Electrochemically exfoliated graphene oxide has been used as a strength-enhancing filler in a polypropylene composite, but was found to exhibit abysmal levels of filler dispersion.
This is thought to reduce the enhancing effects the filler can impart on the matrix, and this phenomenon is investigated and sought counteracted in this report, using a base-catalysed functionalisation procedure.
A micromechanical model is also developed and it showed better dispersion coincided with higher stiffness increase, although only to a minor degree.
The employed functionalisation procedure did not influence the agglomeration of the filler, but could increase the stiffness of the composite by around 60\%.
Composites of graphene oxide in polyvinyl-alcohol is also tested, as the filler disperses well in such a composite due to the particular method of mixing and/or the good chemical affinity between the two.
A five-fold increase in stiffness was observed, compared to specimens of pristine polyvinyl-alcohol.
From the aforementioned results it is concluded the poor degree of dispersion observed in polypropylene composites were not a result of the method of exfoliation, but rather the manner in which the filler was mixed with the polymer.