which stand for temperature at the initial
increase of G’, maximum value of G’ during heating, tan d at G’max,
temperature at G’max, G’ at temperature rising to 90 C, G’ at
temperature cooling to 5 C, tan d at 5 C, and breakdown ratio of G’
(G’BDr¼ (G’maxG0
90 C)/G’max 100%) during heating, respectively
(Fig. 1A).