A study of Time of Cure on the Morphology of NR/IIR Blends and Its Effect on Flex Characteristics

Blends of natural rubber (NR) with butyl rubber (UR) were prepared by Banbury internalmixer. The effect of time of cure on the NRJIIR blends which may govern the morphologicalstructure of domains of the individual phases in the blends have been investigated and arediscussed. It was found that if the blends under investigation were cured immediately aftermixing, a blend with better mechanical properties. e.g. flex characteristics, was produced.Morphological studies of polymer blends, cured immediately after mixing showed betterdispersion of the second phase i.e IIR in the matrix i.e NR. Each blend composition producedwas treated with oxidizing 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 ofscanning electron microscopy (SEM).