Plasma-treated Abaca Fabric/Unsaturated Polyester Composite Fabricated by Vacuum-assisted Resin Transfer Molding

To improve the adhesion and wetting between the abaca fibers and matrix, the surface of abaca fabric was modified using plasma polymerization. Different plasma exposure times were conducted to determine the effect of plasma treatment on the properties of the composites. A combination of plasma and other surface modification processes was also investigated to determine whether double treatments could further enhance the properties of these composites. Combined treatments involve plasma polymerization of the fabric after pretreatment with one of the following surface-modification reagents: a) gamma-methacrylopropyltrimethylsilane, b) triethoxyvinylsilane, and c) 2%(w/w) NaOH (aq). The abaca fabric/unsaturated polyester composites were fabricated using the vacuum-assisted resin transfer molding (VARTM) technique. SEM results showed that 10 to 20 seconds plasma treatment gave the right amount of surface roughness for maximum fiber and matrix adhesion leading to improved mechanical properties of the composites. Longer plasma treatment time and double treatment however resulted in composites with lower mechanical properties. Although the composite with alkali and plasma-treated fabric showed the lowest mechanical properties it exhibited the lowest water uptake in both distilled water and brine solution.