Effects of Surface Modifiers on Mechanical and Rheological Properties of Halogen-Free Flame Retarded Polyethylene Composites

Abstract

ABSTRACT Halogen-free flame-retarded linear low density polyethylene (LLDPE) composites were prepared in a melt process using magnesium hydroxide (MH) as a flame retardant. The effects of surface modifiers on mechanical properties and rheological behavior of the filled LLDPE have been studied. The results show that the use of surface modifiers with low molecular weight (MW) such as stearic acid or its salts, and silane coupling agents can improve greatly the elongation at break of the composites, and decrease the tensile strength in most cases. However, PE- g -DBM (LLDPE grafted with dibutyl maleate) as a polymeric compatibilizer can make the strength and elongation at break of the composites increase simultaneously. It was found from the rheological measurements that the composites containing low MW surface modifiers exhibited a lower viscosity compared with that of the composites without them, whereas the use of PE- g -DBM compatibilizer increased the viscosity of the composites. In addition, their effects on the morphological structure of the flame-retarded LLDPE composites containing surface modifiers have been investigated using scanning electron microscope (SEM).