Studies on the structure, morphology and thermal properties of HDPE/ petroleum resin blends

Abstract

AbstractThe phase structure, crystallization and melting behavior of high density polyethylene (HDPE) blends with hydrogenated petroleum resin P-100 were investigated by polarized optical microscopy (POM), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Results of polarized optical microscopy and scanning electron microscopy indicated that the structures of blends had a three-dimensional bi-continuous network. The network sizes depended on the blends composition and crystallization conditions, when the blends were quenched or cooled down slowly below the melting temperature of HDPE from molten state; the network sizes decreased with both the increasing of HDPE content and the decreasing of the quenching temperature. Differential scanning calorimeter analysis revealed that the melting point and crystallization temperature of HDPE in blends shifted to lower temperature with the decreasing of HDPE concentrations. The depression of HDPE melting point and crystallization temperature in blends were attributed to the smaller sizes of HDPE crystallites in presence of petroleum resin. The activation energy values and nucleation activity values indicated HDPE had lower crystallization activation energy and P-100 acted as a more effective nucleating agent only at low HDPE concentration