3.2.2. Tear strength
In the as-received and treated UHMWPE fibers/NR systems, the
tear strength increases by 36% and 43% than that of NR (shown in
Fig. 6). A crack that happens in the matrix during drawing process
cannot propagate across the fibers and has to stop there. Or the
growing direction of the crack has to be changed to different directions.
As a result, the interfaces between the fibers and natural
rubber are peeled off to make larger crack at the expense of the
energy. According to these behaviors, the strength is considered to
be increased [23]. However, the strength increases no longer in the
region of fiber content more than 4 wt%. It may be due to the
occurrence of default in the interfacial region when the content of
the fibers is high.