Effect of surface modification of carbon black (CB) on the morphology and crystallization of poly(ethylene terephthalate)/CB masterbatch

In order to improve the compatibility between poly(ethylene terephthalate) (PET) and carbon black (CB), CB was modified with a titanate coupling agent, tris(dodecylbenzenesulfonato-kO)(2-propanolato)– (NDZ-109) by means of solid and liquid state, respectively. The graft of NDZ-109 on CB was confirmed by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and contact angle (CA) measurement. Wide angle X-ray diffraction (WAXD) indicates that NDZ-109 has little effect on crystal lattice of CB. Then, the modified CB and pristine CB were blended respectively with PET to fabricate PET/CB masterbatch using a separate feeding technique. The state of dispersion and interfacial interaction between PET and CB were investigated by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), respectively. The glass transition temperature and crystallization temperature can reflect the dispersion state of CB. WAXD results of the original masterbatch show that the nucleation effect of CB and modified-CB (m-CB) in pelletizing process is negligible.