Effect of hot water and corona discharge treatments on the bonding behavior of jute fibers in polyester matrix

The inherent polarity and hydrophilic nature of lignocellulosic fibers and the nonpolar characteristics of polyolefins create challenges in achieving good adhesion between the two materials. This study aimed to evaluate the effect of surface activation of jute fibers on the fiber-matrix interface of a jute fiber-polyester composite. The fibers were pretreated with hot water and exposed to corona discharge for 5 or 10 min. The fibers were evaluated by thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopy. Pullout tests were conducted to evaluate the behavior of jute fibers in the polyester matrix when embedded at 5, 10, 20, and 30 mm depths. The pretreatments did not affect the thermal properties of the fibers; however, they promoted oxidation and increased surface roughness. Hot water pretreatment resulted in partial removal of surface waxes and enhanced bonding. Pullout tests revealed that fibers subjected to hot water immersion, followed by 10 min of corona discharge, exhibited approximately a 34% increase in adhesion strength compared to untreated fibers. It was concluded that corona pretreatment improves fiber-matrix adhesion by activating the surface and increasing the roughness of the fibers.