Characterization of henequen fibers and the henequen fiber/poly(hydroxybutyrate-co-hydroxyvalerate) interface

The henequen fiber/poly(hydroxybutyrate-co-hydroxyvalerate) resin (PHBV) in terfacial shear strength was characterized by single-fiber fragmentation (S FF) (also called the single-fiber composite test) and microbond techniques. The surface microstructure and tensile properties of henequen fibers were characterized using a scanning electron microscope (SEM) and an Instron ten sile testing machine. The moisture content of the fibers was measured using a Brabender rapid moisture/volatile tester. SEM photomicrographs of the lo ngitudinal views of the henequen fibers showed their fibrillar structure an d the transverse views showed their hollow/multicellular nature and noncirc ular cross-section. The henequen fiber/PHBV interfacial shear strength was 6.97 MPa, as measured using the SFF test, and 5.24 MPa, as measured using t he microbond test. These results are surprisingly close in spite of the dif ferent stresses experienced during the SFF and microbond tests. SEM photomi crographs showed interfacial failure. The interfacial shear strength was at tributed mainly to the mechanical interlocking resulting from the fiber sur face roughness, since no hydrogen-bonding possibility existed for PHBV. The fiber/resin mechanical interlocking, however, may also be Limited because of the high viscosity of the resin, which limits its ability to penetrate i nto and around the cells.