Unidirectional Abaca Fiber Reinforced Thermoplastic Starch Composite

Unidirectional abaca fiber reinforced thermoplastic starch composite was prepared via compression molding by varying the fiber volume fraction, compression pressure and fiber treatment. Factorial analysis at 95% confidence level has shown that changing fiber volume from 5% to 10% has a significant effect on the tensile strength of the composite. A treatment-pressure interaction was also found to have significant effect on the tensile strength of the composite. Result of tensile test showed that composite fabricated using 6.89 MPa (1000 psi) compression pressure, 10% fiber volume, and treated fibers exhibited the highest tensile strength of 19.73MPa while composite fabricated using 6.89 MPa (1000 psi) compression pressure, 10% fiber volume and untreated fibers exhibited only a tensile strength of 12.30 MPa. Scanning electron microscopy (SEM) on the transverse cross section has shown that alkali treatment was able to improve the interfacial bond between the fibers and the thermoplastic starch matrix resulting to an increase in strength of the composite fabricated at 6.89 MPa (1000 psi). However, using a compression pressure of 13.79 MPa (2000 psi) during fabrication induced damage, i.e. internal cracking, on the alkali treated fibers, thereby reducing the strength of the composite.