Kenaf bast fiber bundle-reinforced unsaturated polyester composites. II: Water resistance and composite mechanical properties improvement.

摘要

Water resistance properties of kenaf bast fiber bundle (KBFB)-reinforced composites with either unsaturated polyester (UPE) or vinyl ester (VE) matrices, developed in previous research, were studied. The effects of styrene content in UPE resin on the neat UPE resin tensile properties and molding pressure on composite flexural properties were evaluated. The effect of laser and plasma radiation on fiber-matrix interfacial shear strengths was studied. The composites exhibited high water uptake during short- and long-term water immersion. Encapsulation by surface coating and edge sealing improved composite water resistance. Statistical analyses indicated that molding pressures of 5 to 7 MPa were preferable to achieve the maximum composite mechanical properties, and 37.6 percent (wt/wt) styrene in the UPE resin gave the highest UPE matrix tensile properties in the studied range. Laser and plasma radiation of the KBFBs significantly improved fiber-matrix interfacial bonding.