When formic acid is added to the WG-based formulations, no
induction period is observed (see Fig. 2). However, after a notable
initial increase, both mixing torque and temperature evolve as the
reference sample does and tend to a very similar constant value.
Moreover, no significant differences are found when 5 and
10 wt.% samples are compared, although slightly higher mixing
temperatures for the lowest acid concentration may be noticed.