were started
by ramping from ambient temperature to 100 ◦C at heating rate of
50 ◦C/min and held for 15 min as above, and then increasing from
100 ◦C to 150 ◦C at a heating rate of 5 ◦C/min and held for 20 min
before being increased from 150 ◦C to 300 ◦C at a heating rate of
10 ◦C/min.