Crystallinity of Linear Low Density Polyethylene and of Blends with High Density Polyethylene

Blends of linear low density and high density polyethylene are examined by x‐ray diffraction and differential scanning calorimetry in order to characterise the crystalline morphology and to investigate the compatibility of the polymers. The polymers are found to form a co‐crystalline phase under a variety of conditions, and can thus be regarded as compatible. The lamellar distributions obtained from the differential scanning calorimetry melting thermograms are found to be dominated by the presence of the high density polyethylene, and this is attributed to the higher mobility of the high density molecules. The lattice parameters of the crystalline phases are found to increase with increasing side branch content.