2.4.1. Toluene absorbency
The toluene absorbency of 2.5phrCTS-t-ENR, 5phrCTS-t-ENR,
10phrCTS-t-ENR, 15phrCTS-t-ENR and 20phrCTS-t-ENR was determined
at room temperature according to ASTM D471. Each test
specimen was in the form of rectangular bar (30 mm long, 5 mm
width and 2.0mmthick). The weight of each sample wasmeasured
before immersed into toluene for 72 h, and the value was taken as
original weight. Each sample was then removed from the solvent
and wiped to remove excessive solvent on the surface and
reweighed, and the value was taken as swollen weight. For comparison,
this experiment was also carried for CTS and the ENR
(0phrCTS-t-ENR). The toluene absorbency was calculated using
Equation (1).