Study on the microstructure evolution of TiO₂‐reinforced HDPE nanocomposites by synchrotron small angle X‐ray scattering

This work studies the effect of titanium dioxide (TiO₂) nanoparticles on mechanical properties, thermal behavior and microstructures of high‐density polyethylene (HDPE). Differential scanning calorimetry (DSC) results showed that melting temperature and crystallinity of the nanocomposites are affected by incorporating TiO₂; the crystallinity reaches maximum at low TiO₂ loading following with a significant reduction when the content of TiO₂ higher than 2 wt%. To deeply understand structure–property relationship, SAXS experiments were carried out. The results indicated that the nanoparticles were homogeneously distributed in the HDPE matrix. The TiO₂ nanoparticles exhibit surface‐fractal characteristic at small scale. At large scale, with TiO₂ content increasing, TiO₂ clusters grow gradually until 2 wt%. The optimum microstructures and mechanical properties of HDPE/TiO₂ nanocomposites were achieved at about 2 wt% loading. POLYM. COMPOS., 39:580–587, 2018. © 2016 Society of Plastics Engineers