Visualization of interfacial zones in lyocell fiber-reinforced polypropylene composite by AFM contrast imaging based on phase and thermal conductivity measurements

Abstract

Abstract The performance of a fiber-reinforced polymer composite depends not only on the properties of the fiber and matrix polymer but also on the interfacial properties. Nanoindentation and numerical simulation in our previous study revealed that the transition zone of the interfacial region between the regenerated cellulose fiber (lyocell fiber) and polypropylene (PP) was less than 1 μm. Interfacial zone was modified with maleic anhydride-grafted PP (MA-g-PP) and γ-amino propyl trimethoxy silane (γ-APS). In the present study, the interfacial zone is investigated by means of contrast imaging techniques based on phase and thermal conductivity in the context of atomic force microscopy. According to the obtained images, the widths of the interfacial zone modified with MA-g-PP were approximately 113–128 nm and modification with MA-g-PP and γ-APS led to an interfacial zone of 109–173 nm.