A Study of the Morphology of Natural Rubber/Ethylene Propylene Diene Monomer and Its Effect on Flex Characteristics

Blends of natural rubber (NR) and ethylene propylene diene monomer (EPDM) were prepared by Banbury internal mixer. Order of mixing which may govern the morphological structure of domains of the individual phases in the blend have been investigated and are discussed. It was found that if the polymers under investigation were added first to the mixer and then permitted to masticate before the addition of the remaining components, then the incorporation of the additives was facilitated and hence, a blend with better mechanical properties. e.g. flex haracteristics, was produced. From morphological study of some polymer blends it was found that incorporation of 4% homogenising agent to 60 NR/40 EPDM percentage by weight led to better compatibility between this blend composition which showed the presence of co-continuous structure in the blend. Each blend composition produced was treated with oxidising acids to remove the unsaturated polymer (NR) from the blend, thus, permitting the assessment of dispersion of the components of the blends with the help of scanning electron microscopy (SEM).

Keywords:

Rubber Blends , Morphology , Elastomers , Diene Rubbers , Flex Characteristics