Structural study of natural rubber thermoplastic elastomers and their composites with carbon black by small-angle neutron scattering and transmission electron microscopy

Structures of natural rubber (NR)/high density polyethylene (HDPE) thermoplastic elastomers (TPE) and their composites with carbon black were investigated by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS). TEM observations revealed that the carbon black nonoparticles were dominantly located in the NR domains of the TPE. The extremely low contrast between crystalline and amorphous HDPE for SANS enabled us to measure the interface thickness between NR and HDPE in the TPE (5-6 nm) as well as that between NR and carbon black in the composite (2.4 nm).