This paper focuses on the use of epoxidized natural rubber (ENR) as a toughening agent for
nylon 6 (PA6). Natural rubber (NR) was used to compare with ENR. Polymer blends were
prepared by using a twin-screw extruder and pressing as a sheet in a compression molding
machine. It was found that NR and ENR decreased yield stress and tensile strength but
slightly increased elongation at break of PA6. NR slightly decreased impact strength of
PA6, whereas this property increased up to sixfold by blending with ENR. This phenomenon
could be explained in terms of blend morphology. Too large a particle diameter of NR
was a cause of the premature failure. The impact strength of the blends increased with increasing
ENR content. Rubber particle diameter also increased but was still much smaller
than natural rubber particles. Phenolic resin was employed for crosslinking ENR. Compounded
ENR increased tensile properties but decreased impact strength of the blends.
This was because the morphology of ENR was changed from small particles to large
patches of rubber after vulcanization