Influence of Aging and Wetting on Dynamic Mechanical Properties of Multi-Functional Epoxy Resins Filled with Aramid Short Fibers.

Influence of aging and wetting on dynamic mechanical properties of multi-functional epoxy resins cured with diamines and filled with pitch-based carbon short fibers treated with coupling agents

“…For some of other specimens, the values of E decreased much more than for this case in the high-temperature range, and the α-peak at 150 • C for the tan δ curve disappeared. Such behavior was also observed in the previously reported cured with diamine [11] UT specimens [12], the matrices and the AFP filled specimens [14]. Table 4 shows the difference (dT ga ) of T g between aged specimens for 5000 h (T ga (5000)) and UA specimens (T g (0)).…”

“…Water-resistance and heat-resistance of short fiber filled multi-functional epoxy resin were evaluated by measuring the dynamic mechanical properties through aging for up to 5000 h and wetting for 5000 h. The relationship between the state change and the dynamic mechanical properties by aging and wetting was reported previously for matrices (multi-functional epoxy resin) [11], for materials filled with pitch-based carbon and graphite short fibers without surface treatment [12] and treated with coupling agents and cured with acid anhydride [13]. A similar study for materials filled with Aramid short fiber of length 1 mm was also reported [14]. In this paper, multi-functional epoxy resin cured with two types of diamine filled with pitch-based carbon short fibers at 22.2 wt% and treated with five types of coupling agents was aged at 130 • C for 5000 h and wetted at 21 • C for 5000 h and its dynamic mechanical properties were investigated over a wide temperature range of −150 • C to +300 • C using the same methods as in previous reports [11][12][13][14].…”

“…A similar study for materials filled with Aramid short fiber of length 1 mm was also reported [14]. In this paper, multi-functional epoxy resin cured with two types of diamine filled with pitch-based carbon short fibers at 22.2 wt% and treated with five types of coupling agents was aged at 130 • C for 5000 h and wetted at 21 • C for 5000 h and its dynamic mechanical properties were investigated over a wide temperature range of −150 • C to +300 • C using the same methods as in previous reports [11][12][13][14]. The results were compared with materials filled with short fibers treated with coupling agents and cured with acid anhydrides [13] and matrices [11].…”

“…Similar to the previous reports [6,7,[9][10][11][12][13][14][15], the dynamic mechanical pproerties were measured by a Rheovibron DDV-25FP (manufactured by Orientec Inc.). An SEM (a JEM-5200 manufactured by Nihon Electron, Inc.) was used to observe the surface and dispersion states of short fibers before and after the aging.…”

“…Processing of the aging and wetting of specimens in order to evaluate heatresistance and water-resistance was carried out in a manner similar to the previous reports [11][12][13][14]. For aging, a gear oven was used at 130 • C for up to 5000 h. For wetting, the specimens were immersed in distilled water to remove air attached on the specimens by degassing and were kept at 21 • C under atmospheric pressure for 5000 h. The change in weight of the specimens due to the treatment was calculated from the difference in weight before and after the treatment.…”