Crystallization behavior and mechanical properties of LDPE/POE blends

The authors prepared blends of low density polyethylene (LDPE)/polyolefin elastomer (POE) with melt blending process, characterized the crystallization behavior of the blends and the interaction between LDPE and POE crystalline by differential scanning calorimetry (DSC) and wide angle X-ray diffractometry (WAXD) and tested the mechanical properties of the blends. As the mass fraction of POE increased, the LDPE's crystallinity decreased a little, crystal perfection and crystal homogeneity deteriorated and particle size of crytalline became smaller. The phenomenon of secondary crystallization appeared during the crystallization process of LDPE from the melt, and it gradually weakened with the increase of the POE content. The hardness, stress at definite elongation (100% and 300%) and melt flow rate (MFR) of the blends lowered with the increase of the POE content, whereas the elongation strain at break augmented. The tensile strength of the blend reached 21.5 MPa as its maximum when the POE content was 30%. The crystallinity of POE diminished as the LDPE content rose.