Dynamic mechanical analysis of snake grass fiber-reinforced polyester composites

Abstract

The dynamic properties of randomly oriented short snake grass fiber-reinforced polyester composites were analyzed with the functions of fiber weight fraction, length, frequency, and temperature. The storage modulus (E ′) of the fiber-reinforced composites was enhanced compared to that of neat resin. The maximum modulus was obtained for 30% W_f of 10 mm fiber length composites. The damping peak height was reduced and the peak shifted toward higher temperature region upon gradual increase in fiber loading. By maintaining constant fiber loading (30% W_f) and upon gradually increasing the fiber length (10–50 mm), the maximum E ′ value of 30 mm fiber length was achieved. The tan δ peaks decreased by varying the fiber length. The Cole–Cole plot was used to analyze the phase behavior of the composites. Among the variations in frequencies, 1 Hz exhibits low tan δ peak. The fiber W_f in the composite increases the activation energy, which in turn reduces the relaxation process of polymer molecules in the composites. Hence, the balance of properties has been achieved for 30% W_f of fiber containing composites having 30 mm fiber length.