Effect of acetone extract from natural rubber on the structure and interface interaction in NR/CB composites

Abstract

The influences of acetone extract (AE) from natural rubber on the interface structure of NR/CB composites were investigated through rubber process analyzer (RPA), scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results demonstrated that the crystallite size of CB was increased by AE, leading to the decrease of dispersive free energy (γ^d_s) on the CB surface, which results in a reduction of CB–NR interaction. Oppositely, AE also increased the number of physical entanglement points in NR/CB matrix for its polarity interaction with CB, which could promote the CB–NR interaction. Consequently, the optimized value of AE in NR/CB matrix is 2 phr, where the optimal mechanical and dynamical properties were obtained. Simultaneously, AE had a negative effect on the strain-induced crystallization behaviors of NR/CB composites. This research may draw attention to the evaluation of quality standards of NR.