Role of amorphous region on the deformation behavior of crystalline polymers

Abstract

As a means of better understanding the role of amorphous chains on the deformation behavior of crystalline polymers, we prepared high density polyethylene (HDPE) having various chain densities by extracting the petroleum resin dissolved in the interlamellar amorphous region of HDPE/petroleum resin blends. The small angle X-ray scattering intensity increased by increasing the amount of petroleum resin extracted, suggesting that the density of the amorphous chain in the interlamellar amorphous region decreases with an increase in the extracted petroleum resin. The yield stress and Young's modulus decreased while the drawing property was improved by decreasing the amorphous chain density in the interlamellar amorphous region. TEM observation of the stretched specimen revealed that the decrease in overall stress is ascribed to the enhancement of the lamellar separation associated with a large void formation and lamellar deflection due to the low number density of tie chains, which act as transmitters of the external force in the interlamellar amorphous region.