI). Nevertheless, the N220 rubber compound exhibits slightly higher hardness than those registered for the N550 compounds. Regarding the mechanical properties under tensile stress, the engineer's findings are comparative for all the samples of the study. However, the rubber compound filled N220 or N550 gives comparable results on mechanical properties.