Linear Low-Density Polyethylene Enriched with Graphene: Effects on Its Rotational Molding and Properties

Abstract

Graphene (GP) belongs to a class of structured carbon compounds with outstanding properties that address its application in energy storage devices, water filtration, biomedical fields, and so on. To take advantage of its high thermal conductivity, this work was thought to study the effect of GP on the rotational molding and properties of linear low-density polyethylene (LLDPE). First, the better molding conditions were determined by different internal peak air temperatures. Once chosen, LLDPE was enriched with a masterbatch containing GP at different contents. Significant energy savings in the rotational process were achieved by addition of GP to LLDPE. Through the drop dart impact test, the presence of GP improved the impact strength. This finding was endorsed by the calorimetric measurement, which revealed a decrease in the LLDPE degree of crystallinity. The melt flow rate showed a slight variation with the GP content. The presence of the GP did not change the rheologic behavior of the composites. Even in very low content, WAXD and Raman spectroscopy revealed the presence of GP in the composites. Thermal conductivity of the composites increased when GP was added to LLDPE which could explain the energy savings in the composites’ processing and their impact property. As a consequence, the increment of thermal conduction affected the cooling rate of LLDPE chains, leading to some extent to the amorphization of the polymer matrix.