Special morphology and its role in mechanical enhancement of linear low‐density polyethylene/multiwalled carbon nanotubes composites

ABSTRACT In this work, multiwalled carbon nanotubes (MWCNTs), as reinforcing agent, were blended with linear low‐density polyethylene (LLDPE), then molded by hot compression molding to prepare LLDPE/MWCNTs composites. Tensile tests indicate that the strength, Young's modulus, and toughness are all improved for LLDPE/MWCNTs composites containing 1 and 3 wt % MWCNTs. Compared with LLDPE, the Young's modulus of LLDPE/MWCNTs composites rises from 144.8 to 270.8 MPa at 1 wt % MWCNTs content. At the same time, increases of 18.5% in tensile strength and 16.6% in yield strength are achieved. Additionally, its toughness is enhanced by 26.7% than that of LLDPE. Microstructure characterizations, including differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy were performed to investigate the variations of microstructure and further to establish the relationship between microstructure and mechanical properties. Homogeneous dispersion of MWCNTs, network formation, and development of an oriented nanohybrid shish‐kebab structure contribute to the enhanced strength and toughness. The increased crystallinity is beneficial to the reinforcement and increased modulus. Additionally, the thermal stability of the LLDPE/MWCNTs composites is enhanced as well. This work suggests a promising routine to optimize polymer/MWCNTs composites by tailoring the structural development. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45525.