Efficiency of interaction between hybrid fillers carbon black/lignin with various rubber-based compatibilizer, epoxidized natural rubber, and liquid butadiene rubber in NR/BR composites: Mechanical, flexibility and dynamical properties

Abstract

This study reports the effect of two different types of compatibilizer, namely epoxidized natural rubber with 50 mol% of epoxide group (ENR-50) and liquid butadiene rubber (LBR-352) for carbon black/lignin-filled natural rubber/polybutadiene rubber (NR/BR) composites in the range of 5–15 parts per hundred rubber (phr). The presence of ENR at concentrations up to 10 phr in carbon black/lignin-filled NR/BR composites reduced cure and scorch time by 33.7% and 21.1% respectively, compared to composites without ENR. This contributed to a better dispersion of the filler and an increase of the 300% modulus by 28.1%. Scanning electron microscopy results (SEM) showed better interaction between carbon black/lignin-filled NR/BR with ENR. Meanwhile, the composites with LBR showed the lowest filler-filler interaction, indicated by a decrease in storage modulus with an increase in strain in the filled compound i.e., Payne effect. Moreover, the utilization of LBR was increased by 168.8% compared to 18.3% with the addition of ENR. It can be concluded that the presence of ENR can enhance the mechanical, flexibility and dynamical properties, while the use of LBR can improve the process-ability and flexibility of rubber composites.