Abbreviation	Meaning
ATR	attenuated total reflection
CH3	methyl group
C=O	carbonyl stretching
C–O–C	asymmetric vibration of the ester group
DSC	differential scanning calorimetry
FTIR	Fourier transform infrared radiation
G′	storage modulus45
G″	loss modulus
KB	kneading block in mixing zone (zone 5), refers to screw configuration
no-KB	without kneading block in mixing zone (zone 5), refers to screw configuration
MFI	melt flow index
PLA	polylactic acid
PLLA	poly (l-lactide)
QSE	quad screw extruder
Tg	glass transition temperature
Tm	melt temperature
TSE	twin screw extrusion
(χc)	crystallinity
ho	zero shear viscosity
η*	complex viscosity
λ	relaxation time