The Effects of Matrix Type and Properties upon the Tensile Properties and Notch Sensitivity of Recycled Jute Mat Reinforced Polymeric Matrix Composites

摘要

The main objective of this research is to study the effects of matrix type and properties on the tensile properties and notch sensitivity of recycled jute mat reinforced polymeric matrix composites. A single recycled jute fiber mat was used as a natural fiber reinforcement system for three kinds of composites made from three types of resins. The three thermoset resins which were used as matrix for these composites are vinyl ester and two types of unsaturated polyester, low and high tensile strength resins. Three types of jute composites having the same fiber weight content were fabricated by the modified hand lay-up method with pre-impregnation stage in vacuum; we developed this method to solve the problem of the poor impregnation in the thick fiber mats using the normal hand lay-up method. This modification showed in this research as well as our previous research a better impregnation of resin throughout the jute mats and lower voids contents in the composites. Tensile tests have been performed on smooth specimens to evaluate the effect of matrix type and properties on the mechanical properties for the all considered composites. Also, tensile tests have been carried out on notched specimens with different center-hole diameters and having similarly geometrical diameter/width ratio to evaluate the notch sensitivity for each composite. All considered jute mat composites exhibited a higher tensile modulus than that of their neat resins. Although the higher tensile strength of the neat unsaturated polyester resin than that of the neat vinyl ester resin, the jute composites with vinyl ester matrix showed a higher tensile strength by 74% and 55% than that of both composites with unsaturated polyester matrix. In comparison with jute composites with high strength unsaturated polyester matrix, the jute composites with vinyl ester matrix showed a higher tensile modulus and strength by 13% and 55%, respectively. The two jute composites with unsaturated polyester matrix showed a notch-sensitive manner whereas the jute composites with vinyl ester matrix exhibited a notch-insensitive.