Interface Modification and Characterization of PVC Based Composites and Nanocomposites

Weak interfaces in composites result in unsatisfactory stiffness and strength of the composites due to poor stress transfer from the matrix to the fibre. Better interfaces can be achieved by physical and chemical modification techniques. Recent studies show a high interest in incorporation of natural fibres in PVC composites as eco-friendly reinforcing component. Common fillers in PVC composites are calcium carbonate and wood flour. Carbon black, copper and nickel metal powders can be added for conductive applications, and ferrite powder for magnetic applications. Plasma treatment has been applied to wood flour and natural fibres to enhance the interface with PVC matrix. Besides this physical modification method, there are many chemical modification techniques, such as treatment of natural fibres with stearic acid or with sodium hydroxide. The use of coupling agents, such as maleic anhydride, silane, titanate, is also a common treatment method to enhance interfaces in composites. The interface can be characterized by several methods, including Fourier Transform Infrared spectrometry, scanning electron microscopy, X-ray computed tomography, pull-out micromechanical tests, dynamic mechanical analyses and rheological tests.