Study and characterization of sisal fiber/zein resin interface

Abstract

The interfacial shear strength (IFSS) between natural sisal fiber and zein protein resin was explored using the microbond test. Commercially available zein protein was processed into resins and their IFSS with sisal fiber was measured. Effects of sorbitol plasticizer content and microfibrillated cellulose (MFC) reinforcement loading on the IFSS with the resin were studied. Scanning electron microscopy (SEM) was used to characterize the fracture surfaces before and after the microbond test. Energy dispersive X-ray spectroscopy (EDX) was utilized to map the residual resin on the sisal fiber surface after the microbond test. The results showed that sisal fiber/ zein IFSS decreased with sorbitol content. At 20 wt% sorbitol content 53% decrease in IFSS was observed. IFSS increased with MFC loading from 1.32 MPa (control) to 2.40 MPa for resin containing 15 wt% MFC. Physical entanglements between sisal fibers and MFC are believed to be responsible for this enhancement in the IFSS.