Ductility Optimization in Blends
A blend of polyethylene and ethylene-propylene rubber
was being developed for an automotive application.
The blended resin exhibited erratic mechanical properties
associated with instabilities in the compounding process.
These problems were traced to inconsistencies in addition
of the reactive compatibilizer for the blend.
In practice, the compounder tended to add more
compatibilizer "to be sure that the blend
was properly compatibilized" if there appeared to be any
difficulties during the processing operation.
A study was conducted to determine the influence of
compatibilizer content on the mechanical properties of
Multicomponent polystyrene/ethylene-propylene rubber blends were
prepared by intensive mixing and tested for tensile properties.
In each case, the content of polystyrene was 80 wt% and rubber
was 20%. However, the amount of compatibilizer in the polystyrene
Mechanical properties were determined by tensile testing.
The optimum amount of compatibilizer led to a ductile
material and superior mechanical
properties. However, the use of too much compatibilizer
resulted in a brittle blend. The manufacturing problems were
solved by more careful control of the compatibilizer concentration.