Anisotropic thermal conductivity of unidirectional natural abaca fiber composites as a function of lumen and cell wall structure

The thermal conductivity of unidirectional abaca fiber–epoxy composites was measured by flash method, which is one of transient state ways based on laser, and studied in model. The results showed that the composites presented increasing longitudinal thermal conductivity but decreasing transverse one as increasing fiber content. The anisotropic thermal conduction properties of the unidirectional composites mainly depend on the lumen and cell wall structure of aligned abaca fiber. The dependency between them can be regulated by selecting suitable volume ratio of lumen to fiber (v) and thermal conductivity ratio of fiber cell wall to matrix (Kfc⊥/Km in transverse direction and Kfc∥/Km in longitudinal direction). It was concluded that the natural fibers or probably other hollow fibers can be utilized to design unidirectional natural fiber composites with anisotropic thermal conduction properties.