The environmental stress crack resistance (ESCR) and impact strength of high densky polyethylene (HOPE) are increased by blending butyl rubber (HR). In case the IIR content is less than 50%

the crystal lattice

crystallinity

melting point of HOPE in the blends keep unchanged

the amount of IIR entering into the amorphous region between HOPE lamellae increases with IIR content. In HOPE lamellae a few IIR segments are wrapped in along the direction of lamellae thickness

they act as if the connecting rods which tie up the HDPE lamellae and lead to outstanding impact strength and ESCR of the blends.