Relationship between the Processing, Structure, and Properties of Microfibrillar Composites

The relationship between processing, morphology, and properties of polymeric materials has been the subject of numerous studies of academic and industrial research. Finding an answer to this question might result in guidelines on how to design polymeric materials. Microfibrillar composites (MFCs) are an interesting class of polymer-polymer composites. The advantage of the MFC concept lies in developing in situ microfibrils by which a perfect homogeneous distribution of the reinforcement in the matrix can be achieved. Their potentially excellent mechanical properties are strongly dependent on the aspect ratio of the fibrils, which is developed through a three-stage production process: melt blending, fibrillation, and isotropization. During melt blending, the polymers undergo different morphological changes, such as a breakup and coalescence of the droplets, which play a crucial role in defining the microstructure. During processing, various parameters may affect the morphology of the MFCs, which must be taken into account. Besides the processing parameters, the microstructure of the composite is dependent on the composition ratio of the blend and viscosity of the components, as well as the dispersion and distribution of the microfibrils. The objective here is to outline this importance and bring together an overview of the processing-structure-property relationship for MFCs.