Thermal analysis tests were carried out using a TA Q20 DSC
apparatus (USA). All measurements were tested under pure nitrogen
gas at a heating rate of 10 C/min. The weight of samples was
kept about 5 mg. The samples were first heated from 20 to 200 C
and held at this temperature for 5 min to remove their thermal history.
The samples were then cooled to 20 C and held for 2 min
before reheating to 200 C. The values of glass transition temperature
(Tg), cold crystallization temperature (Tc), and melting temperature
(Tm) were determined from the second heating scans. Xc
values of PLA in the ramie/PLA composites were evaluated as
follows: