3.2.4. Dynamic mechanical properties of UHMWPE fibers/NR
composites
The dynamic mechanical properties of NR and UHMWPE fibers/NR composites were also performed. The variation of storage modulus (E0) and tangent delta (tan d) as a function of temperature are reported in Figs. 8 and 9. The dynamic properties reflect the amount of the energy in the composite stored as elastic energy and the amount of energy dissipated during the strain process. These properties are highly dependent on the existence of fillers: dispersion within the matrix, volume fraction, geometrical characteristics,and load transfer from the filler to the matrix [24]. As illustrated in Fig. 8, at low temperatures, NR was in the glassy state and its storage modulus remained roughly constant at 1.5 GPa. This was due to the fact that in the glassy state, the molecular motions were largely restricted to vibration and short-range rotational
motions. The glassy modulus are 1.9 and 0.5 GPa with the addition
of as-received and treated UHMWPE fibers, respectively.