Experiments
Dynamic mechanical test
The dynamic mechanical properties of the neat epoxy
resins and composites were measured by using a non-resonance
tensile method with a dynamic viscoelastometer
(Rheogel-E4000, UBM). The specimen was 40 mm long,
5 mm wide, and 2 mm thick.The dynamic complex moduli of the specimens for the
tensile oscillation with a frequency of 10 Hz were measured
at each 1 K ranging from 223 to 493 K. The heating
rate was 1 K min-1
. The glass transition temperature, Tg,
was determined at peaks of the maximum tan d.
Bending test
Three-point bending tests were performed on the specimens
at room temperature in accordance with ASTM
standard D790-07 to measure the bending elastic moduli
and the bending strengths. The geometry of the three-point
bending test is shown in Fig. 1. The specimens cut from the
cured materials were 100 mm long, 15 mm wide, and
5 mm thick. The span length between the supports was
60 mm. The constant deflection rate (50 lm s-1
) at the
loading point was applied and the load was recorded by
using a universal materials testing machine (Shimadzu,
AGS-J).