Abstract: Morphology and mechanical properties of (NR+SBR)/PE blends with rubber uncured or fully cured by either dynamic or static vulcanization were studied by transmission and scanning electron microscopy. The results showed that in the case of non-vulcanization PE existed as a dispersed phase at (NR+SBR)/PE ratio(w/w) of 70/30 and as a continuous phase with ratio ≤50/50. The blends obtained by static vulcanization had the same morphology as the uncured blends. When the rubber was cured by the. dynamic method, PE always ex-isted as a continuous phase.The tensile strength of the (NR+SBR)/PE blends increased with increase in PE content. The DSC and dynamic mechanical test results proved that method of rubber vulcanization was the prime factor responsible for the compatibility between blend components. The blends cured by static vulcanization had higher tensile strength than those by the dynamic method. This is considered as due to the difference in interpenetration between rubber and PE molecules, the penetration bein g in a higher degree in the static than in the dynamic vulcanization.

Key words: Natural rubber, Styrene-butadiene rubber, Polyethylene Blend Vulcanization, Morphology, Mechanical property